Malocclusion associated with temporomandibular joint changes in young adults at autopsy.

The purpose of this study was to identify variables of malocclusion that might be associated with previously reported temporomandibular joint morphologic findings. Before removing the left TMJ from each of 96 cadavers (age means equals 26.4 +/- 6.8 years), an intraoral examination was performed. Angle classification, crossbite, overbite, and overjet were evaluated. These parameters were analyzed with respect to their association with the following TMJ features: overall shape of the condyle and temporal bone, gross and histologic evidence of remodeling, and position of the articular disk. When combined with age, Angle Class II and III dentitions were associated with temporal and condylar deviation in form (DIF) (P less than 0.05) and more Class II dentitions were accompanied by histologic evidence of remodeling changes in the TMJs. Crossbite was associated with increasing presence of DIF in all components (P less than 0.01). Anterior crossbite was associated with DIF on the articular eminence (P less than 0.01). Deep overbite was more common in persons with flat condyles, open mandibular fossae, and anterior extension of the temporal articular surfaces (P less than 0.05). Abnormal overjet was more evident in those with DIF in the disk (P less than 0.05); greater overjet was associated with disk displacement (P less than 0.05). Considered together, abnormal overbite and overjet were associated with more extensive DIF on the condyle (P less than 0.05). In conclusion, malocclusion was associated with morphologic changes in the TMJ, particularly when combined with age. This evidence supports the belief that longer exposure to malocclusion may be associated with more extensive TMJ changes.