Ultrasound to Assess the Temporomandibular Joint of Children With Juvenile Idiopathic Arthritis: A Systematic Review.

Objective: This systematic review assessed the diagnostic capability of ultrasound (US) to evaluate temporomandibular joint (TMJ) arthritis in children with Juvenile Idiopathic Arthritis (JIA), with MRI, CT, or CBCT as reference standards. Material and Methods: A search was conducted on electronic databases (Medline, Embase, Cochrane, Web of Science, and Scopus) and partial gray literature without restrictions of language and time. Eligibility criteria included diagnostic studies (randomized clinical trials, cohort studies, observational studies) evaluating the diagnostic potential of 2D or 3D US in assessing the TMJ (i.e., disc displacement, joint effusion, condylar changes) of children with JIA compared to CBCT/CT and/or MRI as the reference standard. The Quality Assessment Tool for Diagnostic Accuracy Studies-2 (QUADAS-2) was used to evaluate risk of bias. Results: After eligibility criteria were applied, eight studies were included. All studies were methodologically acceptable, presenting low applicability concerns, although none fulfilled all QUADAS-2 criteria. Results from individual studies ranged from poor to excellent, with a sensitivity (SN) of B-mode US ranging between 21% and 85% and a specificity (SP) between 36.4% and 89%, depending on the TMJ alterations assessed (condylar changes - CC, joint effusions - JE, synovial thickness, and lateral periarticular space - LPAS). The certainty of the evidence for the diagnostic performance of US to detect TMJ involvement in JIA was graded low for SN and moderate for SP. Conclusion: This systematic review demonstrated that although MRI remains the reference standard imaging modality, US shows promising diagnostic capability in assessing the TMJ of children with JIA. It can provide valuable supplementary information to assist in diagnosis alongside clinical examination and guide the need for advanced diagnostic assessment.