摘要
目的本研究利用正常萌出尖牙的根尖位置确定牙弓形态,确定阻生尖牙与正常萌出尖牙根尖位置的差异,并试图确定唇腭侧阻生尖牙的根尖位置是否存在差异。方法21例正常未萌出的尖牙、19例腭侧阻生尖牙、16例牙槽窝阻生尖牙、25例唇侧阻生尖牙。采用锥形束计算机断层扫描获得图像,利用Planmeca Romexis 3D软件确定根尖的X、Y、Z坐标。通过在腭平面上投影,将获得的三维坐标转换为二维坐标,对转换后的二维坐标进行处理,一元二次项函数拟合绘制根尖弓形图。结果4组根尖弓形图分布不同。腭侧组的阻生尖牙与对侧非阻生尖牙的位置有明显差异(P<0.05);牙槽窝组的阻生尖牙与对侧非阻生尖牙的位置无差异(P>0.05);腭侧组与牙槽窝组、唇侧组的阻生尖牙位置存在显著差异,有统计学意义(P<0.05);唇侧组与牙槽窝组的阻生尖牙位置无统计学差异(P>0.05)。阻生尖牙根尖距离弓形的平均距离最远5.60 mm,阻生尖牙根尖分布更倾向于第一前磨牙根尖的位置。结论未完全钙化的未萌出牙齿在随后正常萌出中呈现出正常的根尖弓形。阻生尖牙根尖距离弓形的距离远于非阻生尖牙,腭侧组的阻生尖牙根尖分布与其他阻生尖牙组不同。
Objective In this study,the shape of the dental arch was determined by using the root apices of normal erupted canines,so as to determine the difference between the root apices of impacted canines and those of normal erupted canines.In addition,we attempted to determine whether the labio-palatal position of the impacted canines have difference.Methods The study included 21 normal unerupted canines(normally erupted canines of the permanent teeth),19 palatal impacted canines,16 midalveolus impacted canines,and 25 labial impacted canines.Images were obtained by conical beam computed tomography(CBCT),and the X,Y,and Z coordinates of root apices were determined by Planmeca Romexis 3D software.By projecting on the palatal plane,the obtained three-dimensional coordinates were converted into two-dimensional coordinates,and the converted two-dimensional coordinates were processed,univariate quadratic function to fit apical arch.Results Four groups of root apex arch have different distributions,there were significant differences between the impacted canines in the palatal group and the contralateral normal canines(P<0.05).There was no difference between the impacted canines in the midalveolus group and the contralateral normal canines(P>0.05).There were significant differences in the position palatal of the impacted canines between the midalveolusand labial groups(P<0.05).There was no significant difference in the position of the impacted canines between the labial and midalveolus groups(P>0.05).The average distance from the apex of the impacted canine was 5.60 mm,the apex of the impacted canine tends to be located at the apex of the first premolar.Conclusion Incompletely calcified,unerupted teeth with a subsequent normal eruption showed a normal arch form of the root apices.The root apices of impacted canines were farther from the arch forms than were the nonimpacted canines.Also,the root apices of impacted canines in the palatal area showed distributions different from those of the other impacted canine groups.
作者
王垚
秦红志
何进伟
王军强
WANG Yao;QIN Hong-zhi;HE Jin-wei;WANG Jun-qiang(Department of Stomatology,Affiliated Hospital of Yan′an University,Yan′an 716000;Medical College of Yan′an University,Yan′an 716000,China)
出处
《延安大学学报(医学科学版)》
2020年第2期74-77,I0003,共5页
Journal of Yan'an University:Medical Science Edition
关键词
上颌阻生尖牙
正常萌出尖牙
根尖弓形
Maxillary impacted canine
Normal eruption canine
Apice arch