Computed Tomographic Evaluation of Condylar Symmetry and Condyle-Fossa Relationship of the Temporomandibular Joint in Subjects with Normal Occlusion and Malocclusion: A Comparative Study.

Abstract

The relationship of the condyle and the mandibular fossa differs in shape with type of malocclusion and skeletal pattern. A review of literature shows till date there are no studies on Temporomandibular Joint (TMJ) condyle-fossa relation to the type of malocclusion based on growth pattern. Computed Tomography (CT) provides optimal imaging of the osseous components of the TMJ. The purpose of this study was to investigate the condyle-fossa relationship and the dimensional and positional symmetries between the right and left condyles in subjects with normal occlusion and malocclusion in different growth patterns utilizing the CT scans of the TMJ. Sixty subjects with age group of 18-30 years were selected for the study. The sample was divided into three groups based on overbite and growth pattern. The groups included 20 subjects with normal occlusion and average growth pattern, 20 patients with horizontal growth pattern and deep bite, 20 patients with vertical growth pattern and deep bite. The depth of the mandibular fossa, the condyle-fossa relationship, and the concentric position of the condyles were evaluated by the images obtained from the sagittal slices. ANOVA was performed to assess the significance. If it was found significant, post-hoc Tukey's test was performed to see which two groups were statistically significant. No statistically significant difference was found in the anterior joint space and the superior joint space in horizontal and vertical growers with deep bite. Statistically significant (p <0.05) posterior positioning of the condyles was observed (nonconcentric positioning) in vertical growers with deep bite. There is a significant change in the position of the condyle in vertical growers compared to average and horizontal growers. Left condyle is more anteriorly placed than the right condyle in all the three groups. There is no significant change in the vertical depth of the mandibular fossa in all the three groups.