# Temporomandibular disorder in children with juvenile idiopathic arthritis with and without temporomandibular joint involvement compared to controls – a two-year prospective multicenter cohort study

## TL;DR

This study found that children with juvenile arthritis are more likely to have temporomandibular disorder symptoms, especially if their arthritis is active.

## Contribution

A two-year longitudinal comparison of TMD in children with and without JIA and TMJ involvement using a standardized diagnostic protocol.

## Key findings

- Children with JIA and TMJ involvement had significantly higher TMD diagnosis rates than controls.
- Active JIA disease increased the risk of orofacial myalgia regardless of TMJ involvement.
- TMD prevalence decreased slightly over two years but remained elevated in JIA groups.

## Abstract

This study compares the prevalence of orofacial signs and symptoms of temporomandibular disorder (TMD) in children with juvenile idiopathic arthritis (JIA) and controls at two study visits two years apart. We also examine the prevalence of TMD diagnoses and their association with general disease activity in children with JIA.

In the NorJIA cohort study, children with JIA aged 4 to 16 years were recruited consecutively from three pediatric rheumatology clinics in Norway and together with an age- and sex-matched non-JIA control group from public dental health service clinics. Children with JIA were classified into temporomandibular joint (TMJ) involvement and no TMJ involvement groups on the basis of magnetic resonance imaging findings. An adapted version of the Diagnostic Criteria for TMD protocol was applied to assess myalgia, arthralgia, headache attributed to TMD, and disc displacement in all children at both visits.

Fifty-five children with JIA and TMJ involvement, 132 with JIA without TMJ involvement, and 189 controls completed TMD examinations at both visits. At Visit I, at least one TMD diagnosis was present in 49% of the children with JIA and TMJ involvement, 19% with JIA without TMJ involvement, and 5% of the controls; after two years, these frequencies were 38%, 16%, and 7%, respectively. Children with active JIA disease at baseline had a higher risk of orofacial myalgia (OR 10.5, 95% CI 3.1–36.4).

TMD was more common in children with JIA than in non-JIA controls. Active JIA disease increased the risk of temporomandibular myalgia, regardless of TMJ involvement. Pediatric rheumatologists and dentists should regularly monitor the orofacial region in all children with JIA.

Registered retrospectively on clinicaltrials.gov (NCT03904459, 03/04/2019).

The online version contains supplementary material available at 10.1186/s12903-026-07738-4.