Comparison of disc position stability and condylar bone remodelling between two open disc repositioning surgeries: a retrospective single-centre cohort study.

BACKGROUND AND OBJECTIVE: Open suturing (OSu) and mini-screw anchor (MsA) are two commonly used open disc repositioning surgeries for anterior disc displacement (ADD) of the temporomandibular joint (TMJ). This study assesses the differences in disc position stability (DPS) and condylar bone remodelling (CBR) between these two surgical procedures in a single centre. METHODS: A retrospective cohort study using MRI scans (pre-operation, 1 week and 12 months post-operation) of all patients who had open TMJ disc repositioning surgery from January 2016 to June 2021 at one centre through two surgical techniques (OSu and MsA) was performed. The predictor variable was technique (OSu and MsA). Outcome variables were DPS and CBR. During follow-up, DPS was rated as good, acceptable and poor, and CBR was graded as improved, unchanged, and degenerated. Multivariate analysis was used to compare the DPS and CBR at 12 months after adjusting five factors including age, sex, Wilkes stage, preoperative bone status (normal, mild/moderate abnormal) and the degree of disc repositioning (normal, overcorrected, and posteriorly repositioned). Relative risk (RR) for DPS and CBR was calculated by multivariate logistic regression. RESULTS: Three hundred eighty-five patients with 583 joints were included in the study. MRIs at 12 months showed that 514 joints (93.5%) had good DPS, and 344 joints (62.5%) had improved CBR. Multivariate analysis revealed that OSu had higher DPS (RR=2.95; 95% CI, 1.27-6.85) and better CBR (RR=1.58; 95% CI, 1.02-2.46) than MsA. Among the factors affecting DPS, females had better results than males (RR=2.63; 95% CI, 1.11-6.26) and overcorrected or posteriorly repositioned discs were more stable than normally repositioned discs (RR=5.84; 95% CI, 2.58-13.20). The improvement in CBR decreased with age increasing (RR=0.91; 95% CI, 0.89-0.93). Preoperative mild/moderate abnormal bone status had a higher probability of improved CBR compared to normal preoperative bone status (RR=2.60; 95% CI, 1.76-3.83). CONCLUSION: OSu had better DPS and CBR than MsA. Sex and the degree of disc repositioning impacted DPS, while age and preoperative bone status affected CBR.

Preliminary evaluation of Kovacs digital occlusal splint in the treatment of temporomandibular disorders: A single-centre, cross-sectional study.

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.