Condylar and mandibular volumetric changes in patients affected by Juvenile Idiopathic Arthritis

Aim: The Juvenile Idiopathic Arthritis (JIA) can lead in children to temporomandibular joint damage with facial development and growth alterations. JIA of the mandibular condyle produces morphological and surface changes, including cortical erosion, flattening, sclerosis, osteophyte formation, and reduced inter-articular space. The aim of this study is to show the importance of Cone Beam Computerized Tomography to volumetrically quantify TMJ damage in patients with JIA, measuring condylar and mandibular real volumes. Material and Methods: 34 children with temporomandibular involvement by JIA were observed by Cone Beam Computerized Tomography. 4 were excluded because of several imaging noises. The mandible was isolated from others craniofacial structures; the whole mandibular volume and its components’ volumes (condyle, ramus, emibody, emisymphysis on right side and on left side) has been calculated by a 3D volume rendering technique. Results: The results show a very significant difference in volume between the healthy and affected condyles (p < 0.001), and the volumes of the hemimandible, ramus, and hemisymphysis differed significantly (P<0,01); however, there was no difference in volume between the hemibodies. The data didn’t show any statistical differences between right side versus left side. In males, the only significant difference in volume was that between the healthy and affected condyles (p = 0.002). This was probably due to the small sample size (n = 7). In females, there were significant differences in volume for the condyle, ramus and hemimandible, and ramus; no differences for the hemibody. Discussion: Early initiation and optimal adjustment of aggressive therapy with disease-modifying anti-rheumatic drugs have been extremely successful in preventing irreversible joint damage. Therefore, the accurate and early diagnosis of JIA and the sensitive monitoring of the disease process are essential. Advanced imaging technology capable of identifying even the slightest trace of erosive joint damage may enable the prediction of future structural and functional deterioration. The use of CBCT and the 3D diagnostic protocol in young patients with JIA enabled reliable, accurate, and precise quantitative and volumetric images of the condylar and mandibular structures and their dimensional relationships. Conclusion: The Cone Beam Computerized Tomography represents a huge improvement in understanding of the condyle and mandibular morphological changes, even in the early stages of the Juvenile Idiopathic Arthritis.