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Title Skeletal Relapse of Mandibular Advancement Procedures Is Similar with Bilateral Sagittal Split Osteotomy (BSSO) and Mandibular Distraction Osteogenesis (MDO)
Clinical Question Will patients who undergo orthognathic surgery for mandibular advancement show similar amount of skeletal relapse, regardless if they are treated with bilateral sagittal split osteotomy (BSSO) or mandibular distraction osteogenesis (MDO)?
Clinical Bottom Line Patients with mandibular deficiency treated surgically by either bilateral sagittal split osteotomy (BSSO) or mandibular distraction osteogenesis (MDO) do not show significant differences in terms of skeletal relapse. This is supported by two large systematic reviews evaluating several randomized controlled trials, controlled clinical trials, and retrospective studies on treated humans, published from 1957 – 2014, in which the amount of skeletal relapse was not significantly different between the two treatment methods. Complications of orthognathic surgery like skeletal relapse are often attributed to the chosen surgical technique and are a major concern for both the surgeon and the patient. Thus, evaluating their occurrence and etiology is crucial for proper treatment planning and prevention of compromised treatment results.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 25857283Al-Moraissi/2015122 patients in 4 included studies (stability only)Meta-Analysis
Key resultsOut of the 215 records selected, 9 publications (357 patients) were included in this review, out of which, a total of 122 patients in 4 articles provided data for evaluation of skeletal relapse in terms of linear (horizontal and vertical) differences and SNB angle changes. In none of the aforementioned categories was any significant difference found; however, in all three categories the findings favored patients who had undergone MDO.
#2) 19837301Ow/2009235 patients in 10 included studies (stability only)Meta-Analysis
Key resultsOut of the 34 articles identified as relevant to stability, 10 were included in this study; 9 articles for 220 patients treated with BSSO and just 1 study of 13 patients treated with MDO. The inclusion criteria included moderate surgical movements (6-10 mm), similar predisposing factors for relapse, and the same type of rigid fixation. The data evaluation showed that for mandibular advancements between 6 and 10 mm the postoperative stability is similar for the first 6-12 months. However, other factors (age, growth, variety of surgical protocols, fixation, type of skeletal discrepancy) affecting skeletal stability were evident, as well as the lack of randomized clinical trials on this subject.
Evidence Search ("Osteotomy"[All Fields] OR "BSSO"[All Fields]) AND “MDO” [All Fields] AND “STABILITY” [All Fields] AND "OSTEOTOMY"[ All Fields])
Comments on
The Evidence
Validity: Both of the reviews included clinical human studies of patients with Class II malocclusion needing orthognathic surgery. However, Al-Moraissi et al. (2015) did not specify the severity of the skeletal malocclusion, the type of fixation used (both factors affecting stability), or the time point of the follow-up period, all contributing factors that slightly undermine the accuracy of the relapse measurements. The review by Ow (2009) specified all the aforementioned factors; however no more than one MDO study of just 13 patients fulfilled the inclusion criteria, introducing a high risk of bias over the 235 BSSO patients. In both studies the validity of the data is compromised by the complicated and multi-factored nature of skeletal stability after orthognathic surgery. Perspective: In order to minimize the effect of the multiple contributing factors that affect postoperative skeletal stability, more randomized clinical trials are needed with increased number of participants, carefully defined pre-operative inclusion criteria, controlled protocol of fixation. and multiple long-term follow-up time points.
Applicability Skeletal relapse after orthognathic surgery has been one of the most concerning complications after mandibular advancement, especially since the causal factors are multiple and correlated. The argument that one surgical procedure might be superior over the others in terms of postsurgical stability can be crucial for treatment planning decisions. These studies, regardless of their limitations, provide a reliable and useful perspective on the stability of the most commonly used procedures for mandibular advancement, and thoroughly summarize the existing clinical evidence.
Specialty/Discipline (Oral Surgery) (Orthodontics)
Keywords orthognathic surgery, bilateral sagittal split osteotomy, mandibular distraction osteogenesis, BSSO, MDO, skeletal stability, osteotomy, skeletal relapse
ID# 3359
Date of submission: 11/15/2018spacer
E-mail karakousoglo@livemail.uthscsa.edu
Author Maria Karakousoglou
Co-author(s) e-mail
Faculty mentor/Co-author Ravikumar Anthony, BDS, MDS, MS
Faculty mentor/Co-author e-mail AnthonyR@uthscsa.edu
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