Three-dimensional Reconstruction And Comparative Study Of Condylar Surface And Volume In Class Ⅰ And Class Ⅱ Patients

ObjectiveTo study the characteristics of mandibular condylar size in Class Ⅰ andClass Ⅱ malocclusion patients and the influence of these two types ofmalocclusion on condylar size, by using three-dimensional reconstructionand imaging technology of cone-beam CT (CBCT) to measure and comparethe surface area and volume of condyle in these two types of malocclusion.Methods70patients with class Ⅰ malocclusion (including35males and35females) and66patients with class Ⅱ malocclusion (including33males and33females), symmetrical faces and no joint symptoms, were randomlyselected from the patients of the orthodontic department in our hospital, aged20to28-year-old, before orthodontic treatment or orthognathic treatment.The samples were examined by CBCT, and the left and right condyle werethree-dimensional reconstructed and measured the surface and volume, andcalculate the condylar morphology index (volume/surface) through Mimics10.0software. The differences of measured values between male and female, between left and right sides, and between the two types ofmalocclusion.Results1. Condylar volume and surface in male patients were both significantbigger than that in women patients (P<0.05), no matter with Class Ⅰ orClass Ⅱ malocclusion. And condylar morphology index were notstatistically different (P>0.05).2.The volume, surface and morphology index of the condyle in Class Imalocclusion patients between left side and right side were not statisticallydifferent (P>0.05).3.The volume and surface of right condyle were statistically bigger thanleft condyle in Class Ⅱ malocclusion patients (P<0.05). Condylarmorphology index was no significant difference (P>0.05).4.The volume and surface of condyle in Class Ⅱ malocclusion weresmaller than that in Class Ⅰ malocclusion (P<0.01). And condylarmorphology index was no significant difference (P>0.05).Conclusion1. The size of mandibular condyle relates to genders, and the condylarsize of males is bigger than that of females in Class Ⅰ or Class Ⅱmalocclusion.2. Class Ⅰ malocclusion patients with symmetrical faces and withoutjoint symptoms have symmetrical condyle. 3. The right and left condyle may actually be symmetrical. It can bejudged by CBCT.4. Patients with different types of malocclusion have differentcondylar sizes. The condylar size is smaller in Class Ⅱ malocclusionpatients than that in Class Ⅰ.