Component Analysis of Craniofacial Type of Xi'an Chinese with Class III Malocclusion in the Early Permanent Dentition

Objective:To analyze craniofacial type composition of Class Ⅲ malocclusion in early permanent dentition in the Xi'an region. Methods:We performed a retrospective study on craniofacial type of the Class Ⅲ malocclusion patients admitted to the Department of Orthodontics,Stomatology Hospital,the Fourth Military Medical University,during 2003-2008. The computer-aided cephalometric X technology had been used and the features of class III malocclusion patients in early permanent dentition were studied. Results:In early permanent dentition,craniofacial types in sagittal directions were mainly manifested as maxillary and mandibular normal or maxillary normal with mandibular hyperplasia. Craniofacial types in vertical direction were mainly manifested as average angle,and seldom as low-angle and high-angle. The cross-analysis of sagittal and vertical craniofacial morphology was performed. Both maxillary and mandibular normal and maxillary normal with mandibular hyperplasia in average angle patients were predominant,and followed by maxillary hypoplasia with mandibular normal combined with average angle. Conclusion:It was demonstrated that class III malocclusion patient in early permanent dentition has either sagittal or vertical features. The component analysis can play a very important role in understanding the detailed features of class III malocclusion. And more important,it is helpful for the future study on the early treatment of class III malocclusion.