Auto-CAD计算机辅助设计软件定点测量儿童上颌窦前壁及上颌结节位置变化

Localizing the anterior wall of the maxillary sinus and maxillary tuberosity using Auto-CAD software

背景:研究上颌窦前壁及上颌结节的位置变化,分析上颌骨的发育情况,并可掌握上颌骨骨量的多少以及发育的时机,来为正畸做更好的准备和分析,但用计算机Auto-CAD软件定点,并研究上颌窦前壁及上颌结节的位置变化尚未见报道。目的:调查分析新疆乌鲁木齐市300名4-14岁汉族儿童生长发育过程中上颌窦前壁及上颌结节的位置变化及其发育的情况。方法:对乌鲁木齐市口腔医院就诊的300例4-14岁儿童,将收录的人群按Hellman’s牙齿发育阶段分为5组(ⅡA组、ⅡC组、ⅢA组、ⅢB组、ⅢC组)。通过Auto-CAD计算机辅助设计软件对全颌曲面断层片进行画图分析,将鼻中隔与硬腭的交点设为O点,硬腭与上颌窦近中面的交点为上颌窦前壁点(PA),将两点连成一线定位X轴,过O点并与X轴垂直的为Y轴,此时O点为(0,0)点,上颌粗隆的后壁与硬腭的交点为上颌粗隆的后壁点(PP),此点会有一个精确的坐标值即(PPX,PPY),将数据进行统计分析,了解牙齿发育的不同时期,上颌窦前壁点与上颌粗隆的后壁点的位置变化。结果与结论:方差分析表明上颌窦前壁点在5个不同时期在X轴上的数值差异不显著(α>0.05)。从IIA期到ⅢA期上颌粗隆后壁的值是明显的水平向后方和垂直向下方的生长。从ⅢA期到ⅢB期,上颌粗隆的后壁点是仅发生了水平向后方的生长,垂直方向的生长不明显。从ⅢB到ⅢC期,上颌粗隆的后壁点出现明显的垂直向下的生长,而水平向后方的生长不明显。即此期是第2磨牙萌出的时间,说明第2磨牙的萌出对上颌骨垂直向的生长有一定作用。

BACKGROUND： To make a better preparation for orthodontic tooth, we investigate the changes in the localization of the anterior wall of the maxillary sinus and maxillary tuberosity, analyze the development of the maxilla, and detect the bone mass of the maxilla and development timing. However, the use of Auto-CAD software has not been reported to localize the anterior wall of the maxillary sinus and maxillary tuberosity. OBJECTIVE： To investigate the localization and growth of the anterior wall of the maxillary sinus and maxillary tuberosity in 300 children aged 4-14 years from the Han ethic group in Urumqi, Xinjiang Uygur Autonomous Region, China. METHODS： Totally 300 children, 4-14 years of age, admitted at the Stomatological Hospital of Urumqi, Xinjiang Uygur Autonomous Region, China, were enrolled. According to Hellman＇s dental developmental staging, these children were divided into five groups： groups ⅡA, ⅡC, ⅡIA, ⅡIB, ⅡIC. Auto-CAD software was used to analyze the panoramic radiographs of the maxilla and mandible. The tracing of each radiograph was digitized by translating the reference points onto an X-Y coordinate system. The straight line that passed the point where the nasal septum intersected with the hard palate（point O） and the point where the medial wall of maxillary sinus intersected with the hard palate（point PA） was designated as the X axis. The straight line that was vertical to the X axis and passed through the point O at a right angle was designated as the Y axis. The X and Y coordinate values of reference point were calculated. And then O point was set as（0, 0）, and the point where the posterior wall of maxillary tuberosity intersected with the hard palate（PP） was set as（PPX, PPY）. Collected data were analyzed statistically to understand the changes in the localization of PA and PP at different stages of dental development. RESULTS AND CONCLUSION： The change of point PA had on significant differences between the five groups（α〉0.05）. Point PP grew obviously in a horizontal rearward and vertical downward manner from stage ⅡA to ⅡIA; this point only presented a horizontal rearward growth from stage ⅡIA to ⅡIB and only a vertical downward growth from stage ⅡIB to ⅡIC. This period was the time of the second molar eruption, indicating that the second molar eruption is helpful to the vertical growth of the maxilla.