Janson Guilherme, Cruz Karina Santana, Barros Sérgio Estelita Cavalcante, Woodside Donald G, Metaxas Angelos, de Freitas Marcos Roberto, Henriques José Fernando Castanha
Department of Orthodontics, Bauru Dental School, University of São Paulo, Brazil.
Am J Orthod Dentofacial Orthop. 2007 Sep;132(3):279.e15-21. doi: 10.1016/j.ajodo.2006.11.018.
In this study, we compared retromolar available space and third molar angulation between the Class I and Class II sides in patients with Class II subdivision malocclusion.
Two samples were obtained from 46 subjects grouped according to the following characteristics: group 1 comprised 29 subjects (17 male, 12 female) with Class II subdivision malocclusion at a mean age of 14.73 years. Group 2 was the control to assist in the asymmetry evaluation and included 17 subjects (11 female, 6 male) with normal occlusion at a mean age of 21.73 years. Corrected oblique radiographs of each patient side were obtained to evaluate right and left retromolar available space and third molar angulation. The retromolar space and third molar angulations in the Class I and Class II sides in each group were compared with paired t and Wilcoxon tests. Asymmetry between the Class I and Class II sides of the Class II subdivision malocclusion group was compared with asymmetry between the right and left sides of the normal occlusion group with independent t and Mann-Whitney tests.
The results demonstrated significant differences between the Class I and Class II retromolar available spaces in the Class II subdivision malocclusion group. Significant angular asymmetry between these sides was observed only for the mandibular third molars. However, when retromolar space asymmetry and third molar angular asymmetry were compared between the Class II subdivision malocclusion and the normal occlusion groups, there were significant differences only for retromolar space asymmetry.
Patients with Class II subdivision malocclusion have asymmetric amounts of maxillary and mandibular retromolar available space and asymmetric angulation of the mandibular third molars between the Class I and Class II sides.
在本研究中，我们比较了安氏II类亚类错牙合患者I类侧和II类侧的磨牙后间隙及第三磨牙角度。
从46名受试者中获取两个样本，根据以下特征分组：第1组包括29名受试者（17名男性，12名女性），患有安氏II类亚类错牙合，平均年龄为14.73岁。第2组作为对照组以协助进行不对称性评估，包括17名受试者（11名女性，6名男性），咬合正常，平均年龄为21.73岁。获取每位患者双侧的校正后斜位X线片，以评估左右磨牙后间隙及第三磨牙角度。每组中I类侧和II类侧的磨牙后间隙及第三磨牙角度采用配对t检验和Wilcoxon检验进行比较。安氏II类亚类错牙合组I类侧和II类侧之间的不对称性与正常咬合组左右侧之间的不对称性采用独立t检验和Mann-Whitney检验进行比较。
结果显示，安氏II类亚类错牙合组中I类侧和II类侧磨牙后间隙存在显著差异。仅在下颌第三磨牙中观察到这些侧之间存在显著的角度不对称。然而，当比较安氏II类亚类错牙合组和正常咬合组之间的磨牙后间隙不对称性和第三磨牙角度不对称性时，仅在磨牙后间隙不对称性方面存在显著差异。
安氏II类亚类错牙合患者上颌和下颌磨牙后间隙量不对称，下颌第三磨牙在I类侧和II类侧之间角度不对称。
