Fig. 1

Classification in slightly and severely affected Group according to Billiau et al. [1]. This figure shows the severity of condyle destruction (black arrowhead). Score 0 (radiologically normal appearance; Score 1 (cortical bony erosions); Score 2 (condylar flattening); Score 3 (condylar flattening with additional erosions); Score 4 (complete loss of the condyle). Results with Score 0–2 were classified as slightly affected (Group I), Score 3–4 as severely affected (Group II)