Influence of clinical, physical, psychological,and psychophysical variables on treatment outcomes in somatic tinnitus associated with temporomandibular pain: evidence from a randomized clinical trial

Abstract

Objective:To assess the influence of clinical, psychological,and psychophysical variables on treatment outcomes afterapplication of exercise combined with education with/with-out manual therapy in people with tinnitus associated withtemporomandibular disorder (TMD).Methods:A secondary analysis of a clinical trial was per-formed investigating the effectiveness of including cervico-mandibular manual therapy into an exercise combined witheducation program in 61 subjects with TMD-related tinnitus.Clinical outcomes including tinnitus severity and tinnitus-related handicap were assessed at 3 and 6 months post-intervention. Patients were assessed at baseline for clinical(tinnitus severity, tinnitus-related handicap, quality of life),physical (range of motion), psychological (depression), andpsychophysical (pressure pain thresholds [PPTs]) variablesthat were included as predictors.Results:The regression models indicated that higher scoresof tinnitus severity at baseline predicted better outcomes 3and 6 months post-intervention (explaining 13% to 41% ofthe variance) in both groups. Higher scores of tinnitus-relatedhandicap at baseline predicted better outcome of tinnitus-related handicap (45% variance) in the manual therapy with exercise/education group. Lower PPTs over the temporalismuscle at baseline predicted poorer clinical outcomes (10.5%to 41% of the variance) in both groups. Other predictorswere sex and quality of life (6.7% variance) in the manualtherapy group and PPTs over the masseter muscle (5.8%variance) in the exercise/education group.Conclusion:This study found that baseline tinnitus severityand localized PPT over the temporalis muscle were predictiveof clinical outcomes in individuals with TMD-related tinnitusfollowing physical therapy. Other predictors (eg, sex, qualityof life) were less influential.