A novel posterior occlusal splint improves symptoms and prognosis of coexisting temporomandibular disorders and deep bite: a retrospective study

Temporomandibular disorders (TMD) are a common syndrome characterized by pain and mandibular dysfunction, with occlusal factors such as deep bite potentially contributing to biomechanical changes in the temporomandibular joints (TMJ). Managing patients with coexisting TMD and deep bite is often complex. This study aimed primarily to evaluate the clinical effectiveness of a novel posterior occlusal splint in improving TMD-related pain and mandibular function, and secondarily to assess overall treatment prognosis and changes in overbite. This retrospective study included 448 patients (355 females, 93 males) with TMD and deep bite, aged 11–66 years (mean ± SD: 26.53 ± 9.93), all with full permanent dentition from the first premolar to the first molar. All patients were treated using a novel posterior occlusal splint. Clinical parameters-including joint tenderness, joint movement pain, push-back mandibular test results, maximum mouth opening, joint noises, and intermittent closed lock-were assessed at baseline (T0) and 1-, 3-, and 6-month follow-ups. Overbite measurements were taken using cone-beam computed tomography (CBCT) at T0) and at the 6-month follow-up (T6). The splint significantly alleviated TMD-related pain, including joint tenderness, joint movement pain, and positive push-back mandibular test results, and demonstrated a stable long-term prognosis with low recurrence rates (2.6%–5%). Improvements were also observed in maximum mouth opening. No significant changes were found in joint noises, intermittent closed lock, or overbite values, with joint noises showing occasional recurrence (7%–10%). The novel posterior occlusal splint demonstrated promising short-term and sustained benefits in treating pain and improving mandibular function in patients with coexisting TMD and deep bite. However, its effectiveness in treating joint noises and deep bite appears limited. This splint offers a clinically effective, patient-friendly alternative to traditional occlusal appliances, particularly during the early stages of treatment for patients coexisting with TMD and deep bite.