3D quantitative measurement of condylar morphological changes in osteoarthritis : statistical stand point

Aim: The aim of this study was to evaluate from a statistical stand point the temporal, metric and clinical variables of the disease in order to plan an effective therapy for primary and secondary prevention, the ultimate purpose being to limit the erosive effects on mandibular condyles, allowing an harmonious dental and bone development of the patients affected by JIA. Materials and Methods: This study enrolled 30 patients with JIA. CBCT has been performed. 3D quantitative measures of the mid-lateral and anterior-posterior diameters and angles of the condyles were taken. The data were captured using an I-CAT™ cone beam 3-D imaging system and processed using I-CAT Vision viewing software, which allows visualization and measurement of the images in three dimensions (3D). Averages, standard deviations and 95% confidence intervals (CI) of the temporal, metric and clinical variables available were performed. Results: The mean age of the study samples was 12.90 years (95% Cl: 11.29-14,50 years) up to 16 June 2009, the incidence of the disease occurred at 7.09 years on average (95% Cl: 5,63-8,55 years). The analysis of the condylar changes showed that the most apparent signs were the erosion (for 44% of samples), the flattening (for 24.5% of the samples) and the presence of osteophytes (for 15%). Only 2% of the study subjects had no damage. The evaluation of metric diameters showed that the mean size of the right as well as left antero-posterior diameters were 15 mm, the mean of the right mid-lateral diameter is 8 mm and that of the left mid-lateral diameter is 7 mm . The average right angle was 33° and the average left angle was 36°. There was a very significant difference in the linear and angular measurements between healthy and affected condyles (p<0.01). Discussion: The use of CBCT and the 3D diagnostic protocol in young patients with JIA enabled reliable, accurate, and precise quantitative and images of the condylar structures and their dimensional relationships. In patients with JIA, temporomandibular joint involvement is often asymptomatic and can lead to severe craniofacial growth disturbances and facial deformities if not treated in the initial stage. TMJ arthritis in JIA patients is difficult to diagnose at an early stage, as there are relatively few symptoms and clinical findings. The pathological process can affect growth long before radiographic changes are seen. None of the clinical signs or symptoms of TMJ dysfunction are predictors of bony destruction of the TMJ. Conclusions: CBCT provides useful information to supplement clinical and laboratory examinations in the diagnosis and treatment of JIA. Patients with CBCT evidence of TMJ damage cannot be identified reliably by clinical examinations. CBCT represents an improvement in quantifying the morphological changes of the condyle and mandible. Furthermore, it gives an accurate picture of these structures in JIA and allows the acquisition of true measurements of the mandibular components.