Temporomandibular joint measurements in normal occlusion: A three-dimensional cone beam computed tomography analysis

Background The purpose of this study was to investigate, three-dimensionally, the position, inclination, and surface area of the temporomandibular joint (TMJ) components, the condyle–fossa relationship, and the dimensional and positional symmetries between the right and left condyles in a sample of subjects with normal skeletal and dental relationships. Methods Cone beam computed tomographic images were taken in 90 subjects from 18 to 25 years of age with skeletal Class I relationship and normal occlusion. Bilateral TMJs were evaluated on the volumetric images, and the following three-dimensional measurements were obtained: 1) mandibular fossa position, inclination, and parameters; 2) mandibular condyle position, inclination, and parameters; 3) TMJ space measurements; and 4) centralization of the condyles in their respective mandibular fossae. The multiplanar images were evaluated for the surface-area measurements. Statistical analysis of the obtained measurements was done. Results The mean measurements of the anterior, posterior, superior, and medial joint spaces were 2.03, 2.64, 4.13, and 2.75 mm, respectively. There was no statistically significant difference in mandibular fossa height between the right and left TMJs. The left side had more mandibular fossa width, tubercular height, and anteriorly positioned fossa (P < 0.05). The left condyle was longer in mediolateral dimension, narrower in anteroposterior dimension, and shorter in vertical dimension. Statistically significant anterior positioning of the condyles (noncentralized position) was observed (P < 0.05). Conclusions Every component in the TMJ was analyzed. The values provided could be used as reference norms for the osseous parameters of the TMJ in individuals with normal Class I skeletal and dental features in future research.