Temporomandibular joint (TMJ) arthritis is common in children with Juvenile Idiopathc Arthritis (JIA); it confers significant functional and psychological morbidity to young people suffering with pain, functional impairment and facial asymmetry, as a result of TMJ destruction. Gadolinium-enhanced MRI is the gold-standard imaging modality for detection of synovitis, however early recognition of TMJ arthritis is challenging: clinical assessment is insensitive and early findings on MRI overlap with non-inflammatory synovial enhancement of normal children. Coupled with the expense and relative scarcity of MRI, there is an absence of international consensus with regard to screening in TMJ arthritis. This observational study aims to understand the characteristics of the JIA patient cohort undergoing TMJ MRI in our centre.Methods
The electronic clinical records of 30 consecutive patients undergoing TMJ MRI between March 2014 and April 2016 were retrospectively reviewed. They were split into two age groups, 0–4 years (n=15) and 5–12 years (n=15). Baseline characteristics including age, sex, JIA subtype, time lag between JIA diagnosis and MRI-TMJ involvement, indications for MRI, MRI reports and whether the MRI changed clinical management were assessed. All TMJ MRIs (n=56) performed on these 30 patients were assessed.Results
Children developed TMJ involvement aged 8–10 years old, regardless of age of onset of JIA. Following diagnosis of JIA, TMJ involvement was identified after 6.75 years (median, range 1.25–9.33 years. Mean 5.92 years) in 0–4 age group, and 1 year (median, range 0–9 year. Mean 1.83 years) in 5–12 group. 40% (6 children, aged 7–11 years) in 5–12 group had TMJ involvement at diagnosis. Most common indications for MRI were pain and restriction (0–4 group), with deviation and asymmetry (5–12 group). The 5–12 group had more bony erosions on MRI report (13/15) and more unilateral disease compared to 0–4 group. The burden of TMJ disease occurs predominantly over the age of 5 (28/30). MRI changed clinical management (18/30).Conclusion
Irrespective of age of onset of JIA, children developed TMJ involvement between 8–10 years of age. This identifies a group upon which to focus targeted MRI surveillance with the aim of detecting early TMJ disease. Further study is required.