To evaluate three-dimensional (3D) condylar and mandibular growth in patients with juvenile idiopathic arthritis (JIA) with unilateral temporomandibular joint involvement treated with a distraction splint.
Cone-beam computed tomography (CBCT) scans were taken for 16 patients with JIA with unilateral TMJ involvement before treatment (T0) and 2 years after treatment (T1). All patients received orthopedic treatment with a distraction splint. Eleven patients without JIA who were undergoing orthodontic treatment without a functional appliance or Class II mechanics and who had taken CBCT scans before and after treatment, served as controls. Reconstructed 3D models of the mandibles at T0 and T1 were superimposed on stable structures. Intra- and intergroup growth differences in condylar and mandibular ramus modifications and growth vector direction of the mandibular ramus were evaluated.
In all patients with JIA there were asymmetric condylar volume, distal and vertical condylar displacement, and ramus length differences that were smaller on the affected side. Condylar displacement was more distal and less vertical in the JIA group than in the control group. A larger distal growth of the condylar head and a more medial rotation of the ramus on the affected side were found in the JIA group.
The orthopedic functional treatment for patients with JIA allows for condylar adaptation and modeling, thereby hindering, although with a widely variable response, a further worsening of the asymmetry. Unilateral affection has a possible influence on the growth of the nonaffected side.