Hierarchy of surgical stability in orthognathic surgery: overview of systematic reviews.

The purpose was to perform an overview of systematic reviews in order to create a hierarchical scale of stability in orthognathic surgery with the aid of the highest level of scientific evidence. The systematic search was conducted in the PubMed, Embase, and Cochrane Library databases. The grey literature was investigated in Google Scholar and a manual search was done of the references lists of included studies. Fifteen studies were included in the final sample, of which eight were systematic reviews and seven were meta-analyses. These were assessed for methodological quality using the AMSTAR 2 tool and all were considered to be of medium to high methodological quality. The clinical studies included in the 15 reviews and meta-analyses were classified by the review authors as having a moderate to high potential for risk of bias. The hierarchical pyramid of stability in orthognathic surgery was established, with two surgical procedures considered highly unstable: (1) maxillary expansion with semi-rigid internal fixation evaluated at the dental level in the posterior region, and (2) clockwise rotation of the mandible with rigid internal fixation of bicortical screws in the sagittal direction.

Stability and surgical complications in segmental Le Fort I osteotomy: a systematic review.

This systematic review was conducted to evaluate the stability and surgical complications of segmental Le Fort I osteotomy. The search was divided into a main search (PubMed, Embase, and Cochrane Library), grey literature search (Google Scholar), and manual search. Twenty-three studies were included: 14 evaluating stability as the outcome and nine evaluating surgical complications. The level of agreement between the authors was considered excellent (κ=0.893 for study selection and κ=0.853 for study eligibility). The segmental Le Fort I osteotomy provides stable outcomes in the sagittal plane, is less stable dentally than skeletally in the transverse plane, and provides little stability in the posterior segment after downward movement. The most frequent complications are oral fistula (six studies) and damage to the adjacent teeth (five studies), but the most prevalent complication is postoperative infection (32.62%). Four studies evaluating stability as the outcome showed a medium potential risk of bias, whereas all studies addressing surgical complications showed a high potential risk of bias. The segmental Le Fort I osteotomy should not be excluded from the technical armamentarium in orthognathic surgery. On the contrary, the literature consulted suggests it to be a useful tool for the three-dimensional surgical correction of maxillary malposition.