Results
U1-SN
One patient in the control group and one in the test group were lost because of Covid-19 outbreak, they refused to come for follow-up, so the trial procedures were completed with 58 patients (n = 29 in the test and control groups, respectively). At baseline, the mean age of the patients was 16.48 ± 2.45 years, 50 were females and 10 were males, and there were no statistical significances between the two groups in these or other baseline characteristics (
Baseline demographic and radiographic characteristics of participantsAfter DR, MRI showed that all discs were repositioned. In the OSu group, the condylar height increased from 19.11 ± 3.83 mm preoperatively to 20.52 ± 3.80 mm at the 12-month follow-up, with a mean increase of 1.42 ± 0.81 mm (
Measurement of the condylar height and jaw position before and 12 months after operation within the two groupsAbbreviated: OSu, open suturing; POS, postoperative splint. *In the OSu with POS group, the condylar height increased from 19.00 ± 3.65 mm preoperatively to 21.83 ± 3.85 mm at a 12-month follow-up, with a mean increase of 2.83 ± 0.75 mm (
Female, 12years old, in the OSu + POS group. 
MRI of patient in Fig. There was no statistical difference in SNA, U1-SN, Sn-G’, L1-MP and U1-L1 between the two groups before and after treatment (
Difference of the condylar height and jaw position before and 12 months after operation between the two groupsAbbreviated: OSu, open suturing; POS, postoperative splint. *
New bone site after disc repositioning by OSu ± post-operative splint treatmentAbbreviated: OSu, open suturing; POS, postoperative splintThe correlation analysis showed that the height of condylar new bone was significantly correlated with wearing POS (r = 0.542, 
Correlation between the height of the new condylar bone and the use of post-operative splints, changes in the position of the jawsAbbreviated: CH, condylar height; POS, postoperative splint. *P < 0.05