Background: The symptoms of temporomandibular disorders (TMD) are directly influenced by numerous factors, and it is thought that additional factors exert indirect influences. However, the relationships between TMD-related symptoms (TRS) and these contributing factors are largely unknown. Thus, the goal of the present study was to investigate influences on TRS in a working population by determining the prevalence of TRS, analyzing contributing factors, and determining their relative influences on TRS.Materials and Methods: The study subjects were 2203 adults who worked for a single company. Subjects completed a questionnaire assessing TRS, psychosocial factors (stress, anxiety, depressed mood, and chronic fatigue), tooth-contacting habit, and sleep bruxism-related morning symptoms, using a 5-point numeric rating scale. Our analysis proceeded in 2 phases. First, all variables of the descriptor were divided into parts by using an exploratory factor analysis. Second, this factorial structure was verified by using a confirmatory factor analysis with structural equation modeling.Results: Of 2203 employees, 362 reported experiencing TRS (16.4%). Structural equation modeling generated a final model with a goodness of fit index of 0.991, an adjusted goodness of fit index of 0.984, and a root mean square error of approximately 0.021. These indices indicate a strong structural model. The standardized path coefficients for “habitual behavioral factors and TRS,” “psychosocial factors and habitual behavioral factors,” “psychosocial factors and TRS,” and “gender and habitual behavior factors” were 0.48, 0.38, 0.14, and 0.18, respectively.Conclusions: Habitual behavioral factors exert a stronger effect on TRS than do psychosocial factors.

Background: In this study, we focused on the habits of wind instrumentalists as well as the presence of playing instruments, and investigated associations between the risk of temporomandibular disorders (TMD) and playing wind instruments in non-professional musicians.Material and Methods: Seventy-two non-professional players of wind instruments (instrument group) (mean(SD), 20.0(1.1) y; 42 women) and 66 non-players (control group) (22.0(2.6) y; 45 women) participated in this study. Factors were investigated using questionnaires (a screening questionnaire for TMD, instrument playing habits, years of experience, and time played per day).Result: The prevalence of a high risk of TMD was not significantly different between the instrument group (29.2%) and control group (21.2%). In the instrument group, the frequency of subjects who felt mouthpiece pressure in the high risk of TMD group (47.6%) was significantly greater than that in the low risk of TMD group (21.6%). Mouthpiece pressure was found to be a significant factor contributing to a high risk of TMD (odds ratio, 3.31; 95% CI, 1.12–9.79).Conclusion: This study suggests that pressure from the mouthpiece was one of the contributing factors related to a high risk of TMD in non-professional wind instrument players.

Objective: To assess the intraoral conditions and oral function of patients with amyotrophic lateral sclerosis (ALS). Material and methods: This single-centre, cross-sectional observational study included 50 ALS patients, who were treated with tracheostomy positive-pressure ventilation (TPPV) while hospitalized. The disease duration, TPPV duration, current number of teeth, number of occlusal units, number of decayed/missing/filled teeth, community periodontal index, bleeding on probing, dental calculus, maximum mouth opening, salivation rate, tongue anomalies (atrophy or hypertrophy) and tongue coating were determined for each patient. Differences in intraoral conditions according to disease duration or TPPV duration were statistically analysed. Results: The maximum mouth opening was low in the included patients, with a mean distance of 13.7 ± 7.4 mm. Furthermore, the maximum mouth opening showed a significant negative correlation with both disease duration and TPPV duration. No statistically significant differences were found between any other intraoral parameters and disease duration or TPPV duration. Conclusions: Severe dental disease is uncommon among hospitalized ALS patients who receive oral care by nurses; however, mouth opening is very restricted in these patients. Early intervention for restricted mouth opening, directed by a dentist or dental hygienist, is essential in this population.

This study aimed at identifying the factors that influence the incidence of temporomandibular disorders (TMD)-related symptoms (TRS) in a Japanese working population.

Background: The effect of awake and sleep bruxism on periodontal disease has not been evaluated separately to date. Furthermore, there are few studies that have focused on awake bruxism with light force. Objective: The study aimed to investigate the frequency of sleep and awake bruxism in patients with periodontal disease. Methods: The subjects were 57 patients with periodontal disease who visited the Department of Periodontics of the Dental Hospital affiliated with Tokyo Medical and Dental University. Subjects were asked to fill out a questionnaire consisting of three items on bruxism (sleep and awake bruxism), and the maximum community periodontal index was investigated. Results: The proportions of individuals with high sleep bruxism-related signs and high awake bruxism-related signs were 6.0% and 44.0%, respectively. No significant difference was found in the comparison of maximum community periodontal index proportions between individuals with high sleep bruxism-related signs and high awake bruxism-related signs. Conclusion: The results of this survey of patients with periodontal disease showed that the proportion of subjects with high awake bruxism-related signs subjects was higher than those of the subjects with high sleep bruxism-related signs. Sleep bruxism has attracted attention as a factor influencing periodontal disease, and our data suggest that patients with periodontal disease demonstrate more bruxism while being awake than during sleep.

Purpose: This network meta-analysis (NMA) of randomized controlled trials (RCTs) aimed to identify effective initial conservative treatment strategies for patients with temporomandibular joint disorders (TMD).Study selection: RCTs comparing treatment options for TMD published between January 2000 and July 2021 were retrieved from the databases of PubMed and Embase via a comprehensive electronic search. Patients diagnosed with myalgia (muscle pain) or arthralgia (joint pain) according to pain-related Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were eligible for inclusion. Twelve treatment options and a placebo were included in the mutual comparisons. The risk of bias was assessed using Risk of Bias 2.0. Forest plots of direct comparisons between individual studies were created using MetaInsight. NMA was performed using R statistical software (netmeta).Results: Twenty-four RCTs involving 1336 patients assessing pain and 12 RCTs involving 614 patients assessing maximal mouth opening were identified. Low-level laser therapy (standard mean difference [SMD]: -2.12, 95% confidence interval [CI]: -3.18, -1.06), self-exercise (SMD: -1.51, 95% CI: -2.82, -0.2), and stabilization splints (SMD: -1.16, 95% CI: -2.02, -0.29) were effective in improving pain; however, the certainty of evidence was very low. Self-exercise (SMD: 0.71, 95% CI: -0.58, 2.01), stabilization splints (SMD: 0.65, 95% CI: -0.09, 1.39), and low-level laser therapy (SMD: 0.63, 95% CI: -0.34, 1.6) were effective in improving maximal mouth opening; however, the certainty of evidence was very low.Conclusions: Stabilization splints, self-exercise, and low-level laser therapy may be effective in the initial treatment of TMD.