Effects of polyarticular and pauciarticular onset juvenile rheumatoid arthritis on facial and mandibular growth

Objective. To characterize the functional and morphologic effects of polyarticular and pauciarticular onset juvenile rheumatoid arthritis (JRA) on the temporomandibular joint (TMJ). Methods. Medical and dental histories, intraoral, lateral cephalometric, and panoramic radiographs, facial photographs, and dental study models were obtained for each of 30 patients with JRA (17 pauciarticular and 13 polyarticular onset). Measures of TMJ dysfunction were gathered during the clinical examination, and an index of condylar morphology was inferred from the panoramic radiographs. The lateral cephalograms were traced, and data from 34 linear and angular measures used to compare the facial morphology of the 2 JRA onset types, both to normative standards and to each other (Student's t test). The Kruskal-Wallis test was used to evaluate the significance of between-group differences for the various ordinal indices. Results. As indicated by the higher TMJ dysfunction and condylar index scores, polyarticular onset JRA affects the form and function of the TMJ more frequently and severely than does pauciarticular onset. Moreover, compared to normative cephalometric standards, the patients with polyarticular onset had small, short faces with underdeveloped mandibles. Conclusion. Both polyarticular and pauciarticular onset JRA have a negative effect on the form, function, and esthetics of the face and mandible; however, the effects are more pronounced with polyarticular JRA than pauciarticular onset.