Computer-assisted condyle positioning in orthognathic surgery.

PURPOSE: Le Fort I repositioning osteotomy can affect the position of the temporomandibular joints (TMJs). During the operation, the surgeon does not have direct visual control of the TMJ. In this study, the TMJ movements in patients undergoing a Le Fort I repositioning osteotomy were recorded intraoperatively using the Surgical Segment Navigator (SSN) computer-assisted navigation system. PATIENTS AND METHODS: Unintended TMJ positions resulting from conventional repositioning of the maxillary segment were recorded. The TMJ positions in these patients were then corrected in relation to the skull base, using information obtained from the SSN. The position of the condyle was then redetermined. The accuracy of conventional and SSN-guided segment adjustments were compared in terms of their influence on TMJ position in the same group of patients. RESULTS: The median spacial malposition of the condyles without navigation was 2.4 mm. Corrective "SSN positioning" on the same patients reduced this to 0.7 mm. CONCLUSIONS: SSN allows accurate intraoperative navigation of the TMJ.     

Prevalence of postoperative complications after orthognathic surgery: a 15-year review.

PURPOSE: This study was conducted to determine the prevalence of postoperative complications after orthognathic surgery and evaluate the use of antibiotic prophylaxis in relation to the infection rate. PATIENTS AND METHODS: All patients undergoing orthognathic procedures between 1990 and 2004 were studied retrospectively by retrieving their individual medical records. Demographic data, intraoperative data (specific orthognathic procedures and duration of operation), and postoperative data (type and duration of antibiotic prophylaxis and presence of postoperative complications) were recorded. Patients noted to have suffered any postoperative complications were studied in detail, and various factors, including gender, age, duration of operation, and use of prophylactic antibiotics, were analyzed using statistical tests in relation to postoperative infection. RESULTS: A total of 2,910 orthognathic procedures were performed on 1,294 consecutive patients in the 15-year period, with 1,070 patients undergoing bimaxillary procedures and 224 patients undergoing single-jaw surgery. The orthognathic surgery-related complication rate was 9.7%, of which 7.4% was related to postoperative infection. Of the cases of infection, 58.3% were acute infection and 41.7% were chronic infection. Patients who received a single preoperative dose of antibiotics had a significantly higher infection rate (17.3%) than those who received postoperative antibiotics for various durations. CONCLUSIONS: The prevalence of infection after orthognathic surgery was relatively low given the complexity of the procedures. No particular orthognathic procedure was more susceptible to infection. A preoperative dose of prophylactic antibiotics together with at least 2 days of postoperative doses was useful in reducing the infection rate compared with only a single dose of prophylactic antibiotics.     

Computer-assisted orthognathic surgery: clinical evaluation of a mandibular condyle repositioning system.

PURPOSE: The purpose of this study was to evaluate a new method for positioning the mandibular condyle during orthognathic surgery based on 3-dimensional optical localization of infrared emitting diodes. PATIENTS AND METHODS: Eleven patients ("empirical group") underwent condylar repositioning using the empirical repositioning method (standard technique) and were considered controls. In 10 patients ("active group"), the computer-assisted system was used to replace the condyle-bearing fragment in its sagittal preoperative position. In these patients, the condylar torque was not controlled. In the third group of 10 patients ("graft group"), the computer-assisted system was used to replace the condyle in all 3 directions. Very often it was necessary in this group to fill the osteotomy gap with a bone graft. The clinical evaluation was based on 4 major criteria: the quality of the postoperative occlusion, the stability of skeletal position on successive cephalometric radiographs, the occurrence of temporomandibular dysfunction (TMD), and the preservation of mandibular motion. Clinical assessment was made at 1, 3, 6, and 12 months follow-up. RESULTS: Forty-five percent of the "empirical group" did not have the expected postoperative occlusion, 5 patients showed evidence of clinical relapse at 1 year, 45% had worsened TMD status, and only 63.37% of mandibular motion had been recovered at 6 months. All the patients in the "active group" had the expected occlusion and only 1 patient exhibited a mild relapse and TMD symptoms; however the average mandibular motion recovery was only 62.65% at 6 months. All the patients in the "graft group" had a good occlusion and no relapse or TMD. Their percentage of mandibular motion recovery was 77.58%. CONCLUSION: The quality of sagittal repositioning is the main factor contributing to a good occlusion and bone stability. Functional results (in particular, recovery of mandibular motion) are more related to limiting condylar torque.     

Minimally invasive orthognathic surgery: a systematic review

Minimally invasive techniques are currently applied in many oral and maxillofacial surgical procedures, including orthognathic surgery. A systematic review on the application of potentially minimally invasive procedures in orthognathic surgery was performed to provide a clear overview of the relevant published data. Articles in English on minimally invasive orthognathic procedures, published in the scientific literature, were obtained from the PubMed, Embase, and Cochrane Library databases, and an additional manual search (revised 31 December 2016). After screening the abstracts and applying the eligibility criteria, 403 articles were identified. All articles reporting the potential for minimally invasive orthognathic surgery were included (n = 44). The full papers were evaluated in detail and categorized as articles on a minimally invasive surgical approach (n = 4), endoscopically assisted orthognathic procedures (n = 17), or the use of a piezoelectric device in orthognathic surgery (n = 25); two articles were each included in two categories. Although a small incision and minimal dissection is the basic principle of a minimally invasive technique, most articles (90.9%) reported the endoscope and piezoelectric instrument as important tools in minimally invasive orthognathic surgery. Evidence from available studies suggests that patients undergoing minimally invasive orthognathic surgery have less morbidity and make a faster recovery. Further research should aim to obtain higher levels of evidence.     

Bone grafting in orthognathic surgery: a systematic review

Bone grafting has been used in orthognathic surgery to fill the gaps created by jaw repositioning, with the intention of improving healing and stability. Since the majority of orthognathic cases have a satisfactory result, the decision to graft or not is a clinical dilemma. A systematic review of the literature was performed on the use of bone grafts in orthognathic surgery. A search of PubMed, MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials yielded 1927 articles published up until 2018. An additional 10 articles were retrieved through manual searching of the reference lists and citations. After title and abstract screening, 58 articles were potentially eligible; full-text screening excluded 10 of these. Thus 48 articles were included in this review. The present literature highlights the benefits of grafting bony gaps during orthognathic surgery in terms of healing, stability, and aesthetic outcomes. Generally, there was no difference between the various types of bone graft, although calcium phosphate cement and hydroxyapatite were found to increase the rate of infection. The conclusion of this review is that there remains a lack of evidence in the literature regarding the grafting of osteotomy sites in orthognathic surgery. Guidelines are proposed based on the present evidence; however, future research is needed to validate these.     

Learning condyle repositioning during orthognathic surgery with a surgical navigation system

Condyle repositioning during bilateral sagittal splint osteotomy (BSSO) is a challenging step for the inexperienced surgeon. We aimed to demonstrate the benefit of navigation for learning the condyle repositioning. We treated 100 patients who underwent a BSSO. A trainee performed the condyle repositioning of one side in two phases. In the first one, the trainee positioned without watching the screen of the Orthopilot Navigation system (ONS). In the second one, the trainee could use the ONS to replace the condyle. Heuristic, anatomical and functional scores of each phase were recorded. Heuristic (17% vs. 75%; p < 0.0001), anatomical (35% vs. 86%; p < 0.0001) and functional (14% vs. 56%; p < 0.0001) scores were significantly greater with the ONS. The ONS is a promising and original intraoperative learning tool for the repositioning of the condyle during BSSO.     

Facial palsy after orthognathic surgery: A systematic review

It was the aim of the systematic review to evaluate the incidence of facial palsy following orthognathic surgery, and to assess the possible mechanisms of injury, subsequent management, and eventual outcomes. The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews. A thorough search of PubMed, Scopus, Cochrane Library, and CINAHL databases up to April 2022 was conducted. In total, 34 articles were selected for this review, including 54 facial palsies in 53 patients. The incidence of facial palsy was estimated to range from 0.04% to 0.77%. Most of the possible etiologies proposed involved intraoperative nerve compression or postoperative edema. Physical therapy and steroid administration were the most frequently employed management approaches. Surgical exploration for the facial nerve was executed in one patient. Forty-three facial palsies (79.6%) attained complete recovery with conservative management, whereas 11 facial palsies (20.4%) continued to show incomplete recovery during the follow-up period. Earlier facial palsy onset (timing after surgery) was related to a higher risk of continuing palsy (p = 0.018). Within the limitations of this review it seems that facial palsy following orthognathic surgery should be treated conservatively whenever appropriate.     

Effectiveness of different protocols to reduce postoperative pain following orthognathic surgery: A systematic review and meta-analysis

Pain management in orthognathic surgery is essential to enhance recovery, reduce hospital stay, and improve the whole experience of the patient. The aim of this systematic review was to evaluate current evidence on pain management in orthognathic surgery.A systematic review of the literature was performed following PRISMA guidelines, and PubMed, EMBASE, and the Cochrane Controlled Trials Registry were searched to retrieve randomised clinical trials (RCTs) published until July 2020. RCTs that compared different pre-emptive analgesia and low-level laser therapy (LLLT) with placebo after orthognathic surgery were included. Outcome variables were pain scores and duration of surgery. The quality of evidence was rated according to Cochrane’s tool for assessing risk of bias. Standardised mean difference (SMD) or mean difference (MD) was used to analyse continuous data. There was significant pain reduction within the first 48 hours after pre-emptive analgesia (very low quality evidence, SMD: ?1.329; confidence interval (CI): ?2.030 to ?0.628; p = 0.001) and LLLT (very low quality evidence, SMD: ?0.690; CI: ?1.172 to ?0.207; p = 0.005) versus placebo. Evidence to support pre-emptive analgesia or LLLT effectively reducing pain scores within the first postoperative 48 hours after orthognathic surgery when compared with placebo, was of low quality.     

Maintenance of condyle-proximal segment position in orthognathic surgery

Twenty patients underwent bilateral sagittal ramus osteotomy for the correction of mandibular retrognathia. A condylar positioning device (CPD) was used intraoperatively in 10 patients to maintain preoperative condyle-proximal segment position, while the CPD was not used in the other 10 patients. Postoperatively, the condyle-proximal segment positions in both groups were compared and evaluated for vertical, horizontal, and rotational changes. A significant improvement (P less than .05) was observed in the vertical and horizontal condylar position in the group in which the CPD was used. However, there was no significant difference in proximal segment rotation.     

Skeletal stability in orthognathic surgery with the surgery first approach: a systematic review

The surgery first approach (SFA) is a therapeutic strategy used in orthognathic surgery that is constantly evolving. With this approach, the pre-surgical orthodontic treatment can be eliminated, the maxilla and the mandible are surgically repositioned into the desired position, and the therapy is ended with a short orthodontic phase. Several studies have reported that the SFA is an acceptable approach, but postoperative stability is unclear. In this study, a systematic review on the SFA was performed. The PubMed, Google Scholar, Scopus, LexisNexis, Web of Science, and Cochrane Library databases were accessed. Studies from which data could be extracted on skeletal stability based on specific cephalometric points were included. The search yielded 2766 publications. Application of the selection criteria resulted in a final group of 14 articles. Five hundred and sixty patients with class III malocclusion underwent orthognathic surgery, 339 with the SFA. Study parameters such as evaluation time points and reference planes varied, making it impossible to perform a meta-analysis. The studies suggest that surgery with the SFA is as stable as surgery with the conventional approach. However, all articles described stability using a penultimate time point of ‘after surgery’ and not ‘after debonding’; hence orthodontic movements and consequent mandibular movements could have influenced cephalometric measurements. Thus, to verify the real stability of the SFA, further research with longer follow-up periods is required, with evaluation at the same time points.     

Outpatient orthognathic surgery: criteria and a review of cases

Over a 9-year period, 87 orthognathic procedures were performed in an outpatient environment. Procedures performed included horizontal mandibular osteotomies, rapid palatal expansions, bilateral sagittal split osteotomies, posterior and anterior maxillary osteotomies, and Le Fort I osteotomies. Fourteen of these patients were subsequently admitted to a hospital for either observation or full inpatient care. The rates of admission varied for each of the procedures, with length of anesthesia statistically related to the frequency of admission. Patient selection criteria and facilities used are reviewed.     

The case for postoperative orthodontics in orthognathic surgery

In patients with orthognathic problems, in whom a combination of surgery and orthodontics is required, it seems to us better to defer orthodontic treatment until after surgery has been completed and a possible relapse tendency has petered out. This conclusion is reached on the basis of arch instability and the incidence of root resorption as reported in the orthodontic literature. The soundness of "permanent retention" after orthodontic therapy is questioned. The author's concepts are illustrated with a few case reports.     

Speech production before and after orthognathic surgery: a review

A review of investigations in which speech production has been studied before and after orthognathic surgery indicates that many subjects demonstrate preoperative articulation errors. The error type most frequently identified was of the distortion variety, which suggests that misarticulating speakers were attempting to produce the sounds but that in most cases the sounds were phonetically incorrect. The /s/ speech sound and the sibilant class in general, of which /s/ is a member, were often found defective in the subjects' speech. Not all speakers had preoperative articulation errors, which suggests the possibility of compensatory articulation patterns. The literature indicates that some persons with certain occlusal and dental conditions do compensate for structural aberrations. Finally, the vast majority of subjects with preoperative misarticulations eliminated or reduced their errors following orthognathic surgery. In the case of speech behavior, it can be stated that surgical alterations in form brought about positive changes in function.     

Condylar positioning devices for orthognathic surgery: a literature review

In the past few years, many devices have been proposed for preserving the preoperative position of the mandibular condyle during bilateral sagittal split osteotomy. Accurate mandibular condyle repositioning is considered important to obtain a stable skeletal and occlusal result, and to prevent the onset of temporomandibular disorders (TMD). Condylar positioning devices (CPDs) have led to longer operating times, the need to keep intermaxillary fixation as stable as possible during their application, and the need for precision in the construction of the splint or intraoperative wax bite. This study reviews the literature concerning the use of CPDs in orthognathic surgery since 1990 and their application to prevent skeletal instability and contain TMD since 1995. From the studies reviewed, we can conclude that there is no scientific evidence to support the routine use of CPDs in orthognathic surgery.     

Skeletal stability of bioresorbable fixation in orthognathic surgery: A systemic review

BackgroundOver the past 20 years, there has been an increase in the use of bioresorbable fixation system in orthognathic surgery, but concerns remain about the stability of fixation. This review is to seek evidence for the effectiveness of bioresorbable fixation systems compared to titanium systems used for orthognathic surgery.MethodsA systematic review of the scientific literature listed on PubMed, Embase, Cochrane Central Register of Systemic Reviews and Cochrane Central Register of Controlled Trials was performed, up to December 2012.ResultsTwenty articles were selected based on inclusion and exclusion criteria: five RCTs and fifteen prospective. We compared these studies, published between 1997 and 2012 and involving 1092 participants examining skeletal stability of bioresorbable fixation in orthognathic surgery.ConclusionThis review found that the published data have shown that bioresorbable fixation systems produce reliable skeletal stability.     

The psychosocial impact of orthognathic surgery: a systematic review.

The aim of this study was to review the reported psychosocial benefits of orthognathic surgery. A systematic review of the literature was conducted using MEDLINE (1966 to December 2000), Web of Science (1981 to December 2000), and reference sections of identified articles. We also hand searched key orthodontic, oral surgery, and psychology journals. No language limitations were imposed. Randomized controlled trials, other controlled clinical trials, prospective studies (with or without controls), and retrospective studies (with or without controls) were considered for inclusion. Two reviewers extracted the data and independently assessed the quality of the studies. In all, 29 studies, including a number of prospective and retrospective studies, were identified as relevant. The results of the review indicated that orthognathic patients experience psychosocial benefits as a result of orthognathic surgery, including improved self-confidence, body and facial image, and social adjustment. However, there were wide variations in the study designs and a lack of uniformity in measuring the psychosocial constructs. This made it difficult to quantify the extent and the duration of the psychosocial benefits.