Clinical and radiographic outcomes of a novel posterior occlusal splint in adults with temporomandibular joint osteoarthritis: a retrospective case series

Objective: To describe the clinical and radiographic outcomes associated with the use of a novel posterior occlusal splint (nPOS) in adults with temporomandibular joint osteoarthritis (TMJ-OA) and its impact on condylar morphology, as assessed by cone-beam computed tomography (CBCT). Methods and materials: This retrospective study included 156 adult patients (24 males, 132 females; mean age: 27.05 ± 9.18 years) diagnosed with TMJ-OA, with 182 osteoarthritis (OA)-like condyles. All patients received treatment with the nPOS between January 2020 and December 2024. Clinical symptoms were evaluated at six time points: T0 (baseline), T1 (1 month), T2 (3 months), T3 (6 months), T4 (12 months), and T5 (24 months) after treatment initiation. CBCT assessments of condylar morphology were performed at T0, T3, T4, and T5. Wilcoxon signed-rank test, paired t test, McNemar test were employed to evaluate longitudinal changes in clinical symptoms. Results: Significant improvements in maximum mouth opening (MMO) were observed from T2 to T4 (P < 0.01). Significant reductions in spontaneous pain were observed at both T3 and T4 (P < 0.01), while reductions in joint tenderness and joint noises were statistically confirmed at T3 (P < 0.01). No significant changes were noted for intermittent closed lock (ICL), muscle pain, push-back mandibular test, or altered mouth opening patterns (P > 0.01). CBCT showed a significant improvement in condylar cortical score at T3 compared to T0 (P < 0.01). Conclusion: In this observational study, the use of nPOS was associated with improvements in key TMJ-OA symptoms and condylar morphology, especially during the early to mid-treatment phase (3–12 months). These findings warrant validation in randomized controlled trials before clinical adoption. Furthermore, long-term effects require further investigation.