Relationship of slightly limited mandibular movements to temporomandibular disorders.

Mandibular movements have been analyzed extensively in the past for prosthodontic reasons, and more recently to study the function of the masticatory system. This study investigated the range of mandibular movements in a young male population, and analyzed the difference in range of mouth opening, right and left lateral movements, and protrusive movement between asymptomatic subjects (control group) and patients with clinical diagnoses of temporomandibular disorders. A total of 180 subjects, aged 19-28 years, were included in the study. The TMD sample comprised 90 patients (30 patients with muscle disorders; 30 patients with disc displacement with reduction; 30 patients with muscle disorders and disc displacement with reduction) and was compared with 90 healthy control subjects. All participants were evaluated by the attending dentist at baseline with a complete physical examination and history questionnaire, which included the Research Diagnostic Criteria for Temporomandibular Disorders Axis I measures. Analysis of variance (ANOVA) showed significant differences in ranges of mandibular movements between and within the groups of healthy control subjects and patients with muscle and temporomandibular joint disorders. It is suggested that there are differences in the range of mandibular movements that clearly separate asymptomatic subjects and patients with temporomandibular disorders in this young male population.