Assessment of mandibular function impairment associated with temporomandibular joint osteoarthrosis and internal derangement

Clinical assessment of function impairment associated with temporomandibular disorders should not only comprise diagnostic assessment of symptoms and signs but also function impairment assessment in the patient's value system. Regarding clinical assessment methods, the range of opening movement has been demonstrated to be one of the few variables that can be measured reliably. However, this variable allows no distinction to be made between articular and muscular causes of movement restriction. To assess joint mobility, a combination of indirect and direct assessments is proposed, including the range of opening movement after passive stretch, the range of horizontal excursion toward the opposite side, and the condylar translatory capacity by palpation. In clinical practice, signs and symptoms needed for diagnosis are frequently used as the only basis for mandibular function assessment. Function assessment in the patient's value system, however, is a neglected area in outcome assessment. The main objective of this study was to design and clinimetrically evaluate a mandibular function impairment questionnaire. The relationship between jaw function impairment and measures of pain, movement restriction, and psychological distress was assessed. The questionnaire appears to be a reliable and valuable complementary tool for assessing mandibular function impairment.