Abstract: Objective: To investigate the features of temporomandibular joint by cone-beam computed tomography (CBCT) in patients with skeletal class Ⅲ malocclusion in mixed dentition, and to explore the mechanism of the growth and remodeling of the temporomandibular joint. Methods: Twenty patients with skeletal class Ⅲ malocclusion and twenty patients with skeletal classⅠmalocclusion in mixed dentition were selected from the Department of Orthodontics, Stomatological Hospital affiliated to Kunming Medical University. NNT viewer 5.3 software was utilized to measure the relevant parameters from the CBCT scanning data. The acquired data were then analyzed. Results: Compared with the patients with skeletal classⅠmalocclusion in mixed dentition, the patients with skeletal class Ⅲ malocclusion in mixed dentition showed characteristics as follow: (1) in sagittal plane, bilateral anterior and superior spaces between the condyle and the fossa were smaller, and the gradient of the articular tublecle were smaller; (2) in coronal plane bilateral medial and superior spaces between the condyle and the fossa were smaller, and the condylar angle were smaller in the right side; (3) in the transverse cross section plane the right condylar anteroposterior diameters were smaller. Conclusion: (1) The temporomandibular joint of patients with skeletal class Ⅲ malocclusion in mixed dentition is not fully developed, and condyle, condylar fossa depth, gradient of articular tubercle, coronal medial and superior joint space are smaller. (2) The condyle usually locates anteriorly near to the roof of the fossa in patients with skeletal class Ⅲ malocclusion in mixed dentition. (3) The image characteristics of the temporomandibular joint in patients with skeletal class III malocclusion are adapted to their biological functions.

Key words: Skeletal, class, Ⅲ, malocclusion, in, mixed, dentition, Skeletal, classⅠmalocclusion, in, mixed, dentition, Temporomandibular, joint, Cone, beam, computed, tomography