Interexaminer Reliability and Validity for Diagnosis of Temporomandibular Disorders of Visual Leg Measurements Used in Dental Kinesiology

Aims: To determine the reliability and the validity of visual leg measurements used in dental kinesiology, which suggests that a masticatory dysfunction, such as occurs in temporomandibular disorders (TMD), can influence the length and the internal rotation of lower limbs. Methods: The leg-length inequality test and the internal foot-rotation test were performed independently by 3 different examiners on 41 subjects who were also screened for TMD. Data were analyzed by means of kappa statistics and by calculation of sensitivity and specificity values. Results: Chance-corrected reliability was generally poor for both the leg-length inequality test (0.33 = k = 0.39) and the internal foot-rotation test (0.15 = k = 0.27). Sensitivity and specificity values of the tests to differentiate TMD and healthy subjects were below acceptable thresholds; they ranged from 0.41 to 0.57. Conclusion: Visual evaluations of leg-length inequality and internal foot rotation were unreliable and are not valid for TMD diagnoses. The results of chiropractic visual leg measurement procedures in dentistry should be interpreted with caution, particularly when clinical decisions may lead to nonreversible dental treatment. Keywords: chiropractic, diagnostic tests, leg-length inequality, reliability, temporomandibular disorders