安氏Ⅱ类1分类错上下颌基骨前后关系诊断指标的可靠性评价

Reliability Evaluation for Thirteen Parameters Describing Anteroposterior Apical Base Relationship in Angle Class Ⅱ Division 1 Patients

目的评价反映安氏Ⅱ类1分类错上下颌基骨前后关系13项指标的可靠性。方法安氏Ⅱ类1分类错患者120例,男60例,女60例,年龄20—28岁。拍摄自然头位(NHP)下的头颅定位侧位片。一金属链悬于头颅前方,其在胶片上的影像作为确定真性水平面(THP)的依据。X线头影测量项目包括ANB角、AB平面角、Wits值、AF-BF、AXB平面角、AB/SN4、AB/PP、AXD平面角、AD/SN、SGn/AB角、APDI角、FABA角、β角及A、B两点在THP上垂足间的距离(AB/HP)。计算各测量项目的相关系数;测量结果按最小相关系数指标分类法行聚类分析。所有测量结果用SPSS11.0统计软件进行分析。结果相关分析表明各项指标除Wits值和SGn/AB角外多数呈高度相关性;聚类分析采用最小相关系数指标分类,结果按0.60水准分为5类。结论在安氏Ⅱ类1分类错患者中,除Wits和SGn/AB外其他11项指标均可作为上下颌基骨前后关系的评价指标。AB/SN4能比较真实地反映上下颌骨的矢状关系;ANB角、AB平面角、β角、AF-BF、AXB平面角、FABA角、AB/PP、APDI角等指标具有相似的临床意义。

Objective To study 13 different cephalometric measurements of the anteroposterior jaw relationship in Angle Class Ⅱ division 1 statistically and geometrically, and to discuss the effects of various factors on this relationship, and then to choose the most adequate measurements. Methods 120 patients with skeletal malocclusion Angle Class Ⅱ division 1 were selected. The samples consisted of 60 men and 60 women between 20 to 28 years of age. Lateral cephalometric radiograph for each patient was taken in natural head posture by the same operator. A wire plumb line and suspended weight recorded the true vertical on each radiograph. The subject was then asked to determine the self-balanced position of the head. After determining the self-balanced neutral position, the subject was asked to look into his/her own eyes in the mirror. ANB angle, A-B plane angle, Wits appraisal, AF-BF distance, AXB angle, AB/SN4 distance, AB/PP distance, AXD angle, AD/SN distance, SGn/AB angle, APDI, FABA angle, beta angle and AB/HP distance were measured. Coefficient correlations among measurements were tabulated to determine which combination would produce a higher value. Fuzzy grouping analysis was made. Results Statistically significant and highly correlated relationships was found among many measurements except Wits appraisal and SGn/AB angle. The thirteen measurements could be divided into five clusters. Conclusion The cephalometric measurements except Wits appraisal and SGn/AB angle can be used to evaluate anteroposterior jaw relationship. The AB/SN4 distance is the most adequate measurements. ANB angle, A-B plane angle, AF-BF distance, AXB angle, AB/PP distance, APDI, FABA angle and beta angle are similar in describing anteroposterior apical base relationship in Angle Class Ⅱ division 1 patients.