TMJ+ n=30 TMJ- n=23 p-values Disease onset age (years) 4.8± 2.8 6.8± 3.0 0.016 Mean age at initial registration (years) 11.3± 1.5 10.8± 1.4 0.32 ILAR classification       Oligoarthritis 8(27%) 4(17% )   Extended oligoarthritis 10(33%) 4(17% )   Polyarthritis, rheumatoid factor negative 6(20%) 7(30%)   Polyarthritis, rheumatoid factor positive   1(4%)   Systemic arthritis 4(13%) 3(13%)   Enthesitis related arthritis 2(7%) 4(17% )   Values arethe mean ± SD, or the number of patients (%)

Table 1: Age and JIA subtypes according to the International League of Associations for Rheumatology (ILAR) classification in 53 juvenile idiopathic arthritis (JIA) children, with (TMJ+) and without (TMJ-) temporomandibular joint involvement