前牙覆相关因素的研究

A study on the cephalometric parameters related with anterior overbite

目的 :探讨不同类型错牙合畸形中与前牙覆牙合相关的多种因素。方法 :恒牙期错牙合 14 4例 ,其中 ,I类骨骼型 74例 ,II类 70例。在自然头位下摄取头颅定位侧位片。以覆牙合值为因变量 ,分析前牙覆牙合与其他头影测量参数的相关关系 ,并建立以覆牙合值为因变量的多元回归方程。结果 :I类骨骼型组多元回归分析显示 ,前牙覆盖、后面高及上切牙高度值越大 ,或下面高及下磨牙高度距离值越小 ,前牙覆牙合越深 ;在II类骨骼型组 ,前牙覆盖、上下切牙角及下切牙倾斜度值越大 ,或下颌角及上磨牙高度值越小 ,前牙覆牙合越深。 2个方程分别能解释 75 .8%和 62 .3 %的前牙覆牙合值的变化。其中 ,前牙覆盖值对前牙覆牙合最具影响。结论 :与前牙覆牙合相关的X头影测量参数包括牙性的和骨性的 ,这些参数相互补偿 ,其中 ,前牙覆盖值对维持正常且稳定的前牙覆牙合起着最重要的作用。

Objective: To investigate the cephalometric parameters related with anterior overbite. Methods: 144 patients with malocclusion in permanent dentition (74 skeletal Class I and 70 skeletal Class II) were recruited into the study. Cephalometric analysis was performed from pre-orthodontic lateral headfilm in natural head position. Both linear correlation analysis and stepwise regression analysis were respectively performed in the two groups. Results: In the stepwise regression equation of Class I group, the larger the overjet, posterior facial height and upper incisor height, or the smaller the lower facial height and lower molar height, the deeper the anterior overbite was. In the 70 Class II, the larger the overjet, interincisal angle and inclination of lower incisors, or the smaller the mandibular angle and upper molar height, the deeper the anterior overbite was. The equations could explain 75.8% and 62.3% overbite variations, respectively. Of all the parameters, overjet took the most important part in maintaining a normal and stable anterior overbite. Conclusion: Those cephalometric parameters correlated with anterior overbite can be both dental and skeletal. They may compensate each other to maintain stable anterior overbite. Of them, anterior overjet may be the main factor.