Janson Guilherme, Graciano João Tadeu Amim, Henriques José Fernando Castanha, de Freitas Marcos Roberto, Pinzan Arnaldo, Pinzan-Vercelino Célia Regina Maio
Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil.
Am J Orthod Dentofacial Orthop. 2006 Jun;129(6):759-67. doi: 10.1016/j.ajodo.2006.02.023.
The purpose of this study was to compare the initial occlusal and cephalometric severity of Class II Division 1 malocclusion patients treated with and without extraction of 2 maxillary premolars.
Dental study models and cephalograms of 62 patients were selected. Those in group 1 (n = 42) were treated without extractions, and those in group 2 (n = 20) were treated with 2 maxillary premolar extractions. Grainger's treatment priority index (TPI) was used to assess the final and the initial occlusal status of each subject. Variables such as overjet and overbite were also evaluated. Independent t tests were used to compare the occlusal variables at the posttreatment stage, the occlusal and cephalometric variables at the pretreatment stage, and the improvement in TPI values between the groups.
Patients treated with 2 maxillary premolar extractions had greater initial occlusal TPI values, overjets, cephalometric apical base anteroposterior discrepancies, maxillary incisor protrusions, and anteroposterior molar discrepancies than those treated without extractions.
For patients with more severe anteroposterior discrepancies, an extraction plan provides more effective treatment with less need for patient compliance.
本研究的目的是比较拔除两颗上颌前磨牙与未拔除的情况下治疗安氏II类1分类错牙合患者的初始咬合及头影测量严重程度。
选取62例患者的牙颌模型和头影测量片。第1组(n = 42)未拔牙进行治疗,第2组(n = 20)拔除两颗上颌前磨牙进行治疗。使用格兰杰治疗优先级指数(TPI)评估每个受试者的最终和初始咬合状态。还评估了覆盖和覆牙合等变量。采用独立t检验比较治疗后阶段的咬合变量、治疗前阶段的咬合和头影测量变量以及两组间TPI值的改善情况。
与未拔牙治疗的患者相比,拔除两颗上颌前磨牙治疗的患者初始咬合TPI值、覆盖、头影测量根尖基骨前后差异、上颌切牙前突以及磨牙前后差异更大。
对于前后差异更严重的患者,拔牙方案能提供更有效的治疗,对患者配合度的要求更低。