Rothstein T, Yoon-Tarlie C
Graduate School of Arts and Sciences, Department of Anthropology, University of Pennsylvania, USA.
Am J Orthod Dentofacial Orthop. 2000 Mar;117(3):320-32. doi: 10.1016/s0889-5406(00)70237-x.
The purpose of this study was to describe and analyze the craniofacial and dentofacial skeletal characteristics associated with Angle's Class II, Division 1 malocclusion. The material examined included 613 lateral head radiographs comprising 2 series: (1) 278 films of children with "normal" occlusion and (2) 335 films of children with Class II, Division 1 malocclusion. Each series was subdivided into 6 samples (3 female and 3 male; skeletal ages 10, 12, 14, [+/-6 months]), representing children with chronological ages ranging from 8.5 to 15.5 years. The radiographs were converted to computer-readable X and Y coordinate data and 52 linear, angular, and coordinate axis measurements were taken. Findings were visually verified by superimposing the computer-drawn composite plots of the Class II, Division 1 series over those of the normal series. In all 6 intergroup comparisons, it was found that: (1) the mandible and its dentition is similar to the controls in size, form, and position except for the position of the lower incisors in males; (2) the forehead (Gl), anteriorcranial base (Nas), maxilla (A) and dentition (molars and incisors) are protrusive (mesial positioned), with an increased frontal bone thickness at the level of the sinus, and a larger A-P maxilla, the palate of which is inclined superiorly at its anterior half; (3) no vertical dysplasia was evident; (4) the cranial base angle is larger, as are the anterior and posterior sections that compose it, but it is not related to mandibular position; (5) angular indexes of maxillary and mandibular position that included point Nasion are highly misleading indicators of maxillary and mandibular size and position. Visualized diagnosis via a composite norm based on age and sex might offer a more reliable alternative or supplement to the numeric reference standards now in use. Enlarged sinuses may contribute to the cause of Class II, Division 1 malocclusion.
本研究的目的是描述和分析与安氏II类1分类错牙合相关的颅面和牙颌面骨骼特征。所检查的材料包括613张侧位头颅X线片，分为2组：（1）278张具有“正常”咬合的儿童的片子；（2）335张安氏II类1分类错牙合儿童的片子。每组又细分为6个样本（3名女性和3名男性；骨骼年龄为10、12、14岁，[±6个月]），代表实际年龄在8.5至15.5岁之间的儿童。将X线片转换为计算机可读的X和Y坐标数据，并进行52项线性、角度和坐标轴测量。通过将安氏II类1分类组的计算机绘制的复合图叠加在正常组的复合图上，对结果进行了视觉验证。在所有6组间比较中，发现：（1）除男性下切牙位置外，下颌骨及其牙列在大小、形态和位置上与对照组相似；（2）前额（Gl）、前颅底（Nas）、上颌骨（A）和牙列（磨牙和切牙）突出（近中位置），鼻窦水平处额骨厚度增加，上颌骨前后径增大，其腭前部向上倾斜；（3）无明显垂直发育异常；（4）颅底角较大，构成颅底角的前后部分也较大，但与下颌位置无关；（5）包括鼻根点的上颌和下颌位置的角度指数对上颌和下颌的大小和位置具有高度误导性。基于年龄和性别的复合标准进行可视化诊断可能为目前使用的数字参考标准提供更可靠的替代方法或补充。鼻窦增大可能是安氏II类1分类错牙合的病因之一。
