Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with bilateral disk displacement with reduction.

The purpose of this study was to evaluate the effect of bilateral disk displacement with reduction (BDDR) on the skeletal and dental pattern of affected individuals. There were 42 symptomatic female patients and 46 asymptomatic normal female volunteers. All study participants had bilateral high-resolution magnetic resonance scans in the sagittal (closed and open) and coronal (closed) planes for evaluation of the temporomandibular joints. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base, and dental characteristics of the two groups. Analysis of variance was used to compare the symptomatic subjects with the control subjects. The length of both the anterior (S-Na) and posterior (S-Ba) cranial base was smaller in the BDDR group. SNA and SNB angles were also smaller in the symptomatic group. There were also significant differences in the denture pattern. The interincisal angle was larger and the upper incisor was more retroclined in the BDDR group. This study showed that alterations in skeletal morphology may be associated with disk displacement (DD). The mechanisms by which DD is produced or the mechanisms that cause that skeletal alteration are yet to be clarified. This study suggests that subjects with BDDR may manifest altered craniofacial morphology. The clinician should be aware of this possibility especially for the growing patients and the orthognathic surgery candidates.