Background Disc repositioning by Mitek anchors for anterior disc displacement (ADD) combined with orthognathic surgery gained more stable results than when disc repositioning was not performed. But for hypoplastic condyles, the implantation of Mitek anchors may cause condylar resorption. A new disc repositioning technique that sutures the disc to the posterior articular capsule through open incision avoids the implantation of the metal equipment, but the stability when combined with orthognathic surgery is unknown. The purpose of this study was to evaluate the stability of temporomandibular joint (TMJ) disc repositioning by open suturing in patients with hypoplastic condyles when combined with orthographic surgery. Methods Patients with ADD and jaw deformity from 2017 to 2021 were included. Disc repositioning by either open suturing or mini-screw anchor were performed simultaneously with orthognathic surgery. MRI and CT images before and after operation and at least 6 months follow-ups were taken to evaluate and compare the TMJ disc and jaw stability. ProPlan CMF 1.4 software was used to measure the position of the jaw, condyle and its surface bone changes. Results Seventeen patients with 20 hypoplastic condyles were included in the study. Among them, 12 joints had disc repositioning by open suturing and 8 by mini-screw anchor. After an average follow-up of 18.1 months, both the TMJ disc and jaw position were stable in the 2 groups except 2 discs moved anteriorly in each group. The overall condylar bone resorption was 8.3% in the open suturing group and 12.5% in the mini-screw anchor group. Conclusions Disc repositioning by open suturing can achieve both TMJ and jaw stability for hypoplastic condyles when combined with orthognathic surgery.

Background: Digital occlusal splint is a novel approach in the treatment of temporomandibular disorders (TMD) and there is a lack of evaluation.Objective: To introduce Kovacs digital occlusal splint (KDOS) and evaluate its clinical and magnetic resonance imaging (MRI) outcomes and influencing factors in the treatment of TMD.Patients and Methods: Patients diagnosed of TMD by MRI and treated with KDOS from June 2020 to December 2021 were retrospectively reviewed. They were divided into three groups: anterior disc displacement with reduction (ADDwR), anterior disc displacement without reduction (ADDwoR) and ADDwoR + osteoarthritis (ADDwoR + OA). Visual analogue scales (VAS) scores of pain, diet, mandibular function, quality of life (Qol) and maximum interincisal opening were compared before and at least 8 weeks after treatment. Binary logistic regression was used to analyse the influence of four factors including age, gender, Wilkes stage and the severity of symptoms on treatment. MRI was used to evaluate the condylar bone status and disc length after at least 3 months treatment.Results: One hundred and eighty-four patients were included in the study. The average age was 30.9 ± 14.2 years and the average follow-up was 19.8 ± 10.0 weeks. Pain, diet, mandibular function and Qol were all significantly improved after KDOS treatment (p < .05), with the effective rates of 71.6%, 56.4%, 55.3% and 54.1%. Binary logistic regression showed that higher probabilities of improvement were related to the patients with older age, ADD without OA and higher VAS scores before treatment. MRI showed that 94.1% of the condylar bone status remained stable or improved and the disc length was unchanged after treatment. Conclusion:KDOS is effective for the treatment of TMD. Older age, ADD without OA and higher VAS scores before treatment had better results.

No abstract