摘要
目的:分析下颌旋转对Beta角的影响,为其临床应用提供依据。方法:选取341名不同骨面型的错牙合患者,分为Ⅰ类、Ⅱ类、Ⅲ类骨面型组,拍摄头颅定位侧位片,测量Beta角、反映下颌旋转的C角及上下颌骨有效长度的比值K,并计算C角和K值的均值、标准差及95%的参考值范围,采用数学软件m atlab描绘出三者的关系曲线,并分析Beta角随C角变化的趋势。结果:随着C角的增大Beta角呈现减小趋势,且K值越大,Beta角随C角增大而递减幅度越大,在骨性Ⅱ类患者中,总体的变化幅度最小,小于2.62°。结论:在骨性Ⅱ类患者中,下颌旋转对Be-ta角的影响较小,Beta角较为稳定。
Objective： The aim of the present study was to assess the effect of mandibular rotation on Beta angle so as to provide an adequate guide assessment of jaw relationship in saggital direction. Methods： The study were comprised of 341 patients according to Beta angle analysis and skeletal classification carried on cephalometrie analysis. Beta angle variation in mandibular rotation and effective length ratio（K） of maxilla to mandible were measured and the arithmetic mean and standard deviation were calculated respectively. The relationship of three parameters was analysed with the software ＂ matlab＂. Results： With the increasing of mandibular rotation angle （C） , Beta angle showed a tendency to decrease. The larger value of K, the more prominent the tendency will be. In skeletal Ⅱ relationship, variation of Beta angle caused by mandibular rotation was limited in 2.62°. Conclusion： In skeletal Ⅱ patients, the effect of mandibular rotation on the Beta angle was not notable and Beta angle remained stable.
出处
《口腔医学研究》
CAS
CSCD
2006年第5期541-543,共3页
Journal of Oral Science Research
关键词
Beta角
下颌旋转
K值
C角
Beta angle Mandibular rotation Ratio K C angle
