ABSTRACT
<p><b>OBJECTIVE</b>This study investigates the effect of temporomandibular joint osteoarthritis (TMJOA) on different stages of condylar three-dimensional position and provides a theoretical basis for clinical application.</p><p><b>METHODS</b>The cone beam computed tomography (CBCT) images of 108 TMJOA patients were analyzed and divided into four stages based on the stage standard of osteoarthrosis X-ray performance proposed by Xuchen Ma in 2005. A total of 28 defect-free temporomandibular joint disorders were used as the control group. Differences in condylar position and condylar axis horizontal angle were evaluated and compared.</p><p><b>RESULTS</b>No significant differences were found in terms of sagittal relationship, but condylar axis horizontal angle showed a significant difference (F = 3.872, P = 0.005). The horizontal angle values of stage 1 in the TMJOA group were lower than those in stages 2 and 3 (P = 0.027, P = 0.000), whereas the horizontal angle values of stage 2 and control groups were lower than those of stage 3 group (P = 0.004, P = 0.047).</p><p><b>CONCLUSION</b>Condylar horizontal angle differed in each stage of TMJOA, but no significant difference between the parasagittal positions of the condyles was observed in each stage.</p>