Noninvasive Ultrasound Imaging in Juvenile Idiopathic Arthritis: Diagnostic and Findings on the Temporomandibular Joint—A Prospective Study

<b>Introduction:</b> Juvenile idiopathic arthritis (JIA) is a chronic autoimmune condition. The temporomandibular joint (TMJ) is one of the most affected joints in JIA. It can bring significant symptoms and impairments if not treated, and routinely instrumental exams are necessary to track its progress during the visits. The purpose of this study was to determine the efficiency in tracking the status of TMJ involvement with ultrasound (US) imaging in patients with a diagnosis of JIA and to assess its effectiveness in detecting different alterations. <b>Materials and Methods:</b> Inclusion criteria included patients previously diagnosed with JIA to be recruited in this prospective observational study. Each patient underwent detailed US evaluation of the TMJ to assess for various pathological changes, including condylar profile alterations, erosive phenomena, bone apposition, osteophyte formation, disc displacement, and soft tissue changes. The assessment was performed by two expert blinded operators. The US findings were compared with clinical manifestations and conventional imaging, for sensitivity, specificity, and predictive values. <b>Results:</b> A total of 46 patients divided into 39 female and 7 males, between 7 and 19 years were recruited. Of the recruited patients, 15% showed discordance and were asymptomatic, while 85% of the patients showed at least one joint manifestations. Sensitivity, specificity, and negative predictive value (NPV) of US for detecting TMJ pathology were calculated using conventional imaging as the reference standard. <b>Conclusions:</b> US showed a good concordance with traditional diagnosis, however it does not substitute traditional imaging for diagnosis. US demonstrated potential to be a reference noninvasive tool for monitoring TMJ secondary lesions in JIA and for monitoring during routine visits, offering advantages, such as noninvasiveness, cost-effectiveness, and real-time dynamic imaging capabilities.