我們進行了一項群集分析，即將欲研究的對象依數個變項去分群組，並以其對牙弓型態的影響，建立一個準則以便於診斷及擬定治療計畫。因此為了確立每一群組的型態特徵，我們應用了主成份分析法。結果：在以下主成份項目中我們得到了顯著的差異：夾甲6(I2-C-P1)上顎前牙曲線前途程度2(M2R-M2L)上顎前牙弓寬度3(A-B)上顎牙弓長度(CR-A-CL)上顎前牙凸出程度。結論:是上顎齒列應依356三項予以分類評估。

We conducted a cluster analysis, which accumulated similar items by grouping intensive subjects embodied with heterogeneous objects, for the establishment of criteria for diagnosis and planning treatment of dentitions by the determination of estimated items and elements affecting the morphology of dental arches. Subsequently, a principal component analysis was performed for the purpose of identification of morphological characters in each cluster. The results observed significant differences between principal components containing estimated items 6∠(I2-C-P1),2(M2R-M2L),3(A-B)and 5∠(CR-A-CL) which represented protrusion of transitional prtion of anterior and buccal segments, width and length of the dental arch, and protrusion of the anterior teeth segment, respectively. Consequently, we concluded that the maxillary dentition could be classified mainly by evaluation of the items 3(A-B),5∠(CR-A-CL) and 6∠(I2-C-P1).