Occlusal and cephalometric Class II Division 1 malocclusion severity in patients treated with and without extraction of 2 maxillary premolars.Am J Orthod Dentofacial Orthop. 2006 Jun; 129(6):759-67.AJ
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.