Classification of temporomandibular joint hypermobility based on lateral TMJ, and magnetic resonance imaging contributing to a nonsurgical treatment protocol

Hypermobility of the temporomandibular joint (TMJ) may present with a wide range of condylar and disk positions. The aim of this study was to evaluate condylar and disk positions in patients with varying degrees of TMJ hypermobility and to propose a new classification system with an associated nonsurgical treatment protocol. A consecutive sample of 144 patients with internal derangement was enrolled. Clinical examinations, lateral TMJ radiographs, and magnetic resonance imaging (MRI) were performed. Patients were classified according to the proposed staging system and treated with the corresponding nonsurgical protocol. The primary outcome variables were maximum voluntary mouth opening and visual analogue scale (VAS) pain scores. The secondary outcome variable was joint sounds. Statistical analysis demonstrated a significant decrease in mouth opening during the study period (P < 0.001 at 12 months posttreatment). VAS scores also showed a statistically significant reduction across all study groups and time points (P < 0.0001 at 12 months posttreatment). Joint sounds improved significantly throughout the study period (P < 0.001 at 12 months posttreatment). The proposed classification system is simple and practical, providing a detailed description of condylar and disk positions in TMJ hypermobility. The associated nonsurgical treatment protocol proved to be effective and tailored to the pathological changes observed in the joint.