Comparative Analysis of Temperature-Responsive Hydrogel (PF 72) for Postoperative Pain After Bimaxillary Surgery: A Retro-spective Study.

Bimaxillary surgery is a painful invasive procedure in plastic surgery. Pain control is typically achieved using intravenous analgesics. We aimed to investigate the efficacy of a novel temperature-responsive hydrogel, PF72, mixed with ropivacaine, as a local pain management solution when applied directly to the surgical site following orthognathic surgery. The study was conducted from October 2022 to July 2023 and included a cohort of 40 candidates for orthognathic surgery, encompassing LeFort I maxillary ostectomy and sagittal split ramus osteotomy. The participants were divided into an Injection group (n = 20), where PF72 was administered at the surgical site before the orthognathic surgery, and a Control group (n = 20), which relied solely on intravenous analgesics. Pain was evaluated at 3, 6, 24, 48, and 72 h after surgery using a numerical rating scale (NRS). The mean NRS scores at 24 h were 6.35 and 4 for the Control and Injection groups, respectively. The mean NRS scores at 72 h were 3.4 and 2.55 for the Control and Injection groups, respectively. Patients who received PF72 experienced less pain than those who received intravenous analgesics. These findings underscore the potential of PF72 as an effective alternative for enhancing pain management in patients undergoing orthognathic surgery.Level of Evidence III Therapeutic study. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of counterclockwise bimaxillary advancement surgery and relapse on upper airway.

OBJECTIVE: The aim of this study was to evaluate the long-term volumetric changes of the upper airway compartments in response to counterclockwise bimaxillary advancement surgery with multi-piece maxillary osteotomy, and to analyse the relationship between the postoperative stability of the maxillomandibular skeletal complex, and the volumetric airway changes over-time. METHODOLOGY: Twenty-seven sets of pre (T0), post (T1) and follow-up (T2) (20.15 months) CBCT scans were used. The upper airway was isolated into five compartments: soft and bony nasal cavity (SNC, BNC), nasopharynx (NP), oropharynx (OP) and hypopharynx (HP) using Mimics V.22 software. The volumetric changes and the correlation between the airway change and the skeletal movements were analysed using repeated measure ANOVA, and Pearson's correlation coefficient, respectively. RESULTS: The results showed a significant decrease in SNC and BNC (10.94% and 7.69%, p < .05) at T1. However, SNC presented a significant recovery (11.73%, p < .05) at T2. NP, OP and HP segments presented significant and stable increases over time (10.41%, 53.62%, 24.70%, p < .05). CONCLUSIONS: This surgical approach produced a significant increase in OP and HP volumes in short and long term without a significant relapse, NP showed a significant increase in long term only, SNC and BNC volumes showed a significant decrease post-surgery which was only partially maintained for BNC.

Structural and functional changes of nasal cavity and maxillary sinus in patients with skeletal class III malocclusion 1 year after bimaxillary surgery.

PURPOSE: This study aimed to analyse changes in the nasal cavity and maxillary sinus structure and function in patients with skeletal class III malocclusion 1 year after bimaxillary surgery. MATERIALS AND METHODS: In this study, cone-beam computed tomography (CBCT) images of 20 patients (10 men and 10 women; mean age 24.3 ± 3.4 years) with skeletal class III malocclusion who underwent Le Fort I osteotomy and bilateral sagittal split osteotomy were obtained before and 1 year after the surgery. CBCT data were stored opened with element 3D (E3D) to establish a nasal airway model (the paranasal sinus includes only the maxillary sinus). Ansys (ANSYS) software is used for simulation and analysis. RESULTS: The maxillary sinus and nasal cavity volumes decreased significantly 1 year after the surgery. After surgery, the volume of nasal cavity decreased by 13.5%, and the average volume of maxillary sinus decreased by 7.8%. There was no significant difference in the degree of deviation of the septum and nasal cavity resistance, and air distribution in the maxillary sinus did not change. The nasal cavity wall shear stress change was similar to that before surgery. CONCLUSIONS: The maxillary sinus volume and nasal cavity volume of patients with skeletal class III malocclusion changed significantly after bimaxillary surgery, but there was no significant change in nasal ventilation function 1 year after surgery.

Comparison of stability and outcomes of surgery-first bimaxillary surgery for skeletal class III deformity between unilateral and bilateral cleft lip and palate.

OBJECTIVES: Some adults with cleft lip and palate (CLP) require orthognathic surgery due to skeletal deformity. This prospective study aimed to (1) compare skeletal stability following bimaxillary surgery for correction of class III deformity between patients with unilateral CLP (UCLP) and bilateral CLP (BCLP), and (2) identify risk factors of stability. MATERIALS AND METHODS: Adults with CLP and skeletal class III deformities who underwent surgery-first bimaxillary surgery were divided into two groups according to cleft type: UCLP (n = 30) and BCLP (n = 30). Skeletal stability was assessed with measures from cone beam computed tomography images of the maxilla and mandible taken before treatment, 1-week and ≥ 1 year postsurgery for translation (left/right, posterior/anterior, superior/inferior) and rotation (yaw, roll, pitch); multiple regression analysis examined risk factors. RESULTS: At follow-up, the maxilla moved upwards in both groups, and backwards in the UCLP group. The mandible moved forward and upward, shifted to the cleft (deviated) side, and rotated upward in both groups. The amount of surgical advancement was a risk factor for sagittal stability in the maxilla (ß = -0.14, p < 0.05). The mandible had three risk factors for sagittal stability: age (ß = -0.23, p < 0.05), surgical team (ß = -1.83, p < 0.05), and amount of surgical setback (ß = -0.32, p = 0.001). CONCLUSIONS: Two years after bimaxillary surgery, patients with UCLP had a higher sagittal relapse of the maxilla compared with patients with BCLP, which was due to a greater surgical advancement in the patients with UCLP. CLINICAL RELEVANCE: Surgery-first bimaxillary surgery results in favorable treatment outcomes for correction of cleft-related class III deformity. Severity of jaw discrepancy and surgeons should be considered in the surgical design of overcorrection.

Fully Digitalized Workflow for One-Stage Mandibular Contouring and Orthognathic Surgery to Correct Severe Facial Asymmetry.

INTRODUCTION: Surgical correction of facial asymmetry is commonly performed in at least two stages. Recently, because of the long duration of a two-step procedure, the demand for a one-step procedure has increased. Our study aims to present a fully digitalized workflow for one-stage mandibular contouring (MC) and bimaxillary surgery to correct severe facial asymmetry using 3D technology. MATERIALS AND METHODS: A retrospective monocentric study was conducted for all patients affected by severe facial asymmetry who had undergone MC and orthognathic surgery between January 2018 and June 2020 at the Face Surgery Center, in Parma, Italy. RESULTS: The final study sample included 20 patients (12 women and 8 men). The mean age of the patients at the time of surgery was 20.8 years (range: 18-25 years). At the one-year follow-up, all patients had stable occlusion with a symmetric face. Mandibular angle degree (Ar-Go-Me) increased significantly from 113. 6° to 122.7° at the left side and from 113.3° to 122.7° at the right side (p < 0.05) (Table 1). The mandibular width (Go-Go) decreased from 116.5 to 106.4 mm (p < 0.05). CONCLUSION: A fully digitalized workflow for one-stage MC and bimaxillary surgery is a safe and valid option to correct facial asymmetry. CAD CAM technology is an indispensable tool to obtain predictable results. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Penehyclidine for prevention of postoperative nausea and vomiting following bimaxillary orthognathic surgery: a randomized, double-blind, controlled trial.

PURPOSE: To investigate the efficacy and safety of low-dose bolus plus continuous infusion of penehyclidine in preventing postoperative nausea and vomiting (PONV) following bimaxillary surgery. METHODS: Three hundred fifty-four patients were randomly allocated into three groups. In the Control group, placebo (normal saline) was injected before anesthesia and infused over 48 h after surgery; in the Bolus group, 0.5 mg penehyclidine was injected before anesthesia, whereas placebo was infused after surgery; in the Infusion group, 0.25 mg penehyclidine were injected before anesthesia, another 0.25 mg penehyclidine was infused after surgery. The primary endpoint was the incidence of PONV within 72 h. RESULTS: A total of 353 patients were included in intention-to-treat analysis. The PONV incidence was 61.0% (72/118) in the Control group, 40.2% (47/117) in the Bolus group, and 28.0% (33/118) in the Infusion group. The incidence was significantly lower in the Bolus group than in the Control group (RR 0.66; 95% CI 0.51-0.86; adjusted P = 0.003) and in the Infusion group than in the Control group (RR 0.46; 95% CI 0.33-0.63; adjusted P < 0.001); the difference between the Infusion and Bolus groups was not statistically significant (RR 0.70; 95% CI 0.48-1.00; adjusted P = 0.144). Emergence agitation occurred more frequently in the Bolus group than in the Control group (36.8% [43/117] vs. 21.2% [25/118], adjusted P = 0.027), but did not differ significantly between the Infusion and Control groups. CONCLUSIONS: A low-dose bolus plus continuous infusion of penehyclidine was effective in preventing PONV without increasing emergence agitation. TRIAL REGISTRATION: Clinicaltrials.gov. Identifier: NCT04454866.

The accuracy of maxillary positioning using digital model planning and 3D printed wafers in bimaxillary orthognathic surgery.

OBJECTIVE: Orthognathic wafers may be made using digital model movements and CAD-CAM technology. This paper analysed the accuracy of maxillary movements using this new process. DESIGN: Retrospective study of pre and post-operative cephalograms. PARTICIPANTS: Thirty consecutive orthognathic patients undergoing bimaxillary osteotomies in a UK hospital. METHODS: Jaw movements were planned using cephalometric and Orthoanalyzer™ software. The resultant intermediate and final wafer occlusal relationships were used for wafer fabrication by 3D printing of the inter-occlusal space. Pre- and post-operative lateral cephalograms were compared in terms of maxillary antero-posterior and vertical movements. Statistical analyses including the paired t-test, two-sample t-test and Fisher's exact test. RESULTS: Wide individual variation was observed between the planned and actual movements. Thirteen cases (43%) had a 2 mm discrepancy in at least one variable. Statistically significant differences between the planned and actual maxillary vertical movements were observed for the molar (U6y: p < 0.0001) and anterior maxillary (Ay: p < 0.01) differences. Analysis of a subgroup with primarily impaction movements demonstrated a statistically significant bias towards excessive maxillary advancement (U1x: p < 0.01) and incisor impaction (U1y: p < 0.01) in this group. CONCLUSIONS: This new digital surgical wafer technique achieves a similar level of accuracy to the conventional facebow and model surgery process.

Three-dimensional evaluation of the pharyngeal airway using cone-beam computed tomography following bimaxillary orthognathic surgery in skeletal class III patients.

OBJECTIVE: The study aims to evaluate the pharyngeal airway space (PAS) following bimaxillary surgery in skeletal class III patients and to compare the changes in PAS between genders using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: In all, 38 patients (16 male and 22 female) with skeletal class III malocclusion underwent bimaxillary surgery. CBCT scans were acquired approximately 1 month before surgery, 3 months after surgery, and 6 months after surgery. The oropharyngeal volume and the minimum cross-sectional area (CSA) were characterized using the InVivoDental imaging software package at each time point. RESULTS: The volume and minimum CSA decreased significantly postoperatively, which was maintained until 6 months postoperatively (p < 0.01). The location of the minimum CSA tended to move into the retropalatal and retroglossal areas postoperatively. A strong correlation between volume and minimum CSA was found. The amount of mandibular setback was not correlated with the change in the airway. By gender, significant decreases in both the volume and minimum CSA were found in females (p < 0.05) but not in males. CONCLUSION: Bimaxillary surgery significantly affects PAS. Gender differences should also be considered when considering changes in PAS. CLINICAL RELEVANCE: An awareness of the effects of bimaxillary setback surgery on the airway should be considered when implementing an orthognathic treatment plan.

Changes in Maxillary Sinus Volume and Mucosal Thickness Post Bimaxillary Advancement Procedures: A Retrospective Study.

Background: Bimaxillary surgery is an elemental procedure in the field of cranio-maxillofacial surgery. It allows for the correction of even the most challenging cases of maxillomandibular disorders, malocclusion, facial asymmetry, and disproportion. The osteotomies and maneuvers carried out during the procedure result in changes to the surrounding tissues, including the maxillary sinuses (MS). The aim of this study was to assess the change in the maxillary sinus volume and the thickness of the mucosa after maxillomandibular advancement (MMA) surgeries. Methods: A group of 25 patients who underwent MMA surgery were included in the study. Computed tomography (CT) of the head and neck region was performed 2 weeks preoperatively and 6 months postoperatively. Acquired Digital Imaging and Communications in Medicine (DICOM) files were analyzed using different software programs to calculate the medium MS mucosa thickness and MS volume. Results: A statistically significant reduction in MS volume was observed (p = 0.015). The change in the median thickness of the MS mucosa was not statistically significant. The median sella-nasion-A point angle (SNA angle) value of the group increased from 80.2 to 83.4 degrees. A weak negative correlation between the SNA delta and the MS volume delta was observed. Spearman's rank coefficient: (ρ s = -0.381, p = 0.060). Conclusions: The MMA surgery results in a reduction in the MS volume. The amount of forward movement of the maxilla may be correlated with the extent of the MS volume reduction.

The Assessment of Upper Airway Volume Changes Following Bimaxillary Advancement Surgery: A Radiological Evaluation in the Supine Position at Multiple Intervals.

Background: Bimaxillary surgeries (BiMax) are an essential part of the craniomaxillofacial specialty. The osteotomies and subsequent spatial rearrangement of the maxilla and the mandible enable the correction of facial deformities, asymmetry, and malocclusion. Moreover, the movements performed during the procedure affect the morphology of surrounding soft tissues, including the upper airway (UA). Objectives: The objective of this study was to radiologically assess the potential volumetric alterations of the UA in the supine position at various intervals following BiMax advancement surgeries. Methods: A group of 31 patients who underwent BiMax advancement surgery were included in the study. Medical computed tomography (CT) of the head and neck region was performed 2 weeks preoperatively, 1 day postoperatively, and 6 months postoperatively. The UA volumes were calculated and analyzed based on the acquired Digital Imaging and Communications in Medicine (DICOM) files using different software applications. The sella-nasion-A point (SNA) and sella-nasion-B point (SNB) angles were evaluated to measure the achieved maxillomandibular advancement. Results: When comparing the volume of the UA before surgery, post-surgery, and 6 months post-surgery, the p-value was <0.001, indicating statistically significant differences in UA volume between the successive examinations. A statistically significant difference was found between UA volume before surgery and 6 months post-surgery and between UA volume after surgery and 6 months post-surgery, with the obtained p-values being <0.001 and 0.001, respectively. A significantly larger UA volume was observed 6 months post-surgery (mean ± SD: 27.3 ± 7.3) compared to the volume before surgery (mean ± SD: 22.2 ± 6.4), as well as 6 months post-surgery compared to the volume assessed shortly after surgery (mean ± SD: 24.2 ± 7.3). Conclusions: BiMax advancement surgeries result in the significant enlargement of the UA. The volume of the UA does not diminish immediately following the procedure and is not constant; it increases significantly during the postoperative observation period.

Assessing the Risks and Benefits of Hypotensive Anesthesia and Piezosurgical Instruments in Bimaxillary Surgery.

The challenge in bimaxillary surgery lies in significant intraoperative bleeding, prompting various strategies to minimize blood loss. Among the methods considered for controlling intraoperative bleeding, hypotensive anesthesia and the use of piezosurgical instruments (Osada, Tokyo, Japan) have been explored. However, hypotensive anesthesia may have adverse effects on cardiac function, and surgical time is likely to be prolonged when using piezosurgical instruments. This study retrospectively examined whether the combined use of hypotensive anesthesia and piezosurgical instruments reduces intraoperative bleeding and whether the combination impacts cardiac function. The combination of hypotensive anesthesia and piezosurgical instruments significantly reduced intraoperative bleeding. Furthermore, the combination was associated with a significantly higher incidence of tachycardia, particularly with the use of nicardipine. Additionally, the combination significantly lengthened the duration of the surgery and may have increased the burden on cardiac function. Landiolol was effectively employed to manage tachycardia. When selecting hypotensive anesthesia as a means to limit bleeding, proactive preparation and preventive small-dose administration of landiolol could be beneficial in managing the potential occurrence of tachycardia.

Assessment of soft- and hard-tissue changes following combined anterior segmental bi-jaw orthognathic surgery.

Background: Anterior segmental Bi-jaw orthognathic surgery is indicated primarily for the correction of dentoalveolar protrusion. They are also indicated for correcting apertognathia, closing interproximal spaces between segments and can be incorporated with other osteotomies to obtain better results. Aim: The aim of this study was to analyze and compare the soft- and hard-tissue changes in patients who underwent combined anterior segmental bi-jaw orthognathic surgery. Settings and Design: To compare and evaluate soft- and hard-tissue changes before and after combined anterior segmental bi-jaw orthognathic surgery by assessing (a) parameters in vertical dimension and (b) parameters in horizontal dimension and patient satisfaction was also assessed following surgery at 6 months' time interval. Materials and Methods: It is a prospective, single center and analytical study with sample size of 20 patients. It required routine setup for orthognathic surgery and manual tracing of lateral cephalograms. The surgical outcomes were assessed by hard tissue (Sella Nasion Point A (SNA) angle, Sella Nasion Point B (SNB) angle, Point A Nasion Point B (ANB) angle, NAPg, U1-NF, L1-MP angles; NA, NB, B-Pg, Nasion-Anterior nasal spine (N-ANS) distance, Anterior nasal spine-Gnathion (ANS-Gn) distance, and overjet and overbite) and soft tissue (facial convexity, NL, LM angles; LM fold, UL and LL protrusions, Upper lip length (ULL), Lower lip length (LLL), Sn-A, Si-B, Pg-Pg*, Ls-U1, Li-L1 distances, interlabial gap, and U1 exposure) variables pre and postsurgery. Statistical Analysis: Descriptive statistics involved the mean and standard deviation, and recorded data were subjected to the statistical analysis using IBM SPSS 20 statistical package. The paired t-test, Pearson correlation coefficient were used. The level of significance P < 0.05 was taken as statistically significant and P < 0.01 as very significant. Results: Overall improvement after surgery in both hard- and soft-tissue parameters was observed and significant changes were seen in every variable, except Si-B (P > 0.05). Correlations between soft- and hard-tissue changes were significant in both sagittal and vertical planes. Patients' satisfaction score showed that all patients had the high overall rate of satisfaction. Conclusions: Our study concludes that combined anterior segmental bimaxillary orthognathic surgery is a simple technique with minimal postoperative complications and limited relapse. The changes in facial esthetics and occlusion following orthognathic surgery depend highly on the stability achieved during the postoperative period.

Effect of bimaxillary surgery on the stress distributions in patients with mandibular retrognathia under unilateral molar clenching.

To investigate the effect of bimaxillary surgery on the stress distribution of the temporomandibular joint (TMJ) in patients with mandibular retrognathia under unilateral molar clenching (UMC). Five patients with mandibular retrognathia (preoperative group) and ten asymptomatic subjects (control group) were recruited. In addition, patients treated with bimaxillary surgery were considered as the postoperative group. The muscle forces corresponding to UMC were applied. The results showed that the discal stresses in the postoperative group were significantly greater than those in the preoperative and control groups. Bimaxillary surgery plus UMC had a detrimental effect on the TMJ.

Sequencing in Orthognathic Bimaxillary Surgery: Which Jaw Should Be Operated First? A Scoping Review.

Bimaxillary orthognathic surgery is widely used for the correction of dentoskeletal deformities. Surgery sequencing (maxilla or mandible first) remains debated, and guidelines and consensus are lacking. This scoping review summarizes the state of the art and compares the advantages and disadvantages of both approaches. The review was conducted following PRISMA-ScR guidelines. Three electronic databases (PubMed, Scopus, Web of Science) were searched using the PICO protocol and key words in orthognathic surgical sequencing. Four reviewers screened the records independently, and disagreement was resolved by consensus. A total of 23 records met the inclusion criteria. The advantages and disadvantages of the two approaches were compared and assessed for accuracy of reporting. Within the limitations of the present study, available evidence for the intrinsic advantages and the accuracy of the mandible-first sequence supports the choice of this approach in most cases. Nevertheless, each clinical case needs to be evaluated individually, as no dogmatic recommendations can be given for sequencing in bimaxillary orthognathic surgery.

Risk Factors for Prolonged Mechanical Ventilation and Delayed Extubation Following Bimaxillary Orthognathic Surgery: A Single-Center Retrospective Cohort Study.

BACKGROUND: Bimaxillary orthognathic surgery bears the risk of severe postoperative airway complications. There are no clear recommendations for immediate postoperative follow-up and monitoring. OBJECTIVE: to identify potential risk factors for prolonged mechanical ventilation and delayed extubation in patients undergoing bimaxillary orthognathic surgery. METHODS: The data of all consecutive patients undergoing bimaxillary surgery between May 2012 and October 2019 were analyzed in a single-center retrospective cohort study. The clinical data were evaluated regarding baseline characteristics and potential factors linked with delayed extubation. RESULTS: A total of 195 patients were included; 54.9% were female, and the median age was 23 years (IQR 5). The median body mass index was 23.1 (IQR 8). Nine patients (4.6%) were of American Society of Anesthesiologists Physical Status Classification System III or higher. The median duration of mechanical ventilation in the intensive care unit was 280 min (IQR, 526 min). Multivariable analysis revealed that premedication with benzodiazepines (odds ratio (OR) 2.60, 95% confidence interval (0.99; 6.81)), the male sex (OR 2.43, 95% confidence interval (1.10; 5.36)), and the duration of surgery (OR 1.54, 95% confidence interval (1.07; 2.23)) were associated with prolonged mechanical ventilation. By contrast, total intravenous anesthesia was associated with shorter ventilation time (OR 0.19, 95% confidence interval (0.09; 0.43)). CONCLUSION: premedication with benzodiazepines, the male sex, and the duration of surgery might be considered to be independent risk factors for delayed extubation in patients undergoing bimaxillary surgery.

A clinico-statistical study of factors associated with intraoperative bleeding in orthognathic surgery.

BACKGROUND: Excessive bleeding is a major intraoperative risk associated with orthognathic surgery. This study aimed to investigate the factors involved in massive bleeding during orthognathic surgeries so that safe surgeries can be performed. Patients (n=213) diagnosed with jaw deformities and treated with bimaxillary orthognathic surgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) in the Department of Oral and Maxillofacial Surgery at the Suidobashi Hospital, Tokyo Dental College between January 2014 and December 2016 were included. Using the patients' medical and operative records, the number of cases according to sex, age at the time of surgery, body mass index (BMI), circulating blood volume, diagnosis of maxillary deformity, direction of maxillary movement, operative duration, incidence of bad split, injury of nasal mucosa, and blood type were analyzed. RESULTS: The results revealed that BMI, circulating blood volume, nasal mucosal injury, and operative time were associated with the risk of intraoperative massive bleeding in orthognathic surgeries. Chi-square tests and binomial logistic regression analyses showed significant differences in BMI, circulating blood volume, direction of maxillary movement, operative duration, and injury to the nasal mucosa. Operative duration emerged as the most important risk factor. Furthermore, a >4-mm upward migration of the posterior nasal spine predicted the risk of massive bleeding in orthognathic surgery. CONCLUSIONS: The upward movement of the maxilla should be recognized during the preoperative planning stage as a risk factor for intraoperative bleeding, and avoiding damage to the nasal mucosa should be considered a requirement for surgeons to prevent massive bleeding during surgery.

Changes in the pharyngeal airway after different orthognathic procedures for correction of class III dysplasia.

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.

A rare complication of an Arteriovenous shunt after bimaxillary surgery.

The most common complications following bimaxillary surgery are inferior alveolar nerve damage, hemorrhage, and relapse. Severe complications are rare, but few cases of vascular arteriovenous malformation, cavernous sinus thrombosis, formation of an aneurysm or arteriovenous shunting are reported in literature. We present a case of a 20-year-old male patient who developed a right sided tinnitus and visible pulsations close to the mandibular angle on the right side after bimaxillary surgery. CT-angiography and subsequent digital subtraction angiography (DSA) six months after surgery showed an arteriovenous fistula (AVF) from the external carotid artery to the external jugular vein. The AVF was treated by endovascular coil embolization. At six months after intervention there were no residual complaints. We discuss the possible etiology and trauma mechanisms that might have caused this pathology and present recommendations to avoid this type of complications.

Is there a hidden blood loss in orthognathic surgery and should it be considered? Results of a prospective cohort study.

The aim of this prospective observational study was to investigate the parameter 'hidden blood loss' (HBL) in the context of orthognathic surgery, incorporating undetected bleeding volumes occurring intra- and postoperatively. Orthognathic bleeding volumes were recorded at three different time points. At the end of the operation the visible intraoperative blood loss (VBL) was measured. Additionally, the perioperative blood loss was calculated 24 h and 48 h postoperatively using the 'haemoglobin balance method'. Analysis of the HBL was based on the difference between the visible intraoperative blood loss (VBL) and calculated blood loss (CBL), determined 48 h after surgery. 82 patients (male 33, female 49) were included in this study, of whom 41 underwent bimaxillary surgery and of whom 41 underwent Bilateral Sagittal Split Osteotomy (BSSO). Statistically significant differences with reference to the absolute bleeding volumes were found when comparing the two treatment modalities. In terms of HBL, a bleeding volume of 287.2 ml (±265.9) in the bimaxillary group and 346.9 ml (±271.3) in the BSSO cohort was recorded. This accounted for 32.2% (bimaxillary surgery) and 62.6% (BSSO) of the CBL after 48 h (BIMAX vs. BSSO, p < 0.001). HBL is a valuable adjunct to record within the perioperative management of orthognathic surgery to further improve patient safety and postoperative outcomes.

Postoperative changes in the pharyngeal airway space through computed tomography evaluation after mandibular setback surgery in skeletal class III patients: 1-year follow-up.

BACKGROUND: This study evaluated the pharyngeal airway space changes up to 1 year after bilateral sagittal split osteotomy mandibular setback surgery and bimaxillary surgery with maxillary posterior impaction through three-dimensional computed tomography analysis. METHODS: A total of 37 patients diagnosed with skeletal class III malocclusion underwent bilateral sagittal split osteotomy setback surgery only (group 1, n = 23) or bimaxillary surgery with posterior impaction (group 2, n = 14). Cone-beam computed tomography scans were taken before surgery (T0), 2 months after surgery (T1), 6 months after surgery (T2), and 1 year after surgery (T3). The nasopharynx (Nph), oropharynx (Oph), hypopharynx (Hph) volume, and anteroposterior distance were measured through the InVivo Dental Application version 5. RESULTS: In group 1, Oph AP, Oph volume, Hph volume, and whole pharynx volume were significantly decreased after the surgery (T1) and maintained. In group 2, Oph volume and whole pharynx volume were decreased (T2) and relapsed at 1 year postoperatively (T3). CONCLUSION: In class III malocclusion patients, mandibular setback surgery only showed a greater reduction in pharyngeal airway than bimaxillary surgery at 1 year postoperatively, and bimaxillary surgery was more stable in terms of airway. Therefore, it is important to evaluate the airway before surgery and include it in the surgical plan.