Comparison of temporomandibular joint shape and size in patients with facial asymmetry

Abstract

Objective To examine the morphologic similarities and differences in mandibular condyle and glenoid fossa between the deviated and non-deviated sides in patients with facial asymmetry using statistical analysis. Methods One hundred eighty-four patients (95 men, 89 women; mean age, 22.30 +/- 3.87 years) with facial asymmetry were examined with cone-beam computed tomography (CBCT). Shape analysis was performed to compare the shapes and sizes of the condyle and fossa between the deviated and non-deviated sides in the frontal and lateral aspects. Ordinary Procrustes analysis (OPA) was used to determine shape variations of the fossa and condyle. Results Shape variations derived from ordinary sum of squares (OSS) suggested that, in the frontal aspect, there was a difference between the two sides in both the fossa and condyle (P < 0.05). In the lateral aspect, there was no difference in fossa shape between the two sides (P > 0.05); however, the shape of condyle was different between the non-deviated and deviated sides (P < 0.05). Size comparison in OPA matching and centroid size (CS) in the frontal aspect demonstrated that the non-deviated side was larger than the deviated side. In the lateral aspect, fossa showed no difference in CS between the two sides (P > 0.05); however, the non-deviated side was larger than the deviated side for condyle (P < 0.05). Conclusions Morphometric differences in condyle and fossa between the deviated and non-deviated sides were observed. Structures of the non-deviated side were relatively larger than those of the deviated side, except for fossa in the lateral aspect.