Juvenile idiopathic arthritis (JIA): a screening study to measure class II skeletal pattern, TMJ PDS and use of systemic corticosteroids.

OBJECTIVE To screen patients with oligoarticular and polyarticular forms of Juvenile Idiopathic Arthritis (JIA) to determine (i) the severity of their class II skeletal pattern; (ii) temporomandibular joint signs and symptoms and (iii) use of systemic corticosteroids. DESIGN Cross-sectional screening. SUBJECTS AND SETTING Sixty-eight children with JIA aged between 9 and 16 years old who were screened at four regional treatment centres in the UK. METHOD Patients were screened clinically and radiographically for the presence of class II skeletal pattern and temporomandibular (TMJ) pain dysfunction syndrome. In addition, the JIA sub-type and history of disease activity and medication were recorded. MAIN OUTCOME MEASURES Class II skeletal pattern, TMJ signs and symptoms, use of systemic corticosteroids. RESULTS The mean ANB values were 4.2 degrees (SD = 2.9 degrees) in the oligoarticular group and 5.1 degrees (SD = 3.8 degrees) in the polyarticular group. Just under one-third of children had a moderate or severe class II skeletal pattern and a further quarter of children had a mild class II skeletal pattern. Clinical signs and symptoms of temporomandibular joint pain dysfunction syndrome were low (<20%), except for crepitus and click which affected between 24 and 40% of JIA children. Radiographically, 57% of oligoarticular and 77% of polyarticular cases exhibited condylar erosion. Use of systemic corticosteroids varied between centres, but overall, was prescribed more in polyarticular cases (P = 0.001). CONCLUSIONS Just under one-third of oligoarticular and polyarticular JIA patients exhibited a moderate or severe class II skeletal pattern. It is, therefore, likely that any future clinical trial to investigate the effect of functional appliance treatment in JIA patients, will need multicentre co-operation to fulfil potential sample size requirements. Clinical signs and symptoms of temporomandibular joint pain dysfunction syndrome were low except for crepitus and click. However, radiographic evidence of condylar erosion was high particularly in the polyarticular group. Use of systemic corticosteroids was prescribed more in polyarticular cases and this is likely to reflect the severity of the disease.