恒尖牙双尖牙近远中径预测方程
作者：彭惠 王昕 陈开云
单位：彭惠(大庆市第一医院口腔科)；王昕(华西医科大学口腔医学院正畸科 610041)；陈开云(华西医科大学口腔医学院正畸科 610041)
关键词：近远中径；恒牙；间隙分析；直线相关；预测方程
华西口腔医学杂志000116 摘 要：目的:为口腔正畸临床混合牙列间隙分析提供简捷、便利的诊断依据。方法:在模型上测量牙冠近远中径,对测量值进行直线回归与相关分析。结果:下切牙与尖牙、双尖牙近远中径存在直线相关关系。结论:建立了汉族人群上、下颌尖牙双尖牙近远中径预测方程。
The Predictation Equation of the Permanent Canine and Premolar Crown
Peng Hui Wang Xin Chen Kaiyun
, 百拇医药
(Orthodontic Department, College of Stomatology, West China University of Medical Sciences)
Abstract：Objective：It is important to predict mesiodistal crown diameter of the permanent canines and premolars in the mixed dentition, which helps to determine malocclusion and its further development. But there is still no article about this equation of Chinese used to predict mesiodistal crown diameter of cuspids and premolars. This research is to measure mesiodistal crown diameters, to study relationship between lower incisors and canines and premolars, and to provide the most accurate and easy basis in orthodontic diagnosis and treatment for Chinese people. Methods: 140 Chinese students (60 male, 80 female) who were from eighteen to twenty-five years old without orthodontic history Chengdu were randomly collected in. All teeth must be free of visible malform, aberration, and fully erupted. Impressions were taken, and measurements were made, parallel to the occlusal plane at the greatest mesiodistal width of each tooth on dental cast with electronic caliper (0.01 mm). Each tooth was measured twice and the average of the two readings was taken as the dimension for that individual tooth. Mesiodistal crown diameters were statistically analyzed with t-test and linear regression, using the SAS (Statistic Analyses System) computer package. Results: It was found that mesiodistal crown diameters had significantly statistical difference in gender. Hence the mesiodistal crown diameters were assessed and investigated separately for the male and the female. It was also found that the total mesiodistal crown diameter of lower incisors was closely correlated with the total mesiodistal crown diameter of canines and premolars. The correlation coefficients between the independent variable and dependent variables were 0.599 for upper canines and premolars and 0.654 for lower canines and premolars in the males and 0.586 and 0.635, respectively, in the females. The P were found to be less than 0.001 for both arches. The correlation coefficients had significantly statistical difference. Conclusion: The equations predicting overall mesiodistal crown diameters of upper and lower unerupted canines and premolars for male and female Chinese people were established respectively: Maxillary (y=10.87+0.51 x (male)), y=11.88+0.46 x(female), Mandibular (y=10.36+0.50 x(male), y=10.03+0.49 x(female)), y(total mesiodistal crown diameter of canines and premolars), and x(total mesiodistal crown diameter of lower incisors).
, 百拇医药
Key words：mesiodistal diameter space analyses linear regression predicting equation▲
Tanaka and Johnston[1]预测方程用于混合牙列间隙分析,通过测量已萌恒下切牙近远中径,预测未萌恒尖牙双尖牙近远中径,以判断混合牙列的拥挤程度,确定治疗方案。由于其简便、准确,在国外正畸临床广为应用。本研究用Tanaka and Johnston方法,建立了适合汉族人群的尖牙、双尖牙近远中径预测方程,为正畸临床提供简捷的诊断依据。
1 材料和方法
1.1 研究对象
纳入标准:①年龄18～25岁,汉族,无正畸史;②所有牙冠完全萌出(包括第三磨牙),无畸形、缺损或修复,无明显磨耗。
, 百拇医药
本研究于1998年在成都大专院校学生中随机选取符合纳入标准者140人,男60人,女80人。用海藻酸钠印模材料取模,超硬石膏灌模。模型清晰,无变形。
1.2 测量方法
用0-150型电子数显卡尺(精确度为0.01 mm)测量模型上每个牙冠的近远中径。测量时使卡尺的横梁与切缘或面平行。每项指标重复测量2次,实测值取2次测量平均值。
1.3 统计学处理
用统计分析系统(statistic analyses system,SAS)计算机软件对测量资料统计分析:①成组t检验,比较同名牙性别间是否有差异;②直线回归与相关分析,以下切牙近远中径之和作为自变量,上、下颌左侧尖牙双尖牙近远中径之和分别为应变量,按照Tanaka and Johnston预测方法,建立汉族人尖牙双尖牙的预测方程。
, 百拇医药
测量误差的评估,根据公式[2]
计算测量者的测量误差,进行测量误差的评估。式中σ为测量误差,D为重复测量的差值,N为样本含量。
2 结 果
2.1 测量结果
本研究测量140名汉族男、女性所有牙冠近远中径的平均值、标准差及性别差异见表1。由表可看出牙冠近远中径男女之间存在显著性差异。
表1 140例汉族青年恒牙近远中径
及性别差异(
±s,mm) 测量项目
上颌
, 百拇医药
下颌
男
女
男
女
中切牙
8.53±0.53
8.32±0.50*
5.57±0.36
5.48±0.34
侧切牙
7.04±0.56
, 百拇医药 7.03±0.56
6.17±0.40
6.07±0.39
尖牙
8.08±0.39
7.84±0.44***
7.22±0.35
6.83±0.41***
第一双尖牙
7.35±0.43
7.23±0.39
, 百拇医药
7.28±0.33
7.06±0.39***
第二双尖牙
6.92±0.41
6.80±0.39
7.20±0.42
7.05±0.42
第一磨牙
10.72±0.51
10.46±0.53**
11.36±0.45
, 百拇医药
11.03±0.42
第二磨牙
10.00±0.53
9.67±0.52***
10.72±0.52
10.30±0.59***
第三磨牙
9.20±0.59
8.88±0.58**
10.41±0.56
9.96±0.60***
, 百拇医药
* P<0.05,** P<0.01,*** P<0.001
2.2 直线回归与相关分析
下颌4个切牙与左侧尖牙双尖牙近远中径的散点图呈直线趋势(图1)。直线相关系数均有统计学上显著性意义(表2)。
图1 下切牙与左侧尖牙双尖牙近远中径的散点图及回归直线
x:下切牙近远中径之和
y:左侧尖牙双尖牙近远中径之和
表2 下切牙与尖牙双尖牙近远中径的相关系数
及显著性检验 部位
, http://www.100md.com
性别
r
P
上颌
男
女
0.559
0.586
0.0001
0.0001
下颌
男
女
, 百拇医药 0.654
0.635
0.0001
0.0001
2.3 建立直线回归方程
根据临床上75%概率水平最有参考价值[1,3],分别在此概率水平建立男、女性上、下颌一侧尖牙双尖牙近远中径的预测方程:
上颌 男 y=10.87+0.51 x
女 y=11.88+0.46 x
下颌 男 y=10.36+0.50 x
女 y=10.03+0.49 x
, http://www.100md.com
式中x为下颌4个切牙近远中径之和,y为一侧尖牙双尖牙近远中径之和。
2.4 测量值的可信度
本研究中测量者重复测量的误差最小值为0.008 mm,最大值为0.184 mm,平均为0.096 mm,与Kiyoshi[4]的研究报道一致。3 讨 论
混合牙列期恒尖牙双尖牙近远中径的预测方法主要有两大类:①X线片预测法:Huckaba等[5,6]学者提出利用X线片上已萌恒牙、未萌恒牙近远中径和模型上已萌恒牙近远中径,建立直线或多元回归方程,预测尖牙双尖牙近远中径。但由于X线投照技术的影响,临床应用较少。②恒牙牙冠间相关关系预测法:Moyers[7]预测表和Tanaka and Johnston预测方程均利用已萌恒下切牙与未萌尖牙双尖牙的直线相关关系,预测未萌恒尖牙双尖牙近远中径。刘福祥等[8]已用Moyers法建立了正常尖牙双尖牙预测表,但用Tanaka and Johnston方法建立国内汉族人尖牙双尖牙预测方程,目前尚未见报道。
, 百拇医药
Tanaka and Johnston原方程的样本来源为北美白人,且未按性别分组。本研究发现汉族人牙冠近远中径男女间存在显著性性别差异,因此预测方程按性别分组建立。为便于临床应用,可将所得方程简化如下：
上颌
男：一侧尖牙双尖牙近远中径之和=11.3+
下切牙近远中径之和
女：一侧尖牙双尖牙近远中径之和=11.1+下切牙近远中径之和
下颌
男：一侧尖牙双尖牙近远中径之和=10.4+下切牙近远中径之和
, 百拇医药
女：一侧尖牙双尖牙近远中径之和=10.0+下切牙近远中径之和
(本文承蒙华西医科大学统计学教研室莫春梅的指导和帮助,特此致谢)■
参考文献：
[1]Tanaka MM, Johnston LE. The prediction of the size of unerupted canines and premolars in a contemporary orthodontic population. J Am Dent Assoc, 1974,88(4):798～801
[2]Dahlberg G. Statistical Methods for Medical and Biological Students. London: Allen and Unwin, 1940:96～109
, 百拇医药
[3]黄金芳.口腔正畸学.北京:人民卫生出版社,1989:72
[4]Kiyoshi. Prediction of coronal size of third molars by factor and multiple regression analyses. Am J Orthod, 1996, 109(1):79～85
[5]Huckaba GW. Arch size analyses and tooth size prediction. Dent Clin North Am, 1964,43(7):431～440
[6]Bishara SE, Staley RN. Mixed dentition mandibular arch length analysis: A step-by-step approach using the revised Hixon-Oldfather prediction method. Am J Orthod, 1984,86(2):130～135
, 百拇医药
[7]Moyers RE. Handbook of Orthodontics for the Student and General Practitioner. Chicago: Year Book Medical Publisher, 1958:146
[8]刘福祥,施崇山,董福生,等.恒牙正常
下切牙总冠宽与尖牙双尖牙总冠宽的相关分析.华西口腔医学杂志,1996,4(1):57～61
收稿日期：1999-07-01
修稿日期：1999-12-26, 百拇医药
单位：彭惠(大庆市第一医院口腔科)；王昕(华西医科大学口腔医学院正畸科 610041)；陈开云(华西医科大学口腔医学院正畸科 610041)
关键词：近远中径；恒牙；间隙分析；直线相关；预测方程
华西口腔医学杂志000116 摘 要：目的:为口腔正畸临床混合牙列间隙分析提供简捷、便利的诊断依据。方法:在模型上测量牙冠近远中径,对测量值进行直线回归与相关分析。结果:下切牙与尖牙、双尖牙近远中径存在直线相关关系。结论:建立了汉族人群上、下颌尖牙双尖牙近远中径预测方程。
The Predictation Equation of the Permanent Canine and Premolar Crown
Peng Hui Wang Xin Chen Kaiyun
, 百拇医药
(Orthodontic Department, College of Stomatology, West China University of Medical Sciences)
Abstract：Objective：It is important to predict mesiodistal crown diameter of the permanent canines and premolars in the mixed dentition, which helps to determine malocclusion and its further development. But there is still no article about this equation of Chinese used to predict mesiodistal crown diameter of cuspids and premolars. This research is to measure mesiodistal crown diameters, to study relationship between lower incisors and canines and premolars, and to provide the most accurate and easy basis in orthodontic diagnosis and treatment for Chinese people. Methods: 140 Chinese students (60 male, 80 female) who were from eighteen to twenty-five years old without orthodontic history Chengdu were randomly collected in. All teeth must be free of visible malform, aberration, and fully erupted. Impressions were taken, and measurements were made, parallel to the occlusal plane at the greatest mesiodistal width of each tooth on dental cast with electronic caliper (0.01 mm). Each tooth was measured twice and the average of the two readings was taken as the dimension for that individual tooth. Mesiodistal crown diameters were statistically analyzed with t-test and linear regression, using the SAS (Statistic Analyses System) computer package. Results: It was found that mesiodistal crown diameters had significantly statistical difference in gender. Hence the mesiodistal crown diameters were assessed and investigated separately for the male and the female. It was also found that the total mesiodistal crown diameter of lower incisors was closely correlated with the total mesiodistal crown diameter of canines and premolars. The correlation coefficients between the independent variable and dependent variables were 0.599 for upper canines and premolars and 0.654 for lower canines and premolars in the males and 0.586 and 0.635, respectively, in the females. The P were found to be less than 0.001 for both arches. The correlation coefficients had significantly statistical difference. Conclusion: The equations predicting overall mesiodistal crown diameters of upper and lower unerupted canines and premolars for male and female Chinese people were established respectively: Maxillary (y=10.87+0.51 x (male)), y=11.88+0.46 x(female), Mandibular (y=10.36+0.50 x(male), y=10.03+0.49 x(female)), y(total mesiodistal crown diameter of canines and premolars), and x(total mesiodistal crown diameter of lower incisors).
, 百拇医药
Key words：mesiodistal diameter space analyses linear regression predicting equation▲
Tanaka and Johnston[1]预测方程用于混合牙列间隙分析,通过测量已萌恒下切牙近远中径,预测未萌恒尖牙双尖牙近远中径,以判断混合牙列的拥挤程度,确定治疗方案。由于其简便、准确,在国外正畸临床广为应用。本研究用Tanaka and Johnston方法,建立了适合汉族人群的尖牙、双尖牙近远中径预测方程,为正畸临床提供简捷的诊断依据。
1 材料和方法
1.1 研究对象
纳入标准:①年龄18～25岁,汉族,无正畸史;②所有牙冠完全萌出(包括第三磨牙),无畸形、缺损或修复,无明显磨耗。
, 百拇医药
本研究于1998年在成都大专院校学生中随机选取符合纳入标准者140人,男60人,女80人。用海藻酸钠印模材料取模,超硬石膏灌模。模型清晰,无变形。
1.2 测量方法
用0-150型电子数显卡尺(精确度为0.01 mm)测量模型上每个牙冠的近远中径。测量时使卡尺的横梁与切缘或面平行。每项指标重复测量2次,实测值取2次测量平均值。
1.3 统计学处理
用统计分析系统(statistic analyses system,SAS)计算机软件对测量资料统计分析:①成组t检验,比较同名牙性别间是否有差异;②直线回归与相关分析,以下切牙近远中径之和作为自变量,上、下颌左侧尖牙双尖牙近远中径之和分别为应变量,按照Tanaka and Johnston预测方法,建立汉族人尖牙双尖牙的预测方程。
, 百拇医药
测量误差的评估,根据公式[2]
计算测量者的测量误差,进行测量误差的评估。式中σ为测量误差,D为重复测量的差值,N为样本含量。2 结 果
2.1 测量结果
本研究测量140名汉族男、女性所有牙冠近远中径的平均值、标准差及性别差异见表1。由表可看出牙冠近远中径男女之间存在显著性差异。
表1 140例汉族青年恒牙近远中径
及性别差异(
±s,mm) 测量项目上颌
, 百拇医药
下颌
男
女
男
女
中切牙
8.53±0.53
8.32±0.50*
5.57±0.36
5.48±0.34
侧切牙
7.04±0.56
, 百拇医药 7.03±0.56
6.17±0.40
6.07±0.39
尖牙
8.08±0.39
7.84±0.44***
7.22±0.35
6.83±0.41***
第一双尖牙
7.35±0.43
7.23±0.39
, 百拇医药
7.28±0.33
7.06±0.39***
第二双尖牙
6.92±0.41
6.80±0.39
7.20±0.42
7.05±0.42
第一磨牙
10.72±0.51
10.46±0.53**
11.36±0.45
, 百拇医药
11.03±0.42
第二磨牙
10.00±0.53
9.67±0.52***
10.72±0.52
10.30±0.59***
第三磨牙
9.20±0.59
8.88±0.58**
10.41±0.56
9.96±0.60***
, 百拇医药
* P<0.05,** P<0.01,*** P<0.001
2.2 直线回归与相关分析
下颌4个切牙与左侧尖牙双尖牙近远中径的散点图呈直线趋势(图1)。直线相关系数均有统计学上显著性意义(表2)。
图1 下切牙与左侧尖牙双尖牙近远中径的散点图及回归直线
x:下切牙近远中径之和
y:左侧尖牙双尖牙近远中径之和
表2 下切牙与尖牙双尖牙近远中径的相关系数
及显著性检验 部位
, http://www.100md.com
性别
r
P
上颌
男
女
0.559
0.586
0.0001
0.0001
下颌
男
女
, 百拇医药 0.654
0.635
0.0001
0.0001
2.3 建立直线回归方程
根据临床上75%概率水平最有参考价值[1,3],分别在此概率水平建立男、女性上、下颌一侧尖牙双尖牙近远中径的预测方程:
上颌 男 y=10.87+0.51 x
女 y=11.88+0.46 x
下颌 男 y=10.36+0.50 x
女 y=10.03+0.49 x
, http://www.100md.com
式中x为下颌4个切牙近远中径之和,y为一侧尖牙双尖牙近远中径之和。
2.4 测量值的可信度
本研究中测量者重复测量的误差最小值为0.008 mm,最大值为0.184 mm,平均为0.096 mm,与Kiyoshi[4]的研究报道一致。3 讨 论
混合牙列期恒尖牙双尖牙近远中径的预测方法主要有两大类:①X线片预测法:Huckaba等[5,6]学者提出利用X线片上已萌恒牙、未萌恒牙近远中径和模型上已萌恒牙近远中径,建立直线或多元回归方程,预测尖牙双尖牙近远中径。但由于X线投照技术的影响,临床应用较少。②恒牙牙冠间相关关系预测法:Moyers[7]预测表和Tanaka and Johnston预测方程均利用已萌恒下切牙与未萌尖牙双尖牙的直线相关关系,预测未萌恒尖牙双尖牙近远中径。刘福祥等[8]已用Moyers法建立了正常尖牙双尖牙预测表,但用Tanaka and Johnston方法建立国内汉族人尖牙双尖牙预测方程,目前尚未见报道。
, 百拇医药
Tanaka and Johnston原方程的样本来源为北美白人,且未按性别分组。本研究发现汉族人牙冠近远中径男女间存在显著性性别差异,因此预测方程按性别分组建立。为便于临床应用,可将所得方程简化如下：
上颌
男：一侧尖牙双尖牙近远中径之和=11.3+
下切牙近远中径之和女：一侧尖牙双尖牙近远中径之和=11.1+
下切牙近远中径之和下颌
男：一侧尖牙双尖牙近远中径之和=10.4+
下切牙近远中径之和, 百拇医药
女：一侧尖牙双尖牙近远中径之和=10.0+
下切牙近远中径之和(本文承蒙华西医科大学统计学教研室莫春梅的指导和帮助,特此致谢)■
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下切牙总冠宽与尖牙双尖牙总冠宽的相关分析.华西口腔医学杂志,1996,4(1):57～61收稿日期：1999-07-01
修稿日期：1999-12-26, 百拇医药