Abstract: [Abstract] Objects: To analyse the skeletal structure of temporomandibular joint in skeletal class Ⅲ with high-angle in mixed dentition by using CBCT. Methods: Twenty normal occlusion children in mixed dentition and twenty skeletal class Ⅲ children with high-angle in mixed dentition were included in this study. CBCT was performed in the intereuspal position. Relevant parameter from reconstructed images of TMJ were calculated with invivo 5 software. Results: compared with normal occlusion group，the condylar mediolateral diameter, fossa width and condylar length were larger while condylar anteroposterior diameter, fossa depth, Tuberculum articulare angle and condylar height were smaller in the skeletal class Ⅲ group in mixed dentition. Conclusion: There are statistical differences of skeletal structure between normal occlusion group and the skeletal classⅢ group in mixed dentition.

Key words: [Key words] CBCT, TMJ, skeletal classⅢ malocclusion, high-angle, mixed dentition