Temporomandibular joint effusion and its relationship with perceived disability assessed using musculoskeletal ultrasound and a patient-reported disability index.

The relationship between effusion of the temporomandibular joint (TMJ) and patient-reported disability is poorly researched. This pilot study explored the link between TMJ inflammation as measured by ultrasound and patient disability assessed by the Steigerwald Maher TMD Disability Index (SMTDI). The study design used a prospective correlational approach involving a sample with TMJ dysfunction (TMD). Twenty-four patients were recruited from the European School of Osteopathy and a Kent dental practice. Participants completed the SMTDI to determine the level of TMD (symptomatic score >20). A SonoSite SLA "Hockey Stick" [13-6 MHz] musculo-skeletal transducer was placed over the TMJ in a transverse direction and effusion was calculated indirectly by measuring capsular width. An upper left quadrant protocol was used throughout. A regression analysis was run with participants' gender, age and capsular width as predictor variables modelled against reported SMTDI. Larger capsular widths were found to be significant predictors of SMTDI scores (r = 0.803, p < 0.0001). The patient profile matched with the previous studies and the TMD sufferer population, indicating external validity. Results suggest that the SMTDI could be integrated into practice life as a quick, accessible and easy tool to monitor patients' progress and assess levels of inflammation, without the need for repetitive imaging. The study design proved reproducible and a larger scale study is indicated.