Comparison of masticatory performance and oral hygiene status using cream-type denture adhesives and home liners: A cross-sectional study using propensity-score matching.

BACKGROUND: Differences in the effects of cream-type denture adhesives and home liners remain unclear. OBJECTIVE: This cross-sectional study aimed to clarify the differences in the oral-hygiene status and masticatory performance between participants using cream-type denture adhesives and those using home liners. METHODS: Masticatory performance with and without cream-type denture adhesives and home liners was evaluated using colour-changeable chewing gum. Oral hygiene was assessed using the tongue coating index (TCI). Propensity-score matching was performed using oral moisture, presence of palatal or mandibular protuberances, type of residual ridge, denture type (complete or partial denture), and denture retention as background factors. Wilcoxon signed-rank test was used to examine the differences in masticatory performance with and without cream-type denture adhesives and home liners and differences in masticatory performance and TCI between the cream-type denture adhesive and home-liner groups. RESULTS: This study included 38 and 40 cream-type adhesive and home-liner users, respectively, and 17 pairs were obtained after propensity-score matching. The Wilcoxon signed-rank tests showed that masticatory performance was significantly different with and without the use of home liners, and higher values were obtained with the use of home-liners. However, the cream-type denture adhesive and home-liner groups showed no significant differences in terms of the change in masticatory performance with the use of them. Furthermore, Wilcoxon signed-rank tests showed that TCI values were significantly high in the cream-type adhesive group. CONCLUSION: The findings in this study suggest that home liners improve masticatory performance and that participants regularly using cream-type denture adhesives have poorer oral hygiene.

Prognoses of new complete dentures from the patient's denture assessment of existing dentures.

OBJECTIVES: The aim was to determine prognostic factors affecting frequent post-delivery adjustments of new complete dentures using patients' assessments of existing complete dentures. MATERIALS AND METHODS: A total of 125 edentulous participants (56 men, 69 women; mean age, 76.4 years) who required new complete dentures evaluated existing dentures using the patient's denture assessment (PDA), a questionnaire regarding the self-assessment of dentures composed of 22 question items and containing six subscales: "function," "lower denture," "upper denture," "expectation," "esthetics and speech," and "importance." Moreover, the numbers of post-delivery adjustments of new dentures were recorded. A multiple logistic regression analysis was performed to identify significant factors for frequent adjustments of new dentures with five subscales of the PDA (excluding "importance"), level of mandibular ridge resorption, and age as independent variables. RESULTS: The analysis showed that "function," "esthetics and speech," and level of mandibular ridge resorption were significant variables for a frequent number of post-delivery adjustments of new complete dentures. CONCLUSIONS: The results suggested that patients' assessments of existing dentures using the PDA might allow a prediction of prognosis for complete denture treatments. Additionally, low "function" scores and high "esthetics and speech" scores for existing dentures and high levels of mandibular ridge resorption were significant prognostic factors affecting frequent post-delivery adjustments of new complete dentures. CLINICAL RELEVANCE: It may be difficult for edentulous persons to adapt to new complete dentures, especially those who have complaints about mastication and swallowing with existing dentures and poor mandibular ridges, but are satisfied with esthetics and speech.

Increased cell proliferation and differential protein expression induced by low-level Er:YAG laser irradiation in human gingival fibroblasts: proteomic analysis.

Erbium-doped yttrium aluminum garnet (Er:YAG) laser treatment has demonstrated favorable wound healing effect after periodontal therapy. One of the reasons may be the positive biological effect of the low-level laser on the irradiated tissues, although the mechanism remains unclear. The aim of this study was to investigate the effect of low-level Er:YAG laser irradiation on cell proliferation and laser-induced differential expression of proteins in human gingival fibroblasts (HGFs) by proteomic analysis. In the first experiment, HGFs were exposed to low-level Er:YAG laser irradiation and the laser-induced cell proliferation and damage were evaluated on day 3. In the second experiment, proteomic analysis was performed on day 1 after irradiation. The peptides prepared from HGFs were analyzed by a hybrid ion trap-Fourier transform mass spectrometer, Mascot search engine, and UniProtKB database. A significant increase in cell proliferation without cell damage after irradiation was observed. Among the total identified 377 proteins, 59 proteins, including galectin-7, which was associated with the process of wound healing, were upregulated and 15 proteins were downregulated in laser-treated HGFs. In the third experiment, the increase in messenger RNA (mRNA) and protein expression of galectin-7 in the irradiated HGFs was validated by various analytical techniques. In addition, the effect of recombinant human galectin-7 on the modulation of HGFs proliferation was confirmed. The results indicate that low-level Er:YAG laser irradiation can promote HGF proliferation and induce a significant change in protein expression and the upregulation of galectin-7 expression may partly contribute to the increase in cell proliferation.

Serum γ-glutamyltransferase level is associated with periodontal disease independent of drinking habits in Japanese adults.

Background Non-alcoholic fatty liver disease is considered a hepatic manifestation of metabolic syndrome. Periodontal disease is a mild chronic inflammatory disease with systemic effects, and many studies have indicated an association between metabolic syndrome and periodontitis. In the present study, we investigated the relationship between periodontitis and liver biochemical parameters according to alcohol drinking habits through a cross-sectional study based on data from Japanese people in occupational settings. Material and Methods The subjects were 1510 employees (1218 males, 292 females, mean age 50.4 years) who underwent dental and medical checkups in 2012. Associations between the presence of periodontal pockets and serum levels of liver biochemical parameters were assessed. Results Alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT) levels were higher in subjects with than without periodontal pockets. Multiple logistic regression analysis (adjusting for age, gender, cigarette smoking, and alcohol drinking habits, and components of metabolic syndrome) with GGT or ALT as the dependent variable revealed that there was a significant association between periodontal pockets and GGT (odds ratio, OR=1.48), but not ALT. Similar associations were observed when an analysis was performed according to the presence or absence of alcohol drinking habits; the OR was higher in subjects without (OR=1.84) than with drinking habits (OR=1.41). Conclusions The presence of periodontal pockets was associated with serum levels of GGT, a liver biochemical parameter, in Japanese adults with no drinking habit, suggesting that periodontal disease is associated with liver function, independent of alcohol ingestion.

Retrospective analysis of odontogenic myxoma and odontogenic myxofibroma in the oral and maxillofacial region: a fibrous tissue-related differentiation.

The clinical differences between odontogenic myxoma (OM) and odontogenic myxofibroma (OMF), and the clinical significance of their classifications, remain unclear. This study reviewed the clinicopathological characteristics of patients with OM or OMF and evaluated the fibrous component of the specimens. Medical records of 21 patients with OM or OMF who underwent tumour resection were reviewed. The percentage of fibrous tissue on the representative sections was evaluated using haematoxylin and eosin- and Masson's trichrome-stained specimens. Histopathological diagnoses included 11 OMs and 10 OMFs with no tumour recurrence except for two cases in which the dredging method was applied. More cortical bone perforation was observed in OM than in OMF cases, without significant differences. Location-locularity and apparent diffusion coefficient value (ADC)-cortical bone perforation were significantly correlated in all OM and OMF cases. The percentage of fibrous tissue in specimens showed bimodal distribution bordered by 45%. There was a significant association between diagnosis based on 45% fibrous tissue criterion and the final pathological diagnosis. Our study showed a tendency for cortical bone perforation in OM compared to OMF and correlation between ADC and cortical bone perforation. According to the histopathological analyses, the fibrous component of each case was bimodal with 45%, which may be a criterion to distinguish between OM and OMF. Accumulating knowledge, such as significant differences in prognosis, may allow for minimal surgical treatment options based on the diagnosis according to this novel histopathological criterion.

Association between occlusal supports and nutritional status in older adults: A systematic review.

Background/purpose: Impaired masticatory performance results in nutritional deficiencies in older adults. This systematic review aims to investigate the following clinical question (CQ): Do occlusal supports impact nutritional intake or nutritional status in older individuals? Materials and methods: An extensive systematic literature search was performed to summarize the currently available knowledge to address the CQ. The cohort and intervention studies with participants of ≧60 years old or a mean age of 65 years performed before May 2021 were included. Studies were required to measure the parameters related to occluding tooth pairs/occlusal units and food/nutrient intake and/or nutritional status. Bias risk was assessed using the Risk of Bias Assessment Tool for Nonrandomized Studies. Results: After an independent screening of 1130 initial records, 24 reports from 22 studies were included. Participants (n = 8684) in the included studies were mainly residents of nursing homes or community-dwelling individuals. Following the assessment of bias risk, it is revealed that all studies had methodological weaknesses. Over half of the studies concluded that there was an association between occlusal support and nutritional intake or status. However, it was also revealed that various confounding factors are involved in the association between occlusal support and nutrition. Conclusion: This systematic review concludes that occlusal support might be associated with nutritional intake or nutritional status in the older population, although there are methodological limitations of each study. The evidence is still insufficient, and more well-designed studies are required.

The Potential of a Saliva Test for Screening of Alveolar Bone Resorption.

Oral health screening is important for maintaining and improving quality of life. The present study aimed to determine whether patients with a certain level of alveolar bone resorption could be screened by salivary bacterial test along with their background information. Saliva samples were collected from 977 Japanese patients, and the counts of each red-complex, that is, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, were measured using quantitative polymerase chain reaction analysis. Mean bone crest levels (BCLs) were measured using a full-mouth periapical radiograph. Multiple logistic regression analysis was used to determine associations between BCLs (1.5-4.0 mm in 0.5 mm increments) and explanatory variables, such as the number of each red-complex bacteria and the patients' age, sex, number of teeth, stimulated saliva volume, and smoking habits. When the cutoff BCL value was set at 3.0 mm, the area under the curve, sensitivity, and specificity values were optimal at 0.86, 0.82, and 0.76, respectively. In addition, all tested explanatory variables, except sex and T. denticola count, were significantly associated with BCLs according to a likelihood ratio test (p < 0.05). Additionally, the odds ratio (OR) was substantially increased when a patient was >40 years old and the bacterial count of P. gingivalis was >107 cells/µL (OR: >6). Thus, P. gingivalis count and patients' background information were significantly associated with the presence of a certain amount of bone resorption, suggesting that it may be possible to screen bone resorption without the need for radiography or oral examination.

Risk factors for postoperative facial swelling at 1 week after bimaxillary orthognathic surgery in Class III patients.

OBJECTIVE: To quantify facial swelling at 1 week after Le Fort I osteotomy and bilateral sagittal splitting ramus osteotomy in Class III patients and to identify factors contributing to the swelling based on clinical, morphologic, and surgical variables. STUDY DESIGN: Data from 63 patients were examined in this single-center, retrospective study. Facial swelling was quantitatively measured by superimposing computed tomography data taken in the supine position at 1 week and 1 year postoperatively and extracting the area of maximum intersurface distance. Age, sex, body mass index, thickness of subcutaneous tissue, and of masseter muscle, maxillary length (A-VRP), mandibular length (B-VRP), and posterior maxillary height (U6-HRP), surgical movement (ΔA-VRP, ΔB-VRP, ΔU6-HRP), drainage method, and usage of facial bandages were examined. Multiple regression analysis was performed using the above factors. RESULTS: The median swelling at 1 week postoperatively was 8.35 IQR (5.99-11.47) mm. Multiple regression analysis revealed three factors that were significantly associated with facial swelling: Use of postoperative facial bandages (P=0.03), masseter muscle thickness (P=0.03), and ΔB-VRP (P=0.04). CONCLUSION: Absence of a facial bandage, thin masseter muscle, and large horizontal mandibular movement are risk factors for facial swelling at 1 week postoperatively.

Er:YAG laser-assisted comprehensive periodontal pocket therapy for residual periodontal pocket treatment: A randomized controlled clinical trial.

BACKGROUND: This study evaluated the effectiveness of a novel pocket therapy (Er:YAG laser-assisted comprehensive periodontal pocket therapy [Er-LCPT]) for residual pocket treatment, compared with conventional mechanical treatment alone, in a randomized controlled clinical trial. METHODS: Two sites in 18 patients having residual periodontal pockets of ≥5 mm depth, extant following initial active therapy, or during supportive therapy, were randomized into two groups in a split mouth design: the control group received scaling and root planing (SRP) by curette, and the test group received Er-LCPT using curette and laser. With Er-LCPT, after root debridement, inflamed connective tissue on the inner gingival surface and on the bone surface/within extant bone defects was thoroughly debrided. Furthermore, removal of proximate oral epithelium and coagulation of the blood clot in the pocket entrance were performed with laser. Clinical parameters were evaluated, before and after treatment, through 12 months. RESULTS: Both groups showed significant improvements in clinical parameters. With Er-LCPT, pocket debridement was thoroughly and safely performed, without any adverse side effects and complications, and favorable healing was observed in most of the cases. At 12 months, Er-LCPT demonstrated significantly higher probing pocket depth reduction (2.78 mm vs. 1.89 mm on average; p = 0.012, Wilcoxon signed-rank test), clinical attachment gain (1.67 mm vs. 1.06 mm; p = 0.004) as primary outcomes, and reduced BOP value (0.89 vs. 0.56; p = 0.031), compared with SRP alone. CONCLUSION: The results of this study indicate that Er-LCPT is more effective for residual pocket treatment, compared with SRP alone.

Risk factors of neurosensory disturbances at 1 year postoperatively after bilateral sagittal split osteotomy.

OBJECTIVE: To investigate morphologic and surgical risk factors causing neurosensory disturbances (NSDs) after bilateral sagittal split osteotomy (BSSO). STUDY DESIGN: A total of 237 patients (with 474 sides) who underwent BSSO were followed up for 1 year. Parameters examined included age, sex, asymmetry, mandibular movement direction, mandible cutting devices, split type, intraoperative exposure of the inferior alveolar nerve (IAN), contact between the IAN and screw, distance between mandibular canal and inner surface of the cortical bone (distance A), distance from lateral osteotomy to mental foramen (distance B), and NSD at 1 year postoperatively. RESULTS: NSD was observed in 62 (13.1%) sides of 51 patients. Exploratory factor analysis determined 4 factors (factor 1: distance A; factor 2: direction of mandibular movement; factor 3: distance B and cutting devices; factor 4: IAN exposure). Logistic regression analysis was performed using the above factors and age, sex, and asymmetry, making a total of 7 variables. Age, factor 1, and factor 4 were significant predictors of NSD. CONCLUSIONS: Advanced age, close distance between mandibular canal and inner surface of the cortical bone, and IAN intraoperative exposure are risk factors for NSD 1 year postoperatively. Cases at high risk for NSD must be treated with great care.

Retrospective analysis of schwannoma in the oral and maxillofacial region: clinicopathological characteristics and specific pathology of ancient change.

Schwannomas are benign tumours that originate from the Schwann cells of the nerve. Despite the frequency of their occurrence in the head and neck, data relating to their clinicopathological features in the region are limited. This study reviews the clinicopathological characteristics and specific pathology of ancient (degenerative) change in 40 cases in the oral and maxillofacial region. Medical records were reviewed of the 40 cases treated at Tokyo Medical and Dental University Hospital Faculty of Dentistry between 2000 and 2020. The most frequently involved site was the tongue, and the average tumour size was 13.2 mm. Degenerative changes were observed in eight cases. All tumours were completely excised through biopsy or local excision, and no recurrence was observed on clinical follow up. Statistical analyses revealed significant associations (p < 0.05) between ancient change and tumour size, and between ancient change and the apparent diffusion coefficient (ADC) value derived from diffusion-weighted magnetic resonance imaging (MRI). Analysis suggests that schwannoma progresses over a long period and subsequently undergoes secondary ancient changes. Pathological events such as cystic formation and haemorrhage that are associated with ancient changes, cause hypocellularity and lead to high ADC values. These values may indicate ancient change and should be considered when distinguishing schwannoma from other lesions.

Porphyromonas gingivalis, the most influential pathogen in red-complex bacteria: A cross-sectional study on the relationship between bacterial count and clinical periodontal status in Japan.

BACKGROUND: Porphyromonas gingivalis is a key pathogen in microbiota associated with periodontitis. The purpose of the present study was to assess the association between salivary counts of red-complex bacteria and clinical periodontal status in a Japanese population. METHODS: A total of 977 subjects who visited a general dental clinic in Japan from 2003 to 2006 were enrolled in the study. Stimulated saliva was obtained, and the amounts of major periodontal bacteria were measured using real-time polymerase chain reaction. Probing pocket depth (PPD), bleeding on probing (BOP), and each subject's average proximal bone crest level (BCL) on dental radiographs were measured. RESULTS: The number of P. gingivalis strongly associated with percentage of 4 mm or more PPD sites, BOP positive percentage, and 1.5 mm or more BCL sites. The detection of P. gingivalis with Treponema denticola and/or Tannerella forsythia showed a high rate of three positive clinical parameters, whereas the only P. gingivalis detected group and those without P. gingivalis had a low rate of three positive clinical parameters. CONCLUSION: Among red-complex bacteria, the amount of P. gingivalis showed the strongest association with the severity of periodontal condition, and co-occurrence of P. gingivalis with T. denticola and/or T. forsythia showed heightened progression of periodontitis.

Poor oral hygiene and dental caries predict high mortality rate in hemodialysis: a 3-year cohort study.

The aim of this study was to investigate the impact of oral hygiene, periodontal diseases, and dental caries on all-cause mortality in hemodialysis. This prospective cohort study included 266 patients with end-stage renal disease who were undergoing hemodialysis. Medical interviews, blood biochemical tests, and comprehensive dental examinations including periodontal pocket examination on all teeth and dental plaque accumulation by debris index-simplified (DI-S), were performed. Survival rates were assessed at a 3-year follow-up. Overall, 207 patients were included in the longitudinal analysis, and 38 subjects died during the follow-up period. Cox proportional hazards analysis of the multivariate model demonstrated that the highest tertile of DI-S had a significantly higher risk of all-cause mortality than the lowest two tertiles after adjustment for age, sex, smoking habit, body mass index, diabetes, prior cardiovascular disease, hemodialysis vintage, high sensitivity C-reactive protein, albumin, and number of remaining teeth (hazard ratio, 3.04; 95% confidence interval, 1.50-6.17; p = 0.002). Moreover, the number of decayed teeth significantly increased the hazard ratio to 1.21 (95% confidence interval, 1.06.1.37; p = 0.003). This study suggests that accumulated dental plaque and untreated decay, but not periodontal disease, may be independently associated with all-cause mortality in patients undergoing hemodialysis.

Association between periodontal disease and metabolic syndrome.

OBJECTIVES: Metabolic syndrome is a complex medical disorder characterized by visceral fat-type obesity involving hypertension, and abnormal glucose and lipid metabolism. The objective of this study was to investigate the relationship between periodontal disease and components of metabolic syndrome (obesity, lipid abnormality, hypertension, and hyperglycemia) in industrial workers of a single company in Tokyo, Japan. METHODS: The study subjects consisted of 2478 adult employees (2028 men and 450 women; mean age: 43.3 years). The association between the presence of periodontal pockets and components of metabolic syndrome was investigated cross-sectionally using multiple logistic regression analysis, odds ratios (ORs), and 95 percent confidence intervals (CIs). RESULTS: Body mass index, blood pressure, triglycerides, fasting blood glucose, and hemoglobin A1c (HbA1c) were significantly elevated (P < 0.05) in patients with periodontal pockets of 4 mm or more. We found that the OR of the presence of periodontal pockets adjusted for age, gender, and smoking habit was 1.8 (96 percent CI = 1.4-2.3) when the subjects with two positive components and without positive component were compared. And it was 2.4 (96 percent CI = 1.7-2.7) when the subjects with three or four positive components and without positive component were compared. CONCLUSIONS: Our findings suggest an association between periodontal disease and metabolic syndrome in Japanese workers between the ages of 20 and 60 years.

Periodontal regenerative effect of enamel matrix derivative in diabetes.

The present study aimed to investigate the periodontal regenerative effect of enamel matrix derivative (EMD) in diabetes. Thirty-six rats were assigned to streptozotocin-induced diabetes or control (non-diabetic) groups. Three-wall intrabony defects were surgically generated in the bilateral maxilla molar, followed by application of EMD or saline. Primary wound closure and defect fill were evaluated via histomorphological analysis and micro-computed tomography. mRNA expression levels of inflammatory and angiogenic factors in the defects were quantified via real-time polymerase chain reaction. Gingival fibroblasts were isolated from control animals and cultured in high-glucose (HG) or control medium. The effects of EMD on insulin resistance and PI3K/Akt/VEGF signaling were evaluated. The achievement rate of primary closure and the parameters of defect fill were significantly higher at EMD-treated site than at EMD-untreated sites in both diabetic and non-diabetic rats, although defect fill in the diabetic groups was significantly lower in the control groups on two-way repeated-measures analysis of variance (for both, p<0.05). Newly formed bone and cementum were significantly increased at EMD-treated sites in diabetic rats than at EMD-untreated sites in control rats (for both, p<0.05). Vegf was significantly upregulated at EMD-treated sites in both diabetic and non-diabetic rats (for both, p<0.05). In vitro, insulin or EMD-induced Akt phosphorylation was significantly lower in cells cultured in HG medium (p<0.05). EMD-mediated Vegf upregulation was suppressed by the Akt inhibitor wortmannin, although the effect was significantly lower in HG medium (p<0.01). In conclusion, EMD might promote periodontal tissue regeneration via Akt/VEGF signaling, even in a diabetic condition.

A cross-sectional study on the periodontal status and prevalence of red complex periodontal pathogens in a Japanese population.

This large-scale study cross-sectionally examined the periodontal status and prevalence of "red complex" bacteria (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) in Japanese adults. A total of 977 participants were enrolled in the study. Probing depth (PD), bleeding on probing (BOP), and bone crest level (BCL) were recorded, and the presence of red complex bacteria in the saliva was examined using polymerase chain reaction. The mean BCL value and the percentage of sites with a PD ≥4 mm or the presence of BOP were significantly higher in older participants. The detection rates of P. gingivalis, T. denticola, and T. forsythia were 46.3%, 76.4%, and 61.1%, respectively. The P. gingivalis detection rate significantly increased with age, while those of T. denticola and T. forsythia were comparably high for all age groups. A close correlation between P. gingivalis and the percentage of sites with PD ≥4 mm was indicated by nonlinear canonical correlation analysis. Current smokers exhibited a more advanced disease condition and a significantly higher P. gingivalis detection rate than non-smokers. In conclusion, periodontal condition worsens with age, and P. gingivalis appears to be the red complex bacterium most closely associated with periodontitis.

Association Between the Duration of Periodontitis and Increased Cardiometabolic Risk Factors: A 9-Year Cohort Study.

BACKGROUND: Epidemiological studies have reported that periodontitis and cardiometabolic disease such as cardiovascular disease and type 2 diabetes are associated; however, there have been very few prospective cohort studies on this topic. Therefore, we conducted a 9-year follow-up study to examine the relationship between the duration of periodontitis and cardiometabolic risk factors, including hypertension, hyperglycemia, dyslipidemia, and obesity. METHODS: The study participants comprised 572 adult industrial workers (417 men and 155 women; mean age, 37.4 years) who had undergone annual medical and dental health examinations from 2003 to 2012; the evaluation of the four cardiometabolic risk factors in 2003 revealed normal values in all the participants. We investigated the relationship between the cumulative duration of the presence of periodontal pockets, which is a major symptom of periodontitis, and the presence of cardiometabolic risk factors after 9 years using multiple logistic regression analysis. RESULTS: The odds ratio (OR) for the presence of ≥1 cardiometabolic risk factor in participants with a cumulative duration of periodontal pockets for ≥6 years was significantly higher than that in participants without pockets. The ORs for the onset of obesity, hypertension, dyslipidemia, and hyperglycemia were higher in participants with a cumulative duration of periodontal pockets for ≥6 years than those in participants without pockets or in participants with a cumulative duration of periodontal pockets for ≤5 years, and all the differences, except dyslipidemia, were significant. CONCLUSIONS: Chronic periodontitis was significantly associated with having cardiometabolic risk factors during the 9-year observation period, suggesting that the risk of cardiometabolic disease might increase in people who have untreated periodontitis.

Association between masseter muscle activity levels recorded during sleep and signs and symptoms of temporomandibular disorders in healthy young adults.

AIMS: To examine whether any signs and symptoms of temporomandibular disorders were significantly associated with masseter muscle activity levels during sleep. METHODS: One hundred three healthy adult subjects (age range, 22 to 32 years) participated in the study. They were asked to fill out questionnaires, undergo a calibrated clinical examination of their jaws and teeth, and perform 6 consecutive nightly masseter electromyographic (EMG) recordings with a portable EMG recording system in their home. The EMG data were considered dependent variables, while the questionnaire and examination data were considered independent variables. Multiple stepwise linear regression analysis was utilized to assess possible associations between these variables. RESULTS: Both gender and joint sound scores were significantly related to the duration of EMG activity. None of the other independent variables were found to be related to any of the muscle activity variables. CONCLUSION: The results suggest that both gender and clicking are significantly related to duration of masseter EMG activity during sleep.

An evaluation of self-reported oral health and health-related quality of life.

The purpose of this study was to investigate the general and oral health status of patients at a dental hospital in Tokyo and examine the correlations between general health and oral health items. One hundred and seventy-four (174) new patients at the Dental Hospital of Tokyo Medical and Dental University participated in this study. The Visual Analog Scale (VAS) was employed to investigate dental demands and symptoms, as well as satisfaction with oral and general health conditions, while SF-36 served an indicator for health-related quality of life (HRQOL). The results were statistically analyzed at a significance level of p = 0.05. The results of VAS were further examined using factor analysis. Several VAS items showed significant correlations with SF-36 subscales (p<0.05). The factor analysis of VAS items suggested a structure involving three factors: self-cognition of oral status, related function and pain, and dental fear and discomfort. The dental fear and discomfort factor showed no significant correlations with SF-36 subscales (p>0.05). Emotional elements and esthetic demands on dental status, as well as physical symptoms, influence HRQOL. Dental discomfort proved to be independent of general health status and was considered a dental-specific item that needs to be measured separately from general health status.

Age-specific prevalence of erosive tooth wear by acidic diet and gastroesophageal reflux in Japan.

OBJECTIVES: To evaluate the age-specific prevalence of erosive tooth wear in Japanese adults. METHODS: The study sample consisted of a total of 1108 adults aged 15-89 yrs in Tokyo, Japan. The subjects were asked to complete a self-administered nutrition-related questionnaire. Two examiners evaluated tooth wear in a full-mouth recording, using a modified tooth wear index developed based on the Smith and Knight Tooth Wear index. Subjects who had frequent acid consumption or gastric reflux and at least one tooth with an initial enamel wear were placed in an erosive wear positive group, and the rest of subjects were placed in the erosive wear negative group. RESULTS: The median (IQR) prevalence of erosion was 19.1 (1.8) at enamel level and 6.5 (3.7) with dentin exposure. There were statistical differences in prevalence of erosive wear among different age groups (p<0.05). Dietary habits found to be frequent in erosive wear positive group included acidic juices for younger subjects (15-39 yrs), and acidic fruits for older subjects (60-89 yrs). The prevalence of gastroesophageal reflux and eating disorder was 3.5%. A severe loss of dental tissue was observed on labial and incisal surfaces of anterior teeth in the erosive wear positive group. CONCLUSIONS: In the studied sample of Japanese adults, 26.1% had signs of erosive wear. CLINICAL SIGNIFICANCE: Erosive wear, in combination with abrasion and attrition, results in severe loss of tooth tissue. Frequent consumption of acidic fruits and drinks was significantly associated with erosive tooth wear at different age groups.