Table 1 Patients characteristics
| Â | Total cohort | MRI cohort | Statistics | ||
|---|---|---|---|---|---|
| Â | All | With TMJ-Arthritis | Without TMJ-Arthritis | Comparison with/without TMJ-Arthritis | |
n = 147 | n = 111 | n = 91 | n = 20 |  | |
Female (% of cohort) | 88 (60%) | 70 (63%) | 60 (66%) | 10 (50%) | p = 0.2 |
JIA subtypes (% of cohort) |  |  |  |  | p = 0.007* |
 Enthesitis related | 19 (13%) | 10 (9%) | 4 (4%) | 6 (30%) | |
 Oligoarticular | 70 (48%) | 49 (44%) | 40 (44%) | 9 (45%) | |
 Extended oligoarticular | 16 (11%) | 15 (14%) | 15 (16%) | 0 | |
 Polyarticular RF neg | 28 (19%) | 26 (23%) | 23 (25%) | 3 (15%) | |
 Psoriatic | 8 (5%) | 7 (6%) | 6 (7%) | 1 (5%) | |
 Systemic | 1 (0.7%) | 1 (1%) | 1 (1%) | 0 | |
 Undifferentiated | 5 (3%) | 3 (3%) | 2 (2%) | 1 (5%) | |
ANA pos (%) | 60 (41%) | 51 (46%) | 46 (50%) | 5 (25%) | p = 0.04* |
RF pos (%) | 1 (0.7%) | 1 (0.9%) | 0 | 1 | Â |
HLA B27 pos/tested (%) | 18/124 (15%) | 12/97 (12%) | 8/78 (10%) | 4/19 (25%) | p = 0.2 |
Uveitis (% of cohort) | 7 (5%) | 7 (8%) | 6 (7%) | 1 (5%) | p = 0.7 |
Age at JIA diagnosis in years (mean; median) | 7.3; 6.9 | 6.6; 6.0 | 6.3; 5.8 | 8.2; 8.4 | p = 0.04* |
JIA disease duration in years (mean; median) | 2.0; 1.9 | 2.2; 2.3 | 2.3; 2.4 | 1.6; 1.6 | p = 0.01* |
Age at TMJ diagnosis in years (mean; median) | Â | Â | 7.0; 6.4 | Â | Â |
Time until TMJ diagnosis in years (mean; median) | Â | Â | 0.7; 0.4 | Â | Â |
Medication | Â | Â | Â | Â | Â |
 NSAID (%) | 126 (86%) | 96 (86%) | 79 (86%) | 17 (85%) |  |
 Methotrexate (%) | 47 (32%) | 44 (40%) | 37 (41%) | 7 (35%) |  |
 Etanercept (%) | 14 (10%) | 14 (13%) | 14 (15%) | 0 |  |
 Infliximab (%) | 7 (5%) | 6 (5%) | 6 (7%) | 0 |  |
 Prednisone (%) | 11 (7%) | 9 (8%) | 8 (9%) | 1 (5%) |  |
 Sulfasalazine (%) | 2 (14%) | 1 (1%) | 0 | 1 (5%) |  |
 Leflunomide (%) | 3 (2%) | 2 (2%) | 2 (2%) | 0 |  |
 Adalimumab (%) | 2 (1%) | 2 (2%) | 2 (2%) | 0 |  |
 Tocilizumab (%) | 1 (0.5%) | 1 (1%) | 1 (1%) | 0 |  |
At least 1 DMARD (%) | 48 (33%) | 45 (41%) | 38 (42%) | 7 (35%) | Â |