Predicting anterior repositioning splint efficacy in disc displacement with reduction using MRI-based texture and quantitative analysis: a retrospective study.

Abstract

Objectives: To quantitatively analyze potential factors influencing the efficacy of anterior repositioning splint (ARS) therapy in patients with disc displacement with reduction (DDWR), and to explore the prognostic value of MRI-based texture analysis.

Materials and methods: 82 patients with 140 joints of DDWR were conducted in the retrospective study from 2020 to 2022. The custom maxillary ARS was fabricated based on incisal edge-to-edge occlusal record. Patients were instructed to wear the ARS full-time and adjusted monthly for at least 6 months. MRI evaluation of 140 joints was conducted at four check-up time: pre-treatment (T0), the initiation of ARS insertion (T1), treatment completion (T2), and follow-up (T3). TMJ disc morphology and position were quantified based on MRI images, and post-ARS therapy outcomes were stratified into three categories: excellent, improved, or poor. In sequence, texture analysis (TA) of the retrodiscal tissue (RDT) was conducted based on MRI images. Five texture parameters were extracted and calculated using a gray-level co-occurrence matrix (GLCM). Statistical analysis including chi-square test, independent samples T test or Kruskal-Wallis test was conducted.

Results: Among 82 DDWR patients (140 joints), 84 joints (60%) achieved excellent outcomes, characterized by high initial disc recapture (98.8%) and new bone formation (15.5%), after ARS treatment, while 47 joints (34%) showed improvement and 9 joints (6%) had poor results. Quantitative analysis revealed that mandibular protrusive distance was significantly greater in the excellent group (3.50 ± 1.70 mm) than in the improved group (2.80 ± 1.20 mm; P = 0.032). Longitudinal MRI images revealed significant reductions in disc displacement distance (mean Δ = 3.11 mm, P < 0.01) and disc-condyle angle (mean Δ = 45.96°, P < 0.01) after ARS treatment, although minor recurrence occurred during follow-up. Multivariable logistic regression analysis revealed that the TA parameter of Angular Second Moment(ASM) exhibited a strong positive association with clinical outcomes in both the excellent (adjusted OR = 9.545, 95% CI: 1.785-51.056, P < 0.05) and improved (adjusted OR = 8.272, 95% CI: 1.568-43.636, P < 0.05) groups compared to the poor group. Each unit increase in ASM was associated with approximately 9.5-fold and 8.3-fold higher odds of achieving excellent or improved outcomes, respectively.

Conclusion: ARS treatment could be used to correct disc-condyle relationship and reduce disc displacement distance in patients with DDWR. Multiple factors influence ARS outcomes. The high disc recapture rate following ARS insertion was correlated with excellent therapeutic outcomes, and mandibular protrusive distance may influence the successful disc recapture. Texture analysis might be identified ASM as a potential predictive imaging biomarker.

Clinical relevance: ARS is a conservative and efficient treatment for the patients with DDWR.

Trial registration: Chinese Clinical Trial Registry (ChiCTR2300078816).