Temporomandibular disorders. Part II: Occlusal factors associated with temporomandibular joint tenderness and...

Two complete classes of 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 the degree of association between observable signs of TMJ disorders and selected combinations of occlusal variables. TMJ tenderness was more frequent in class II, division 2 than in class I (p less than .05), but overall was not associated with occlusal factors such as deep overbites, length of a symmetric RCP-ICP slide, and unilateral contact in RCP. Overall, clicking was not associated with Angle class, deep overbite, length of symmetric RCP-ICP slide, or unilateral RCP contact. Among subjects with unilateral RCP contact, those with no clinically obvious RCP-ICP slide (p less than .005) and those with asymmetric slides (p less than .05) had more TMJ clicking than subjects with symmetric slides. Luxation clicking of the condyle over the articular eminence on wide opening was absent in class II, division 2 subjects, but was most frequent in subjects with some teeth in unilateral posterior crossbite, particularly when this was a unilateral condition (p less than .001). Certain occlusomorphologic conditions may require less adaptation in the TMJs. This article indicates that an ICP anterior to the RCP in association with bilateral occlusal stability may be protective.