Occlusal risk factors for temporomandibular disorders.

OBJECTIVE: To determine the role of occlusal variables (overbite; overjet; number of anterior and posterior teeth; bilateral canine guidance on lateral and protrusive movements; anterior centric slide; Angle Classes I, II, and III malocclusion) as risk indicators for the development of temporomandibular disorders (TMDs). MATERIALS AND METHODS: Seventy-two TMD patients with myofascial pain, with or without limited opening and arthralgia, as well as 30 age- and gender-matched pain-free concurrent controls were included. The association (critical odds ratio [OR] = 2.0) between the significant occlusal variables and TMD was calculated. Confounders were controlled in the inclusion-exclusion criteria as well as in the analysis stage (unconditional logistic regression) by variation in the OR (15%). RESULTS: Angle Class II malocclusion (crude OR = 8.0, confidence interval [CI] = 2.2 to 29.3) and the absence of bilateral canine guidance on lateral excursion (crude OR = 3.9, CI = 1.6 to 9.7) were statistically more common in patients than in controls. Spontaneous pain as well as pain on palpation (Class II or higher) were also statistically worse in TMD patients. Significant confounders (ie, employment, age, cigarette and alcohol consumption) acted as effect modifiers not changing the critical OR (adjusted OR Angle Class II and bilateral canine guidance = 8.3 to 12.4 and 2.2 to 4.1, respectively). CONCLUSIONS: Absence of bilateral canine guidance on lateral excursion and particularly Angle Class II malocclusion were considered important risk indicators for the development of TMD in this investigation, even when some sociodemographic factors were considered as effect modifiers.

Sleep and depression as risk indicators for temporomandibular disorders in a cross-cultural perspective: a case-control study.

PURPOSE: We conducted this case-control study to determine the role of 2 neuropsychologic variables (sleep and depression) as possible risk indicators for the development of temporomandibular disorders (TMD). MATERIALS AND METHODS: Neuropsychologic tests, traditional signs and symptoms of TMD, and social and economic variables were analyzed. Seventy-two predominantly muscle-related TMD patients (Research Diagnostic Criteria for TMD groups Ia, Ib, and IIIa) and 30 age- and sex-matched pain-free controls were included in the population. RESULTS: Overall, TMD patients had statistically significantly higher sleep and depression scores on the Sleep Assessment Questionnaire and on the Brazilian Portuguese version of the Beck Depression Inventory, with odds ratios of 5 and 1.6, respectively. These results remained unchanged even after controlling for 8 confounders in the logistic regression analysis. Spontaneous pain and pain on palpation (grade 2 or higher) were also statistically significantly worse in TMD patients. In the forward-step logistic regression analysis, we also found that the combination of our best TMD predictors (ie, sleep, cigarettes, alcohol) had a better predictive value (percent agreement = 78.69%) than when the variables were analyzed alone. CONCLUSION: Sleep and depression are considered important risk indicators for the development of TMD.