Systematic review and meta-analysis: Mandibular plane change after orthognathic surgery and distraction osteogenesis in cleft lip and palate patients

Introduction: The aim was to examine treatment change and relapse of mandibular plane in three types of maxillary surgery for cleft patients; (1) conventional orthognathic surgery (CO), (2) extraoral distraction osteogenesis (EDO) and (3) intraoral distraction osteogenesis (IDO). Methods: 396 abstracts were retrieved from 6 electronic databases; Medline, Embase, Cochrane, ISI, Scopus, and Google Scholar. 138 vertical skeletal measurements of maxillary surgical cleft patients were screened from 141 full-text papers. Finally, only SN-MP at pre-treatment, post-treatment and 1-year follow-up, recruited from 12 articles, were eligible to be investigated by meta-analysis. Heterogeneity test and estimation of pooled means were performed. Difference of SN-MP of the three surgical techniques was examined by 95% confidence interval (CI). Results: SN-MP at pre-treatment, post-treatment, and follow-up in CO group were 37.8 degrees, 39.9 degrees, 38.5 degrees, in EDO group were 35.1 degrees, 37.5 degrees, 36.8 degrees, in IDO group were 34.2 degrees, 38.2 degrees, 34.6 degrees respectively. All groups demonstrated clockwise rotation of mandible with the estimate change of 2.08 degrees, 2.39 degrees and 3.98 degrees for CO, EDO and IDO respectively. All groups showed counter-clockwise rotation of mandible with the estimate amount of relapse at 1-year follow-up of -1.33 degrees, -0.7 degrees, -3.61 degrees and relapse rate of -63.9%, -29.28% and -90.70% for CO, EDO and IDO respectively. Conclusions: SN-MP showed tendency to rotate clockwise in all three groups after surgery. At 1 year follow-up, the mandibular plane rotated counter-clockwise in all groups. The amount of relapse rate was largest in IDO group. SN-MP at 1 year follow-up in CO was greater than IDO. (C) 2015 Elsevier Ltd and the Japanese Orthodontic Society. All rights reserved.