Soft tissue assessment before and after mandibular advancement or setback surgery using three-dimensional images: systematic review and meta-analysis.

The aim of this systematic review was to evaluate the effects of mandibular advancement or setback surgery on the facial soft tissue assessed using three-dimensional images. An electronic search was performed in the MEDLINE, Cochrane Library, Scopus, Virtual Health Library (VHL), Web of Science, and OpenGrey databases. Inclusion criteria comprised studies that evaluated the soft tissues of adult patients before and after mandibular advancement or setback surgery using computed tomography or magnetic resonance imaging. The risk of bias was analyzed. A total of 3501 studies were retrieved. The titles and abstracts of 2071 studies were read and 2040 of them were excluded. Thirty-one articles were read in full and six fulfilled the eligibility criteria and were included. A meta-analysis was performed using three of these articles. The correlation was significant and strong in the chin area (r=0.876 and r=0.868) and moderate for the lower lip/lower incisor (r=0.690). The ratio for lower lip/infradentale was 78% and for Pog'/Pog was 98%. Due to the limited number of articles included, there is weak evidence to infer that changes in the facial soft tissue due to mandibular advancement or setback are significant, but changes in the lower lip tend to be smaller than changes in the chin area.

Upper airway dimensions in patients undergoing orthognathic surgery: a systematic review and meta-analysis.

The objective of this systematic review was to evaluate the effect of different types of orthognathic surgery on the dimensions of the upper airways assessed using three-dimensional images. An electronic search was performed in Cochrane Library, Medline, Scopus, VHL, Web of Science, and the System for Information on Grey Literature in Europe, ending January 2015. Inclusion criteria encompassed clinical studies in humans, patient age >15 years, patients submitted to maxillary or mandibular advancement or setback surgery, isolated or in combination, and presentation of airway measures, specifically volume and/or minimum cross-sectional area (CSA), obtained from computed tomography or magnetic resonance imaging. Additional searches were conducted on the references of included articles and in the NLM catalogue. An assessment of the risk of bias was performed. A total of 1180 studies were retrieved, of which 28 met the eligibility criteria; one was later excluded as it presented a high risk of bias. A meta-analysis was performed. There is moderate evidence to conclude that the upper airway minimum CSA increases significantly (124.13 mm(2)) after maxillomandibular advancement (MMA); the total volume increases significantly after MMA (7416.10mm(3)) and decreases significantly after maxillary advancement+mandibular setback (-1552.90 mm(3)) and isolated mandibular setback (-1894.65 mm(3)).