Abstract: Objective: To study metabolism and morphological symmetry of bilateral TMJ of adult patients with mandibular deviation by utilizing SPECT-CT. Methods: Thirty-six adult patients with mandibular deviation were conducted SPECT. The images of condyle process, mandibular ramus and angle of mandible were gathered and rebuilt from coronal, sagittal and cross section planes. Then, the radioactive count ratios were calculated and acquired fusion images after CT scanning and three-dimensional reconstruction. The condyle process height, internal and external diameters, back bevel slant angle and back bevel length were measured and compared according to bilateral TMJ's anatomic relation. Results: The radioactive counting ratios in different areas (condyle process, mandibular ramus, angle of mandible) were different, the radioactive counting ratios in the lateral side were lower than those of the opposite side, and the radioactive counting ratios of both sides showed statistical difference (P＜0.05). The condyle process height, internal and external diameters in the lateral side were smaller than those in the lateral side (P<0.01); Back bevel slant angle and length in the lateral side were larger than those in the opposite side (P<0.01). Conclusion: SPECT-CT bone imaging plays a crucial role in diagnosing and assessing mandibular deviation of adult patients.