Three dimensional accuracy and stability of segmented Le Fort I osteotomy – a systematic review

BACKGROUND: Segmental Le Fort I osteotomy has traditionally been regarded as less predictable and stable, a perception largely based on two-dimensional evaluation methods. Despite existing systematic reviews on clinical outcomes, a dedicated synthesis of three-dimensional assessments of surgical accuracy and postoperative stability is lacking. PURPOSE: This systematic review evaluated three-dimensional (3D) assessment methods and outcome of planning accuracy and postoperative stability in segmented Le Fort I osteotomies. The aim was to determine the reliability of 3D methods in capturing surgical accuracy and long-term skeletal stability. STUDY SELECTION: Medline, Embase, Web of Science, and Cochrane were searched up to October 25, 2024. Eligible studies included randomized controlled trials, prospective or retrospective studies, or case series with > 5 patients reporting 3D evaluation of planning accuracy or stability. Exclusion criteria were systematic reviews, meta-analyses, single case reports, ex-vivo or animal studies, and studies involving syndromic patients, facial trauma, or prior maxillofacial surgery. Risk of bias and quality of evidence were assessed using the GRADE approach. Twenty-two studies met inclusion criteria: three randomized and nineteen non-randomized controlled trials. Fourteen assessed planning accuracy, five evaluated stability, and three examined both. RESULTS: Twenty-two studies met the inclusion criteria and were included in the qualitative synthesis. Considerable methodological heterogeneity limited direct comparison and precluded meta-analysis. Overall, segmented Le Fort I osteotomy demonstrated clinically acceptable accuracy; however, certain movements-particularly transverse widening, advancement, and pitch-were more prone to underachievement, with discrepancies ranging from 0.77 to 1.41 mm, 0.55 to 2.69 mm, and 0.12° to 5.22°, respectively. During follow-up, transverse relapse was more pronounced at the dental level (0.39-1.41 mm) compared to skeletal changes (0.05-0.86 mm). CONCLUSION: Segmented Le Fort I osteotomy shows reliable outcomes in 3D evaluations, but some maxillary movements remain difficult to achieve and maintain such as advancement and pitch. Standardized, voxel-based 3D assessment protocols are recommended to improve comparability and strengthen the evidence base. (PROSPERO registration: CRD42018111854).