Surgically Assisted Rapid Palato-Maxillary Expansion With/Without Pterygomaxillary Disjunction: A Systematic Review and Meta-Analysis

Abstract

A consensus in the literature has not been reached on the necessity and stability of Pterygo-Maxillary Dysjunction (PMD) in Surgically Assisted Rapid Palatal Expansion (SARPE). Some surgeons prefer not to separate the pterygoid processes due to the risk of injury to the pterygoid plexus. The purpose of this review was, therefore, to evaluate the outcome measures of anterior expansion, posterior expansion, and complications following with or without PMD. A computerized database search was performed using PubMed, CINAHL, Cochrane, Scopus and Web of Science and was supplemented with Google Scholar and ProQuest searches to overcome publication bias as much as possible. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement guidelines were observed. PICO was defined as: The patient population (P) included individuals indicated to undergo SARPE. The intervention (I) included SARPE with PMD with a comparator (C) of SARPE without PMD. The evaluated outcomes (O), based on the retrieved studies, comprised of (i) anterior expansion, (ii) posterior expansion, and (iii) complications. Finally, the study design (S) included any controlled intervention. Included were human trials where patient population did not have significant anomalies, the indications for SARPE were clearly stated, specific emphasis was placed on PMD, comparator population was clearly mentioned and grouped. Kappa statistics was used to measure the author agreement on the inclusion of the studies. The Effective Public Health Practice Project (EPHPP) quality assessment tool for quantitative studies (QATQS) was used to assess the quality of the available evidence. The two first authors independently assessed the quality of the included studies and any discrepancies were resolved by discussion and consensus. Kappa statistics were used to assess inter-rater agreement on the quality assessment results. It was decided to perform meta-analyses of the included articles whenever commonality of variables, proper statistical analyses, and homogeneity of the studies allowed. From the original 125 combined results, 3 met the inclusion criteria (Kappa = 0.806; “very good” inter-rater agreement) which based on EPHPP were assessed as 2 weak reports and 1 moderate report (Kappa = 1.000; “perfect” inter-rater agreement). Included were 48 patients, 11 males and 37 females. Transverse discrepancy was > 4 mm in 28 patients. 23 SARPE were done without PMD. A tooth-borne fixed hyrax-type palatal expansion screw appliance was used for all cases, activated 1 to 2 mm intraoperatively and after a latency period of 3 to 7 days, activated 0.5-0.6 mm per day for 38 patients and 0.25 mm for the other 10 until adequate expansion. Post-expansion retention was done using ligature wired Hyrax in 18 patients for 4 months. The comparisons were made based on CBCT projections, study models only, or a combination of study models, anteroposterior cephalometric radiograms, and occlusal radiographs. The time to measure the changes ranged from before fixed orthodontic retention to 6 months after the completion of the active expansion. The main outcome variables in the included studies could be categorized into four groups based on a modification of the Sygouros et al classification according to skeletal, dentoalveolar, dental, and periodontal measurements of either linear or angular nature. Linear dental measurements for inter-canine (anterior dental expansion), inter-premolar, and inter-molar (posterior dental expansion) were possible. A meta-analysis was only possible for anterior (p = 0.965) and posterior (p = 0.476) dental expansions. There were no “statistically significant” differences between the SARPE-induced skeletal, dentoalveolar, dental, and periodontal changes with or without PMD.