The role of temporomandibular joint ultrasound in children and young patients with juvenile idiopathic arthritis

Aim: The purpose of this study was to show our experience in using ultrasonography for the detection of temporomandibular joint (TMJ) changes in children with Juvenile Idiopathic Arthritis (JIA). Methods: Between June 2013 and December 2014 we investigated prospectively 70 patients (55 female and 15 male; mean age 9.11 years, range 2-18 years) with diagnosis of JIA. Examinations were performed with 11-18 MHz array transducers according on pts size. Each joint was analyzed with regard to condylar irregularity, capsular thickness (effusion/synovial thickness), condylar disk dislocation, vascular increasing on Color-Doppler examination and symmetry in condylar translation between open- and closed-mouth position. Results: 24 out of 70 patients (34%) had normal US appearance on both side. Irregularities of the bony surface were found in 67 joints (90%) whereas capsular thickness in 49 ones (30%). Vascular signal was increased in 5 joints and always associated with other abnormalities, the same as disk dislocation (3 joints). Translational asymmetry between open and closed mouth position was found in 11 joints and could not be evaluated just 3 patients , the youngest ones (2 - 3 years). Conclusions: Ultrasonography could be an helpful screening method for the detection of TMJ involvement in children with JIA. It can be used and well tolerated even in very young children (2 years) without sedation or radiation risk. US identifies the patients that need further investigations and it can be used for monitoring the progression of TMJ involvement and its response to therapy even if not all parts of the TMJ are visible for ultrasonography. High-resolution ultrasonography is a valuable tool through in particular situations: (i) when MRI examination is not available; (ii) when children are afraid of MRI examination; (iii) in more advanced stages of JIA.