Abstract: PURPOSE: To investigate the difference between spiral CT, cone-beam CT (CBCT) and MRI in radiologic examination of temporomandibular joint disorder (TMD). METHODS: A retrospective analysis of 208 TMJs from 104 patients was obtained by using spiral CT, CBCT or MRI examination of TMDs. Each side of the joint space,articular disc,bone change of the condyle and joint effusion were evaluated and compared among the 3 groups by 2 independent radiologists. The data was analyzed with SPSS 19.0 software package. RESULTS: Except significant difference in the right-anterior and left-superior joint space between spiral CT group and CBCT group (P<0.05), the other groups had no statistically significant difference (P>0.05). The articular disc can not be clearly shown by CBCT and spiral CT, but it can be displayed completely by MRI scanner. In 208 TMJs from 104 patients, there was no significant difference in the bone changes of condyle between spiral CT and CBCT group (P>0.05), but there was significant difference between spiral CT and MRI group, CBCT and MRI group, respectively. The structure of the bone trabeculae was displayed clearly only by CBCT. Meanwhile, only MRI scanner revealed the joint effusion clearly and the rate of display was 18.27%. CONCLUSIONS: Spiral CT, CBCT and MRI are valuable in the diagnosis of TMD. Among them, MRI could displayed the disc more distinctly than spiral CT and CBCT. Spiral CT, CBCT and MRI can accurately display the joint space, and their reconstruction images of the joint space are the same. Only CBCT can display the structure of the condylar trabeculae clearly.

Key words: Spiral CT, MR, Cone-beam CT, Temporomandibular joint disorders