[Study of the incisive alveolar structure in different vertical facial types between osteal Class III malocclusion and normal occlusion].

ABSTRACT

PURPOSE: To investigate the relationship of the incisive alveolar structure and vertical facial type between osteal Class III malocclusion and normal occlusion. METHODS: Forty-seven lateral cephalometrics of patients with osteal Class III malocclusion and forty-three lateral cephalometrics of controls with normal occlusion were randomly selected before treatment. Then the incisive alveolar structure was measured and analyzed, the results were analyzed with Student's t test. RESULTS: (1) In osteal Class III malocclusion; the UP value in the group of high mandibular angle decreased significantly than that in the groups of middle and low mandibular angle (P<0.05); the LA and MxAD value in the group of high mandibular angle decreased significantly than that in the group of middle mandibular angle (P<0.05). (2) In normal occlusion, the MdAD and LA value in the group of high mandibular angle decreased significantly than that in the groups of middle and low mandibular angle(P<0.05). (3) In patients with the same mandibular angle,the LA and MdAD value in normal occlusion increased significantly than those in osteal Class III malocclusion (P<0.05);the UP value, in normal occlusion increased significantly than osteal Class III malocclusion within the groups of middle and low mandibular angle (P<0.01). CONCLUSIONS: The incisive alveolar structure was different in different vertical facial type and the same vertical facial types between osteal Class III malocclusion and normal occlusion.