Reliability of Clinical Measurement in Temporomandibular Disorders

Summary The ability to dependably measure clinical signs and symptoms is a minimum requirement for arriving at rational diagnoses and treatment plans for any health problem. This report examines interexaminer reliability as it applies to the measurement of signs and symptoms of temporomandibular disorders (TMDs). Interexaminer reliability is defined as the degree of consistency among examiners when making observations of the same clinical variable. Review of available data and results from our own studies lead us to the following conclusion regarding the dependable assessment of clinical signs and symptoms of TMDs. Training of examiners emerges clearly as a crucial consideration to even approximate dependable assessment of TMD signs and symptoms. Certain signs and symptoms associated with TMDs appear to be more consistent than others, less susceptible to spontaneous change over time, and probably less susceptible to being influenced by the clinical examination procedure itself. By marked contrast, other groups of TMD signs and symptoms appear less reliable, either because they change spontaneously over time, as we believe is the case with temporomandibular joint sounds, or because the examination procedures themselves may cause changes, as may be the case with repeated muscle palpations. These findings have clear clinical relevance. Experienced and competent clinicians who specialize in treatment of TMDs but who are not extensively trained in standardized methods of examination and diagnosis may easily disagree on the evaluation of a patient. Clinicians and researches should work together to develop examination procedures, measurement scales, and clinical criteria that can serve as a common basis from which to assess reliability and report clinical findings.