Skeletal factors of Angle classⅡdivision 1 malocclusion / 实用口腔医学杂志

ABSTRACT

Objective: To examine the skeletal factors of Angle's classⅡdivision 1 malocclusion in order to find a reasonable treatment protocol. Methods: The skeletal factors were measured and compared between 86 cases aged 12～25 years with AngleⅡ 1 malocclusion and 86 cases at the same age with normal occlusion. Thirteen measurements were chosen on lateral cephalometric radiograph for the comparison. Results: In the group of maloculsion, some measurements standing for sagittal skeletal pattern were statistically defferent from those in the group of normal occlusion, such as decreased SNB angle and SL linear and increased ANB angle, whereas some were not significently different, such as the SNA angle and PNS-ANS linear; some measurements standing for the vertical skeletal pattern were statistically defferent, such as decreased UM-PP linear and LM-MP linear and increased UI-PP linear, whereas some were not significently different, such as LI-PP linear;some measurements standing for growth pattern of mandibular were statistically defferent, such as decreased SN-MP angle. Conclusion: There are posterior alveolar defficency and mandibular retroposition as well as counterclockwise rotation of mandile in the patients with Angle class Ⅱ 1 malocclusion. The treatment for Angle Ⅱ 1 malocclusion should be to make mandibular move forward and downward in accordance with the characteristic skeletal pattern.