Evaluation Of Surgery-first Approach To Orthognathic Surgery For Skeletal Malocclusion

Objective:Skeletal malocclusion is one of the most common dental-maxillofacial deformity.The conventional approach to orthognathic surgery for skeletal malocclusion involving a variable length of preoperative orthodontic preparation,followed by the surgery,and a relatively stable period of postoperative orthodontics.Recently,the acknowleged dogma of surgery-first,followed by orthodontic treatment for orthognathic surgery was introduced in different orthodontic centers in the world.This concept and technique is called "surgery-first approach"(SFA),which has been used to obtain early improvement in facial profiles,reduce total treatment duration and increase patient' s satisfaction.However,the postsurgical stability and relapse rate of SFA is still a controversial issue.Therefor,the aims of this meta-analysis were to compare the postsurgical stability and relapse rate between patients treated with CA and SFA protocols.Methods:An electronic search of PubMed,Cochrane Library,EMBASE,OVID was performed from January 2000 to January 2017.The search strategy was designed to include terms related to the orthognathic surgery and terms related to the surgery first approach.According to inclusion and exclusion criteria,papers were included in the final analysis.The main end points were the horizontal and vertical changes of chosen landmarks(A-point:innermost point of the contour from ANS to the crest of the maxillary alveolar process;B-point:innermost point of the contour from the bony chin to the alveolar bone junction;Pog:pogonion;Angle SNB)timing of before treatment(t0),the immediately after surgery(t1)and at debonding(or at least lyear after surgery,t2).Statistical analyses were performed using RevMan software(version 5.3).Results:7 articles fulfilled the inclusion criteria and were selected for Meta-analysis.Consequently,all end point showed no significant difference during t0 to t1 between patients treated with CA and SFA protocals.However,in terms of t1 to t2,B-ponit and Pog in vertical plane?Pog in horizontal plane,Results Significant difference between the two groups(P<0.05),which means,higher relapse rate and worse mandibular stability was found in SFA group.Conclusion:The results of this study show that SFA group have relatively low mandibular stability in both vertically and horizontally,which are similar to those reported previously.Nevertheless,the results of this meta-analysis should be interpreted with caution because of the low evidence levels of the retrieved articles,the wide variety of outcome variables,the substantial reporting biases,and the lack of prospective long-term follow-ups.