Odontology via MedWorm.com

Effect of particle diameter on air polishing of dentin surfaces

Odontology — Mon, 15 Feb 2010 06:40:16 +0100

We examined the abrasiveness of glycine powders with particle diameters of 63 and 100 μm by measuring the depth and volume of defects produced during air polishing of human dentin. A total of 36 extracted human teeth were embedded in acrylic resin. The resin blocks were polished until the dentin surfaces were exposed. The nozzle of an air polisher was mounted 4 mm from the dentin surface, and the dentin surface was treated for 5 s at one of two angles of incidence (45° or 90°). Three materials were used in the polishing process: NaHCO3 powder with a mean particle diameter of 100 μm (Handy Jet Powder), glycine powder with a mean particle diameter of 63 μm (Handy Jet Powder PMTC), and glycine powder with a mean particle diameter of 100 μm (Handy Jet Powder Recall). The defect dep...

Ice cube stimulation helps to improve dysgeusia

Odontology — Mon, 15 Feb 2010 06:40:16 +0100

Abstract Dysgeusia causes a decrease in appetite, and it is one of the major factors in undernutrition. Dysgeusia is elicited by numerous causes, and in many cases it is still difficult to treat the various symptoms complained of by patients. We herein report a case in which dysgeusia was improved by transient cooling of the mouth. Content Type Journal ArticleCategory Case ReportDOI 10.1007/s10266-009-0110-yAuthors Rie Fujiyama, Nagasaki University Integrative Sensory Physiology, Graduate School of Biomedical Sciences 1-7-1 Sakamoto Nagasaki 852-8588 JapanShingo Ishitobi, Nagasaki University Hospital of Medicine and Dentistry Special Care Dentistry Nagasaki JapanKeiko Honda, Nagasaki University Hospital of Medicine and Dentistry Special Care Dentistry Nagasaki JapanYukio ...

Cephalometric evaluation of maxillary sinus sizes in different malocclusion classes

Odontology — Mon, 15 Feb 2010 06:40:15 +0100

Abstract We found few studies on the association between maxillary sinus size and malocclusion in an electronic search using PubMed. The purpose of this study was to investigate maxillary sinus size in different malocclusion groups and the association between maxillary sinus size and dentofacial morphology by the use of lateral cephalometric radiographs. A total of 120 lateral cephalograms were used. These radiographs were derived from subjects with skeletal Class I, Class II, and Class III malocclusions, classified on the basis of the A-N-B angle. Each malocclusion group consisted of 20 boys and 20 girls ranging in age from 12 to 16 years. Two linear measurements and three area measurements were made to evaluate maxillary sinus size, and four angular and eight linear meas...

Rabson-Mendenhall syndrome: two case reports and a brief review of the literature

Odontology — Mon, 15 Feb 2010 06:40:15 +0100

We report on Rabson-Mendenhall syndrome in two siblings and briefly review the literature. Content Type Journal ArticleCategory Case ReportDOI 10.1007/s10266-009-0106-7Authors Renuka J. Bathi, Sharda University (Deemed University) Department of Oral Medicine & Radiology, School Of Dental Sciences Plot #32-34, Knowledge Park III Greater Noida, U. P. 201306 IndiaSameena Parveen, S.B. Patil Dental College Department of Oral Medicine and Radiology Bidar Karnataka IndiaSunil Mutalik, S.D.M. College of Dental Sciences & Hospital Department of Oral Medicine and Radiology Dharwad, Karnataka IndiaReema Rao, Terna Dental College & Hospital Department of Oral Medicine and Radiology Kargar, Navi Mumbai India Journal OdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal Volume Vo...

Three-dimensional observation of the mouse embryo by micro-computed tomography: composition of the trigeminal ganglion

Odontology — Mon, 15 Feb 2010 06:40:15 +0100

Abstract The purpose of this study was to demonstrate a micro-computed tomography (CT) method for observations of the mouse embryo. At 13.0 days post-coitum, mouse embryos were fixed in 4% paraformaldehyde for 24 h and stained en bloc by osmium tetroxide overnight. The embryos were then embedded in paraffin using standard methods for 24 h. Specimens were analyzed by micro-CT and image processing was performed. Organs containing nervous and blood systems could be viewed as a result of different osmium-staining densities. The trigeminal ganglion was imaged using three-dimensional techniques. Observation of the embryo was possible by micro-CT with osmium tetroxide staining. Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s10266-009-0112-9Authors Hidekazu ...

Experimental study of antiangiogenic gene therapy targeting VEGF in oral cancer

Odontology — Mon, 15 Feb 2010 06:40:13 +0100

This study aimed to investigate the effectiveness of systemically available antiangiogenic gene therapy targeting vascular endothelial growth factor (VEGF), which is one of the most important angiogenesis accelerators. We administered a soluble form of VEGF receptor-expressing gene incorporated into adenovirus (AdVEGF-ExR) intraperitoneally to nude mice to which oral cancer cell lines (SAS, HSC-3, and Ca9-22) had been transplanted subcutaneously in vivo to inhibit angiogenesis and tumor proliferation. Then, we measured tumor volumes over time, and tumors were enucleated and examined histopathologically and immunohistologically at 28 days after AdVEGF-ExR administration. Compared to the controls to which we administered AdLacZ or saline, significant antiproliferative effects were obse...

Quantification of disc displacement in internal derangement of the temporomandibular joint using magnetic resonance imaging

Odontology — Mon, 15 Feb 2010 06:40:11 +0100

In conclusion, most of our results quantitatively support previously reported findings in imaging, surgical, and histopathological studies of TMJ internal derangement. We suggest that our measure of disc position of the TMJ would be useful to assess the status and response to treatment of internal derangements of the TMJ. Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s10266-009-0115-6Authors Raweewan Arayasantiparb, The Nippon Dental University Quantitative Diagnostic Imaging Program, Graduate School of Life Dentistry at Niigata Nippon JapanMakoto Tsuchimochi, The Nippon Dental University Quantitative Diagnostic Imaging Program, Graduate School of Life Dentistry at Niigata Nippon Japan Journal OdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal ...

Pain is associated with an endophytic cancer growth pattern in patients with oral squamous cell carcinoma before treatment

Odontology — Mon, 15 Feb 2010 06:40:11 +0100

This study was undertaken to elucidate significant risk factors associated with spontaneous pain in patients with untreated oral squamous cell carcinoma (OSCC) before treatment. A total of 113 patients (82 men, 31 women; median age, 64 years) with untreated OSCC were examined. Correlations between spontaneous pain in the primary site and sex, age, primary site, TN stage, clinical stage, and clinical growth type of cancer (exophytic or endophytic), as well as the degree of histological differentiation and the histological mode of invasion were evaluated. At the initial examination, 42 (37%) of patients had spontaneous pain. In univariate statistical analyses, reported pain correlated significantly with patient age and the clinical growth type of the cancer, as well as with the degree ...

Clinical application of a custom-made bioresorbable raw particulate hydroxyapatite/poly-l-lactide mesh tray for mandibular reconstruction

Odontology — Mon, 15 Feb 2010 06:40:11 +0100

In conclusion, the customized HA/PLLA tray was easily adapted to the mandible, and fine bone quality was obtained. These cases show that this tray system contributed to functional oral rehabilitation with dental implants. Content Type Journal ArticleCategory Case ReportDOI 10.1007/s10266-009-0111-xAuthors Akira Matsuo, Tokyo Medical University Department of Oral and Maxillofacial Surgery 6-7-1 Nishishinjuku, Shinjuku-ku Tokyo 160-0023 JapanHiroshige Chiba, Tokyo Medical University Department of Oral and Maxillofacial Surgery 6-7-1 Nishishinjuku, Shinjuku-ku Tokyo 160-0023 JapanHidetoshi Takahashi, Tokyo Medical University Department of Oral and Maxillofacial Surgery 6-7-1 Nishishinjuku, Shinjuku-ku Tokyo 160-0023 JapanJun Toyoda, Tokyo Medical University Department of Oral and Maxil...

Can interaction of materials with the dentin-pulp complex contribute to dentin regeneration?

Odontology — Mon, 15 Feb 2010 06:40:09 +0100

Abstract Understanding outcomes of the interaction between a dental material and tooth tissue is important in terms not only of biocompatibilty but also of the potential for the material to modulate the response of the tissue. This interaction is influenced by many factors, including the chemistry of the material and any of its eluted components or degradation products, and the manner in which the tissue responds to these agents. Past studies of this interaction have primarily been aimed at identifying cytotoxic effects. More recently, investigations have focused on specific cellular responses, and in particular, on understanding how the materials themselves actually may contribute to regenerative processes in the tooth. Recent work has demonstrated the solubilization of p...

Odontology receives an impact factor

Odontology — Mon, 15 Feb 2010 06:40:09 +0100

Content Type Journal ArticleCategory EditorialDOI 10.1007/s10266-010-0119-2Authors Yukio Miyagawa, The Nippon Dental University School of Life Dentistry at Niigata The Society of The Nippon Dental University Division of Biomaterials, Advanced Research Center Niigata JapanMakoto Tsuchimochi, The Nippon Dental University School of Life Dentistry at Niigata Department of Oral and Maxillofacial Radiology 1-8 Hamaura-cho, Chuo-ku, Niigata Niigata 951-8580 Japan Journal OdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal Volume Volume 98 Journal Issue Volume 98, Number 1 / February, 2010 (Source: Odontology)

Antifungal drug resistance of oral fungi

Odontology — Mon, 15 Feb 2010 06:40:09 +0100

Abstract Fungi comprise a minor component of the oral microbiota but give rise to oral disease in a significant proportion of the population. The most common form of oral fungal disease is oral candidiasis, which has a number of presentations. The mainstay for the treatment of oral candidiasis is the use of polyenes, such as nystatin and amphotericin B, and azoles including miconazole, fluconazole, and itraconazole. Resistance of fungi to polyenes is rare, but some Candida species, such as Candida glabrata and C. krusei, are innately less susceptible to azoles, and C. albicans can acquire azole resistance. The main mechanism of high-level fungal azole resistance, measured in vitro, is energy-dependent drug efflux. Most fungi in the oral cavity, however, are present in multis...

The relationship between physiologic halitosis and periodontopathic bacteria of the tongue and gingival sulcus

Odontology — Mon, 15 Feb 2010 06:40:09 +0100

Abstract To determine the influence of oral status on halitosis, the relationship between halitosis and periodontopathic bacteria present in plaque on the tongue and the subgingival sulcus was examined in 62 periodontally healthy adults. Halitosis indicators used were the organoleptic score; gas chromatography results [total volatile sulfur compounds (VSCs) = H2S + CH3SH + (CH3)2S]; Halimeter values; and the results of three clinical tests, plaque control record (PlCR), plaque index (PlI), and tongue coat status. Significant correlations with organoleptic scores was observed for PlCR, PlI, tongue coat status, VSC amounts, and Halimeter values, indicating that halitosis in periodontally healthy subjects tended to originate from tongue plaque deposits. Polymerase chain reacti...

Bond strength of adhesives to dentin contaminated with smoker’s saliva

Odontology — Mon, 15 Feb 2010 06:40:08 +0100

Abstract The purpose of this study was to determine the effects of contamination with smoker’s and non-smoker’s saliva on the bond strength of resin composite to superficial dentin using different adhesive systems. The interfacial structure between the resin and dentin was evaluated for each treatment using environmental scanning electron microscopy (ESEM). Freshly extracted human molars were ground with 600-grit SiC paper to expose the superficial dentin. Adhesives [One-Up-Bond-F-Plus (OUFP) and Adper-Prompt-L-Pop (APLP)] and resin composite (TPHSpectrum) were bonded to the dentin (n = 8/group, 180 total specimens) under five surface conditions: control (adhesive applied following manufacturers’ instructions); saliva, then 5-s air dry, then adhesive; adhesive, saliva...

Treatment of dentoskeletal bimaxillary protrusion: additional extraction of maxillary second molars

Odontology — Tue, 28 Jul 2009 18:47:25 +0100

Abstract This case report describes the orthodontic treatment of an 18-year-old female patient with Class II malocclusion with dentoskeletal bimaxillary protrusion. An acceptable treatment result was obtained with a four first premolar extraction and an additional maxillary two second molar extraction plan. Standard edgewise appliances were placed after the premolars were extracted. A positive soft tissue response to treatment was achieved, and the patient’s profile was improved, with a reduction of lip protrusion and mentalis strain. Dentally, the interincisal angle improved significantly as both the maxillary and mandibular incisors were uprighted after space closure. The occlusion remained stable during 2 years of follow-up. Content Type Journal ArticleCategory Case...

The effect of angiotensin II on the proliferation of human gingival fibroblasts

Odontology — Tue, 28 Jul 2009 18:47:24 +0100

Abstract Angiotensin not only raises blood pressure and modifies body fluids and electrolytes but also induces differentiation and proliferation of fibroblasts in the circulatory system in order to repair damage. The purpose of the present study was to observe the influence of the addition of angiotensin II (AngII) or nifedipine (NIF) alone or both sequentially on proliferative activity, the intracellular Ca2+ concentration ([Ca2+]i), and the inositol-1,4,5-triphosphate (IP3) level in cultivated human gingival fibroblasts. Addition of 10−8−10−4 M NIF or 10−5−10−4 M AngII alone increased the proliferation of cultivated gingival fibroblasts, and the interaction of NIF and AngII suppressed proliferation. Addition of AngII alone increased [Ca2+]i, with a peak 60 s af...

Root and canal morphology of mandibular first and second permanent molar teeth in a Ugandan population

Odontology — Tue, 28 Jul 2009 18:47:24 +0100

Abstract We investigated root and canal morphology of permanent mandibular molar teeth in a Ugandan population. Mandibular first (n = 224) and second (n = 223) molars were collected from patients visiting dental clinics in Kampala and prepared by a clearing technique. An endodontic access cavity was prepared in each tooth. The teeth were consecutively immersed in 5% sodium hypochlorite, 10% nitric acid, and 99% methyl salicylate. India ink was coronally injected into the pulp chamber and withdrawn apically by suction. The teeth were viewed under a magnifying lens and the numbers of root canals and their configurations, lateral canals, intercanal communications, and multiple apical foramina were recorded, along with the number of roots and their morphology. Student’s t test...

Relative efficiency of radiation sources for photopolymerization

Odontology — Tue, 28 Jul 2009 18:47:24 +0100

Abstract The aim of this study was to evaluate the characteristics of new-generation light-emitting diode (LED) units in comparison with the conventional tungsten-halogen, plasma arc, and first-generation LED units reported in our previous study. The irradiance of light from new-generation LED units, the temperature rise of the bovine enamel surface, and the depth of cure of composites exposed to each unit were investigated. The irradiances in the range 400–515 nm emitted from the new-generation LED units were greater than those from the first-generation LED units. The temperature increase was 15–25°C for new-generation LED units compared with a typical value of 5°C for the first-generation LED units at 10 s of irradiation. The relationship between the depth of cure ...

Evaluation of two dual-functional primers and a tribochemical surface modification system applied to the bonding of an indirect composite resin to metals

Odontology — Tue, 28 Jul 2009 18:47:23 +0100

Abstract We evaluated the effects of two dual-functional primers and a tribochemical surface modification system on the bond strength between an indirect composite resin and gold alloy or titanium. Disk specimens (diameter, 10 mm; thickness, 2.5 mm) were cast from type 4 gold alloy and commercially pure titanium. The specimens were wetground to a final surface finish using 600-grit silicone carbide paper. The specimens were then air-dried and treated using the following four bonding systems: (1) air-abrasion with 50–70 μm alumina, (2) system 1 + alloy primer, (3) system 1 + metal link primer, and (4) tribochemical silica/silane coating (Rocatec). A light-polymerizing indirect composite resin (Ceramage) was applied to each metal specimen and polymerized according to the ...

Diagnosis and treatment of xerostomia (dry mouth)

Odontology — Tue, 28 Jul 2009 18:47:23 +0100

Abstract Xerostomia (dry mouth) is a common complaint with widespread implications such as impaired quality of life, oral pain, and numerous oral complications. There are a variety of salivary and nonsalivary causes of xerostomia, the most frequent being medication side effects and systemic disorders. A systematic approach should be employed to determine the etiology of this condition, with distinctions made between patients with subjective complaints of xerostomia alone and those with measurable salivary gland dysfunction. Management is multidisciplinary and multimodal. This review summarizes the current literature on the etiology, diagnosis, and complications of xerostomia, and on the management of patients with xerostomia. Content Type Journal ArticleCategory Review A...

Periodontal disease and risk of atherosclerotic coronary heart disease

Odontology — Tue, 28 Jul 2009 18:47:22 +0100

Abstract Atherosclerosis is an important component of coronary heart disease (CHD), which is the leading cause of death worldwide, including in Japan. Because atherosclerotic processes are typified by chronic inflammatory responses, which are similar to those elicited by chronic infection, the role of infection in promoting or accelerating atherosclerosis has received considerable focus. Increasing evidence supports the notion that periodontitis is associated with increased risk of atherosclerosis through dysfunction of endothelial cells induced by either periodontopathic bacteria or their products, or inflammatory mediators derived from infected periodontal tissue. Here we review whether periodontitis represents a risk factor for CHD or atherosclerosis, particularly in a ...

Bone regeneration during distraction osteogenesis

Odontology — Tue, 28 Jul 2009 18:47:21 +0100

Abstract Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connective tissues in the gap area between two separated bone segments. This procedure has received much clinical attention as a way to correct congenital growth retardation of bone tissue or to generate bone to fill skeletal defects. The process of bone regeneration involves a complex system of biological changes whereby mechanical stress is converted into a cascade of signals that activate cellular behavior resulting in (enhanced) formation of bone. Over the last decade, significant progress has been made in understanding the bone regeneration process during distraction osteogenesis. The mechanical and biol...

Histopathologic changes in the pulpal and periapical tissues after surgical removal of the coronal pulp chamber of rat lower molar

Odontology — Wed, 06 May 2009 22:19:33 +0100

Abstract With the specific aim of the examination of tissue-damage and repair of surgically exposed pulp and periapical region in rat molar model, 14 female Sprague-Dawley rats were used. The coronal portion of lower first molars was surgically removed and the teeth remained untreated for 3 weeks prior to euthanasia of the animals. During this experimental period, all animals were injected with fluorochrome agents twice at the 12th and 19th days, in order to monitor formation of hard tissues in the exposed pulpal chamber and on the surfaces of cementum and alveolar bone. For histologic examination using microradiography and fluorescent and light microscopy, resin-embedded ground sections and serial decalcified sections were prepared. Observations revealed that: (1) over ha...

A comparative morphological study on the tongue and the lingual papillae of some marine mammals —Particularly of four species of odontoceti and zalophus—

Odontology — Wed, 06 May 2009 22:19:32 +0100

Abstract We observed the structure of the tongues of some aquatic mammals in four species of Odontoceti (Stenella coeruleoalba, Lagenorhynchus obliquidens, Tursiops truncatus andMesoplodon stejnegeri) andZalophus californianus californianus using light microscopy (LM) as well as scanning electron microscopy (SEM) and compared the characteristics of the tongue of each animal species. In the four species of Odontoceti, the dorsal surface of the anterior part of the tongues had a smooth surface. However, after removal of the epithelium, slender conical connective tissue cores (CTCs) were densely distributed. At the boundary between the lingual body and the root ofTursiops truncatus, several round vallate-like structures were observed and inLagenorhynchus obliquidens, they had a ...

Studies on penetration of peroral new quinolone, levofloxacin to rabbit oral soft tissues with influence of stomachics sankyo magen mittel

Odontology — Wed, 06 May 2009 22:19:32 +0100

Abstract It is a well-known fact that theoretically the absorption of new quinolones in the intestinal tract is significantly inhibited as a result of their interaction with metal cations. In order to study the effects of S. M powder, which is frequently used in the department of dentistry, on the tissue transfer of new quinolones, we administered S. M powder in combination with levofloxacin (LVFX) to rabbits and made comparative studies of soft tissue transfer rates. Prior to the initiation of the present study, we confirmed that there is a significant difference in tissue transfer rates of ofloxacin (OFLX) and LVFX, based upon the fact that LVFX is an optical activator of the OFLX. We obtained the following results in this study: 1) All the samples including t...

A study on kinetic frictional properties in Begg/KB orthodontic appliances at posterior sites

Odontology — Wed, 06 May 2009 22:19:29 +0100

Abstract In Begg and KB techniques, the kinetic frictional force generated between their characteristic orthodontic appliances at posterior sites and the orthodontic wire affects the efficiency of tooth movement. We compared the kinetic frictional force between the recent orthodontic appliances for posterior sites: the by-pass loop-KB buccal tube system (loop-KB tube system) and the conventional by-pass clamp-round buccal tube system (clamp-round tube system), and elucidated the frictional properties of the loop-KB tube system. We used 016"/018" round wires (016/018 round) and 022" × 016" ribbon wire (022 ribbon) with anchorage bend/curve applied. The results obtained were as follows: 1) The kinetic frictional energy was significantly larger in the loop-KB tube...

Modes of occlusion in humans: A comparison of traditional aborigines and modern Japanese

Odontology — Wed, 06 May 2009 22:19:27 +0100

Abstract A study of the modes of occlusion of permanent teeth among Australian Aborigines was conducted at the University of Adelaide Faculty of Dentistry. From 1951 to 1971, 1,708 intra-oral plaster molds were taken at longitudinal changes from 444 Aborigines leading a traditional lifestyle in Northern Australia. Comparisons and analyses then were made with molds of modern Japanese. 1) In contrast to previous reports, occlusion among Aborigines was found to be characterized by a mixture of psalidodontia (approximately 55%), deep overbite (approximately 30%), and labidodontia, and in general this was similar to that of modern Japanese. 2) Labidodontia was found in a mere 6.3% of Aborigines and it is believed that previous occlusal studies failed to d...

An anatomical study of the adult human face: Distribution of elastic fibers and collagen fibers in the skin and subcutaneus tissue

Odontology — Wed, 06 May 2009 22:19:27 +0100

This study was carried out at the histochemical, immunohistochemical and scanning electron microscopic levels to elucidate morphology, distribution of elastic fibers and extracellular matrices (type I and III collagens). Specimens were collected from 26 cadavers (18 males and 8 females; 50–90 years of age) which had no muscular disease in the human face. 1. Observation by macroscopy: A tight attachment between skin and connective tissue was found in the frontal and inferior labial regions, but at the superior labial, orbital and modiolus regions showed loose attachment in the face skin. 2. Observation by microscopy: The elastic fibers (EF) were located in the epithelium, intercellular substance, connective tissue near muscle fibers, and the perimysium and en...

The rate of appearance intraoral pain and discomfort caused byCandida

Odontology — Wed, 06 May 2009 22:19:27 +0100

Abstract Patients sometimes complain of pains and/or discomfort in the tongue or oral mucosa, even though they are diagnosed to have no abnormalities at dental and prosthetic examinations and maintain good health. It is extremely difficult to identify the exact cause of pain in these patients, who have only the complaint of subjective symptoms, without any symptoms such as rubber or swelling. Such pains and discomfort might beCandida. However, reports of the rate of appearance were rare. In the present study, we examined patients with primary complaints of intraoral pain and discomfort thought to be caused byCandida at their first visit to our clinic during the period between March and June 1994, out of 173 geriatric patients. The age of 173 patients was ranging from 65 t...

Longitudinal changes in the permanent dentition of traditional aborigines: Movements of the first molar and the anterior dentition

Odontology — Wed, 06 May 2009 22:19:26 +0100

Abstract Changes in the permanent dentition that occur with growth in traditional Australian Aborigines have been reported by J. M. Barrett et al. (1965) and T. Brown et al. (1983–92). We undertook research on the longitudinal changes in the size of the permanent dentition of Aborigines by using a different method from that of the aforementioned studies. By focusing on the first molars, we analyzed movements in the anterior permanent dentition. We collected intra-oral plaster models of 50 male Aborigines and 50 female Aborigines, and measured the lengths and widths of the upper and lower dental arch triangles connecting the central fossae of the right and left first molars and the contact points of both central incisors of the subjects at around the ages of 8, 11, 15 a...

Pantographic reproducibility of mandibular border movements in patients with craniomandibular disorders

Odontology — Wed, 06 May 2009 22:19:26 +0100

Abstract The change of the reproducibility of maximum border movements in patients with CMD has been studied in the United States. Clayton and others reported a change of PRI, pantographic reproducibility index. There is no information on this in the Japanese population. Also, there is found no study on each section of a scribed line, pantographic reproducibility value (PRV). The purpose of this study is to analyze each section’s characteristics with a Japanese population. 30 craniomandibular disorder patients were used in study. The Denar pneumatic pantograph has used. The average PRI before treatment was 35.5 and after treatment was 14.8 Statistically significant correlation (r=0.56) was found in PRI between before and after treatment. All 12 sections showed a stasisti...

A cohort study on prevalence of dental caries concerning primary schoolchildren in one village of Niigata Prefecture

Odontology — Wed, 06 May 2009 22:19:26 +0100

Abstract To review the previous preventive measures against the incidence of dental caries in children, we started to examine the state of dental health in children at the age of 18 months. The annual dental examination continued up to 12 years of age (sixgraders). Enrolled in this study were a total of 225 children living in a Town T and born between 1980 and 1982. Meanwhile, we made surveys in order to gauge the degree to which the subjects and their parents have concern for oral health. The findings and their relationships to the caries incidence were analyzed using an epidemiological technique. The annual dental examinations revealed that in primary dentition the incidence of caries tends to increase in 3-year-olds while in permanent dentition the carious process ext...

Bonding effect of adhesive resin cement to ZrO2−Al2O3 composite ceramics (3Y20A)

Odontology — Wed, 06 May 2009 22:19:25 +0100

Abstract ZrO2−Al2O3 Composite Ceramics (3Y20A) has been discussed as a reinforcing material for castable glass ceramics. It is a goal of this study to obtain stable adhesive strength of 3Y20A using adhesive resin cement. As for the experimental conditions, four types of adhesive resins and three surface treatment methods were selected, and the effect of their bonding strength was compared. As a result, the surface roughness of 3Y20A was increased and its bonding strengh was improved with a 46% hydrofluoric acid treatment and 5-atm alumina sandblasting. In addition, the use of a silane coupling agent has a tendency to improve bonding strength. After 10,000 thermal cycles, the bonding strength of Panavia 21 was more stable than that of Super Bond C & B, Imperva Dual ceme...

Clinical evaluation of analgesics against pulsating pain in dental diseases

Odontology — Wed, 06 May 2009 22:19:22 +0100

Abstract To investigate the effect of analgesics on pulsating pains, we studied the effect of pyrazolone and salicylate analgesics on the onset time and duration of analgesia, the course of analgesics response, and the recurrence of pain. The overall effective rate was 90.2%, 97.4% for the pyrazolone analgesics tested and 83.3% for the salicylate analgesics. In the pyrazolone group, the onset time and duration of analgesia were shorter than in the salicylate group. The time course of analgesics response was as follows: Fifteen minutes after ingestion of the pyrazolone analgesics, “severe” pain was reduced to “moderate” or “mild” in half of the patients; By 60 min after ingestion “severe” and “moderate” pains had disappeared; and the maximum analgestic e...

Pharmacokinetic-pharmacodynamic modeling of pentazocine under general anesthesia —Effect of infusion period on respiratory rate—

Odontology — Wed, 06 May 2009 22:19:21 +0100

Abstract The respiratory rates following intravenous administration of pentazocine during general anesthesia were measured, in order to determine the effect of pentzocine on respiration from immediately after administration. When respiratory rates were compared among infusion periods of pentazocine (1 mg/kg) for 1, 3 and 6 minutes, it was found that the faster the infusion rate, the shorter the duration to reach the maximum reduction of respiratory rate, showing a significant difference (p<0.05). However, the maximum reduction of respiratory rate did not significantly differ among different infusion periods, indicating the lack of marked effect of infusion period on the maximum reduction of respiratory rate. When respiratory rates were compares between different doses...

Bactericidal effect of newly developed electrically oxidized water against several genera of bacteria

Odontology — Wed, 06 May 2009 22:19:21 +0100

Abstract The purpose of this study is to investigate the bactericidal effects of newly developed electrically oxidized water (EOW) against several genera of bacteria and fungi. This EOW contained hypochlorous acid with chloride ion cuncentrations at 31.1±0.77 ppm in pH 5.20±0.09. Each genus of bacteria (initial concentration of 108 cells/ml) was incubated with EOW for 30sec., one minute, two minutes and five minutes at room temperature. Then the survival rate was determined by colony formation. For the genusStreptococci, E. coli, A. viscosus, F. nucleatum, P. gingivalis andA. actinomycetemcomitans, survived cells were less than 102 cells/ml. But for the genusStaphylococci, B. subtilis, P. aeruginosa andC. albicans more than 103 cells/ml survival. The bactericidal activity w...

Statistics for the analysis of tenderness score summation in patient with craniomandibular disorders

Odontology — Wed, 06 May 2009 22:19:20 +0100

Abstract Digital palpation has been used to evaluate patients with craniomandibular disorders. Tendemess at each site is classified on a 0 to 3 scale and evaluated as total summation. Tendernes were ranked on the scale. Nonparametric statistics were applied to analyze these data. 34 kind 64 sites makes 192 steps in total summation. Increase of step yielded similer results in parametric and nonparametric statistics. The purpose of this study is to clarify the difference in results between nonparametric and parametric statistics. 100 female CMD patient data were used to make group of 13, 25, 50 and 100 subject group. 16 kind 30 sites, 23 kind 44 sites and 34 kind 64 sites were anlysed as summation. The Wilcoxon test and t-test were used to analyse before and after treatment ...

Differential responsiveness against mechanical stress between osteoblastic cells and periodontal ligament cells

Odontology — Wed, 06 May 2009 22:19:20 +0100

Abstract Using the human osteosarcoma-derived osteoblastic cell line, HOS cells, and the human periodontal ligament-derived fibroblast-like cells (Periodontal ligament cells; PDL cells), we examined the responsiveness against mechanical stress (continuously applied compressive force) in HOS and PDL cellsin vitro. SDS-PAGE revealed that loading of mechanical stress (10 g/cm2) promoted intracellular protein production (approx. 30–35 kDa, 40kDa, 55kDa, 65–70kDa) in HOS cells, which are different sizes from those in PDL cells reported previously. Mechanical stress also enhanced heat shock protein (HSP) production in HOS cells and PDL cells: however, the responsiveness was different between HOS cells and PDL cells. In PDL cells, mechanical stress enhanced HSP 60 production m...

A study on the influence of preoperative radiotherapy to proliferating cell nuclear antigen (PCNA) for oral cancer cells

Odontology — Wed, 06 May 2009 22:19:19 +0100

Abstract In order to evalute the effects of preoperative irradiation therapy on oral cancer, monoclonal antibody to proliferating cell nuclear antigen (PCNA) was used to calculate PCNA positive rates before and after 30Gy irradiation therapy. The subjects were 24 patientas with oral cancer. Based on the results, the relation between PCNA positive rate and the histolosical effects of irradiation therapy was quantitatively analyzed. The conclusions are summarized as follows. 1) The average pretreatment PCNA positive rate was 33.4±11.4% while the average posttreatment rate was 24.0±7.9%. 2) Subjects were classified according to the degree of differentiation for pretreatment and posttreatment comparison. However, there existed no significant difference ...

Establishment and characterization of cultured human gingival keratinocytes immortalized by Transfection of origin (−) SV40 DNA and c-fos gene

Odontology — Wed, 06 May 2009 22:19:19 +0100

Abstract In order to establish human oral epithelial cell lines, secondary cultures of human oral keratinocytes from normal gingival tissues obtained from 20–29-yr-old females were transfected with origin (−) SV40 DNA (pRNS-1) and human c-fos gene (pBK 28) using Transfectam reagent® (Promega, WI). Out of 20 cultures transfected with pRNS-1, only one culture escaped senescence. After the transfection with origin(−) SV40 (87 days in culture), human c-fos (pBK 28) was introduced into ori− cells. Ori− cells and ori− cells transfected with c-fos, designated NDUSD-1 cells, were subjected to G418 selection (25μg/ml) for 125 days of culture. NDUSD-1 cells were immortal with continious growth for more than 1000 days in culture. Southern blotting analysis demonstrated tha...

Gold-silver-palladium alloys for laser irradiation —Effects of gold addition—

Odontology — Wed, 06 May 2009 22:19:18 +0100

Abstract The clasp arms are fatigued by wearing a denture, by taking it off, and by occlusion. We routinely use laser irradiation to harden only the surface layer of clasp arms consisting of gold-silver-palladium alloy partially hardened by laser irradiation to resist fatigue. Recently we tested laser irradiation on silver-palladium-copper alloys, and obtained the following results: 1) The surface hardness of the mother alloy No. 12 (52.5Ag−12.5Pd−35.0Cu alloy (wt%)) was 299.7HV after laser irradiation, 155% harder than after casting. 2) The surface hardness of the 18Au−40Ag−20Pd−22Cu alloy (wt%) was 235.0HV after laser irradiation, 91% harder than after being softened, 15% harder than that after being hardened. The brightness (L*) of the ...

Anatomical study and clinical application of fibular osteocutaneous flap —For maxillo-mandibular reconstruction and dental implant installation—

Odontology — Wed, 06 May 2009 22:19:15 +0100

Conclusions are as follows: 1. Two to eight cutaneous branches, with averaged 3.7±1.1 per leg, are located at the mid-portion of leg. The mean inner diameter of peroneal artery and vein were 2.2±0.6mm and 2.7±1.0mm respectively. The mean of length of vascular pedicle was 3.8±0.9 cm. Fibular bone, which can be harvested, was 21.2±1.8cm. 2. Vertical bone height when minimum length of horizontal section is 6mm in diameter at each four portions per leg, total number of 240 cross-sectional faces of 60 legs were measured. 72 sections of 32 legs (30.0%) were shorter than 10mm, 16 sections of 8 legs (22.2%) in male and 56 sections of 24 legs (77.8%) in female. 3. Ideal mandibular contour could be reformed using osteotomy technique at several portiu...

Distribution of type II collagen in human mandibular condyle during development —Color image analyzer with computer system—

Odontology — Wed, 06 May 2009 22:19:15 +0100

Abstract The formation of the cartilage in mandible of human fetuses, which ranged from 12 to 32 weeks gestation, was systematically investigated with immunohistochemystry linked to an image color analyzer. One of the extracellular matrix proteins (type II collagen) was found mainly in the hypertrophic layer of the condyle from 16 weeks gestation. The percentage of type II collagen per 10,000μm2 area using a computer system with an image color analyzer gradually increased from 16 weeks gestation. This analyzer system revealed the value of cell activity by using immunoperoxidase staining. These results suggested that type II collagen effects the formation of mandibular condyle and the temporomandibular joint during embryonic stages. Content Type Journal ArticleDOI 10.1...

An anatomical study of muscle-bone junction in human masticatory muscles —Macroscopic, immunohistochemical and scanning electron microscopic analyses—

Odontology — Wed, 06 May 2009 22:19:14 +0100

In this study, seventy adult humans were selected at autopsy from donations at Nippon Dental University for macroscopic, histochemical, and scanning microscopic analyses of the muscle-bone junction in mandible. The following results were obtained. 1) Macroscopic analysis at human muscle-bone junction in mandible showed that various attachments were found in each masticatory muscle, however there were no strong correlations between measurments values and aging and sex. 2) Immunohistochemical analysis also revealed that anti PCNA (cyclin proliferating cell nuclear antigen) positive cells were observed predominatly at the muscle-bone junction, and the percentage of these cells in pterygoid muscles was higher than in other muscles. Different distributions of the E...

A clinical study of maxillary and malar bone fracture

Odontology — Wed, 06 May 2009 22:19:14 +0100

Abstract A clinical and statistical analysis on 180 patients with 58 maxillary and 147 malar fractures, treated at the hospital of the Nippon Dental University, School of Dentistry at Niigata, Department of Oral and Maxillofacial Surgery II from July 1974 to December 1992, was retrospectively perfomed. Of fifty five patients, 37 maxillary fractures and 36 malar fractures could not be classified into either Le Fort classification or Night and North type classification assessed by radiographic image. Based on this fact, preliminary type of classification was newly developed for these fractures, i.e., Type I: infra-mid-third facial fracture, Type II: lateral-midthird facial fracture, a; without dislocation or b; with dislocation, Type III: zygomatic bone fracture only. Type I...

Clinical and histopathological study of simus lift procedure

Odontology — Wed, 06 May 2009 22:19:13 +0100

Abstract Sixteen sinuses of 11 patients performed by sinus lift procedure were retrospectively discussed clinically and histopathological investigations from grafted materials. Grafted materials were 10 autogenous bones harvested from 1 iliac crest and 9 chin bones, 1 non-resorbable hydroxyapatite plus mandibular alveolar ridge bone, and 1 mixed of resorbable hydroxyapatite plus human freezed dry bone. Histopathological investigation on several small speciemens taken from grafts of these different materials was performed. New bone formation, small amount of bone resorption and fibrous encapsuling tissue were observed for autogenous bone graft, but new bone formation was delayed around non-resorbable hydroxyapatite particles, and most of all grafted specimens of human freez...

A case of lipoma of the buccal mucosa

Odontology — Wed, 06 May 2009 22:19:13 +0100

Abstract Lipoma is generally regarded as a benign nonepithelial tumor consisting of mature adipose cells. Although lipoma is said to develop everywhere adipose tissues physiologically exist, it frequently develops in the subcutaneous tissues of extremities and trunk. Therefore the incidence of lipoma of mouth is relatively low. The author experienced a case of lipoma which developed in the buccal mucosa and reported the treatment course. The patient was a 70-year-old female who presented herself in the department of oral surgery with a chief complaint of a mass in the right buccal mucosa. She was treated in the outpatient clinic and underwent tumorectomy under local anesthesia. According to the histopathological findings, the lipoma was a subepithelial tumor with well-defi...

Orthodontic treatment of severely protruded maxillary anterior teeth in a middle age adult female

Odontology — Wed, 06 May 2009 22:19:12 +0100

Abstract The multi-disciplinary concept of dental care in the adult patient, especially the middle age group, has recently received considerable attention in orthodontics. The author presents the orthodontic treatment of a middle age female with severe overjet. The patient was forty-one years and eleven months old female with a Class II, Division 1, malocclusion. Besides a severe skeletal discrepancy in the anterior-posterior relationship, the U1-SN was 123.5 degrees. There were spaces in the maxillary anterior segment and a large space was present between the canine and first premolar. The mandibular right first and second premolars occluded in lingual position. Begg plastic brackets were placed in the maxilla and C.A.T. brackets were placed in the mandible. The severe ...

Bactericidal effect of acidic electrolyzed water against EHEC O157:H7

Odontology — Wed, 06 May 2009 22:19:12 +0100

Abstract The bactericidal effect of acidic electrolyzed water (AEW) generated by an apparatus of EIKEN Industry Co, was investigated. We used 3 strains ofEscherichia coli O157: H7, 96003 strain producing VT1, 96140 and 96141 with both VT1 and VT2 which were isolated in Gunma Prefecture. The bactericidal effect of the AEW was investigated in a serial dilution of AEW with or without the presence of serum. No. 96140 was killed at 25% of AEW and No. 96003 and 96141 were killed at 10% of AEW within 1 min. The bactericidal effect of AEW was greatly decreased in the presence of a low concentration of serum as low as 1%. Content Type Journal ArticleDOI 10.1007/BF03039047Authors Kazuko Saito, The Nippon Dental University School of Dentistry at Niigata Department of Oral Microbio...

Relationship between children’s state of oral environment and school dental activities —differences among schools in Niigata Prefecture according to school size—

Odontology — Wed, 06 May 2009 22:19:07 +0100

Abstract The effects of school health activities on the children’s state of oral health were investigated in a total of 299 elementary schools in Niigata Prefecture which had not yet expanded their school dental health program to include fluoride mouthrinsing. The relationship of the caries incidence of cares to the way each school is implementing its health program was analyzed according to the size of school. The results showed that there was no difference in the incidence of tooth decay among pupils in the second grade or above regardless of the size of school. However, the school dental health program was carried out differently depending on the size of school. In small-scale schools, emphasis was placed on health supervision, while in medium-size and large-size sc...

Stress analysis of porcelain laminate veneer on lower central incisors with three-dimensional photoelastic experiments

Odontology — Wed, 06 May 2009 22:19:07 +0100

Abstract We performed stress analysis by the three-dimensional photoelastic experiments in order to elucidate dynamic behavior in porcelain laminate veneer restoration of the lower central incisors. We employed two models in preparing the crown: Model 1 (incisal edge not covered with laminate shell) and Model 2 (incisal edge covered with laminate shell). We used two conditions of loading: Loading 1 (load applied to the labial mesial angle near the incisal edge from the side at an angle of 45° against the tooth axis) and Loading 2 (load applied to the incisal edge in parallel to the tooth axis). 1) Below the loading point during Loading 1 in Model 1 suggesting the possbility of laminate shell detachment. 2) In a wide range in the distal part of shel...

Eluted micro ingredients from titanium and titanium alloy embedded in the thighbone of rabbits

Odontology — Wed, 06 May 2009 22:19:07 +0100

Abstract Titanium and/or titanium alloys are useful materials for dental implant. To investigate the effect of these materials on the living body, specimens made of titanium or titanium alloy were embedded to the thingbone of rabbits for long terms (27 weeks) and following results were oblained: 1. In general interim observation, apperance, behavior and increasing rate of weight of rabbits and also chemical analysis of blood gave no abnormal finding. 2. In tissue structure findings, the embedded specimens were nearly surrounded by bone and partially by a thin layer of connective tissue but no other changes were observed, particularly on soft tissue. 3. From the results of ICP analysis, any material which seemed to be eluted from the sp...

Tenderness in patients with craniomandibular disorders before and after the splint therapy part IV: Intraoral sites

Odontology — Wed, 06 May 2009 22:19:06 +0100

In this study, 7 intraoral sites were analyzed. The results were compared with previous studies (high to low). 1. The order of pain was: 1. Lateral pterygoid muscle 2. Medial pterygoid muscle 3. Posterior part of tongue and Anterior belli of digastrics 5. Temporalis insertion and middle part of tongue 7. Anterior part of tongue. This order was constant before and after the splint therapy. 2. Intraoral sites showed significantly higher tenderness compared to corresponding intraoral sites. Temporalis showed 2.29 times or more in before treatment and 10.85 times or more after treatment. Medial pterygoid shows 1.47 times higher before and 5.32 times higher after treatment. Anterior belli of digastrics shows 1.34 times higher before and 2.49 times higher after trea...

Trigeminal subnucleus interpolaris neurons relaying sensory information from the salivary glands

Odontology — Wed, 06 May 2009 22:19:06 +0100

This study suggests that neurons in the trigeminal subnucleus interpolaris or in its surrounding area are involved in relaying sensory information from salivary glands. Content Type Journal ArticleDOI 10.1007/BF03039157Authors Teruo Nakajima, The Nippon Dental University School of Dentistry at Niigata Department of Oral Physiology Niigata JapanKen’Ichi Ishizuka, The Nippon Dental University School of Dentistry at Niigata Department of Oral Physiology Niigata JapanToshiki Murakami, The Nippon Dental University School of Dentistry at Niigata Department of Oral Physiology Niigata Japan Journal OdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal Volume Volume 86 Journal Issue Volume 86, Number 1 / June, 1998 (Source: Odontology)

Ultrastructural study on the interface between the original enamel and fluorapatite formed upon the tooth surface

Odontology — Wed, 06 May 2009 22:19:06 +0100

Abstract There have been few reports addressing the state of bond between synthesized fluorapatite on the enamel by the gel method and the existing enamel. The purpose of the present study is to examine the ultrastructure of the interface between the existing enamel and synthesized fluorapatite. The results are as follows. 1. Scanning electron microscopy revealed a distinct border between synthesized fluorapatite and the existing enamel surface. Observation after acid erosion showed the evidence of demineralization at the interface. 2. Transmission electron microscopy identified two distinct patterns at the interface between large fluorapatite crystals and the enamel surface: one involving a gap and the other with a direct contact. Synthesized fluor...

Pantographic reproducibility of mandibular border movements in subjectively normal subjects

Odontology — Wed, 06 May 2009 22:19:06 +0100

Abstract The Pantographic Reproducibility Index (PRI) has been developed to evaluate mandibular dysfunction through the reproducibility of lateral border movements. There exist no data on the Japanese population regarding PRI. The purpose of this study is to determine the normal range of PRI in normal subjects. Those data will be compared to the patient data and an evaluation of the treatment outcome. Ten male and ten female Japanese who reported no signs and symptoms of Craniomandiubular Disorders were used in this study. 1. The average PRI in males was 6.95 (5.93). In females the average was 7.30 (4.45). There was no statistical difference between sexes. 2. One male subject showed a PRI at 25 and was classified to the slight dysfunction category ...

A case of peripheral cementifying fibroma of the mandible

Odontology — Wed, 06 May 2009 22:19:06 +0100

Abstract Peripheral cementifying fibroma is a rare tumor. It is classified as an osteogenic neoplasm by the WHO classification (1992). We encountered a 67 years old man who developed it on the buccal gingiva in the left lower posterior molar region of the mandible. The lesion was diagnosed clinically as epulis osteoplastica. The lesion was surgically excised under local anesthesia with first and second molar extractions. Histopathological examination indicated the lesion to be a peripheral cementifying fibroma. The post operative course was good. Content Type Journal ArticleDOI 10.1007/BF03039158Authors Kazuyoshi Ozawa, Joetsu General Hospital Department of Dentistry, Oral and Maxillofacial Surgery Niigata JapanKaoru Ishii, The Nippon Dental University School of Denti...

Fluoride release from fluoride-releasing orthodontic materials and the effect of saliva on etched enamel Part 1. Evaluations of fluoride release in de-ionized water and factors influencing the fluoride rechargeable ability

Odontology — Thu, 30 Apr 2009 05:55:08 +0100

The objective of the present study was to determine the F release from two fluoride-releasing orthodontic materials in de-ionized water, and to evaluate the effects of the products, the F concentration of NaF solutions (0.02, 2%) and the immersion time (3, 6min) on the F rechargeable ability, during a two week trial. The results indicated that both the F releasing and the F rechargeable abilities were significantly different between products, and the effect of NaF immersion on the rechargeable ability was greater for the F concentration of NaF solution than for the effect of immersion time. Content Type Journal ArticleDOI 10.1007/BF03039024Authors Kensaku Takahashi, The Nippon Dental University School of Dentistry at Tokyo Department of Preventive Dentistry Tokyo JapanMasaaki I...

The effects of mutastein and dextranase on the synthesis of insoluble glucans byStreptococcus mutans B13

Odontology — Thu, 30 Apr 2009 05:55:07 +0100

Abstract The investigation of the effects of mutastein and dextranase on the crude GTF derived fromS. mutans B13, and liveS. mutans B13, were made, and the following results were ohtained. 1) The amount of insoluble glucans formed on the surface of the wall of a test tube in the presence of mutastein or dextranase decreased with the increase in the concentration of mutastein or dextranase. The amount of synthesized water-soluble glucans and insoluble non-adherent glucans increased with the increase in the concentration of mutastein or dextranase up to a certain point. 2) The formation of plaques in the presence of live bacteria was significantly suppressed when mutastein or dextranase was added. 3) By observation with the observation with...

Histocytological study of the guided bone regeneration using the rat mandible

Odontology — Thu, 30 Apr 2009 05:55:06 +0100

We examined the rat-mandibles which had been operated by the GBR technique and obtained following results: 1. Bone regeneration at both experimental sides promoted due to the obstruction of invasion of muscle tissue around the defect area. 2. The regeneration of small vessels was observed in the defective area on the both experimental sides, especially at the GTAM side. 3. Loose connective tissue was found for long periods on the both experimental sides. 4. Regenerated bone began at the bony edge of the defect area, and irregular sponge-like new bone was detected on the both experimental sides and exhibited lamella structure due to a remodeling. New bone particles were scattered in the middle of bony defective at the GTAM side. ...

A case of Papillon-Lefèvre syndrome —Longitudinal observation for 20 years—

Odontology — Thu, 30 Apr 2009 05:55:04 +0100

Abstract We have followed a case of Papillon-Lefèvre syndrome over 20 years since the patient was brought to our hospital at the age of four. During this period, we inserted two sets of primary dentition dentures each into the upper and lower jaws, and later five sets of permanent dentition dentures in the both jaws corresponding the changes in the oral condition tootn erupution, exfoliation and the number of remaining teeth. From the longitudinal odservation, we have arrived at the conclusions as follows: 1. The replacement of missing parts in the dental arch with plate dentures culd achieve restoration of dental function as well as esthetics. 2. Early exfoliation had no serious effect on the growth of either the maxillae or the mandidles. 3....

Terminal care for oral cancer patients in hospital dentistry and oral and maxillofacial surgery at a local area

Odontology — Thu, 30 Apr 2009 05:55:04 +0100

Abstract A sequential study concerning suicide of patients with oral cancer, notification of oral cancer, terminal care of patients with oral cancer at home, etc. has been performed in our department. As part of the study, a possible role of hospital dentistry and oral and maxillofacial surgery at a local area was examined recently with reference to the terminal alleviating care provided to three patients with oral cancer at Joetsu General Hospital. The result was as follows: It is natural that most patients want to die at home in the presence of their family. In order to fulfill such a desire, it is considered necessary that a hospital dentistry and oral and maxillofacial surgery must handle terminal alleviating care. However, many problems still remain in managing pati...

Anthropological studies of human skeletal remains from Cook Islands, Polynesia —Prehistoric skulls from Pukapuka atoll—

Odontology — Thu, 30 Apr 2009 05:55:03 +0100

This study describes several features revealed from analyses on the skulls of 6 males. 1) The craniometrical comparison of the skulls with the heads of modern Pukapukan males revealed a feature, that the prehistoric specimens were mesocranic, whereas the modern people showed brachycephalic. 2) The craniometrical comparison with prehistoric specimens from other islands in Oceania populations demonstrated that the prehistoric Pukapukan exhibited typical features of prehistoric Polynesians, that they are larger than the specimen from other regions in sagittal frontal arc, sagittal chord, bimaxillary breadth and mandibular ramus breadth. 3) The craniometrical comparisons with Japanese specimens in Jomon, Yayoi, Kamakura, Edo and modern periods reveal...

Surgical treatment of mandibular condylar fracture by direct approach to reach the facial nerve

Odontology — Thu, 30 Apr 2009 05:55:03 +0100

Abstract Surgical treatment of 10 condyles of 8 patients with mandibular condylar fracture by direct approach to reach the facial nerve was retrospectively discussed. In three lower condylar fractures, open reduction and fixation by means of a mini-plate system were perfomed under direct vision and resulted in successful clinical outcomes. In 7 upper condylar fractures, condylar segments were removed because they were not able to reduce and fix. Postoperatively, temporal facial paralysis of tomporal or zygomatic branches occured at five operated sites and completely recovered two to four months. We recognized that this approach, which can make a broad exposure and a wide operative fieled, is very suitable for lower and upper condylar fracture. Content Typ...

Dynamic studies of luting cement layer on full cast crown

Odontology — Thu, 30 Apr 2009 05:55:02 +0100

This study was undertaken to elucidate the dynamic behavior of the cement layers of the full cast crowns under the following conditions: 1) four marginal designs 2) two material properties of the cement. Stress distribution and the three values at the margin of the cement layer were analyzed using the three-dimensional finite element model. The results can be summarized as follows: 1) When the model crown was vertically loaded, compression tended to decrease on the crown and there was no high stress concentration at any site. 2) When the crown model was obliquely loaded, compression tended to decrease at the margin of the crown on the side of the loading, and there was floating of the margin of the crown and a marked tensile stress concentration on the non-...

Fluoride release from fluoride-releasing orthodontic materials and the effect of saliva on etched enamel Part 2. Effect of fluoride release on etched enamel in artificial saliva

Odontology — Thu, 30 Apr 2009 05:55:01 +0100

In this study, a 2% NaF solution and a 6min immersion period for the rechargeable treatment were applied, and then F and Ca concentrations in the artificial saliva with etched or non-etcnhed bovine enamel were determined. Moreover, each enamel specimen was analyzed by EPMA. The results obtained are as follows: (1) F release in artificial saliva was significantly different between the products, but little F rechargeable abilities was observed. (2) A significant negative correlation was observed between F and Ca concentrations for the first two weeks. (3) EPMA analysis showed that the F uptake was increased with F release and was greater for the etched bovine enamel. These result shows that the application of F-releasing material may be beneficial for orthodontic treatment. Conten...

Histological changes in the mouse submandibular gland subjected to parasympathetic nerve block or ischemia: Comparison between chorda tympani resection and trophic vessel transection

Odontology — Thu, 30 Apr 2009 05:55:00 +0100

Abstract The purpose of this study was to determine the effect of disorders of parasympathetic innervation or trophic vessels on the parenchymal tissue of the submandibular gland. ICR mice underwent resection of the chorda tympani nerve or transection of the trophic vessels. After treatment, the submandibular glands were removed at intervals and processed for examination using light and electron microscopy. 1. From 1 week after nerve resection, the submandibular gland parenchymal tissue showed expanded blood vessels, infiltration of wandering cells and growth of connective tissue fibers, etc. Degeneration of the acinar cells extended from the periphery of the gland proper toward the inside, and by 3–4 weeks degeneration was evident over a wide area of the glan...

Clinical study of patients whose dental implants were removed

Odontology — Thu, 30 Apr 2009 05:54:59 +0100

Abstract Twenty-nine cases including 13 males and 16 females, aged 24 to 71 years (average age of 53.7±11.6), whose dental implants were removed at our deparments for past thirteen years from 1985 to 1998 have been retrospectively discussed. Implants were placed in 26 partial edentulous and 3 totally edentulous, 14 for maxilla, 13 for mandible, 2 for both jaws were removed. These implants included 14 blade, 6 endosseous, 14 subperiosteal, 3 endodontic, and 2 home-made implants. Durations from implant placement to removal were 10 days to 20 years (average of 78.3±83.7 months). Causes of removal were 12 local infections, 4 maxillary sinusitis, 2 nerve disturbances and 1 psycologic problem. Content Type Journal ArticleDOI 10.1007/BF03039017Authors Akira Sato, The Nipp...

A study of the surface-roughness and fit of crowns made with gypsum-bonded investment mixed with smectite solutions

Odontology — Thu, 30 Apr 2009 05:54:58 +0100

Abstract Gypsum-boned investment was mixed with various concentrations of water-solube smectite with marked thixotropy, and the effects of smectite on the surface-roughness and fit of crowns were studied. In the experiment, two kinds of commencial gypsum-bonded investment were mixed with four different concentrations of smectite solutions at the standard water mixing ratio Specular resin patterns and model crown wax patterns were used, and the moulds were heated at four different temperatures. Results: As the concentration of smectite increased, the fit of the cast crowns increased for cristobalite investment, but decreased for quartz investment. The fit of crowns increased for SWN but decreased for SWF, and the surface-roughness decreased for both. The surface-roughness...

Stress analysis of tooth and supporting tissue using the finite element method —Effect of properties of periodontal membrane—

Odontology — Thu, 30 Apr 2009 05:54:57 +0100

Abstract We investigated changes in natural teeth under loading and the correspondence of simulated models to these results using the finite element method. Four kinds of models were analyzed according to loading conditions at the periodontal membrane. Two models for linear analysis and two models for nonlinear analysis were established. The influences of these 4 models on stress distribution were compared. The following results were obtained. 1) The differences Young’s modulus at the Periodontal membranes greatly affected the structure analysis; 2) a loading-deviation curve approximating actual values was observed under the loading condition of NL-2 at the periodontal membrane; and 3) comparison of stress distribution at the alveolar bone in linear and nonlinear analysi...

Influence of thickness on color stability of body and incisal porcelains

Odontology — Thu, 30 Apr 2009 05:54:57 +0100

Abstract Knowledge of the relationship between thickness and shade of body porcelain and incisal porcelain is essential for producing esthetic porcelain restoration. We thus performed an experimental study to clarify the effect of thickness on shade of body porcelain and incisal porcelain. The main results were: 1) In a two-layered restorstion of opaque porcelain and body porcelain, the values of L*, a* and b* decreased with increasing thickness of body porcelain. The effect of the thickness of body porcelain on shade was strongest in A1 and weakest in C4. 2) The effect of the thickness of two-layered restoration on shade was stronger as the color number of the restoration was decreased. 3) With a three-layered restoration of opaque porce...

Immersion test of the Ag−Pd−Cu alloy system

Odontology — Thu, 30 Apr 2009 05:54:55 +0100

Abstract Silver-palladium alloys are widely used as substitutes for gold alloys. Pure silver, three Ag−Cu eutectics, three Ag−Pd solid solutions and nine Ag−Pd−Cu ternary alloys were prepared. The specimens were immersed in three kinds of solutions, Ringer’s, 0.1% sodium sulfide, and 1% lactic acid solutions. The change of the reflectance and the color was examined using CIE, Yxy notation. The reflectance of polished specimens was maximum in the pure silver specimen. It decreased with the decrease of silver content, or with the increase of palladium content. In Ringer’s solution, only Ag−Pd eutectic alloys decreased the reflectance. In sodium sulfide sulution, all of the specimens decreased the reflectance, but pure Ag and Ag−Pd entectics showed th...

A study on the fit of the base plate —Influence of canditions of storage—

Odontology — Thu, 30 Apr 2009 05:54:55 +0100

Abstract The aims of this study was to define the effect of storage conditions of base plates, which consist of self-curing resin. Examinantions were made on the dimensional accuracy with the passage of time of base plate stored in water and air on a plaster model for standerdized maxillary edentulous. The following conclusions were obtained; 1. The fit of base plate stored in water proved to be beter than that stored in air. 2. No significant difference was noted among 7 times points. 3. In terms of sites of measurement along the base plate, the more posteror the site of measurement, the greater the gap between a base plate and a cast, was observed. 4. The best fitting base plate proved to be Ostron II. The second best fitt...

Classification of angioarchitectural structures of the rabbit tongue foliate papillae in scanning electron microscopic specimens

Odontology — Thu, 30 Apr 2009 05:54:53 +0100

Abstract Although may ultrastructural morphological studies have been undertaken on the lingual papillae of the rabbit tongue, relatively few have dealt with the microvascular structure and classification of the foliate papillae (FoP) in microvascular cast specimens (MVCS) by means of scanning electron microscopy (SEM). For the present study, a three-dimensional observation and classification was carried out by SEM. The morphological characteristics of the outer frame structure composed of the ascending and descending capillary branches, were observed by means of MVCS of FoPs which were located on both posteroperipheral parts of the tongue. They showed a bead-like appearance and consisted of 14∼18 even, transverse and slightly bent fin-like structures, running from the d...

Clinical evaluation of urinary 6-hydroxymethylpterin (6-HMP) in patients with cancer of the digestive organs

Odontology — Thu, 30 Apr 2009 05:54:52 +0100

Conclusions were as follows: 1. Cut off level of urinary 6-HMP was defined as 0.079 μg/ml, from 87 normal subjects. 2. The daily profile of urinary 6-HMP in normal subjects was highest in morning and lowest at bedtime and daily changes were continuously under the cut off level. 3. Sensitivity, specificity and accuracy of urinary 6-HMP were 64.2%, 77.6% and 70.5% respectively. 4. In patients with malignant diseases, the overall positive rate was 64.2% and was clearly higher than benign diseases. 5. The positive rate of urinary 6-HMP levels in malignant diseases was highest in pancreatic cancer (75.0%) and lowest in hepatocellular carcinoma (55.8%). 6. Urinary 6-HMP elevated several days after operation and ret...

A study on tooth mobility following periodontal surgery

Odontology — Thu, 30 Apr 2009 05:54:52 +0100

Abstract The purpose of this study was to evaluate the quantitative changes in tooth mobility before and after periodontal surgery using a tooth mobility tester. The tester was so designed as to be able to measure the cycle of sympathetic vibrations produced when a tooth was tapped with a impact hammer. Initially the degrees of tooth mobility, which were clinically classified from 0 to 3, were observed and the mode of mobility was assessed by the tester. Then, we examined the changes of tooth mobility after flap surgery. The following is a summary of findings. 1) The coefficient of change in measurements had a tendency to decrease at the buccal site and the cervical site. 2) At 1 week after flap surgery, the degree of tooth mobility was increased sign...

Restorative methods for the Er: YAG laser application

Odontology — Thu, 30 Apr 2009 05:54:52 +0100

Abstract The purpose of this study was to determine if a cavity prepared using the Er: YAG laser could be restored with restorative materials other than composite resin. A class V cavity for the composite resin and a class I cavity for the amalgam, gold foil, and inlay, were prepared in the human premolars an using the Er: YAG. laser. The cavities were restored with these restorative materials. The boundaries between the teeth and the restorative materials were observed using a DIGITAL MICRO SCOPE-6300. The following results were odtained; 1. Because all the margins of the cavities were rough, it was suggested that those should be trimmed using a rotary cutting instrument. 2. For composite resin restoration, the need of the further investigation of th...

Molecular mechanisms of taste transduction in vertebrates

Odontology — Wed, 25 Feb 2009 11:39:56 +0100

Content Type Journal ArticleCategory ErratumDOI 10.1007/s10266-009-0098-3Authors Yoshiro Ishimaru, The University of Tokyo Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-8657 Japan Journal OdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 (Source: Odontology)

Molecular mechanisms of taste transduction in vertebrates

Odontology — Thu, 29 Jan 2009 08:13:59 +0100

Abstract Among the five senses, taste and olfaction play crucial roles in the detection of chemical substances in the environment and are referred to as chemical senses. In the past decade, much progress has been made in studies on molecular mechanisms of the gustatory system by methods such as those based on molecular and cellular biology, genetics, and bioinformatics. This review covers recent studies on taste receptors, intracellular signaling transduction in taste receptor cells, and taste coding at the periphery in vertebrates from fish to mammals. Content Type Journal ArticleCategory Review ArticleDOI 10.1007/s10266-008-0095-yAuthors Yoshiro Ishimaru, The University of Tokyo Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Scien...

Mandibular permanent second molar with four roots and root canals: a case report

Odontology — Thu, 29 Jan 2009 08:13:57 +0100

Abstract Although four-rooted mandibular first molars have been observed on a few occasions in the literature, to the best of our knowledge, four-rooted second molars have not been reported. Here, we describe a mandibular second molar with four roots and canals: two mesial and two distal. Mesial roots were separated in the cervical one-third near the cervical margin, while distal roots were divided at a lower level in the middle one-third of the root. We discuss the possibility of different root and canal variations of the mandibular second molar from a developmental point of view. Content Type Journal ArticleCategory Case ReportDOI 10.1007/s10266-008-0091-2Authors Roshan Peiris, Nihon University Graduate School of Dentistry at Matsudo Department of Anatomy and Physical...

Trigeminal neuralgia secondary to epidermoid cyst at the cerebellopontine angle: case report and brief overview

Odontology — Thu, 29 Jan 2009 08:13:57 +0100

Abstract Trigeminal neuralgia (TN) is a paroxysmal shock-like pain restricted to the innervations of the areas of one or more trigeminal branches, often set off by light stimuli in a trigger zone. Pain attacks occur spontaneously, and can also be triggered by a nonpainful sensory stimulus to the skin, intraoral mucosa surrounding the teeth, or tongue. The pathogenesis of TN is uncertain and typically is idiopathic, but it may be due to a structural lesion. Various proposed causes include traumatic compression of the trigeminal nerve by neoplastic or vascular anomalies, infectious agents such as human herpes simplex virus, and intracranial tumors or demyelinating conditions such as multiple sclerosis. Here we report a case of a young patient diagnosed with trigeminal neural...

Effects of maxillary second molar extraction on dentofacial morphology before and after anterior open-bite treatment: a cephalometric study

Odontology — Thu, 29 Jan 2009 08:13:54 +0100

Abstract The purpose of the present study was to probe into the effects of maxillary second molar extraction on dentofacial morphology by the use of cephalometric radiographs taken before and after anterior open-bite treatment. The subjects were 30 Japanese patients who had received multiloop edgewise archwire therapy without premolar extraction. They were divided into two groups. Group 1 consisted of 15 patients who had their maxillary second molars removed. Group 2 comprised 15 patients who had been treated without extraction of maxillary second molars. Lateral cephalograms were taken before and after treatment. Seventeen angular and 31 linear measurements were obtained from the lateral cephalograms. Paired and unpaired t tests were used to determine the significance of ...

Dental occlusion: modern concepts and their application in implant prosthodontics

Odontology — Thu, 29 Jan 2009 08:13:53 +0100

This article discusses, among other things, concepts of occlusion of implant-supported restorations, occlusal material, cantilevers, and occlusal risk factors. Within the limitations of the review, it was concluded that many factors can influence implant failure and peri-implant bone loss but that little is known of the relative importance of such factors. Most probably, however, occlusal factors and details of occlusion are in general of minor importance for the outcome of implant restorations. Occlusion can be managed successfully by using simple methods for jaw registration and different occlusal concepts. Content Type Journal ArticleCategory Review ArticleDOI 10.1007/s10266-008-0096-xAuthors Gunnar E. Carlsson, University of Gothenburg Department of Prosthetic Dentistry, The ...

Tannerella forsythia and the HLA-DQB1 allele are associated with susceptibility to periodontal disease in Japanese adolescents

Odontology — Thu, 29 Jan 2009 08:13:53 +0100

Abstract Periodontal disease is a multiple factor disease caused by genetic factors, environmental factors, and periodontal bacteria (periodontal pathogens). The present study aimed to elucidate the risk factors for periodontal disease in Japanese adolescents. Subjects (11–16 years old) were classified into three groups: localized aggressive periodontitis (LAP), periodontal attachment loss (PAL), and periodontally healthy (PH) groups. Genomic DNA isolated from the buccal mucosa was used for single-nucleotide polymorphism analyses of the candidate genes (interleukin-1α-889; interleukin-1α +4845; interleukin-1β +3954; an immunoglobulin G Fc gamma receptor, FcγRIIa-R/H131; and a human leukocyte antigen class II allele, HLA-DQB1) of aggressive periodontitis. Subgingival pl...

Immortalization of normal human gingival keratinocytes and cytological and cytogenetic characterization of the cells

Odontology — Thu, 29 Jan 2009 08:13:53 +0100

Abstract Most in vitro studies of oral carcinogenesis in human cells are carried out with oral keratinocytes immortalized by human papillomavirus type 16 DNA. However, because various etiological factors for oral cancer are known, it is important to establish new human keratinocyte cell lines useful for studying the mechanism of oral carcinogenesis. Normal human gingival keratinocytes in secondary cultures grown in serum-free medium were either transfected with origin (−) SV40 DNA or sequentially transfected with origin (−) SV40 DNA and human c-fos. The transfected cells were continually passaged and analyzed for cytological and cytogenetic characterizations. Four immortal cell lines were grown for over 1100 days in culture and maintained a vigorous growth for over 250 ...

Oral motor function and masticatory performance in the community-dwelling elderly

Odontology — Thu, 29 Jan 2009 08:13:53 +0100

This study was performed to ascertain the relationships between oral motor functions, such as those of the tongue and lips, and age in the community-dwelling elderly, as well as to investigate the effects of these factors on masticatory performance. The subjects were 268 healthy elderly Japanese living in Kyoto. They were divided into four age groups and further classified into the following two groups by the presence or absence of posterior occlusal support: Eichner A or B1-B3 (group A), and Eichner B4 or C (group B). They were wearing removable or fixed dentures if they had missing teeth. Oral function evaluation items included (1) masticatory performance and (2) oral motor skills. Significant differences were noted among the age groups in tongue pressure within group A (P < 0.0...

Immunocytochemical study of granular duct cells with a hormonally enhanced granular cell phenotype in the mouse parotid gland

Odontology — Thu, 29 Jan 2009 08:13:52 +0100

Abstract In the parotid glands (PGs) of intact male mice (12 weeks of age, ICR strain), immunofluorescence labels for a true tissue kallikrein, mK1, and for nerve growth factor (NGF) were recognized through the subluminal edges of the striated duct (SD) segments and interlobular duct segments. Because of their small size, secretory granules were not detectable by light microscopy in any of the duct cells. Full-fledged granular cells, containing large secretory granules that were visible by light microscopy, were induced in the SD segments of male mice after the injection of 5α-dehydrotestosterone (DHT) and triiodothyronine (T3), given either alone or in combination every other day for 2 weeks. A stronger effect was detected in the mice that were concomitantly injected with...

Impact of Streptococcus mutans on the generation of fluorescence from artificially induced enamel and dentin carious lesions in vitro

Odontology — Sat, 26 Jul 2008 10:24:58 +0100

Abstract The purpose of this study was to examine whether Streptococcus mutans is implicated in the generation of fluorescence detected in carious lesions. Enamel surfaces and dentin cavities of extracted human teeth were subjected to artificial caries generation by exposing them either to a culture medium containing S. mutans or to a lactic acid buffer for 2 weeks. Fluorescence from the lesions was detected with confocal laser scanning microscopy or fluorescence microscopy at various excitation wavelengths, and maximum fluorescence radiance was computed using imageanalyzing software. Culture media of S. mutans were also examined for fluorescence generation. The results demonstrated that S. mutans-induced enamel and dentin lesions exhibited increased fluorescence in the red a...

Toward guided tissue and bone regeneration: morphology, attachment, proliferation, and migration of cells cultured on collagen barrier membranes. A systematic review

Odontology — Sat, 26 Jul 2008 10:24:57 +0100

Abstract Collagen barrier membranes are frequently used in both guided tissue regeneration (GTR) and guided bone regeneration (GBR). Collagen used for these devices is available from different species and is often processed to alter the properties of the final product. This is necessary because unprocessed collagen is rapidly resorbed in vivo and demands for barrier membranes are different in GTR and GBR. This systematic literature review attempts to evaluate possible effects of collagen origin and mode of cross-linking on the potential of different cells to attach to, proliferate on, and migrate over barrier membranes in vitro. Seventeen original studies, selected by a systematic process, are included in this review. The results show that fibroblasts of different species ...

Measurement accuracy and perceived quality of imaging systems for the evaluation of periodontal structures

Odontology — Sat, 26 Jul 2008 10:24:57 +0100

Abstract The aim of this study was to compare the subjective diagnostic quality of F-speed film images and original and enhanced storage phosphor plate (SPP) digital images for the visualization of periodontal ligament space (PLS) and periapical (PB) and alveolar crestal bone (CB) and to assess the accuracy of these image modalities for the measurement of alveolar bone levels. Standardized images of six dried mandibles were obtained with film and Digora SPPs. Six evaluators rated the visibility of anatomical structures using a three-point scale. Alveolar bone levels were measured from the coronal-most tip of the marginal bone to a reference point. Results were compared by using Friedman and Wilcoxon signed-ranks tests. The kappa (κ) statistic was used to measure agreement...

Difference in physiological responses to sound stimulation in subjects with and without fear of dental treatments

Odontology — Sat, 26 Jul 2008 10:24:56 +0100

Abstract The effects of sound generated by an ultrasonic dental scaler and a dental turbine on heart rate, systolic and diastolic blood pressure, and hemodynamic changes in the frontal cortex were measured and compared with those of pure tone stimulation in 17 young volunteers. Near-infrared spectroscopy and the Finapres technique were used to measure hemodynamic and cardiovascular responses, respectively. The dental sound changed the various physiological parameters. To determine if this change was related to participants’ previous experiences with dental treatment, participants were divided into two groups: those who had a previous unpleasant experience with dental treatment and those who had not. Participants with previous unpleasant dental experiences showed a signif...

Serum p53 antibodies as a prognostic indicator in oral squamous cell carcinoma

Odontology — Sat, 26 Jul 2008 10:24:55 +0100

Abstract The purpose of the present study was to investigate the clinical usefulness of the detection of serum p53 antibodies (p53 Abs) in patients with oral squamous cell carcinoma (SCC). Preoperative values of p53 Abs were measured by enzyme-linked immunosorbent assay in 113 patients with primary oral SCC and seropositive patients were reevaluated postoperatively. The positivity rate of p53 Abs was 16%, and the 5-year survival rate of patients positive for p53 Abs was significantly lower than that of patients negative for p53 Abs (56.2% vs. 80.7%; P = 0.018). The preoperative presence of p53 Abs was found to be an independent prognostic factor in a multivariate analysis (P = 0.028, hazards ratio = 3.34), and its positivity was significantly related to secondary cervical l...

Immunohistochemical analysis of type III collagen expression in the lingual mucosa of rats during organogenesis of the tongue

Odontology — Sat, 26 Jul 2008 10:24:54 +0100

We examined the distribution of immunofluorescence due to immunostaining of type III collagen, differential interference contrast (DIC) images and images obtained in the transmission mode after toluidine blue staining by laser-scanning microscopy of semi-ultrathin sections of epoxy resin-embedded samples, during morphogenesis of the filiform papillae, keratinization of the lingual epithelium, and myogenesis of the rat tongue. Immunoreactivity specific for type III collagen was distributed widely in the mesenchymal connective tissue in fetuses on day 15 after conception (E15), at which time the lingual epithelium was composed of one or two layers of cuboidal cells and the lingual muscle was barely recognizable. Immunoreactivity specific for type III collagen was clearly detected on th...

Effects of a palatal augmentation prosthesis on lingual function in postoperative patients with oral cancer: coronal section analysis by ultrasonography

Odontology — Sat, 26 Jul 2008 10:24:53 +0100

Abstract A palatal augmentation prosthesis (PAP) is used in postoperative patients with oral cancer as an intraoral appliance. The purpose of this study was to use ultrasound imaging to evaluate the effects of a PAP on lingual movement dynamics when postoperative patients with oral cancer swallowed food while wearing a PAP and to elucidate the effectiveness of the PAP. The subjects were seven patients with tongue cancer. They wore a PAP as an intraoral device to compensate for postoperative dysfunction after surgery for tongue cancer. The measurements were made by using ultrasonography. Ultrasound images of the lingual movement dynamics of the center of the tongue (central grooving of the tongue in a coronal plane, passing through the distal surfaces of both the left and r...

Gene expression profile changes correlated with lymph node metastasis in oral squamous cell carcinoma

Odontology — Sat, 26 Jul 2008 10:24:52 +0100

Abstract The purpose of this research was to identify biomarkers for predicting cervical lymph node metastasis in oral squamous cell carcinoma (OSCC). We surveyed the expressions of 1289 cancer-related genes in 41 cases of OSCC by cDNA array analysis. We extracted genes upregulated or downregulated in their expression in association with lymph node metastasis. Of 1289 cancer-related genes, we identified 39 genes differentially expressed in OSCC with or without lymph node metastasis. Expression levels of 9 genes were lower, and those of 30 genes were higher, in node-positive cases. The genes expressed at higher levels in node-positive cases included angiogenesis-related molecules, cell adhesion molecules, and proteolytic enzymes. We suggest that these characteristic genes c...

The change in retentive force of magnetic attachment by abrasion

Odontology — Sat, 26 Jul 2008 10:24:51 +0100

Abstract Magnets are frequently applied to removable dentures as retentive attachments. A magnet-retained removable overdenture might be slightly shifted from side to side by eccentric movement in the mouth, and the surface of magnetic attachment may be worn as a result. However, the relationship between the retentive force of magnetic attachment and its surface abrasion has not been reported. The purpose of this research is to investigate this relationship. Ten Mgfit DX 400 magnetic attachments for natural tooth roots were used for this experiment. The magnetic attachments were embedded in autopolymerizing acrylic resin, and ten pairs of specimens were fabricated. A 5-mm repeated gliding motion was applied on each pair of specimens until 30 000, 50 000, or 90 000 cycles h...

Long root of deciduous anterior teeth

Odontology — Sat, 26 Jul 2008 10:24:51 +0100

Abstract A 24-year-old female Japanese patient presented with remarkably long roots of retained deciduous anterior teeth and permanent anterior teeth in the upper and lower jaw. Four lower anterior teeth were extracted for esthetic reasons. The patient had no apparent clinical syndrome related to the teeth or jaw, nor did there appear to be a family history of this condition. The extracted teeth and their lengths were as follows: the lower right deciduous lateral incisor was 25.55 mm long (root length, 18.95 mm); the lower left deciduous lateral incisor was 22.10 mm long (root length, 17.25 mm); the lower right deciduous canine was 27.95 mm long (root length, 20.60 mm); and the lower left deciduous canine was 23.90 mm long (root length, 17.65 mm). Content Type Journal Ar...

Effects of moisture conditions of dental enamel surface on bond strength of brackets bonded with moisture-insensitive primer adhesive system

Odontology — Sat, 26 Jul 2008 10:24:51 +0100

Abstract The purposes of this study were to evaluate the effects of different degrees of water contamination on the shear bond strength of orthodontic brackets bonded to dental enamel with a moisture-insensitive primer (MIP) adhesive system and to compare the modes of bracket/adhesive failure. A total of 68 human premolars were divided into four groups by primers and enamel surface conditions (desiccated, blot dry, and overwet). In group I, the hydrophobic Transbond XT primer adhesive system was used under desiccated conditions for bonding the brackets; in group II, the hydrophilic Transbond MIP adhesive system was used under desiccated conditions; in group III, the hydrophilic Transbond MIP adhesive system was used under blot dry conditions; and in group IV, the hydrophil...

Assessment using human dental pulp cells of clastogenicity of antiseptics used in dental practice and agents for root canal enlargement and cleaning

Odontology — Sat, 28 Jul 2007 06:48:48 +0100

Abstract Numerous and varied chemical agents are used as topically applied drugs in dental practice. As they are administered directly to the oral cavity, it is important to study the safety of these agents. In the present study, to assess safety regarding mutagenicity, we investigated the abilities of six antiseptics to induce chromosome aberrations in human dental pulp cells. The antiseptics tested were benzalkonium chloride, benzethonium chloride, iodine glycerin, iodine tincture, oxydol, and povidone–iodine. In addition, we tested two agents used for root canal enlargement and cleaning, ethylenediaminetetraacetic acid and sodium hypochlorite. Chromosome aberrations were induced only in cells treated with the highest concentration of iodine tincture for 30 h. The ot...

Expression of keratin 14 in the basal cells of the lingual epithelium of mice during the morphogenesis of filiform papillae: visualization by fluorescent immunostaining and confocal laser-scanning microscopy in the transmission mode

Odontology — Sat, 28 Jul 2007 06:48:48 +0100

We examined the expression of keratin 14 (K14) on the lingual epithelium by immunofluorescent staining while monitoring morphological changes in the filiform papillae of mice by confocal laser-scanning microscopy in the transmission mode of the same sections to define both the histology and the morphology of cells. It is difficult to visualize histological details of the fetal lingual epithelium of the mouse on semi-ultrathin sections by light microscopy after immunohistochemical staining because the histological structures in such sections cannot be distinguished by standard counterstaining. To solve this problem and to visualize the immunoreactivity specific for K14, we analyzed the results of immunofluorescent staining of semi-ultrathin sections in combination with an examination ...

Root and canal morphology of permanent mandibular molars in a Sri Lankan population

Odontology — Sat, 28 Jul 2007 06:48:48 +0100

Abstract The main purpose of this study was to investigate the root and canal morphology of Sri Lankan mandibular molars and to determine the affinities of these morphological variations to those of people of European and Asian origin. Two hundred mandibular first and second molars were examined. The number of roots and the prevalence of C-shaped (gutter-shaped) roots in mandibular second molars were recorded. Root canal morphology was studied using a clearing technique. The examination of root canal systems of the teeth was based on Vertucci's classification. Among mandibular first molars, only 3% had three roots. Mesial roots of the first molar typically presented with two canals and two apical foramina with type IV, V, or VI canal configuration. Most distal roots of the...

Temporomandibular disorders: the past, present, and future

Odontology — Sat, 28 Jul 2007 06:48:48 +0100

This article traces the history of the development of the current diagnostic and therapeutic approaches to the management of temporomandibular disorders, with emphasis on the mistakes or misconceptions that occurred during their development and the lessons that can be learned from these errors. It also makes recommendations for future areas of investigation, and methods for facilitating such studies, in order to improve the future treatment of these patients. Content TypeJournal Article JournalOdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal VolumeVolume 95 Journal IssueVolume 95, Number 1 / July, 2007 (Source: Odontology)

Applicability of Bolton's tooth size ratios to a Japanese orthodontic population

Odontology — Sat, 28 Jul 2007 06:48:47 +0100

This study was carried out to determine anterior and overall ratios in a Japanese population and to compare them with Bolton's ratios. Numerical data were obtained from 60 pairs of dental casts of 30 male and 30 female Japanese orthodontic patients. The mesiodistal widths from first molar to first molar were measured on each cast to the nearest 0.01 mm, by using digital calipers, and the anterior and overall ratios were calculated. The Kolmogorov-Smirnov test, the parametric t test, and Student t test were used for statistical analyses. No statistically significant difference between men and women was found in either the anterior or overall ratio. The combined male and female anterior and overall ratios were 78.39 � 2.18% and 91.60 � 2.11%, respectively. The combined male and f...

Epigenetic inactivation of E-cadherin by promoter hypermethylation in oral carcinoma cells

Odontology — Sat, 28 Jul 2007 06:48:47 +0100

In this study, we determined the methylation status of cytosine within CpG islands of the E-cadherin promoter region in relation to the expression level of SIP1, a major E-cadherin repressor in oral carcinoma cells. Methylation-specific polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism analyses showed that the expression of E-cadherin was downregulated in parallel with promoter hypermethylation. The use of a bisulfite-modified sequence further validated that methylation was observed in 22.6 � 38.7% (mean � 1 SD) of cytosines in carcinoma cells negligibly expressing E-cadherin, in contrast to 7.5 � 1.8% in E-cadherin-expressing cells. Treatment with a demethylating reagent, 5-azacytidine, induced upregulation of E-cadherin in some E-cadherin-expressin...

A study on craniofacial morphology of Japanese subjects with normal occlusion and esthetic profile

Odontology — Sat, 28 Jul 2007 06:48:47 +0100

This study was designed to properly characterize the cephalometric values of Japanese individuals with both normal occlusion and esthetic profiles. Multivariate statistics were applied to analyze the collected data. Cephalometric values identified are expected to help in the simplification of orthodontic diagnosis. Lateral cephalometric radiographs from 50 men and 50 women with normal occlusion were traced and the dimensions of hard and soft tissues recorded. The corresponding values were classified by cluster analysis, and selected representative values were subjected to principal component analysis. From these values, characteristics of hard and soft tissue morphology were extracted. The subjects were grouped by sex, and subdivided into esthetic and unesthetic profile groups. The p...

Regulation of osteoclast polarization

Odontology — Sat, 28 Jul 2007 06:48:47 +0100

Abstract Osteoclast function consists of several processes: recognition of mineralized tissues, development of ruffled borders and sealing zones, secretion of acids and proteolytic enzymes into the space beneath the ruffled border, and incorporation and secretion of bone degradation products using the transcytosis system. One of the most important questions concerning osteoclast function is how osteoclasts recognize bone and polarize. During the past decade, new approaches have been taken to investigate the regulation of osteoclast polarization. Attachment of osteoclasts to some proteins containing the Arg-Gly-Asp sequence motif through vitronectin receptors is the first step in inducing the polarization of osteoclasts. Physical properties of bone such as hardness or rough...

The effect of tooth bleaching on the bond strength of an experimental primer to enamel

Odontology — Sat, 28 Jul 2007 06:48:46 +0100

This study evaluated the effect of tooth bleaching on the microtensile bond strength (�TBS) of an experimental primer to enamel. Materials used were an experimental tooth manicure system (Shofu) composed of primer and light-cured flowable resin composite. Flattened enamel surfaces of bovine teeth were bleached with Nite White Excel (Discus Dental) or Hi-Lite (Shofu), with nonbleached teeth used as a control group. Each bleaching group was subdivided into three bonding modes. These were group A, application of primer for 3 s, followed by 5 s of air blowing; group B, application of primer for 10 s, followed by 5 s of air blowing; and group C, application of 20% phosphoric acid for 10 s, spraying with water for 5 s, and then air blowing for 5 s. The flowable resin paste ...

In vitro chromosome aberration tests using human dental pulp cells to detect the carcinogenic potential of chemical agents

Odontology — Sat, 28 Jul 2007 06:48:46 +0100

Content TypeJournal Article JournalOdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal VolumeVolume 95 Journal IssueVolume 95, Number 1 / July, 2007 (Source: Odontology)

In vitro chromosome aberration tests using human dental pulp cells to detect the carcinogenic potential of chemical agents

Odontology — Sat, 23 Sep 2006 08:08:31 +0100

Abstract To examine if human dental pulp cells are useful for assessing the carcinogenic potential of chemical agents, we cultured human dental pulp cells from adults and studied the ability of chemical agents known to be carcinogenic to induce chromosome aberrations in these cells. We confirmed that human dental pulp cells in primary or secondary cultures had the capability of accumulating calcium in vitro as detected by Alizarin red staining and generating dentin-like tissue in immunocompromised mice. These phenotypes were maintained even in cells at seven passages. Next, we examined if chromosome aberrations were induced by exposure of human dental pulp cells (designated here as D824 cells) at seven to nine passages to chemical agents with carcinogenic activity. Statistically s...

Biofilms, a new approach to the microbiology of dental plaque

Odontology — Sat, 23 Sep 2006 08:08:31 +0100

Abstract Dental plaque has the properties of a biofilm, similar to other biofilms found in the body and the environment. Modern molecular biological techniques have identified about 1000 different bacterial species in the dental biofilm, twice as many as can be cultured. Oral biofilms are very heterogeneous in structure. Dense mushroom-like structures originate from the enamel surface, interspersed with bacteria-free channels used as diffusion pathways. The channels are probably filled with an extracellular polysaccharide (EPS) matrix produced by the bacteria. Bacteria in biofilms communicate through signaling molecules, and use this “quorum-sensing” system to optimize their virulence factors and survival. Bacteria in a biofilm have a physiology different from that of plankton...

Repeated androgen and thyroid hormone injection modulates the morphology of hormone-responsive duct cells in the mouse parotid gland

Odontology — Sat, 23 Sep 2006 08:08:31 +0100

Abstract When the parotid glands of normal male and female ICR mice (12 weeks of age) were examined under a light microscope, no granular cells were seen in the duct system. However, transmission electron microscopy revealed that, in both sexes, many striated duct cells contained a few electron-dense secretory granules in their subluminal cytoplasm and had formed so-called granular striated tubules (GSTs) in some of the striated duct segments. These secretory granules were not large enough to be visible with a light microscope. Fully fledged granular cells, containing large secretory granules visible with a light microscope, could be induced in the GST segments of the glands of males by injection with 5α-dihydrotestosterone (DHT), triiodothyronine (T3), and dexamethasone (Dex), g...

Expression of keratin 18 in the periderm cells of the lingual epithelium of fetal rats: visualization by fluorescence immunohistochemistry and differential interference contrast microscopy

Odontology — Sat, 23 Sep 2006 08:08:30 +0100

We examined the expression of keratin 18 (K18), by immunofluorescence staining, while monitoring morphological changes in the periderm on the lingual epithelium of rats by laser-scanning microscopy of epoxy resin-embedded, semi-ultrathin sections. We also examined differential interference contrast (DIC) images of the same sections to define the histology and morphology of the cells. It is difficult to visualize histological details of the fetal lingual epithelium of the rat on semi-ultrathin sections by light microscopy after immunohistochemical staining, because the histological structures in such sections cannot be distinguished by standard counterstaining. To solve this problem and to visualize keratin 18 (K18), we used a combination of immunofluorescence staining of semi-ultrath...

Cephalometric evaluation of anterior open-bite nonextraction treatment, using multiloop edgewise archwire therapy

Odontology — Sat, 23 Sep 2006 08:08:30 +0100

Abstract There are very few reports of extensive and detailed cephalometric investigations of nonextraction treatment changes for patients with anterior open bite. The purpose of this study was to evaluate changes in dentomaxillofacial morphology by way of lateral and oblique cephalograms of patients who had undergone multiloop edgewise archwire (MEAW) therapy for anterior open-bite correction. The subjects consisted of 21 Japanese female patients who received MEAW therapy without premolar extraction. The mean pre- and posttreatment ages were 16 years 9 months and 19 years, respectively. Lateral and oblique cephalograms were taken before and after treatment. Fifteen angular and 29 linear measurements were obtained from the lateral cephalograms; 17 angular and 20 linear measurement...

N-Methyl-D-Aspartate (NMDA) and non-NMDA receptor antagonists suppress the superior sagittal sinus-evoked activity of C1 spinal neurons responding to tooth pulp electrical stimulation in rats

Odontology — Sat, 23 Sep 2006 08:08:30 +0100

Abstract The aim of the present study was to determine whether there is a convergence of inputs from tooth pulp (TP) and the superior sagittal sinus (SSS) on rat C1 spinal neurons, and to examine the effects of iontophoretically applied N-methyl-d-aspartate (NMDA) and non-NMDA receptor antagonists on the SSS-evoked activity of C1 neurons. Extracellular single unit-recordings were made from 20 C1 units responding to TP electrical stimulation with a constant temporal relationship to a digastric electromyogram signal, using a multibarrel electrode in pentobarbital-anesthetized rats. Ninety percent of C1 neurons (18/20) responding to TP stimulation also responded to the SSS stimulation. These neurons were considered to be SSS-afferent inputs from Aδ-fibers (5.8 ± 0.6 m/s; n = 18), ...

Periodontal disease and systemic conditions: a bidirectional relationship

Odontology — Sat, 23 Sep 2006 08:08:30 +0100

Abstract For decades, physicians and dentists have paid close attention to their own respective fields, specializing in medicine pertaining to the body and the oral cavity, respectively. However, recent findings have strongly suggested that oral health may be indicative of systemic health. Currently, this gap between allopathic medicine and dental medicine is quickly closing, due to significant findings supporting the association between periodontal disease and systemic conditions such as cardiovascular disease, type 2 diabetes mellitus, adverse pregnancy outcomes, and osteoporosis. Significant effort has brought numerous advances in revealing the etiological and pathological links between this chronic inflammatory dental disease and these other conditions. Therefore, there is rea...

Ibuprofen as a pre-emptive analgesic is as effective as rofecoxib for mandibular third molar surgery

Odontology — Sat, 23 Sep 2006 08:08:30 +0100

The objective of this study was to compare the pre-emptive analgesic effect of rofecoxib, a cyclooxygenase (COX)-2 inhibitor, with a more traditional and commonly used analgesic, ibuprofen, for mandibular third molar surgery, utilizing a prospective, randomized, double-blind, placebo-controlled clinical trial. Fifty-five healthy patients who were scheduled to undergo surgical removal of an impacted mandibular third molar as outpatients at one of two government dental clinics in Fiji were enrolled. The patients were divided randomly into three groups to receive 50 mg rofecoxib or 400 mg ibuprofen, or a placebo 1 h prior to surgery. A dose of 1000 mg paracetamol was offered as rescue medication. Participants recorded their pain intensity on a 10-cm visual analogue scale 1 h b...

Decreased response of osteoblasts obtained from aged Cohen diabetic sensitive rats to sex steroid hormones and 1,25(OH)2D3 in culture

Odontology — Sat, 23 Sep 2006 08:08:29 +0100

In conclusion, the metabolic status (HSD and diabetes) in rats prior to culture affected the phenotype of cultured osteoblasts, decreasing their response to bone-modulation hormones. This decreased response, especially to estradiol, may be a major cause of the osteopenia observed in diabetes. Content TypeJournal Article JournalOdontologyOnline ISSN 1618-1255Print ISSN 1618-1247 Journal VolumeVolume 94 Journal IssueVolume 94, Number 1 / September, 2006 (Source: Odontology)

Adding problem-based learning tutorials to a traditional lecture-based curriculum: a pilot study in a dental school

Odontology — Mon, 19 Sep 2005 15:54:43 +0100

This article reports on the implementation of a problem-based learning (PBL) tutorial in our advanced program for second year students within an existing curriculum. The program was opened on the last 5 days of the summer vacation and students could volunteer to be part of the group. Students separated themselves into small groups by random sampling. The PBL tutorials were done during the first 3 days for medical problems according to our original scenarios (based on medical cases), and during the last 2 days, students made presentations of their learning outcomes, using information technology (IT) by themselves. Throughout this program, students were expected to engage in self-learning, except for a 11/2-h group session with a tutor. Assessment was done by attendance at a group session an...

Pathogenesis of degenerative temporomandibular joint arthritides

Odontology — Mon, 19 Sep 2005 15:54:43 +0100

Over the past decade, remarkable progress has been made in the study of molecular mechanisms involved in degenerative temporomandibular joint arthritides. Based on recent findings, models of degenerative temporomandibular joint disease predict that mechanical loads trigger a cascade of molecular events leading to disease in susceptible individuals. These events involve the production or release of free radicals, cytokines, fatty acid catabolites, neuropeptides, and matrix-degrading enzymes. Under normal circumstances, these molecules may be involved in the remodeling of articular tissues in response to changing functional demands. However, if functional demands exceed the adaptive capacity of the temporomandibular joint or if the affected individual is susceptible to maladaptive responses,...

Ability of 13 chemical agents used in dental practice to induce sister-chromatid exchanges in Syrian hamster embryo cells

Odontology — Mon, 19 Sep 2005 15:54:43 +0100

To evaluate the genotoxic potential of 13 chemical agents used in dental practice, the abilities of these agents to induce sister-chromatid exchanges (SCEs) were examined using Syrian hamster embryo (SHE) cells. Statistically significant increases in the frequencies of SCEs were observed in SHE cells treated with all seven of the chemical agents used as endodontic medicaments: p-chlorophenol, m-cresol, formaldehyde, guaiacol, hydrogen peroxide, p-phenolsulfonic acid, and sodium hypochlorite (P < 0.01; Student t test). Assessment of two chemical agents that are applied to the oral mucosa as antiseptics showed that SCEs were induced by iodine (P < 0.01), but not by chlorhexidine. Of three chemical agents that are used as dyes for disclosing dental plaque, erythrosine B had no effect on SCE i...

The effects of epinephrine in local anesthetics on plasma catecholamine and hemodynamic responses