Objective: A systematic review of the existing literature was done to evaluate the effects of therapeutic extraction of first and second premolar on mandibular plane angle and in turn on the vertical facial dimension. Methods: Electronic database searches (MEDLINE, EBSCO host and Google Scholar) of published literature were performed with no publication date or language restrictions followed by manual searches for eligible studies. Extraction of data was done independently and in duplicate by two authors. Risk of bias was assessed using Cochrane's tool, ROBINS-I (Risk of bias in nonrandomized studies – of interventions). Results: Only four studies, 2 prospective and 2 retrospective, satisfied the eligibility criteria and were included in the current systematic review. All selected studies had a first and second premolar extraction group. The parameters evaluated were Sella-Nasion/Mandibular plane (SN/MP angle), lower anterior facial height (LAFH), total anterior facial height (TAFH) and lower anterior facial height ratio (LAFH/TAFH). The pretreatment and post treatment measurements in the included studies showed no statistical significance to suggest a decrease in mandibular plane angle after premolar extraction. Conclusion: With the limited data that was assessed, it can be concluded that extraction of premolars regardless of it being first or second does not cause any anterior mandibular rotation. Since there was no reduction in mandibular plane angle and vertical facial dimensions, the wedge effect hypothesis has been proved wrong