Changes in Temporomandibular Disorder Symptoms Following Occlusal Splint Therapy: A Prospective Single-Arm Before-After Study.

Objective The objective of this study was to evaluate changes in symptoms associated with temporomandibular disorders (TMDs) before and after occlusal splint therapy. Materials and methods We conducted a prospective, single-arm, uncontrolled before-after intervention study including 76 patients aged 14-60 years who attended the Orthodontics Department at the Regional High Specialty Hospital of Ixtapaluca, Ixtapaluca, State of Mexico, between March and December 2024. All participants were diagnosed with TMD according to the International Classification of Diseases, Tenth Revision (ICD-10). Patients presenting with temporomandibular joint or masticatory muscle pain and/or difficulty opening or closing the mouth were included, whereas those with degenerative joint disease, condylar fractures, or complete edentulism were excluded. Dental casts and clinical records were obtained, and a symptom questionnaire was administered before and after occlusal splint therapy. Data were analyzed using the chi-square and McNemar tests. Results A total of 76 patients were included, comprising 85.5% (n = 65) women and 14.5% (n = 11) men. At baseline, 100.0% (n = 76) of the participants presented at least one TMD-related symptom. The most prevalent symptom was joint clicking, reported by 69.7% (n = 53) of the participants. Muscle pain was significantly more frequent among women, affecting 47.7% (n = 31 of 65) compared with 9.1% (n = 1 of 11) of men (P = 0.020). After occlusal splint therapy, the proportion of patients presenting at least one symptom decreased from 100.0% (n = 76) to 78.9% (n = 60), whereas 21.1% (n = 16) became symptom-free (P < 0.001). Significant reductions were observed in headache, facial, or neck pain, from 48.7% (n = 37) to 14.5% (n = 11); joint fatigue, from 50.0% (n = 38) to 11.8% (n = 9); muscle pain, from 42.1% (n = 32) to 10.5% (n = 8); and joint clicking, from 69.7% (n = 53) to 40.8% (n = 31) (all P < 0.001). Conclusions Reductions in TMD-related symptoms were observed between baseline and the end of the six-month occlusal splint treatment period, particularly for joint fatigue, muscle pain, and headache. Given the uncontrolled before-after design, these findings should be interpreted as temporal associations and do not establish treatment efficacy. Controlled studies using standardized diagnostic criteria and validated outcome measures are needed to confirm these findings.