Title Increased Horizontal Stability After Mandibular Setback Surgery in Patients with Skeletal Class III Malocclusion with Pre-Surgical Orthodontics
Clinical Question Does pre-surgical orthodontics increase the horizontal stability of surgical treatment In Patients with skeletal class III malocclusion undergoing mandibular set back surgery?
Clinical Bottom Line Pre-surgical orthodontics increases the horizontal stability of mandibular set back surgery in patients with skeletal class III malocclusion.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
24268965 Kim/2014n=61 Cohort Retrospective
Key results61 patients were divided into a group with pre-surgical orthodontic treatment and a group without pre-surgical orthodontics and compared using lateral cephalograms taken preoperatively, right after surgery, and at the time of orthodontic debonding. The mean setback of the mandible at the B point was almost similar (pre-surgical orthodontics group, 8.7 mm; surgery first group, 9.1 mm; difference, P > .05), but the horizontal relapse in the surgery first group (2.4 mm) was significantly larger compared to the pre-surgical orthodontics group (1.6 mm; P < .05). 39.1% of the surgery first group included patients with horizontal relapse more than 3 mm, compared with 15.8% of the pre-surgical orthodontic group (P < .05), which shows a better horizontal stability of hard tissue landmarks in skeletal class III patients who had been treated orthodontically before undergoing surgical mandibular set back procedure.
Evidence Search The following search keywords used in PubMed, Mesh terms: Class III malocclusion, mandibular set back surgery, pre-surgical orthodontics, B point set back, sagittal split ramus osteotomy, skeletal stability
Comments on
The Evidence
The study design, modified for reading anatomic landmarks on cephalogram, making measurements more accurate and reproducible. The diagnostic radiograph protocol is comprehensive and equally applied on an acceptable number of cases. Analysis is based on the hard tissue land marks which bypasses soft tissue unfavorable effects on the result. Predictor variables (timing and groups), outcome variables (cephalometric analysis), and other variables, such as baseline characteristics, take part in evaluation to calculate the difference in stability of mandibular positions like B point. However the better approach in measuring the radiographic variables could be the implementation of CBCT (3D modeling). The result of this study are in accordance with similar studies on this subject like Ko EW et. al., (2013, PMID: 23455415) who determined the influencing variables and measured hard tissue anatomic locations after a surgical only approach.
Applicability According to Kim et. al, the result of this study applies to oral surgeons and orthodontists who question the horizontal stability of mandibular setback procedure in patients with skeletal class III malocclusion. Skeletal stability needs to be addressed and anticipated before planning the surgery first approach
Specialty (Oral Surgery) (Orthodontics)
Keywords Class III malocclusion, mandibular set back surgery, pre-surgical orthodontics, B point set back, sagittal split ramus osteotomy, pre-surgical orthodontics
ID# 2723
Date of submission 04/15/2014
E-mail hooman.abdolisereshki@ucdenver.edu
Author Hooman Abdolisereshki
Co-author(s) e-mail
Faculty mentor Thomas Borris, DDS
Faculty mentor e-mail Thomas.Borris@ucdenver.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available