Evaluation of new extraction protocol in the camouflage treatment of skeletal class III malocclusion – A retrospective study

Abstract

BACKGROUND: The present study aims to assess the skeletal, dental and soft tissue changes following the extraction of mandibular single premolar in adult borderline Skeletal Class III patients, by comparing pre- and post-treatment lateral cephalograms and study models. METHODS: Twelve patients (seven male and five female) with “borderline” skeletal Class III malocclusion were included in the study. The age of the patients ranged from 17 to 24 years with a mean age of 20 years All the patients were treated with extraction  of a single mandibular premolar. Pre-treatment and post-treatment lateral cephalograms and study models were examined. Groups were compared for change using Mann-Whitney U tests. RESULTS: The change in overjet (p < 0.01) and the increase in chin thickness (p < 0.05) were statistically significant at the end of treatment. Model analysis revealed a statistically significant change of 9.4% in the Bolton’s overall ratio (p < 0.01). The average increase in the upper arch perimeter and a minor decrease in the lower arch perimeter of 4.5mm and 1.7mm respectively showed statistical significance (p < 0.01)  which attributed to the treatment changes following the specific extraction pattern. The anterior crossbite was corrected, and an ideal overjet and overbite were achieved. The Class III subdivision molar relationship was maintained with a bilateral Class I canine relationship. The upper and lower midlines matched with a stable occlusion. CONCLUSION: The goals of functional efficiency, structural stability, and esthetic harmony are imperative for all Orthodontic cases. In that aspect, the new extraction protocol suggesting extraction of single mandibular premolars can be widely incorporated as a successful treatment option for Skeletal Class III subdivision cases