Occlusal Equilibration vs. Sham Therapies for TMDs: Post-Trial Follow-up (OEST)

Chronic temporomandibular disorders (TMDs) affect the masticatory muscles, the temporomandibular joints (TMJs), and associated structures. Except in cases of trauma, their etiology remains uncertain, debated, and multifactorial. Conservative therapies-including no active intervention-often alleviate symptoms; however, approximately 3% of the population develops persistent forms associated with substantial individual suffering and significant social and economic burden. At the Unit of Occlusion and Prosthodontics of the University of Santiago de Compostela (USC), Physiologically Oriented Occlusal Equilibration (POOE) has been used for chronic painful TMDs since 1985. POOE aims to correct unilateral mastication patterns and to establish appropriate non-working side contacts in order to protect the temporomandibular joints from mechanical overload. Singh (Cochrane, 2024) emphasized that occlusal interventions should be evaluated with long-term follow-up of at least 3-5 years. This is a single-blind study: the evaluator remains blinded to treatment allocation during outcome assessment. The aim of this observational study is to assess the long-term effectiveness of POOE treatments for chronic TMDs from 1985 to the present. Treatment effectiveness will be confirmed if the reduction in pain achieved with POOE is statistically significant and clinically meaningful (≥1.5/10 on a 0-10 visual analog scale) compared with sham therapy at ≥3 years post-intervention relative to baseline. Additionally, effectiveness will be supported if the proportion of individuals meeting criteria for chronic TMD ("affected") is lower in the POOE-treated group than in those receiving alternative therapies.