上颌中切牙内收与消耗牙弓间隙量的相关性研究

Linear regression analysis of correlation between the amount of maxillary central incisor retraction and arch space consumption

目的 探究上颌中切牙内收量与其消耗牙弓间隙量的比例关系。方法选择拔除上颌第一前磨牙的前牙深覆盖成年正畸患者203例,对治疗前、后的锥形束CT进行三维重建,测量上颌中切牙内收量(X_(1))、尖牙间宽度变化量(X_(2))及尖牙远中移动量。数字化扫描仪扫描治疗前的上颌石膏模型,测量上颌前段牙弓拥挤度。将上颌中切牙内收量、尖牙间宽度变化量与消耗的总牙弓间隙量(Y)进行相关分析、线性回归分析。结果上颌中切牙内收量与牙弓间隙的消耗量呈强正相关(r=0.726,P<0.001),尖牙间宽度变化量与牙弓间隙消耗量呈负相关(r=-0.317,P<0.001),消耗的总牙弓间隙量(Y)与上颌中切牙内收量(X_(1))、尖牙间宽度变化量(X_(2))的回归方程为Y=1.25X_(1)-0.494X_(2)-2.299。结论上颌中切牙每内收1mm,消耗的牙弓间隙为1.250mm,尖牙间宽度每缩减1mm,消耗的牙弓间隙为0.494mm。

Objective To explore the relationship between the amount of maxillary central incisor retraction and the consumption of dental arch space. Methods Two hundred and three adult orthodontic patients with overjet and extraction of the maxillary first premolars were selected. Three-dimensional reconstruction of the cone-beam CT before and after treatment was established. The amount of maxillary central incisor retraction(X;), intercanine width(X;) and the amount of distal movement of canines were measured. The digital scanner was used to scan the maxillary plaster casts before treatment, and the crowding of the anterior segment of the maxillary arch was measured. The amount of the maxillary central incisor retraction, the change of intercanine width and the total amount of dental arch space consumption(Y) were analyzed using correlation analysis and linear regression analysis. Results The amount of maxillary central incisor showed strong positive correlation with the consumption of dental arch space(r=0.726,P<0.001), while the change of maxillary canines width and the consumption of dental arch space showed negative correlation(r=-0.317,P<0.001). The regression equation of maxillary central incisor retraction(X;), intercanine width(X;) and the total arch space consumption(Y) was Y=1.25X;-0.494X;-2.299. Conclusion For every 1 mm of maxillary central incisor retraction, the arch space required is 1.250 mm, and for every 1 mm reduction in the width between canines, arch space required is 0.494 mm.