Introduction: The extraction of premolars is now a procedure frequently practiced as part of orthodontic treatment although it is subject to controversy. Its main objective which is very often the repositioning of the incisors, considered a guarantee of stability of an orthodontic treatment, is likely to reduce the arch perimeter and therefore the space dedicated to the tongue resulting in a reduction in the dimensions of the upper airway (VAS). The aim of this study was to highlight the impact of premolar extractions for orthodontic treatment on the upper airway. Methodology: This was a systematic review of the literature including cohort studies, case-control studies and randomised clinical trials. The study population consisted of patients with malocclusion requiring extractions of 4 premolars for orthodontic purposes, without gender or age restriction. The intervention consisted of comparing changes in the dimensions of the VAS in patients who had undergone orthodontic treatment with extraction of 4 premolars, regardless of the orthodontic mechanics used, the type of appliance, the technique used and the duration of treatment, with patients before treatment, treated without extractions or not treated. To do this, the databases chosen for our bibliographic research are Medline, Science Direct, Scopus and Cochrane Library and during a period between 01/11/20015 and 01/11/2023. Results: The initial comprehensive literature search of databases using different Boolean keywords and equations resulted in a total of 930 titles. After deleting the duplications and critical reading of the abstracts, only 12 articles were selected that met the eligibility criteria of our study. The 12 studies that met the eligibility criteria for this study were included with a total of 758 patients, 547 women (72%) and 211 men (28%). Conclusion: It is difficult to draw definitive conclusions from this systematic review of retrospective clinical studies. The hypothesis is that premolar extraction reduces the arch perimeter, thereby restricting the space for the tongue and positioning it further back. This adaptation of the tongue to its new habitat would lead to constriction of the oropharyngeal airways. Several studies have been designed to test this hypothesis, but to date, solid evidence is lacking.
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