Reliability of clinical findings in temporomandibular disorders

The aim of the present investigation was to study the interexaminer reliability of orthopedic tests and palpation techniques routinely used in the clinical diagnosis of disorders of the masticatory system. The tests were performed by a dentist and a physiotherapist, who both used the tests routinely when examining patients with temporomandibular disorders. Seventy-nine patients participated in this study. In the analysis, percentage agreement, intraclass correlation, and Cohen's kappa were used. The interexaminer reliability of the tests measuring maximal active mouth opening and registration of clicking during active mouth opening was high. The interexaminer reliability was fair for the tests measuring the intensity of pain during active movements and moderate for tests recording joint sounds (k=0.47 to 0.59). There was high interobserver agreement on several items of the traction and translation tests, although the kappa values were low. The interexaminer reliability of the multitest scores for compression was substantial for joint sounds (k=0.66) and fair for pain (k=0.40). The interexaminer reliability of the multitest scores for muscle palpation and joint palpation was moderate (k=0.51) and fair (k=0.33), respectively. It can be concluded that most variables determined during active movements can be measured with satisfactory reliability, whereas variables for other tests are not measured with the same reliability on the basis of the kappa scores. The main symptoms of temporomandibular disorders can be evaluated reliably with multitest scores. It is recommended that clinicians calibrate their techniques regularly to improve the reliability of results in daily practice.