Abstract: PURPOSE: This research evaluated the morphological differences of temporomandibular joint (TMJ) between patients with obstructive sleep apnea hypopnea Syndrome (OSAHS) and normal population using magnetic resonance imaging (MRI). METHODS: Eighteen OSAHS patients were admitted from January 2014 to May 2016 and 18 healthy adults were chosen as control. OSAHS patients were divided into three sub-groups (n=6), i.e. the mild group, the moderate group and the severe group, according to apnea and hypopnea index (AHI). All subjects underwent TMJ MRI for measurement of joint space. Statistical analysis was performed using SPSS 17.0 software package. RESULTS: There was no significant difference between the two groups in age, gender, superior joint space and displacement of condyle. The left anterior joint space [(2.63±0.18)mm vs (2.48±0.17)mm, P<0.05] and right anterior joint space [(2.63±0.18) mm vs (2.48±0.17) mm, P<0.05] of the TMJ of OSAHS patients was bigger than that of healthy people. The left posterior joint space [(2.43±0.20) mm vs (2.51±0.19) mm, P<0.05] and right posterior joint space [(2.44±0.20) mm vs (2.60±0.13) mm, P<0.05] of the TMJ of OSAHS patients was smaller than that of healthy people. The left anterior joint space [(2.53±0.26) mm vs (2.73±0.07) mm, P<0.05] and right anterior joint space [(2.54±0.11) mm vs (2.74±0.14) mm, P<0.05] of the TMJ of OSAHS patients in the mild sub-group was smaller than that of the OSAHS patients in the severe sub-group; the left posterior joint space [(2.56±0.29) mm vs ( 2.29±0.09) mm, P<0.05] and right posterior joint space of OSAHS patients in the mild sub-group was bigger than that of the OSAHS patients in the severe sub-group. CONCLUSIONS: The condyle of OSAHS patients is at the posterior position of glenoid compared with heath people. The tendency of posterior position of condyle at glenoid is related to the severity of OSAHS.

Key words: Obstructive sleep apnea hypopnea syndrome, Temporomandibular joint, Joint space