Dento-skeletal Sequel of Hyrax in Nonsyndromic Cleft Lip and Palate: A Systematic Review and Meta-analysis

Abstract

Aim: To critically evaluate and review the dento-skeletal outcomes of hyrax with or without nonsurgical protraction therapy in nonsyndromic cleft lip and palate (CLP) patients. Materials and methods: Electronic databases were searched from PubMed, Cochrane, Scopus, SciELO, Lilacs, and Google Scholar from January 2005 to April 2022 to identify studies reporting on the dento-skeletal effect of hyrax with or without nonsurgical protraction therapy among children aged 7–15 years with CLP before the secondary alveolar bone grafting (SABG) procedure. Abstracts and subsequently eligible full-text articles were screened. The risk of bias in the included randomized and nonrandomized studies was assessed using Cochrane collaboration’s risk of bias tool. The random-effects meta-analyses of the mean difference were carried out. Results: A total of 423 studies were identified. After a thorough screening, 19 studies met the inclusion criteria. Of these 19 studies, 13 studies were conducted with only hyrax appliances, six studies had hyrax with nonsurgical protraction therapy. Conclusion: Hyrax had increased intermolar width, anterior nasal cavity width, and posterior maxillary width compared to inverted mini hyrax with p-values=0.027, 0.004, and 0.03, respectively. Inverted mini hyrax had more canine inclination on noncleft than hyrax. Hyrax and fan-type expanders had an equivalent effect on the dento-skeletal structures indicating that hyrax can be used as an alternative to fan-type expanders. Hyrax with protraction therapy had a remarkable change in ANB angle compared to noncleft patients.