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Background and Objectives: The most popular surgical procedures among orthognathic surgeries for Class II and III patients are Le Fort 1 osteotomy for the maxilla and bilateral sagittal split ramus osteotomy (BSSRO) for the mandible. Keeping the condyle in its proper place during fixation is one of the difficulties of orthognathic surgery. One of the worst post-orthognathic surgery consequences in the temporomandibular joint (TMJ) area may be condylar resorption. Condylar remodeling refers to a group of processes that occur in reaction to forces and stress placed on the temporomandibular joint in order to preserve morphological, functional, and occlusal balance. A systematic review of the literature was performed with the aim of identifying the mandibular condylar component of TMJ changes after orthognathic surgery in class II and III patients. Materials and Methods: An electronic search was carried out using the PubMed, Cochrane Library, and Google Scholar, databases. The inclusion criteria included trials in non-growing patients upon whom orthognathic surgery was performed due to Angle II or Angle III classes malocclusion; in addition, a CT or cone beam computed tomography (CBCT) scan was performed before and after surgery to track the mandibular condylar component of TMJ changes. The quality of the studies was evaluated by two independent authors. The risk of bias was assessed by using the Downs and Black checklist. Results: The electronic and manual literature search yielded 12 studies that fulfilled all necessary inclusion criteria. Observed studies were evaluated as good (3), fair (8), and poor (1) quality. Two studies evaluated class II patients, six studies observed class III patients, and four studies were comparative. Most of the studies evaluated condyle angle and space changes, and the condylar surface and volume changes were also observed. However, the methodology of evaluation in the publications differs. Conclusions: Reduction of bone density, especially in class II patients, and morphological condyle reshaping, with the apposition of the bone, is the main adaptive mechanism after orthognathic surgery. However, all of the studies we examined were conducted using different methods of evaluation, measurement, and reference points. [ABSTRACT FROM AUTHOR]

Background/purpose: The extent of three-dimensional soft tissue changes in patients with varied facial skeletal patterns following mandibular setback surgery remains unclear. In this study, we aimed to investigate the postoperative changes in soft tissue chin thickness among mandibular prognathism patients, focusing on those presenting different divergence patterns, such as hyperdivergent and normodivergent patients. Materials and methods: Cone-beam computed tomography images were obtained from 56 skeletal Class III patients who underwent only mandibular setback. Based on vertical craniofacial skeletal relationship, patients were divided into normodivergent group (27°37°) group. The three-dimensional displacements of Infradentale (Id), B point (B), and Pogonion (Pog), the soft tissue thickness of Id-Li (Labrale inferius), B-B' (soft tissue B point), and Pog-Pog’ (soft tissue Pog point) were measured. Factors influencing the change in soft tissue thickness were investigated. Results: Preoperative B-B' and Pog-Pog’ thickness were significantly thinner in the hyperdivergent group than normodivergent group. Postoperative changes in B-B' and Pog-Pog’ thickness were significantly larger in the hyperdivergent group than normodivergent group. A significant correlation was found between soft tissue thickness change (B-B' and Pog-Pog’) and the preoperative soft tissue thickness and superior movement (B and Pog). Conclusion: Hyperdivergent patients with skeletal class III have thinner preoperative soft tissue thickness (B-B' and Pog-Pog’) than normodivergent patients in the preoperation. Postoperative changes in B-B' and Pog-Pog’ thickness were significantly larger in the hyperdivergent group than normodivergent group. Postoperative superior movement of B and Pog correlated with postoperative change of soft tissue thickness.

The extent of three-dimensional soft tissue changes in patients with varied facial skeletal patterns following mandibular setback surgery remains unclear. In this study, we aimed to investigate the postoperative changes in soft tissue chin thickness among mandibular prognathism patients, focusing on those presenting different divergence patterns, such as hyperdivergent and normodivergent patients. Cone-beam computed tomography images were obtained from 56 skeletal Class III patients who underwent only mandibular setback. Based on vertical craniofacial skeletal relationship, patients were divided into normodivergent group (27°37°) group. The three-dimensional displacements of Infradentale (Id), B point (B), and Pogonion (Pog), the soft tissue thickness of Id-Li (Labrale inferius), B-B' (soft tissue B point), and Pog-Pog' (soft tissue Pog point) were measured. Factors influencing the change in soft tissue thickness were investigated. Preoperative B-B' and Pog-Pog' thickness were significantly thinner in the hyperdivergent group than normodivergent group. Postoperative changes in B-B' and Pog-Pog' thickness were significantly larger in the hyperdivergent group than normodivergent group. A significant correlation was found between soft tissue thickness change (B-B' and Pog-Pog') and the preoperative soft tissue thickness and superior movement (B and Pog). Hyperdivergent patients with skeletal class III have thinner preoperative soft tissue thickness (B-B' and Pog-Pog') than normodivergent patients in the preoperation. Postoperative changes in B-B' and Pog-Pog' thickness were significantly larger in the hyperdivergent group than normodivergent group. Postoperative superior movement of B and Pog correlated with postoperative change of soft tissue thickness. [ABSTRACT FROM AUTHOR]

Background and Objectives: The most popular surgical procedures among orthognathic surgeries for Class II and III patients are Le Fort 1 osteotomy for the maxilla and bilateral sagittal split ramus osteotomy (BSSRO) for the mandible. Keeping the condyle in its proper place during fixation is one of the difficulties of orthognathic surgery. One of the worst post-orthognathic surgery consequences in the temporomandibular joint (TMJ) area may be condylar resorption. Condylar remodeling refers to a group of processes that occur in reaction to forces and stress placed on the temporomandibular joint in order to preserve morphological, functional, and occlusal balance. A systematic review of the literature was performed with the aim of identifying the mandibular condylar component of TMJ changes after orthognathic surgery in class II and III patients. Materials and Methods: An electronic search was carried out using the PubMed, Cochrane Library, and Google Scholar, databases. The inclusion criteria included trials in non-growing patients upon whom orthognathic surgery was performed due to Angle II or Angle III classes malocclusion; in addition, a CT or cone beam computed tomography (CBCT) scan was performed before and after surgery to track the mandibular condylar component of TMJ changes. The quality of the studies was evaluated by two independent authors. The risk of bias was assessed by using the Downs and Black checklist. Results: The electronic and manual literature search yielded 12 studies that fulfilled all necessary inclusion criteria. Observed studies were evaluated as good (3), fair (8), and poor (1) quality. Two studies evaluated class II patients, six studies observed class III patients, and four studies were comparative. Most of the studies evaluated condyle angle and space changes, and the condylar surface and volume changes were also observed. However, the methodology of evaluation in the publications differs. Conclusions: Reduction of bone density, especially in class II patients, and morphological condyle reshaping, with the apposition of the bone, is the main adaptive mechanism after orthognathic surgery. However, all of the studies we examined were conducted using different methods of evaluation, measurement, and reference points.

Objectives: This retrospective study aimed to determine the angulation changes of the proximal segment following bilateral sagittal split osteotomy (BSSO) setback and its correlation with the amount of immediate postoperative surgical movement. The correlation between postoperative relapse of the distal and proximal segment at six months postoperatively was also evaluated. Materials and methods: The CBCT-generated lateral cephalometric images of 39 patients who underwent BSSO setback with or without Le Fort I osteotomy were evaluated preoperatively (T0), immediately postoperative (T1), and six months postoperatively (T2). Results: The mean surgical setback was 7.28 ± 4.45 mm at B point. The proximal segment's immediate postoperative mean posterior rotation was 2.13 ± 3.59 degrees. Six months after the operation, the mean distal segment relapse was 0.89 ± 3.03 mm at B point. The proximal segment relapse was 0.81 ± 1.63 degrees. A significant moderate correlation was found (P < 0.05) between the surgical movement and the immediate postoperative proximal segment rotation and between the surgical movement and the distal segment relapse. A significant correlation was found between the distal segment relapse and the average and left proximal segment relapse. There was no significant correlation between immediate postoperative proximal segment rotation and distal segment relapse. Conclusion: The immediate postoperative posterior rotation of the proximal segment had a negligible effect on mandibular relapse. The amount of surgical movement, on the other hand, was more related to distal segment relapse. The intraoperative proximal segment rotation should thus be minimized in cases with a significant surgical setback. [ABSTRACT FROM AUTHOR]

Background/Purpose: Postoperative skeletal relapse is the most important issue in patients undergoing orthognathic surgery. This study aimed to investigate clinical skeletal relapse (≥2 mm) after mandibular setback surgery (intraoral vertical ramus osteotomy: IVRO) using receiver operating characteristic curve (ROC curve) analysis. Methods: Serial cephalograms of 40 patients with mandibular prognathism were obtained at different time points: (1) before surgery (T1), (2) immediately after surgery (T2), and (3) at least with a 2-year follow-up postoperatively (T3). The menton (Me) was used as the landmark for measuring the amount of mandibular setback and postoperative skeletal relapse. Postoperative stability (T32) was divided into groups A and B by skeletal relapse ≥2 mm and

Background/purpose: Postoperative skeletal relapse is the most important issue in patients undergoing orthognathic surgery. This study aimed to investigate clinical skeletal relapse (≥2 mm) after mandibular setback surgery (intraoral vertical ramus osteotomy: IVRO) using receiver operating characteristic curve (ROC curve) analysis.Methods: Serial cephalograms of 40 patients with mandibular prognathism were obtained at different time points: (1) before surgery (T1), (2) immediately after surgery (T2), and (3) at least with a 2-year follow-up postoperatively (T3). The menton (Me) was used as the landmark for measuring the amount of mandibular setback and postoperative skeletal relapse. Postoperative stability (T32) was divided into groups A and B by skeletal relapse ≥2 mm and <2 mm, respectively. The area under the ROC curve (AUC) was used to determine the cut-off point for mandibular setback.Results: At the immediate surgical setback (T21), the amount of setback in group A (15.55 mm) was significantly larger than in group B (10.97 mm). Group A (T32) showed a significant relapse (4.07 mm), while group B showed a significant posterior drift (1.23 mm). The amount of setback had the highest AUC area (0.788). The cut-off point was 14.1 mm (T21) that would lead to a clinical relapse of 2 mm (T32).Conclusion: In IVRO, the postoperative mandibular positions reveal posterior drift and anterior displacement (relapse). The experience of clinical observation and patient perception of postoperative skeletal relapse was ≥2 mm. In the ROC curve analysis, the cut-off point of setback was 14.1 mm. [ABSTRACT FROM AUTHOR]

(1) Background: The purpose of this study was to evaluate stability and complications following mandibular setback using intraoral vertical ramus osteotomy (IVRO) and provide an assessment of IMF (Inter-maxillary Fixation) compliance. (2) Methods: This is a retrospective cohort study. It included a total of 39 patients who underwent 78 IVRO for the treatment of mandibular prognathism between 2005 and 2021 at Sheba Medical Center. Radiographic and clinical examinations were performed preoperatively (T0), 3 days post-surgery (T1) and 8 months post-surgery (T2). Measurements of dental and skeletal stability, as well as neurosensory disturbances and TMJ dysfunctions, were statistically analyzed. (3) Results: The mean mandibular setback was 5.6 mm. A relapse of less than 2 mm was observed at T2. A short-term neurological disturbance was reported in 38.46% of the 39 patients, and 17.94% of them showed full recovery by T2. In 21 patients who underwent IVRO without genioplasty, only 14.28% reported long-term sensory disturbance. In addition, when a vertical osteotomy was performed, neurological damage was 174% higher as compared to oblique osteotomy. The IMF compliance rate for the 6 weeks postoperatively was 100%. (4) Conclusions: IVRO is still a relevant and valid technique for the treatment of mandibular prognathism that provides stable results with minimal complications rate. [ABSTRACT FROM AUTHOR]

Objective: Maxillofacial Orthognathic surgery is performed to repair or correct the skeletal anomalies of the jaw and its associated dental and facial structures. There is a conflict on whether orthognathic surgery has a negative or positive effect on temporomandibular disorders (TMD). The aim of this study is to review the disorders of the temporomandibular joint after orthognathic surgery. Materials and Methods: Data for this review was obtained from the articles published between 2010-2020 via PubMed, Google scholar, Web of Sciences, and Scopus engines. The content keywords matched those used in PubMed and Mesh engines. Based on the inclusion and exclusion criteria; 27 articles were included. Results: Most of the selected articles were retrospective reviews and performed on class II and class III patients. Ages ranged from 19- 47 years. Pain reduction was reported in 11 studies, while 8 studies reported a click reduction post orthognathic operation. In 2 studies, decreased joint noises was reported after orthognathic operation, and 7 articles reported a decrease in maximum mouth opening. Three studies reported a Bilateral Sagittal split Osteotomy (BSSO) and in one study, reduced and improved symptoms after Le Fort I + (BSSO) were reported. One study exhibited that BSSO orthognathic surgery is less predictable in reducing TMD symptoms in retrognathic patients. Three articles showed that orthognathic patients with TMJ click have a high predictive value. Conclusion: To accomplish accurate results regarding temporomandibular joint disorders post orthognathic surgery; a larger number of subjects and clinical trial studies are required, as well as extended long term follow-up. Keywords: Temporomandibular joint; Mandibular advancement; Mandibular setback; Maxillary impaction; Maxillary advancement.

Correction of severe anteroposterior skeletal discrepancy, as described in this case of Extreme Skeletal Class III Malocclusion, can be challenging and fraught with difficulties. Conventional, single stage Bi-jaw Orthognathic surgery, with pre-and post-surgical orthodontics is associated with drawbacks such as risk of relapse and an unsatisfactory outcome, with persisting occlusal discrepancies and skeletal abnormalities, especially when the magnitude of skeletal correction is large. Excessive mandibular setback restricts tongue space, narrows the posterior airway and pharyngeal spaces, and is prone to relapse from the forward pterygomasseteric pull; while large maxillary advancements are accompanied by wound dehiscence, bone exposure and delayed union at the site of pterygomaxillary disjunction, and risk of relapse due to backward palatopharyngeal pull. Bi-jaw surgeries invariably involve considerable blood loss and prolonged operating time with its attendant anaesthetic risks.These drawbacks may be obviated by employing a two staged protocol of Bi-jaw surgeries allowing a minimum time period of 3 months to elapse between them, which allows the oral and maxillofacial musculature to adapt itself to the new jaw position following the first surgery, thus creating a better and more stable environment for the succeeding one. This reduces the chance of relapse thereafter, and produces more effective and stable long term results. The intervening time period also allows for observation of the repositioned jaw and arch relations achieved, and scrutiny for any positional changes in this post-surgical phase, which thereby allows modifications in the planned surgery of the next jaw, thereby achieving the most ideal final outcome.

Objective: This study was conducted to compare changes in pharyngeal airway after different orthognathic procedures in subjects with class III deformity. Methods: The study included CBCT scans of 48 skeletal class III patients (29 females and 19 males, mean age 23.50 years) who underwent orthognathic surgery in conjunction with orthodontic treatment. The participants were divided into three groups of 16, as follows: Group 1, mandibular setback surgery; group 2, combined mandibular setback and maxillary advancement surgery; and group 3, maxillary advancement surgery. CBCT images were taken 1 day before surgery (T0), 1 day (T1), and 6 months (T2) later. The dimensions of the velopharynx, oropharynx, and hypopharynx were measured in CBCT images. Results: In all groups, there was a significant decrease in airway variables immediately after surgery, with a significant reversal 6 months later (P < 0.05). In subjects who underwent maxillary advancement, the airway dimensions were significantly greater at T2 than the T0 time point (P < 0.05), whereas in the mandibular setback and bimaxillary surgery groups, the T2 values were lower than the baseline examination (P < 0.05). The alterations in airway variables were significantly different between the study groups (P < 0.05). Conclusions: The mandibular setback procedure caused the greatest reduction in the pharyngeal airway, followed by the bimaxillary surgery and maxillary advancement groups, with the latter exhibiting an actual increase in the pharyngeal airway dimensions. It is recommended to prefer a two-jaw operation instead of a mandibular setback alone for correction of the prognathic mandible in subjects with predisposing factors to the development of sleep-disordered breathing. [ABSTRACT FROM AUTHOR]

Objective: To investigate volumetric and circumferential pharyngeal airway space (PAS) changes and stability over time as evaluated with cone beam computed tomography (CBCT) before and after orthognathic surgery 2 years postoperatively. Materials and methods: One hundred twenty-eight patients underwent bimaxillary orthognathic surgery at the Department of Maxillofacial Surgery of University Hospitals, Leuven, Belgium, were recruited prospectively. Patients were divided into 4 groups based on the amount of mandibular advancement in 5 mm increments (< 0 mm, 0–5 mm, 5–10 mm, or > 10 mm). CBCT data was acquired preoperatively and 1–6 weeks, 6 months, 1 year, and 2 years postoperatively. Patients with a history of maxillofacial trauma or surgery, obstructive sleep apnoea syndrome, or craniofacial anomalies were excluded. Nasopharyngeal, oropharyngeal, and hypopharyngeal PAS volumes and constriction surface areas (mCSA) were measured and compared between each time point with a paired t-test. Results: The largest significant increase in oropharyngeal volume and mCSA were observed in the 5–10 mm (+ 13.3–21.7%, + 51.3–83.0%)) and > 10 mm (+ 23.3–44.6%, + 92.3–130.0%) mandibular advancement groups. This increase only remained stable 2 years postoperatively in the > 10 mm group. In other mandibular advancement groups, short-term oropharyngeal volume and mCSA increases were noticed, which returned to baseline levels 6 months to 1 year postoperatively. Conclusion: Bimaxillary advancement osteotomy significantly increases oropharyngeal volume and mCSA, which remains stable between 6 months to 1 year postoperatively. Clinical relevance: Long-term stable volumetric and mCSA enlargements were found with > 10 mm mandibular advancements over a period of 2 years. Return towards baseline levels was observed in the other mandibular advancement groups. [ABSTRACT FROM AUTHOR]

Abstract Maxillomandibular advancement (MMA) is effective for the treatment of obstructive sleep apnea (OSA). In previous studies, the airway was increased in the anteroposterior and transverse dimensions after MMA. However, the effect of the opposite of mandibular movement (mandibular setback) on the airway is still controversial. Mandibular setback surgery has been suggested to be one of the risk factors in the development of sleep apnea. Previous studies have found that mandibular setback surgery could reduce the total airway volume and posterior airway space significantly in both the one-jaw and two-jaw surgery groups. However, a direct cause-and-effect relationship between the mandibular setback and development of sleep apnea has not been clearly established. Moreover, there are only a few reported cases of postoperative OSA development after mandibular setback surgery. These findings may be attributed to a fundamental difference in demographic variables such as age, sex, and body mass index (BMI) between patients with mandibular prognathism and patients with OSA. Another possibility is that the site of obstruction or pattern of obstruction may be different between the awake and sleep status in patients with OSA and mandibular prognathism. In a case-controlled study, information including the BMI and other presurgical conditions potentially related to OSA should be considered when evaluating the airway. In conclusion, the preoperative evaluation and management of co-morbid conditions would be essential for the prevention of OSA after mandibular setback surgery despite its low incidence.

(1) Background: The purpose of this study was to evaluate stability and complications following mandibular setback using intraoral vertical ramus osteotomy (IVRO) and provide an assessment of IMF (Inter-maxillary Fixation) compliance. (2) Methods: This is a retrospective cohort study. It included a total of 39 patients who underwent 78 IVRO for the treatment of mandibular prognathism between 2005 and 2021 at Sheba Medical Center. Radiographic and clinical examinations were performed preoperatively (T0), 3 days post-surgery (T1) and 8 months post-surgery (T2). Measurements of dental and skeletal stability, as well as neurosensory disturbances and TMJ dysfunctions, were statistically analyzed. (3) Results: The mean mandibular setback was 5.6 mm. A relapse of less than 2 mm was observed at T2. A short-term neurological disturbance was reported in 38.46% of the 39 patients, and 17.94% of them showed full recovery by T2. In 21 patients who underwent IVRO without genioplasty, only 14.28% reported long-term sensory disturbance. In addition, when a vertical osteotomy was performed, neurological damage was 174% higher as compared to oblique osteotomy. The IMF compliance rate for the 6 weeks postoperatively was 100%. (4) Conclusions: IVRO is still a relevant and valid technique for the treatment of mandibular prognathism that provides stable results with minimal complications rate.

Background: The principle goal of orthognathic surgery is to establish a balanced and stable dento-skeletal facial complex. This mandates the surgeon and the orthodontist to be able to predict the soft tissue changes to the orthognathic surgery precisely, which is accurately possible using 3-D imaging. Aims: To evaluate the soft tissue changes following mandibular advancement and mandibular setback orthognathic surgeries using 3-D imaging. Methods and Material: This review was conducted according to Preferred Reporting Items for Systematic Reviews and meta-Analyses guidelines systematically searching the six databases including PubMed, Cochrane, Google Scholar, LILACS, Directory of Open Access Journals, and OpenGrey. Conclusion: In mandibular advancement surgeries, the hard to soft tissue movement ratio was 1:0.97. There is an increase in volume of both lip area and chin. In mandibular setback, there was increased gradient of change from upper lip and lower lip to the chin. It was also seen to extend from the midline (stomion) to the lateral (Chelion). The ratio of the soft tissue to bony movement was about 66 % at the Li point. [ABSTRACT FROM AUTHOR]

Abstract Purpose It has been reported before that the amount of pharyngeal airway space (PAS) significantly decreases following mandibular setback (MS) surgery in patients with mandibular prognathism (MP). Further, MP patients with an anterior open-bite (AOB) presentation may show a larger decrease in PAS compared with those without AOB. However, studies on postoperative PAS changes in MP patients with AOB remain rare. This study sought to evaluate changes in PAS and hyoid bone positioning following MS surgery in MP patients with and without AOB. Patients and methods Twenty patients who underwent two jaw surgery involving MS movement were included. Patients were divided into a non-AOB group (n = 10; overbite > 2 mm) and an AOB group (n = 10; overbite < − 4 mm). Three-dimensional changes in PAS and hyoid bone positioning were compared and statistically evaluated pre- and postoperatively using computed tomography (CT). Results The mean magnitude of MS was 6.0 ± 2.8 mm and 5.6 ± 3.2 mm in the non-AOB group and AOB group, respectively. The oropharyngeal volume and upper hypopharyngeal volume were significantly reduced after surgery in both the groups (p = 0.006 and p = 0.003), while the retroglossal cross-sectional area was significantly reduced only in the AOB group (p = 0.028). Although the AOB group showed a larger decrease in PAS, the difference was not statistically significant between the groups. The position of the hyoid bone showed significant posterior and inferior displacement only in the AOB group, while the vertical displacement of the hyoid bone showed a statistically significant difference between the two groups. Conclusion PAS was significantly decreased after MS in both the groups, while only the AOB group presented a statistically significant reduction in the retroglossal cross-sectional area. Vertical displacement of the hyoid bone showed a statistically significant difference between the groups, while the PAS change was not. Surgeons should be aware of potential postoperative airway problems that may arise when performing MS surgeries.

Introduction: Correction of a severe anteroposterior skeletal discrepancy, as described in this case of extreme skeletal class III malocclusion, can be quite challenging and fraught with difficulties. Conventional, single-stage bi-jaw orthognathic surgery with pre-and post-surgical orthodontics is associated with drawbacks such as the risk of relapse and an unsatisfactory overall long-term outcome, with persisting occlusal discrepancies and skeletal abnormalities, especially when the magnitude of skeletal correction required is large. Excessive mandibular setback can restrict tongue space, cause narrowing of posterior airway and pharyngeal space, and be prone to relapse from the forward pterygomasseteric muscle pull, while large maxillary advancements are often accompanied by wound dehiscence and bone exposure at the site of pterygomaxillary disjunction, delayed union or malunion at the osteotomy and disjunction sites, and risk of relapse due to backward palatopharyngeal muscle pull. In addition, bi-jaw surgeries invariably involve an appreciable blood loss and a prolonged operating time with its attendant anaesthetic risks such as respiratory insufficiency. Aim and Objectives: To develop an orthosurgical protocol wherein excessive skeletal discrepancy can be successfully managed, achieving the desired magnitude of correction, with little or no relapse. To assess its efficacy and superiority over the hitherto-employed single-stage bi-jaw procedures in the management of severe skeletal discrepancies. Materials and Method: A two-staged, shorter 'single-jaw at a time' operative procedure with an intervening period of three months between the two surgical phases was employed. Results: Drawbacks of conventional orthognathic surgery may be obviated by employing a two-staged protocol of bi-jaw surgeries allowing a minimum time period of 3 months to elapse between them. This period of time intervening between the maxillary advancement and mandibular setback allows the oral and maxillofacial musculature to adapt itself to the new jaw position following the first surgery, thus creating a better and more stable environment for the succeeding one, thereby reducing the chances of relapse thereafter, and producing more effective and stable long-term results. Moreover, the intervening time period also allows for observation of the repositioned jaw and arch relations achieved, and scrutiny for any positional changes in this post-surgical phase, which thereby allows modifications in the planned surgery of the next jaw, so as to achieve the most ideal final outcome following the second jaw surgery. A shorter operating time, reduced operator fatigue and less blood loss are other obvious advantages over the conventional bi-jaw procedures. Conclusion: An effective and stable correction of the extreme class III skeletal deformity and malocclusion was achieved, with a dramatic enhancement of facial balance, symmetry and proportion in this patient, following a modified orthosurgical management protocol. The staged protocol of 'maxilla first and mandible after' orthognathic surgery with conventional pre- and post-surgical orthodontics helped in pushing the envelope of skeletal discrepancy correctable by orthognathic surgery, thereby achieving large quantum of jaw movements, with ideal and stable functional as well as aesthetic results. This is suggestive of its efficacy and superiority over the hitherto-employed single stage bi-jaw procedures in the management of severe skeletal discrepancies. [ABSTRACT FROM AUTHOR]

To perform a systematic review to answer the clinical question "What are the longitudinal skeletal and airway changes after mandibular setback orthognathic procedures?" A systematic search including computer search of different databases with specific keywords, manual search through three international journals and reference list search was performed. Articles that were reporting the skeletal and airway changes after mandibular setback orthognathic procedures were evaluated with five predetermined criteria. Six articles with a total of 217 patients entered the final review. All were rated to be of moderate bias risk. Four studies evaluated the skeletal and airway changes using two-dimensional (lateral) cephalometric radiographic imaging, whereas the other two studies used three-dimensional imaging with cone-beam computed tomography. In the two-dimensional studies, skeletal relapses from T0 (immediate postoperative) to T1 (postoperative 1–6 months) ranged from −2.14 mm to 0.30 mm, whereas skeletal relapses from T1 to T2 (postoperative 1 year) ranged from −0.90 mm to 1.23 mm. In the three-dimensional studies, skeletal relapse from T1 to T2 ranged from −0.26 mm to 1.53 mm. All included studies reported that there were no significant skeletal relapses after mandibular setback procedures. Regarding airway changes, airway changes from preoperative to T0/T1 ranged from −0.30 mm to −2.32 mm in the two-dimensional studies. Airway changes from T0 to T1 ranged from −0.70 mm to −1.63 mm, whereas airway changes from T1 to T2 ranged from 0.11 mm to 0.60 mm, respectively. This systematic review showed there was insignificant skeletal relapse after mandibular setback orthognathic procedures. It was noted a small increase of the airway over the first post-operative year in studies using 2-dimensional radiography. However, such finding was not consistent in studies using 3-dimensional imaging with volumetric analysis of the airway changes. [ABSTRACT FROM AUTHOR]

Background and Aim: Mandibular setback surgery is one of the common treatments in patients with mandibular prognathism. In this surgery, the mandible is placed backward from its original position, and as a result, the soft tissue, tongue, and hyoid bone are slightly displaced, all of which can affect the dimensions of the airway. Given that these changes in the dimensions of the airway can lead to obstructive sleep apnea, it is important to examine these changes and their stability. In this regard, cephalometric radiography can be used, which haslowcost and dose in comparison to 3D radiographs, to examine changes in airway dimensions. The aim of this study was to evaluate the short-term and long-term changes in airway dimensions following mandibular steback surgery with the help of cephalometric radiography. Materials and Methods: The study was conducted by review method. Using the keywords ‘orthognathic surgery,’ ‘mandibular setback,’ ‘Malocclusion angle class III,’ ‘prognathism,’ ‘airway,’ ‘posterior airway space,’ ‘PAS,’ ‘pharyngeal space, ‘hypopharynx, a review of articles in PubMed and Embase databases, Google Scholar, and Cochrane databases was performed. The range of article searches was from 2000 to 2020. Conclusion: The results of studies showed that in the first 6 months after surgery, the dimensions of the airway decrease, but over time, due to the adaptation of the surrounding tissues and relapse after surgery, there is an improvement in the dimensions of the airway; Also, the study of index-related breathing disorders during sleep disorders during sleep showed that this surgery does not necessarily lead to obstructive sleep apnea. Keywords: Orthognathic surgery; Mandibular setback; Malocclusion angle class III; Prognathism; Airway; Posterior airway space; PAS; Pharyngeal space; Hypopharynx.

The purpose of this case report is to describe and discuss a combined surgical and orthodontic technique for the management of transverse maxillary deficiency and mandibular prognathism in the treatment of skeletal Class III malocclusion in a mature patient. Skeletal Class III malocclusion can present with maxillary deficiency or retrognathism, mandibular excess or prognathism, or a combination. The maxillary arch is narrow and often requires expansion. A 25-year-old patient presented with a constricted maxilla, a skeletal Class III malocclusion with a large mandible, Angle's Class III malocclusion, retroclined lower incisors, proclined upper incisors, crowding of maxillary and mandibular teeth, and bilateral posterior crossbite. The case report shows that an adult patient with Class III malocclusion (constricted maxilla and large mandible) can be treated with rapid maxillary expansion accompanied by bilateral maxillary osteotomies, followed by a reduction bilateral sagittal split osteotomy (BSSO). As the patient was 25 years old with a bilateral crossbite, a surgically assisted rapid maxillary expansion procedure was performed. As the diastema space was available at the end of expansion, it proved to be beneficial for the presurgical decompensation of Class III, thus creating a negative overjet, followed by which a BSSO setback was done. [ABSTRACT FROM AUTHOR]

Abstract Background Bimaxillary orthognathic surgery with maxillomandibular setback is often accompanied by changes in airway space. We analyzed the changes in airway space before and after surgery and assessed their association with obstructive sleep apnea. Methods This study is based on the cohort of 13 adult patients (9 males, 4 females, average age 23.85 years) who underwent bimaxillary orthognathic surgery with maxillomandibular setback. We performed computed tomography and portable polysomnography before and after the surgery to assess changes in airway space and Apnea-Hypopnea Index (AHI) values (total, supine, non-supine). Results The oropharyngeal airway volume decreased by 29% after the surgery, which was statistically significant (p

Q4: Horizontal changes occur following bilateral sagittal split osteotomy (BSSO) in skeletal class III patients. The aim of this study was to assess the ostoperative changes in intergonial (IG) width and compare them between the positional screw and miniplate fixation methods in BSSO. This study evaluated patients who had mandibular prognathism and underwent BSSO for mandibular setback. Internal fixation was performed bilaterally, either with positional screws in the lateral ramus or with a miniplate. Postero-anterior cephalograms were obtained preoperatively (T1), at 1 month postoperative (T2), and at 6 months postoperative (T3). The IG widths and the alterations in IG width postoperative (T2 − T1, T3 − T2) were measured. No correlations were observed between the amount of setback and changes at T2 − T1 or T3 − T2. The IG width values decreased after mandibular setback and internal fixation with both methods. Statistical analyses showed a significant difference between T3 and T1 in the miniplate group (P = 0.045). No significant difference in the postoperative change in IG width (T2 − T1 and T3 − T2) was found between the two fixation groups. The magnitude of this change was smaller for positional screws when compared to miniplates for fixation. The amount of mandibular setback showed no correlation with postoperative changes in IG width.. [ABSTRACT FROM AUTHOR]

Maxillomandibular advancement (MMA) is effective for the treatment of obstructive sleep apnea (OSA). In previous studies, the airway was increased in the anteroposterior and transverse dimensions after MMA. However, the effect of the opposite of mandibular movement (mandibular setback) on the airway is still controversial. Mandibular setback surgery has been suggested to be one of the risk factors in the development of sleep apnea. Previous studies have found that mandibular setback surgery could reduce the total airway volume and posterior airway space significantly in both the one-jaw and two-jaw surgery groups. However, a direct cause-and-effect relationship between the mandibular setback and development of sleep apnea has not been clearly established. Moreover, there are only a few reported cases of postoperative OSA development after mandibular setback surgery. These findings may be attributed to a fundamental difference in demographic variables such as age, sex, and body mass index (BMI) between patients with mandibular prognathism and patients with OSA. Another possibility is that the site of obstruction or pattern of obstruction may be different between the awake and sleep status in patients with OSA and mandibular prognathism. In a case-controlled study, information including the BMI and other presurgical conditions potentially related to OSA should be considered when evaluating the airway. In conclusion, the preoperative evaluation and management of co-morbid conditions would be essential for the prevention of OSA after mandibular setback surgery despite its low incidence. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the factors influencing three-dimensional changes in pharyngeal airway space after mandibular setback surgery. Airway changes in 48 skeletal class III patients who had undergone mandibular setback surgery alone (n = 25, group 1) or with maxillary surgery (n = 23, group 2) were analyzed. Linear parameters, cross-sectional area, and volumes of the pharyngeal airway were evaluated before (T0), immediately after (T1), and 1 year after surgery (T2) by cone beam computed tomography. Although the reduced airway volume and cross-sectional area recovered slightly in the long term after surgery, the total pharyngeal airway volume (TPV) was significantly reduced compared to baseline, by 15% in group 1 and 12% in group 2. Regression analysis showed that maxillary posterior impaction in two-jaw surgery had a protective effect on preserving TPV. A change in body mass index from T0 to T2 was an important predictor of decreased TPV in one-jaw surgery patients. Maxillary posterior impaction can be a reliable option for compensating the pharyngeal airway reduction after mandibular setback surgery. Postoperative weight gain can increase the risk of postoperative pharyngeal airway reduction. Therefore, these factors need to be considered before and after mandibular setback surgery. [ABSTRACT FROM AUTHOR]

The possible negative outcomes of mandibular setback surgery (MSS) on the upper airway (UA) have become an important issue in recent years. The purpose of the present study was to compare the different amounts of MSS and to confirm the accepted maximum amount of mandibular setback by using Computational Fluid Dynamics (CFD) method. An anatomically similar UA model was constructed from magnetic resonance images of a systemically healthy individual. Two out of six models were kept as control models and the remaining four models were created to represent MSS scenarios with different amounts to correct Class III skeletal abnormality. The airflow was assumed laminar, incompressible, and the surrounding soft tissue was assumed to be linear elastic. The sixth model that was representative of 15 mm of MSS showed statistically significant differences from the other models (p < 0.05). No significant differences were observed among other models in terms of all the parameters (p > 0.05). CFD has been recently used in researches by modeling the UA flow; however, to the best of our knowledge, none of the studies have proved the maximum limits of MSS amounts with this technique. Graphical abstract ᅟ. [ABSTRACT FROM AUTHOR]

Summary Background Maxillary retrognathia is a well-known consequence of abnormal facial growth in patients with cleft lip and palate. Orthognathic surgery improves facial appearance and occlusion but may induce velopharyngeal insufficiency. The aim of this study was to evaluate the effect of orthognathic surgery on velopharyngeal function by using speech analysis and lateral cephalometric radiographs. Patients and Methods We conducted a retrospective study of 47 patients who underwent maxillary advancement ± mandibular setback between 2006 and 2016. Preoperative and 1 year postoperative audio recordings were blinded for scoring by three trained speech therapists. Preoperative and 1 year postoperative lateral cephalometric radiographs were used to obtain information about skeletal movement and its relationship with the velopharyngeal area. Correlations between speech outcomes and cephalometric radiographs were determined. Results Hyponasality improved significantly after surgery (p < 0.05), whereas hypernasality deteriorated significantly only in patients who underwent maxillary advancement alone (p < 0.05). No difference in speech parameters was found between patients with hypernasality or patients who had a pharyngoplasty preoperatively and the rest of the group. No correlation was found between the amount of maxillary advancement and hypernasality. A significant correlation (r < -0.49, p < 0.05) was found between the preoperative velar length and hypernasality postoperatively. Conclusions Maxillary advancement has a negative impact on velopharyngeal function, whereas bimaxillary surgery seems to protect from deterioration. No difference was found in the amount of maxillary advancement or in velopharyngeal measurements between the Le Fort I group and the bimaxillary group. A short soft palate is a predictor of hypernasality after orthognathic surgery. [ABSTRACT FROM AUTHOR]

The cheek line (face reading) is an aesthetic element of the facial profile. The purpose of our study was to investigate the changes in the cheek line after mandibular setback surgery. Forty patients (20 female and 20 male, mean (SD) age 22 (5) years) were diagnosed with mandibular prognathism and treated by intraoral vertical ramus osteotomy alone. Cephalograms were obtained before operation (T1), at least a year postoperatively (T2), and final surgical changes over a year (T2-T1). The cheek line and landmarks (soft and hard tissues) were compared using the paired t test. The hypothesis was that the cheek line did not change significantly after mandibular setback. At the time of the final follow-up (T2-T1), the mean (SD) horizontal setback of pogonion (Pog) was 12.3 (3.5) mm for women and 11.7 (4.3) mm for men. The ratios of soft:hard tissue, labrale inferius:incisor inferius, labiomental sulcus:point B, soft tissue Pog:Pog, and cheek point:Pog in women were 0.96, 0.98, 0.98, and 0.08, and in men 0.91, 1.01, 0.94, and 0.13, respectively. The nasolabial and cervicomental angles in women were significantly increased by 11.1° and 11.4°, respectively, and in men the nasolabial angle was significantly increased by 11.1° and the mentolabial angle reduced by 9.9°. The cheek line (T2-T1) was moved significantly forwards. The hypothesis was therefore rejected. In conclusion, the cheek line was advanced significantly after isolated mandibular setback. [ABSTRACT FROM AUTHOR]

A combination of orthodontic and orthognatic surgery was planned for a 18-year-old male with class III malocclusion, mandibular asymmetry, unilateral crossbite and open bite. After 10 month of pre-surgery orthodontic treatment, mandibular setback was done. Unexpectedly, two weeks later the right fixation plate were exposed intra-orally and had to be removed. Eventually, the return of mandibular assymetry and midline shifting were inevitable. This required an extensive post-surgery orthodontic treatment to distalize the right lower segment using miniscrew. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the postoperative longitudinal skeletal changes and stability following intraoral vertical ramus osteotomies (IVRO) for orthognathic mandibular setback, and the possible risk factors that might affect the stability. A retrospective cohort study was conducted. Lateral cephalograms were analyzed for the predictor (magnitude of setback and adjunctive procedures) and outcome (stability of vertical and horizontal dimensions) variables at six time points. A total of 152 patients (mean age 24.2 years) were included in the study. Following IVRO, the mandible measured at B-point had moved a mean 0.50 mm posteriorly at 1 week after the removal of intermaxillary fixation (7 weeks postoperative); this was followed by progressive small anterior relapse. At 2 years postoperative, the mean relapse of the mandible after IVRO measured at B-point was 0.05 mm (standard deviation 1.14 mm), representing 0.7% of the mean surgical movement. Large setback (>8 mm) showed significantly higher relapse compared to small setback (<4 mm) at 2 years after surgery ( P = 0.021). Patients who underwent adjunctive mandibular surgeries other than IVRO showed no significant differences in relapse compared to those who underwent IVRO alone. In conclusion, IVRO for mandibular setback is a stable procedure in the long term, with small relapse of 0.05 mm after 2 years. [ABSTRACT FROM AUTHOR]

Orthognathic surgery is undertaken to correct anteroposterior, vertical, and transverse anomalies of the maxilla and mandible. Surgery has significant effects on the overlying soft tissue envelope. Some of these effects are beneficial while others may be detrimental to facial aesthetics. This review aims to update the reader on what soft tissue changes occur following orthognathic surgery to the mandible and maxilla. It is important to anticipate the detrimental effects of orthognathic surgery as this will allow the patient to be warned about them before treatment and in some cases, adjunctive procedures may be planned to limit the unwanted changes. [ABSTRACT FROM AUTHOR]

Objective: This study is aimed at assembling, through a systematic review and meta-analysis, scientific evidence related to the effects of mandibular setback (MdS) surgery and bimaxillary surgery for the correction of Class III malocclusion on the cross-sectional area (CSA) and volume of the upper airway as assessed using CT.Methods: An electronic search was conducted on Cochrane Library, EMBASE, PubMed, Scopus and Web of Science up to June 20, 2016. The inclusion criteria were prospective or retrospective studies, with the aim of comparing the impact on the upper airway space of orthognathic surgery for the treatment of the skeletal class III malocclusion. The methodological index for non-randomized studies (MINORS) was chosen as the evaluation instrument and Revman5.3 was used for the meta-analysis.Results: A total of 1213 studies were retrieved, of which only 18 met the eligibility criteria. The results of meta-analysis showed that the mean decrease in the upper airway volume after MdS surgery was 3.24 cm3 [95%CI (-5.25,-1.23), p = 0.85]; the mean decrease in minimum CSA after a combined surgery of maxillary advancement with mandibular setback (MdS + MxA) was 27.66 mm2 [95%CI (-52.81,-2.51), p = 0.51], but there was no significant decrease in upper airway volume (mean 0.86 cm3); comparison between MdS + MxA and isolated MdS showed significant differences in the CSA of the posterior nasal spine plane (PNS) and epiglottis plane (EP); statistically significant differences in nasopharynx volume (P < 0.0001) and upper airway total volume (P = 0.002) were observed, but no statistically meaningful variations existed in oropharynx volume (P = 0.08) and hypopharynx volume (P = 0.64).Conclusion: The results of this study suggest that bimaxillary surgery promotes less decrease on the upper airway than mandibular setback surgery alone for the correction of the skeletal class III malocclusion. [ABSTRACT FROM AUTHOR]

This study aimed at comparing the transverse and sagittal angulations of proximal segment after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO), and examining their influences on the stability of distal segment. Methods: Patients who received SSRO (n = 21) or IVRO (n = 11) for mandibular setback were included. Lateral and posteroanterior cephalograms taken within 1 month before surgery (T1), within 1 week after surgery (T2), and at least 6 months after surgery (T3) were analyzed. The angulation of each proximal segment relative to the upper orbital margin line was measured on posteroanterior cephalogram and the sum of both angles (total ramus angle, TRA) was obtained. On lateral radiograph, ramus inclination angle (RIA) relative to a horizontal reference line 7° to the sella–nasion was assessed and B-point position was measured. Results: From T1 to T2, more increases in TRA and RIA were noted after IVRO than after SSRO. From T2 to T3, TRA and RIA significantly decreased in IVRO group but remained relatively stable in SSRO group. ΔTRAT1–T2 positively related to upward rotation of distal segment for SSRO and downward rotation for IVRO from T2 to T3. For SSRO only, ΔRIAT1–T2 significantly related to forward movement of distal segment during remodeling. Conclusion: TRA and RIA increase significantly after IVRO and then regress, whereas they increase mildly after SSRO and remain stable. Increase in TRA significantly relates to distal segment rotation during remodeling for both surgeries, but increase in RIA relates to forward relapse of the distal segment only for SSRO. The reasons underlying the correlations are not certain and deserve future investigations.

OBJETIVO: o objetivo deste estudo foi avaliar as alterações causadas por cirurgia ortognática de recuo mandibular associada ou não à cirurgia maxilar combinada nas vias aéreas superiores (VAS). MÉTODOS: foram avaliadas radiografias cefalométricas de perfil pré-cirúrgicas e pós-cirúrgicas imediatas de 17 pacientes com Classe III. Foram realizadas medições do diâmetro do espaço aéreo (EA) no plano sagital, nas regiões correspondentes à hipofaringe e à orofaringe; também foram registradas as alterações na posição do osso hioide. Utilizou-se o teste t pareado e o coeficiente Pearson, buscando possíveis associações entre as alterações esqueléticas e as ocorridas no EA. RESULTADOS: observou-se redução significativa do EA na região da hipofaringe (média de 3,10mm, p=0,024). O osso hioide sofreu deslocamento inferior e posterior, além de diminuição da distância entre o mesmo e a região anterior da mandíbula. Não foi possível correlacionar, quantitativamente, a redução anteroposterior do EA com o recuo mandibular. Entretanto, observou-se correlação forte entre o diâmetro inicial do EA e a quantidade de redução observada ao nível da hipofaringe, e moderada em relação à orofaringe. CONCLUSÕES: o recuo mandibular pode causar estreitamento significativo das VAS, principalmente na porção mais inferior (hipofaringe). Portanto, deve-se atentar para sua avaliação durante o plano de tratamento ortocirúrgico, já que não foram descartados possíveis efeitos deletérios dessas alterações nas funções do indivíduo.OBJECTIVE: The purpose of this study is to evaluate the alterations caused by mandibular setback surgery combined or not with maxillary surgery in the upper airways. METHODS: Preoperative and immediate postoperative lateral cephalometric radiographs of 17 Class III patients were evaluated. Measurements of the diameter of air space (AS) in the sagittal plane were performed in regions corresponding to the hypopharynx and oropharynx; changes in the position of the hyoid bone were also registered. The paired t test and Pearson coefficient were used to provide possible associations between skeletal changes and those occurred in the AS. RESULTS: There was a statistically significant reduction of AS in the hypopharynx region (average of 3.10 mm, p = 0.024). The hyoid bone moved backward and downward after the surgery, and the distance between this bone and the anterior region of mandible decreased. It was not possible to correlate, quantitatively, the anteroposterior reduction of the AS after the mandibular setback. However, there was a strong correlation between the initial diameter of AS and the amount of reduction seen at the hypopharynx; this correlation was found to be moderate at the oropharynx level. CONCLUSIONS: The mandibular setback surgery can cause significant narrowing of the upper airways, especially in hypopharynx region. Therefore, it is important to evaluate this structure during treatment planning of combined orthodontic and surgical cases. Possible deleterious effects of these changes on individuals' functions were not yet discarded.

Objectives: This study examined the changes in temporomandibular joint dysfunction (TMD) symptoms and investigated the variations in the disc position, disc and condylar morphology following sagittal split ramus osteotomy (SSRO) with rigid fixation in patients with mandibular prognathism. Furthermore, the authors examined the correlation between mandibular setback and TMD symptoms.Methods: The study included 24 Japanese patients with jaw deformities who were treated using bilateral SSRO and Le Fort I osteotomy. The clinical and magnetic resonance imaging findings in the temporomandibular joint were evaluated preoperatively and at three and six months postoperatively.Results: The preoperative TMD symptoms were significantly associated with the prevalence of TMD symptoms at six months postoperatively. Anterior disc displacement improved in four joints with slight displacement and with no morphological change. There were no postoperative changes in condylar morphology. There was no significant correlation between mandibular setback and the postoperative TMD symptoms.Conclusion: Postoperative TMD symptoms may be influenced mainly by preoperative TMD symptoms rather than mandibular setback using SSRO with rigid fixation. Therefore, patients with TMD symptoms require physical examination and MRI for appropriate diagnosis preoperatively. [ABSTRACT FROM AUTHOR]