Radiographic and histological assessment of root resorption associated with conventional and mini-screw assisted rapid palatal expansion: a systematic review

The aim of this systematic review and meta-analysis was to evaluate root resorption after maxillary expansion with conventional rapid palatal expansion (RPE) and mini-screw assisted rapid palatal expansion appliances (MARPE) using 2D and 3D radiographic methods and histologic methods of measuring root resorption. A search of PubMed/MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, Global Index Medicus, Dissertations & Theses Global, ClinicalTrials.gov registry, ISRCTN Registry, National Research Register, OpenGrey, and the Trip Database was performed. The studies that had analysed root resorption after RPE or MARPE were selected for the systematic review. The database research, elimination of duplicate studies, data extraction, and risk of bias were performed by the authors independently and in duplication. This systematic review included prospective studies to evaluate root resorption following RPE after tooth-borne (TB), tooth-tissue borne (TTB), bone-borne (BB), and tooth-bone borne (TBB) expansion appliances. A total of 13 prospective trials (six randomized clinical trials and seven non-randomized prospective clinical trials) were identified for inclusion in this systematic review. Histological studies revealed that most teeth experience root resorption on the buccal surfaces after maxillary expansion. MARPE designs with BB and TBB expansion appliances were found to lead to reduced volumetric root resorption than conventional RPE using micro-computed tomography. However, one study using cone beam computed tomography showed no difference in the root resorption with MARPE and RPE designs. Maxillary expansion with RPE can lead to root resorption of maxillary posterior teeth. Root resorption occurs more frequently on buccal surfaces on maxillary posterior teeth. Limited evidence suggests that MARPE may lead to reduced root resorption than RPE. This systematic review was conducted following the Cochrane handbook for systematic reviews and interventions and reported according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The protocol was registered at PROSPERO database (https://www.crd.york.ac.uk/prospero/; registration number: PROSPERO CRD42021271181).