Objective: Abnormalities covered by the generic term “oculo-auriculo-vertebral spectrum” (OAV) form an exceptional heterogeneous dysmorphic complex characterized by unilateral malformations of the miscellaneous craniofacial structures. The aim of the present study was to objectify the maxillo-facial asymmetry particularly with regard to the mandible.
Methods: CT-data sets of 18 patients suffering from this syndrome were analyzed according to the Katsumata asymmetry classification index. In addition, the volume, the maximum horizontal diameter, the condyle rotation and the trabecular bone density of the TMJ as well as the ramus height and the corpus length were measured by utilizing the VoXim®software. The measuring results of the affected and the non affected side were compared using the Wilcoxcon signed rank test.
Results: The results indicated unilateral asymmetries within maxilla and marked asymmetrical discrepancies concerning the mandible. The mean difference in TMJ volume was 1.12ml, which is in accordance with a mean reduction factor of 0.33. On the basis of this result the TMJ hypoplasia of the affected TMJs could be classified into three severity grades. Accordingly the mean difference in horizontal TMJ diameter was 3.69mm accompanied by a condyle rotation discrepancy of 14.85° on average. The ramus height showed mean differences of 7.78mm and 13.69mm for total mandibular length by comparing the affected and the non affected side of the mandible.
Conclusions: CT based data analysis proved to be an excellent tool for quantitative three-dimensional evaluation of skeletal parameters.