Changes in condylar dimensions in temporomandibular joints with disk displacement.

OBJECTIVES

The aim of this study was to investigate the condylar dimensions of the temporomandibular joint (TMJ) with respect to disk displacements and sex by using computed tomography (CT) and magnetic resonance imaging (MRI).

STUDY

DESIGN

Disk displacements were divided into 3 groups based on MRI findings: normal disk position (NR), disk displacement with reduction (DDR), and disk displacement without reduction (DDNR). After the angular and linear condylar dimensions were calculated from CT images, differences in condylar dimensions with respect to disk displacements and sex were analyzed with 2-way analysis of variance.

RESULTS

Condylar depth and condylar height were significantly smaller in condyles with DDNR compared with those with NR or DDR (NR = DDR > DDNR). Condylar width gradually decreased significantly from NR to DDNR (NR > DDR > DDNR). The anterior condylar angle was significantly larger in condyles with NR compared with those with DDR or DDNR (NR > DDR = DDNR). Condyles with DDNR exhibited significantly larger horizontal condylar angles than those with NR or DDR (NR = DDR < DDNR). Altered condylar dimensions associated with disk displacement were not significantly different between men and women.

CONCLUSIONS

Condylar dimensions may be significantly associated with disk displacements of the TMJ, irrespective of sex.