Relapse following bilateral sagittal split osteotomy with rigid internal fixation.

[DATA SOURCES] PubMed, Ovid (including OLDMedline), Google Scholar Beta, the Cochrane Library and references of identified articles were used to identify data sources.

[STUDY SELECTION] Studies were included if they involved more than 10 adults, a followup of greater than 6 months, and mandibular advancement by bilateral sagittal split osteotomy (BSSO) with rigid internal fixation. Studies that included another surgical intervention (eg, Le Fort I osteotomy), syndromic or medically compromised patients, case reports, case series, descriptive studies, review and opinion articles or abstracts were excluded.

[DATA EXTRACTION AND SYNTHESIS] The following data items were extracted: year of publication, study design, followup, number and mean age of patients, ethnic background of patients, number of surgeons operating, type of rigid internal fixation, use of MMF (maxillomandibular fixation), use of genioplasty, mean advancement, mean relapse, correlations between relapse and different variables, proportion of patients with more than 2 mm of sagittal relapse, and authors' conclusions. A quality assessment of the included studies was undertaken following selection. Studies were categorised as medium or low quality based on study design, sample size, selection descriptions, withdrawals, valid methods, confounding factors, method error analysis, blinding in measurements and adequate statistics. None of the included studies met the criteria of the high-quality category.

[RESULTS] Twenty-four articles were finally included, comprising six prospective and 18 retrospective studies. The range of postoperative study records was 6 months to 12.7 years. The short-term relapse for bicortical screws was between 1.5 and 32.7%, for miniplates between 1.5 and 18.0%, and for bioresorbable bicortical screws between 10.4 and 17.4%, at point B (the deepest concavity on the anterior profile of the maxilla). The long-term relapse for bicortical screws was between 2.0 and 50.3%, and for miniplates between 1.5 and 8.9%, at point B.

[CONCLUSIONS] To obtain reliable scientific evidence, further short-term and long-term research into BSSO advancement with rigid internal fixation should exclude additional surgery, ie, genioplasty or maxillary surgery, and include a prospective study or randomised controlled clinical trial (RCT) design with correlation statistics.