Temporomandibular disorders. Part I: Functional status, dentomorphologic features, and sex differences in a nonpatient population.

Freshman dental and dental hygiene students, 120 men and 102 women (mean age 23.9 years), were assessed for the presence of masticatory pain or dysfunction by questionnaire, clinical examination, and evaluation of dental casts according to strict criteria. The purpose was to identify and analyze the level of signs and symptoms in a nonpatient population and describe occlusal variation. The prevalence of TMJ signs and symptoms was notable even though two thirds reported only mild or early symptoms, with only 3% reporting severe symptoms. This population was noted for the absence of locking, the low frequency of severe pain or severe TMJ dysfunction, and the low prevalence of restricted ranges of mandibular movement and TMJ crepitation. Women showed significantly more headache, TMJ clicking and tenderness, and muscle tenderness than men. Men were noted for the absence of severe and widespread muscle tenderness and severe TMJ tenderness. TMJ clicking was not always clinically confirmable in subjects with widespread muscle tenderness. This group was considered compatible with previous epidemiologic findings, and also matches the age range of most subjects seeking treatment for TMJ disorders. Therefore, the subjects in the study were considered a representative group of young adults and suitable for study of the possible associations between early signs of TMJ disorders and variables of morphologic malocclusion, which are discussed in Parts II and III of this article.