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.
The treatment of dentofacial deformity often calls for a combined orthodontic and surgical approach to obtain satisfactory functional and aesthetic results with long-term stability . Many anomalies affect the width of the maxillary arch as well as the curve of Spee . In this context, the preeminent technique for surgical correction is the segmental Le Fort I osteotomy, which provides coordination of the premaxilla with the posterior segments while simultaneously enabling an improvement in the transverse dimension .
The segmental Le Fort I osteotomy is recommended for the single-stage correction of transverse maxillary deficiencies up to 6–7 mm , the correction of anterior open bite when there is a difference in the occlusal planes between the posterior and anterior segments of the maxilla not amenable to orthodontic correction, and the correction of severe proclination of the anterior teeth . According to Proffit et al., 30% of patients with a dentofacial deformity who seek treatment present a transverse maxillary deficiency component . Nevertheless, surgeons may hesitate to use the segmental Le Fort I osteotomy because the safety and stability of this technique remain unclear .
Concern about stability is based on the tenet that maxillary expansion is considered the least stable surgical procedure , and that many factors contribute to post-surgical instability, such as masticatory muscle activity, incorrect orthodontics, intraoperative complications, inadequate maxilla mobilization, the type and amount of surgical movement, inappropriate or no bone grafting, soft tissue tension, and segmental stabilization .
Doubts about safety, in turn, are based on the increased risk of intraoperative and postoperative complications , due to the adverse sequelae that can occur in the anatomical structures adjacent to the segmental osteotomies, such as tooth damage, oral fistula, non-union, and partial or total segment loss .
Research into the long-term stability and surgical complications of this technique could help patients, orthodontists, and surgeons estimate the benefit of an elective operation versus its imminent risks, as well as prevent the occurrence of complications and facilitate their management . Within this context, systematic reviews are particularly relevant, as they are able to summarize and organize data from interventional studies – thus improving effect estimates – and analyze the risk of bias in the published literature .
This systematic review was conducted to evaluate the stability and surgical complications related to the segmental Le Fort I osteotomy. The two specific questions for which answers were sought were the following: (1) Can this surgical procedure provide and maintain stability in the postoperative period? (2) What are the main complications and their causal factors?
A systematic search of the PubMed, Embase, and Cochrane Library databases was performed, using the PICO strategy (population: dentofacial deformity or orthognathic surgery; intervention: segmental Le Fort I osteotomy or segmented Le Fort I osteotomy; comparison: multi-segmented Le Fort I osteotomy and/or Le Fort I osteotomy; outcome: stability and/or complications). No restrictions were placed on language or year of publication, and Boolean operators (“OR” and “AND”) were used for the combinations of thesaurus terms related to dentofacial deformity, segmental Le Fort I osteotomy, stability, and surgical complications.
The PubMed search strategy employed the following medical subject heading (MeSH) entry terms: [(“Dentofacial Deformities” OR “Deformities, Dentofacial” OR “Deformity, Dentofacial” OR “Dentofacial Deformity” OR “Dentofacial Abnormalities” OR “Abnormalities, Dentofacial” OR “Abnormality, Dentofacial” OR “Dentofacial Abnormality” OR “Dentofacial Dysplasia” OR “Dentofacial Dysplasias” OR “Dysplasia, Dentofacial” OR “Dysplasias, Dentofacial” OR “Orthognathic Surgery” OR “Orthognathic Surgery” OR “Orthognathic Surgeries” OR “Surgeries, Orthognathic” OR “Surgery, Orthognathic” OR “Maxillofacial Orthognathic Surgery” OR “Maxillofacial Orthognathic Surgeries” OR “Orthognathic Surgeries, Maxillofacial” OR “Orthognathic Surgery, Maxillofacial” OR “Surgeries, Maxillofacial Orthognathic” OR “Surgery, Maxillofacial Orthognathic” OR “Orthognathic Surgical Procedures” OR “Orthognathic Surgical Procedure” OR “Procedure, Orthognathic Surgical” OR “Procedures, Orthognathic Surgical” OR “Surgical Procedure, Orthognathic” OR “Surgical Procedures, Orthognathic”) AND (“Maxillary Osteotomy” OR “Maxillary Osteotomies” OR “Osteotomies, Maxillary” OR “Osteotomy, Maxillary” OR “Osteotomy, Le Fort” OR “Le Fort Osteotomy” OR “Osteotomy, LeFort” OR “LeFort Osteotomy”) AND (“Recurrence” OR “Recurrences” OR “Recrudescence” OR “Recrudescences” OR “Relapse” OR “Relapses” OR “Intraoperative Complications” OR “Complication, Peroperative” OR “Complications, Peroperative” OR “Peroperative Complication” OR “Peroperative Complications” OR “Complication, Intraoperative” OR “Complications, Intraoperative” OR “Intraoperative Complication” OR “Injuries, Surgical” OR “Injury, Surgical” OR “Surgical Injury” OR “Surgical Injuries” OR “Postoperative Complications” OR “Complication, Postoperative” OR “Complications, Postoperative” OR “Postoperative Complication”)].
For Embase, the PICO search strategy was employed, with the following Emtree terms and their synonyms: “dentofacial deformity”, “orthognathic surgery”, “maxilla osteotomy”, “relapse”, “recurrence risk”, “postoperative complication”, and “peroperative complication”. The specific search query was the following: [(‘dentofacial deformity’/exp OR ‘dentofacial deformities’ OR ‘dentofacial deformity’ OR ‘dentofacial malformation’ OR ‘orthognathic surgery’/exp OR ‘orthognathic surgery’ OR ‘orthognathic surgical procedures’) AND (‘maxilla osteotomy’/exp OR ‘Le Fort operation’ OR ‘Le Fort osteotomy’ OR ‘maxilla osteotomy’ OR ‘maxillary osteotomy’ OR ‘osteotomy, Le Fort’ OR ‘osteotomy, maxilla’) AND (‘relapse’/exp OR ‘relapse’ OR ‘recurrence risk’/exp OR ‘recidivation risk’ OR ‘recidivism risk’ OR ‘recurrence rate’ OR ‘recurrence risk’ OR ‘relapse rate’ OR ‘risk recidivism’ OR ‘risk, recurrence’ OR ‘postoperative complication’/exp OR ‘complication, postoperative’ OR ‘complication, surgical’ OR ‘post-operative complication’ OR ‘post-operative complications’ OR ‘postoperative complication’ OR ‘postoperative complications’ OR ‘postsurgical complication’ OR ‘surgical complication’ OR ‘peroperative complication’/exp OR ‘complication, peroperative’ OR ‘intra-operative complication’ OR ‘intra-operative complications’ OR ‘intraoperative complication’ OR ‘intraoperative complications’ OR ‘per-operative complication’ OR ‘per-operative complications’ OR ‘peri-operative complication’ OR ‘peri-operative complications’ OR ‘peroperative complication’ OR ‘peroperative complications’ OR ‘peroperative complication’ OR ‘peroperative complications’)].
The Cochrane Library search strategy was based on MeSH terms: [(“Dentofacial Deformities” OR “Orthognathic Surgery”) AND (“Maxillary Osteotomy” OR “Osteotomy, Le Fort”) AND (“Recurrence” OR “Intraoperative Complications” OR “Postoperative Complications”)].
This search strategy was designed to retrieve studies published in journals not indexed by the major databases or identified with key words not included in MeSH or in the Emtree thesaurus. For this purpose, the Google Scholar database was searched using two queries: (1) Systematic 1, using MeSH terms as for the Cochrane Library Search; (2) Systematic 2, using the PICO strategy key words: [(“Dentofacial Deformities” OR “Orthognathic Surgery”) AND (“Segmental Le Fort I Osteotomy” OR “Segmented Le Fort I Osteotomy”) AND (“Stability” OR “Intraoperative Complications” OR “Postoperative Complications”)].
The reference lists of all articles retrieved through the main search and grey literature strategy were hand-searched for additional relevant papers.
The systematic database searches were performed by one author (OLHJ), while studies were selected independently by two authors (OLHJ and APSG). After an analysis of titles and abstracts, studies were assessed against the study eligibility criteria and those that fulfilled these were selected for full-text reading. The inclusion criteria were: (1) intervention study; (2) includes analysis of stability and/or complications after maxillary osteotomy. The exclusion criteria were: (1) case report; (2) review of the literature; (3) patient sample integrated completely with patients with cleft lip and palate or other craniofacial syndromes.
Studies that did not meet all of these prerequisites were excluded. In the case of disagreement between the authors, the study was selected for full-text reading. The eligibility of the selected articles was then assessed.
The kappa statistic (κ) was used to evaluate the level of agreement between OLHJ and APSG.
The same two authors assessed the selected studies for eligibility independently. To facilitate and maintain consistency in the analysis of articles after full-text reading, a standardized form was created and used to check studies against the following inclusion criteria: (1) the research topic is segmental maxillary osteotomy; (2) the article reports data on stability and/or complications after maxillary osteotomy; (3) the article reports data on the segmental Le Fort I osteotomy, not only anterior or posterior segmental osteotomy of the maxilla; (4) the article reports an original study.
At this stage, any disagreement between the two independent investigators regarding the eligibility of the study was discussed with a third author (RGM).
Studies that did not meet the eligibility criteria were excluded from further analysis and the reason for exclusion was recorded.
The kappa statistic (κ) was used to evaluate the level of agreement between authors.
The same two authors (OLHJ and APSG) independently extracted demographic data, methodological data, and data on stability outcomes and/or complications for analysis. In the event of disagreement, the article was discussed with a third author (RGM); if doubts persisted, the corresponding author of the study in question was contacted via e-mail.
Analysis of surgical stability
The stability of the surgical procedure was assessed using the mean and standard deviation (SD) of dental and/or skeletal recurrence in the anterior and posterior segments of the maxilla, between the immediate postoperative period (mean surgical changes – T1) and the moment of the last follow-up (mean stability changes – T2). Results were expressed in millimetres (mm). Surgical movement in the sagittal, vertical, and transverse planes was taken into account.
Analysis of surgical complications
The following complications were assessed: intraoperative bleeding, postoperative bleeding, blood transfusion, segmental necrosis, tooth damage, periodontal damage, soft tissue damage, nerve damage, oral fistula, bad split, infection, non-union, and relapse. The prevalence of each complication was assessed in relation to the sample reported by the authors.
Analysis of methodological quality
The assessment of methodological quality was performed using the same risk of bias scale for small intervention studies employed in a previous study by Haas Jr et al. . The criteria take into account sample selection, comparison of intervention effects, blinding of outcome assessors, validation of measures, statistical analysis, definition of inclusion and exclusion criteria, and postoperative follow-up.
Studies were classified as having a low risk of bias if all items were present, as having a medium risk of bias if one or two items were missing, and as having a high risk of bias if three or more items were missing.