Relationship between temporomandibular joint (TMJ)-related pain and morphological changes of the TMJ condyle in patients with temporomandibular disorders

Objectives: The purpose of this study was to analyse the relationship between temporomandibular joint (TMJ)-related pain and morphological change of the TMJ condyle in patients with temporomandibular disorders. Methods: Data were obtained from 178 joints in 89 patients. The joints were clinically assessed for pain on mandibular function and on lateral palpation of the TMJ. They were also assessed for radiographic evidence of bone change at the articular surface (OAAS) and resorption of the lateral part of the condyle (RLC). Results: A higher prevalence of joint pain on function was observed in joints with OAAS than in those without OAAS (Chi-square test of independence, P < 0.05). Significant relationships were found between palpation pain and OAAS and between palpation pain and RLC (Chi-square test of independence, P < 0.05). In addition, patients with RLC showed a significantly lower pain threshold for external mechanical stimuli than those without RLC (Welch's t-test, P < 0.05). Conclusions: These results suggest a possible relationship between pain on function and OAAS as well as a relationship between palpation pain and RLC. Pain on lateral palpation may be related to the pathological conditions that induce RLC.