BackgroundNon-syndromic clefts lip and/or palate (CL/P) defects may have manifold significant and detrimental consequences for the affected individuals and their family environment. Although the use of pre-surgical infant orthopedics (PSIO) was introduced as a means to improve management and treatment outcomes, there still remains a controversy.ObjectiveTo investigate the effectiveness of PSIO in patients with non-syndromic CL/P and evaluate the quality of the available evidence.Search methodsSearch without restrictions, together with hand searching, until May 2016.Selection criteriaRandomized clinical trials investigating the effects of pre-surgical infant orthopedic appliances.Data collection and analysisFollowing study retrieval and selection, data extraction and individual study risk of bias assessment using the Cochrane Risk of Bias Tool took place. The overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development and Evaluation approach.ResultsFinally 20 papers (3 unique trials) were identified, involving a total of 118 patients with unilateral complete CL/P and 16 with cleft of the soft and at least two thirds of the hard palate. Eight publications were considered as being of low, four of unclear and eight of high risk of bias. In general, the investigated appliances did not present significant effects when compared to each other or to no treatment in terms of feeding and general body growth, facial esthetics, cephalometric variables, maxillary dentoalveolar variables and dental arch relationships, speech and language evaluation, caregiver-reported outcomes, economic evaluation, as well as, adverse effects and problems. Overall, the quality of the available evidence was considered low.ConclusionsThe aforementioned findings could provide initial guidance in the clinical setting. However, given the multitude of parameters, which may have affected the results, good practice would suggest further research, in order to reach more robust relevant recommendations for management decisions in individual cases.