Vertical Skeletal Changes After Extraction and Non-Extraction Orthodontic Treatment

Introduction: Based on the constant battle regarding the controversial topic of orthodontic extraction, this study aims to assess the changes in vertical dimensions of patients treated with premolar extractions compared to non-extraction orthodontic patients.
Methods: A prospective study was conducted on a sample of 60 patients (30 in the extraction group, 30 in the non-extraction group) that were recruited from Nov 2018 to July 2020. Eleven pre-treatment cephalometric measurements were recorded using WebCephTM and patients were followed-up until the completion of treatment to record post-treatment cephalometric measurements of the same variables. Intra-group and inter-group comparisons were done using paired t-test and two-sample independent t-test, respectively.
Results: The intra-group comparison revealed that in the extraction group, the vertical dimension was significantly increased post-treatment for four cephalometric measurements i.e., Mandibular Plane Angle (MPA) (p<0.05), Palatal Plane Angle (PPA) (p<0.05), Frankfort Mandibular Plane Angle (FMA) (p<0.05), and y-axis (p<0.05). In the comparison of the post-treatment values of the Extraction group with the Non-Extraction group, the mean differences of the post-treatment values for SN-GoGn angle (p=0.008), the total anterior (p=0.050) and lower anterior facial heights (p=0.011) were significantly higher while the jaraback ratio was significantly (p=0.006) lower in the extraction group as compared to the non-extraction group.
Conclusion: There is a significant impact of orthodontic extraction in increasing the vertical dimension at the end of orthodontic treatment. The increase in vertical dimension is significantly higher in the extraction group as compared to the non-extraction group.
Keywords: Vertical dimension, bicuspid, Malocclusion, Angle Class II / therapy*, cephalometry/methods