Retrospective evaluation of transverse arch dimensional changes in non-extraction and premolar extraction cases using a passive self-ligating bracket system

Abstract

The effect of extraction and non-extraction treatment protocols on the dental arch width has comprehensively been researched. The effect of non-extraction protocols using passive selfligating systems has also been adequately investigated. Although the literature comes to contrasting conclusions and further research is always encouraged, the impact on the dental arch width using an extraction protocol in combination with a passive self-ligating system has not been defined thoroughly. Aim: this study investigated the effect of 2 treatment protocols on transverse arch width, before and after treatment, using a passive self-ligating system. The null hypothesis to be tested was that treatment with a second premolar extraction protocol would result in no difference in transverse arch width changes compared to treatment with a non-extraction protocol.