Orofacial Manifestations Common Among Children With Juvenile Idiopathic Arthritis

Because of the high incidence of orofacial manifestations among children and adolescents with juvenile idiopathic arthritis (JIA), clinical examination must be prioritized in this population, according to study findings published in Arthritis & Rheumatology.

The researchers of the study sought to estimate the cumulative incidence of orofacial disorders linked to the temporomandibular joint (TMJ) in patients with JIA, from disease diagnosis in childhood to transition to adult care, and identify aspects of JIA related to involvement of the TMJ.

Between January 2000 and May 2018, researchers collected real-world data from the Aarhus JIA TMJ cohort database in the Regional Specialist Craniofacial Clinic (RSCC) in the Section of Orthodontics of Aarhus University, Denmark. Data included disease-specific background information, orofacial signs/symptoms, TMJ involvement, and JIA-generated dentofacial deformity.

TMJ arthritiswas defined as the presence of magnetic resonance imaging (MRI)-verified active TMJ inflammation. TMJ involvementwas defined as a condition that included both TMJ arthritis and abnormalities as a consequence of previous TMJ arthritis, and typically diagnosed based on clinical and radiologic findings caused by prior TMJ inflammation, such as TMJ deformity and orofacial signs and symptoms.

Data were collected on age at diagnosis of JIA, category of JIA, total number of active joints observed at baseline, blood work, including antinuclear antibody (ANA) levels, human leukocyte antigen (HLA) B27, and  rheumatoid factor, and systemic medication used from initial diagnosis through adulthood.  

Of a total of 613 participants included in the study, 66.2% received orofacial examinations until their transition to adult care. The remaining participants (33.84%) included those without any recurring TMJ flares or other orofacial conditions following discontinuation of their pediatric rheumatology care.

The mean ages at the first and final orofacial examinations in these participants were
10 years 7 months and 14 years 7 months, respectively, in the first and second group of participants (66.2% and 33.84% of the cohort, respectively). Overall, the median total observation time reported was 61.2 months per participant and the number of radiologic orofacial cone-beam computed tomography examinations totaled 503.

On transition to adult care, the cumulative incidence of TMJ reported was 30.1% (95% CI, 26.5%-33.7%), which included both TMJ arthritis and other disorders recognized as being associated with prior TMJ inflammation. For 30.1% of the cohort, the distributions of subclassifications were unilateral TMJ involvement (16.0%), bilateral TMJ involvement (12.6%), and TMJ with signs of arthritis detected during examinations (1.5%).

The cumulative incidence of participants receiving orthopedic treatment with a dental appliance for the correction of dentofacial deformity was 20.6% of the cohort. An overlap of 100% was observed among the 20.6% of participants who received a diagnosis of dentofacial deformity and those who received a dental appliance. Patients who were had an orthopedic appliance were diagnosed with JIA-induced dentofacial deformity.

At the time of transition to adult care, 50.4% of the participants reported at least 1 event associated with orofacial symptoms and 23.5% reported at least 2 events linked to orofacial symptoms.

From JIA diagnosis to transition into adult care, 76.2% of the cohort reported at least 1 event of orofacial dysfunction during their clinical examination. Overall, the cumulative incidence of several orofacial dysfunction events reported was 52%. Baseline features that were significantly related to TMJ involvement at the time of transition to adult care included young age, the female sex, and ANA positivity. On the other hand, HLA-B27 positivity was associated with a lower risk for involvement of TMJ.

Study limitations included that the lack of routine TMJ contrast-enhanced MRIs restricted estimation of the cumulative incidence of cohort participants who had active TMJ arthritis and that a small percentage of the total JIA population in the Western portion of Denmark was not evaluated.

“Our results emphasize the importance of including orofacial conditions in contemporary examination and treatment strategies of JIA,” the study authors concluded.