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Protecting the adjacent soft tissues using a channel retractor prevents complications, such as excessive bleeding, during sagittal split ramus osteotomy. However, the saucer-shaped blade of the conventional channel retractor fits poorly into the posterior border of the mandibular ramus during medial osteotomy, which is typically performed parallel to the occlusal plane. Therefore, a novel channel retractor was developed with an adjusted blade bending angle, based on cephalometric data. The lateral cephalograms of 339 Japanese patients with jaw deformities were collected. Cephalometric landmarks were identified based on the definitions of the Downs-Northwestern analysis, and the acute angle between the occlusal and ramus planes was calculated. Based on the consistent mean and median occlusal ramus angles obtained, the blade was bent at 70° in the sagittal plane to fabricate the angled channel retractor. The engagement at the posterior border of the mandibular ramus during medial osteotomy enhances its stability. Furthermore, owing to the bending direction, the angled channel retractor used for medial osteotomy on one side can be used as a channel retractor for lateral osteotomy on the other side. The proposed angled channel retractor offers both stability and versatility for osteotomy manoeuvres., Competing Interests: Competing interests None., (Copyright © 2024 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

This article describes a novel minimally invasive technique for bilateral sagittal split osteotomy (BSSO) that aims to reduce surgical trauma while maintaining bone overlap and rigid internal fixation for proper consolidation of the bone segments. The technique involves a small vestibular mucoperiosteal incision made on the lateral aspect of the mandible between the first and second molars, enabling a standard ramus split, surgical segment movement, and miniplate fixation. A retrospective evaluation of 67 consecutive patients who underwent BSSO using this protocol showed favorable split of the mandible with no unfavorable splits or non-union. Patients were discharged from hospital within an average of 17 h with minimal postoperative complications. This technique provides good surgical visualization with a very small incision and allows standard BSSO surgery without difficulty., Competing Interests: Competing interests None., (Copyright © 2024 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The surgical treatment for mandibular repositioning using a bilateral sagittal split osteotomy (BSSO) favours the development of techniques that result in adequate repair and stability. In Puricelli's mandibular sagittal split osteotomy (PMSSO) proposal, the vertical lateral cut osteotomy is located in the interradicular space between the lower first molar and second premolar., Objectives: This in silico study aimed to investigate the mechanical stability of PMSSO and compare it with the classical Obwegeser-Dal Pont technique for mandibular advancement., Materials and Methods: A computational geometric model of the mandible was created in a virtual environment using computer-aided design (CAD) software. After reproducing the advancements, two test groups were developed: GTOD10, Obwegeser-Dal Pont osteotomy, and GTP10, Puricelli osteotomy, both simulating a 10-mm mandibular advancement, allowing for measuring the area of overlap between bone segments. With the geometric changes promoted by the osteotomy, boundary conditions of displacement and force were applied to a CAD software based on finite element analysis (FEA), allowing for quantitative and comparative analysis of the stress and vertical displacement of the mandible, mechanical measurements that may be associated with strength and stiffness., Results: A 17.48% higher stress was observed in the GTP10 group than in GTOD10. However, the region of highest stress in GTP10 was found in a part of the bone that was still intact and far from the area of fragility caused by lateral vertical osteotomy. In contrast, in GTOD10, the region with high stress was in a less resistant bone region. The GTP10 group showed a 28.73% lower displacement than GTOD10. The area of overlap between the proximal and distal segments of the mandible was 33.13% larger in the GTP10 than in the GTOD10 group., Conclusion: The PMSSO method, performed in large mandibular advancements, keeps the point of highest stress away from the mandibular fragility zone. Considering the same amount of advancement, it also promotes less displacement and larger areas of bone overlap., Clinical Relevance: The results suggest that PMSSO, applied in large mandibular advancement, presents greater postoperative stability., (© 2024. The Author(s).)

The aim of this study was to investigate the stability of the proximal mandibular reference structures that have been proposed in the literature for superimposition. Forty proximal mandibular segments of 20 patients who underwent bilateral sagittal split osteotomy (BSSO) for advancement were reconstructed from a pair of pre- and postoperative (2 years) cone beam computed tomography scans, and spatially divided into the mandibular condyle, the coronoid process, and 20 mandibular ramus regions. To assess the stability of the anatomical regions, the volumetric and surface discrepancy between the superimposed pre- and postoperative regions were calculated. One-sample t-tests were applied to analyse the statistical stability of the individual regions. Two statistically stable (P < 0.05) structures in the proximal segment of the mandible following BSSO were identified: (1) the posterior part of the mandibular ramus above the gonial angle and below the condylar neck, and (2) the sub-coronoid area below the coronoid process/mandibular notch. Using these stable structures for superimposition resulted in an assessment discrepancy in the condylar displacement of up to 1.1 mm and in the volumetric change of up to 2.8%. Hence, it is suggested that these two identified stable structures are used as reference areas when assessing condylar displacement and change using superimposition., Competing Interests: Competing interests None. Competing Interests No competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: It is necessary to determine whether the sequence of maxillary and mandibular surgeries in bimaxillary orthognathic surgery affects the accuracy of surgical outcomes., Purpose: The study aimed to measure and compare the accuracy among patients who underwent maxilla-first versus mandible-first bimaxillary surgery to correct a class III skeletal pattern., Study Design, Setting, Sample: This retrospective cohort study included consecutive patients treated by a single surgeon at one center using Le Fort I and bilateral sagittal split osteotomy surgery. Exclusions included patients scheduled for one-jaw or maxilla-segmental surgery and those with craniofacial syndromes, such as clefts., Predictor Variable: The predictor variable was operative sequence for bimaxillary operations, divided into maxilla- or mandible-first groups., Outcome Variable: The outcome variable was accuracy, measured using linear discrepancies between landmarks in the virtual plan and actual operative outcomes. The measurement of linear discrepancy that was closer to 0 was considered the more accurate result., Covariates: Sex, age, maxilla sagittal rotation degree, amount of posterior maxilla impaction, mandibular autorotation (°), and intermediate splint thickness (mm) were the covariates., Analyses: Statistical analysis was performed using Student's t-test and Pearson's correlation, with statistical significance set at P < .05., Results: The sample comprised 60 patients with a mean age of 22.8 ± 3.7 years, of whom 36 (60%) were male. In the maxilla-first group, there were 30 subjects (60% male; mean age: 23.1 ± 4.2 years), with a mean mandibular autorotation of 0.41° (range: 0°-2.5°). The mandible-first group comprised 30 patients (60% male; mean age: 22.6 ± 3.3 years), with a mean mandibular autorotation of 5.46° (range: 1.9°-9.2°). The linear discrepancies for all landmarks did not significantly differ between mandible- and maxilla-first groups (P > .18). The mean three-dimensional discrepancies for all landmarks in maxilla-first group was 1.23 ± 0.5 mm and 1.23 ± 0.33 mm in mandible-first group, with no significant difference observed between the groups (P > .98). The amount of mandibular autorotation for intermediate splint application showed no significant correlation with the linear discrepancies (P > .58)., Conclusion and Relevance: In patients with skeletal class III malocclusion, mandible-first surgery in bimaxillary orthognathic surgery demonstrates accurate outcomes comparable to maxilla-first surgery., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate the recovery of lingual nerve (LN) neurosensory function in patients undergoing sagittal split osteotomy (SSO) with a low and short medial horizontal cut., Methods: This was a prospective study of patients with mandibular deformities undergoing SSO with a low and short medial horizontal cut over a 4-year period. The outcomes of interest were neurosensory recovery of the LN, as assessed objectively using functional sensory recovery (FSR) and subjectively by patient report., Results: The sample included 123 SSOs in 62 subjects with a mean age of 19.3 ± 3.1 years. Thirty-seven subjects (61.7%) were female. Mandibular advancements were performed in 52 SSOs (42.3%); mandibular setbacks were performed in 71 SSOs (57.7%). One subject underwent revision BSSO. FSR was achieved at 122 LNs (99.1%) within 6 weeks postoperatively, with 120 sites (97.5%) having S4 sensation at 6 weeks. Decreased LN sensation was reported at 10 (8.3%) sites at 1 week postoperatively. At 6 weeks postoperatively, 118 sites (97.5%) had reported normal sensation. By 12 weeks postoperatively, all LN sites had S4 sensation and there were no subjective complaints. Revision sagittal split osteotomy was associated with prolonged (≥6 weeks) time to S4 sensation ( P = 0.02) and subjective complaint of decreased sensation ( P = 0.02)., Conclusions: LN sensory recovery occurs rapidly following the low and short SSO, with 99% of sites achieving FSR and subjectively normal sensation within 6 weeks of surgery and all patients achieving FSR with S4 sensation by 12 weeks postoperatively. LN sensory recovery may be prolonged in patients undergoing revision SSO., Clinical Question/level of Evidence: Therapeutic, IV., (Copyright © 2023 by the American Society of Plastic Surgeons.)

Purpose: This retrospective study aimed to evaluate sequential changes in soft tissue thickness after bilateral sagittal split ramus osteotomy (BSSRO) in skeletal class III patients with facial asymmetry and to explore their correlation with surgical movements for optimal postoperative facial symmetry and esthetic outcomes., Material and Methods: This study included 37 patients with class III malocclusion and > 4 mm Menton (Me) deviation who underwent BSSRO. Posteroanterior cephalograms were captured at preoperative (T0), 6 weeks (T1), 6 months (T2), and 1 year (T3) postoperative intervals to analyze changes in Me deviation, fronto-ramal inclination (FRI), and soft tissue thickness. Statistical analysis was conducted to assess the changes in soft tissue thickness over time and the effects of surgical correction., Results: Significant improvements in facial asymmetry were noted after surgery, with reductions in Me deviation and FRI on both the deviated side (DS) and non-deviated side (NDS). An increase in soft tissue thickness was observed on both the DS and NDS after surgery, with the NDS showing a continued increase between 6 months and 1 year, indicating an ongoing compensation for symmetry restoration. The study also identified a positive correlation between the surgical movement of the FRI and the increase in soft tissue width on the NDS after 6 months., Conclusion: This study established that soft tissue thickness continues to adapt and change up to 1 year after BSSRO, underscoring the need for a long-term evaluative approach in orthognathic surgery for patients with facial asymmetry., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Purpose: PEMF (pulsed electromagnetic fields) founds application in several medical fields to accelerate bone wounds healing and to reduce inflammation. The aim of our study was to evaluate the effectiveness of PEMF in reducing postoperative swelling and pain in patients undergoing orthognathic surgery., Methods: A prospective observational monocentric study was conducted on a sample of 30 patients undergone to orthognathic surgery in Maxillofacial Surgery Unit of University of Naples Federico II. The patients who followed these inclusion criteria were enrolled in the study: age ≥ 18 years, Class III malocclusion, Surgical procedure of Le Fort I osteotomy + Bilateral Sagittal Split Osteotomy (BSSO), Written informed consent. Patients were divided into two groups: Group SD) postoperative standard treatment with medical therapy and cryotherapy, Group SD + PEMF) postoperative standard therapy + PEMF. Each patient underwent a 3D facial scan, at one (1d) and four (4d) days after surgery to compare the swelling reduction. The pain score was assessed through VAS score and analgesics administration amount., Results: In SD + PEMF group, the facial volume reduction between 1d and 4d scan was on average 56.2 ml (6.23%), while in SD group, it was 23.6 ml (2.63%). The difference between the two groups was 3.6% (p = 0.0168). VAS pain values were significantly higher in SD group compared to SD + PEMF group in the second day after surgery (P = 0.021) and in the total 4 days (P = 0.008)., Conclusions: Our data suggest that PEMF is valid tool to promote faster postoperative swelling and pain reduction in patients undergoing orthognathic surgery., (© 2024. The Author(s).)

Purpose: The study aims to analyse the effects of condylar rotation on the biomechanical environment of the TMJ after bilateral sagittal split ramus osteotomy (BSSRO) through the finite element method (FEM)., Methods: Thirteen patients with mandibular prognathism and twenty-three normal subjects were recruited. The three-dimensional (3D) models were reconstructed. 13 representative morphological parameters were measured for comparison. A patient was selected to perform virtual BSSRO surgery by rotating the condyles in MIMICS. The preoperative and postoperative 3D models of the patient were subsequently imported into ABAQUS for finite element analysis. The preoperative and postoperative stresses and joint spaces in the TMJs were investigated., Results: The maxillofacial morphologies of the patients with mandibular protrusion was significantly different from those of the asymptomatic subjects (P<.05). Stresses in the postoperative group were lower than those in the preoperative group. The rotation of the condyle could cause the variations in stress levels and joint spaces within the TMJs. Inward and upward rotation of the condyle was associated with higher stress in the TMJ, whereas the lowest stress was observed when the condyle remained stationary following surgical intervention., Significance: Lateral, medial and superior joint spaces were more related to the stresses in the TMJs. The condyle should be kept in place as much as possible to avoid disrupting the balance of the TMJ in patients with mandibular protrusion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Purpose: Intraoral vertico-sagittal ramus osteotomy (IVSRO) was first reported by Choung in 1992 as a surgical procedure to decrease postoperative condylar dislocation. In 2017, Iwanaga et al. developed modified L-shaped IVSRO (mIVSRO) to reduce postoperative nerve dysfunction and achieved favorable outcomes. This study aimed to clarify the effect of mIVSRO on changes in temporomandibular joint (TMJ) symptoms and three-dimensional condylar position., Methods: We conducted a retrospective study of thirty sides in fifteen Japanese adults diagnosed with jaw deformities who underwent mIVSRO and sagittal split ramus osteotomy (SSRO). TMJ symptoms were assessed chronologically, and the condylar long axis and the condylar position were analyzed two- and three-dimensionally using axial cephalograms and cone-beam computed tomography., Results: Postoperative TMJ symptoms improved by 90% (9/10 sides) in the mIVSRO group and by 50% (7/14 sides) in the SSRO group. The mIVSRO group exhibited outward rotation of the condylar long axis, while the SSRO group exhibited inward rotation. Moreover, mIVSRO induced residual anteromedial-inferior deviation of the condyle. The inclination angle of the condylar process was not significantly different between the two procedures pre- and postoperatively., Conclusion: These results clearly demonstrated the effect of mIVSRO on symptomatic TMJ. Residual changes in the position of the condyle following mIVSRO may not affect jaw function., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: The aim of this study was to evaluate the effect of maxillary movements in orthognathic surgery on nasal airway volume change and its correlation with airflow and resistance., Materials and Methods: This study included 25 patients (8 male, 17 female) with Class II (6 patients) or Class III (19 patients) malocclusion. All patients underwent Le Fort I and bilateral sagittal split ramus osteotomy. Nasal airflow and resistance were measured by using rhinomanometry and acoustic rhinometry pre and six months post-operatively. Nasal volume was measured using computed tomography before surgery and six months after surgery., Results: Nasal volume increased in 10 out of 11 patients with CCW (counterclockwise) rotation and decreased in 1 patient while, nasal volume increased in 5 patients with CW (clockwise) rotation and decreased in 9 patients. Superior nasal airway volume increased significantly, while the effects on nasal flow and resistance were not significant. Additionally, no significant correlation was found between airway volume changes and variations in airflow and resistance., Conclusion: CCW rotation in orthognathic surgery patients significantly increased superior nasal airway volume but did not improve nasal airway flow and resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: One of the key features of orthognathic surgery is altering temporomandibular joint (TMJ) condylar positions., Purpose: This multivariate study aimed to identify surgical interventions and patient factors significantly associated with changes in TMJ spatial dimensions after the surgical correction of skeletal Class II deformities., Study Design, Setting, Sample: This is a retrospective cohort study including patients who had undergone an isolated bilateral sagittal split ramus osteotomy (BSSO) or a bimaxillary osteotomy (BMO) for mandibular advancement and a control sample of patients treated with the removal of odontogenic cysts in the mandibular posterior region. Excluded were those who presented with specific radiographic signs of TMJ osteoarthrosis, severe facial asymmetry, or deformity secondary to trauma., Predictor/exposure/independent Variable: The primary predictors were condylar position at baseline (anterior, concentric, and posterior), time points (T0, preoperatively; T1, immediately after surgery; and T2, 1-year follow-up), and surgical intervention type (BSSO, BMO, and control group)., Main Outcome Variables: The primary outcomes were changes in posterior spatial dimension (PSD), superior spatial dimension, and medial spatial dimension assessed by cone-beam computed tomography preoperatively, immediately after surgery, and at 1-year follow-up., Covariates: Covariates included sex, age, and amount of mandibular advancement., Analyses: Estimations of independent effects of primary predictors on outcome variables were made by applying generalized estimation equation models. The value of statistical significance was P < .05., Results: The study sample included 88 participants. The BSSO samples included 39 patients, and the BMO group included 22 patients; the control group comprised 27 subjects. The average age was 31.2 years; the majority were female (61.4%). Adjusted generalized estimation equation models yielded a significant time interaction between BSSO and spatial dimensions over time (PSD, P < .001). Key predictors of spatial dimension changes were the baseline posterior (PSD, P < .001) and the central condylar position (PSD, P < .001)., Conclusion and Relevance: This controlled study, for the first time, provides scientific evidence on the effects of surgical intervention type and baseline condylar position on spatial dimension changes in the TMJ. It shows a more favorable outcome in long-term spatial dimension changes for patients treated by a BMO procedure., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Orthognathic surgery has a high incidence of postoperative nausea (PON) and vomiting (POV), delaying mobility initiation and postoperative recovery. Bleeding is another risk associated with this surgical procedure. We aimed to compare total intravenous anesthesia (TIVA) and volatile anesthesia in patients undergoing orthognathic surgery in terms of postoperative nausea and vomiting (PONV) incidence and hemodynamic changes. This retrospective study included 82 patients who underwent bilateral sagittal split ramus osteotomies at Saga University Hospital between April 2016 and April 2021. We compared the effects of TIVA and volatile anesthesia on PONV onset after surgery, acute postoperative hemodynamic changes (blood pressure and heart rate), and factors contributing to PONV. PON was significantly lower in the TIVA group than in the volatile anesthesia group. The total dose of fentanyl contributed to the onset of POV, while the onset of PON was associated with low volumes of fluid infusion and urine in the TIVA and volatile anesthesia groups, respectively. Furthermore, post-extubation hemodynamic change was significantly smaller in the TIVA group than in the volatile anesthesia group. Therefore, TIVA could have a reduced risk of PONV and hemodynamic changes in patients undergoing orthognathic surgery. Employing TIVA could mitigate perioperative complications and enhance patient safety., (© 2024. The Author(s).)

Purpose: We evaluated the changes in the strain energy density (SED) in the temporomandibular joint (TMJ) disk after sagittal split ramus osteotomy (SSRO) at three time points. A finite element model (FEM) based on real patient-based computed tomography (CT) data was used to examine the effect of SSRO on the TMJ., Methods: Measurements of the condylar position and angulation in CT images and FEM analyses were performed for 17 patients scheduled to undergo SSROs at the following time points: before surgery, immediately after surgery, and 1 year after surgery. SED on the entire disk was calculated at each of the three time points using FEM. Furthermore, the relationship between individual SED values and the corresponding condylar position was also evaluated., Results: No significant change was observed in the condylar position at the three time points. The FEM analysis showed that SED was the highest and lowest immediately after and 1 year after surgery, respectively. A possible SED distribution imbalance between the left and right joints was improved 1 year after SSRO. Concerning the effect of fossa morphometry and condylar position, wide and deep glenoid fossae and a more posterior condylar position tended to show lower SED., Conclusion: SED in the articular disk temporarily increased after surgery and significantly decreased 1 year after surgery compared with that before surgery. SSRO generally improved the imbalance between the left and right joints. Thus, SSRO, which improves maxillofacial morphology, may also improve components of temporomandibular disorders., (© 2023. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Purpose: Conventional orthognathic surgical planning has limitations in accurately transferring the relationship between soft tissue and bone. Virtual planning offers enhanced accuracy and visualization through computer simulation. This study aimed to compare the need for reoperation between patients who underwent conventional and virtual surgical planning for orthognathic surgery., Material and Methods: The study included 352 patients who underwent orthognathic surgery. Reoperation rates and reasons for reoperation were evaluated in patients with conventional model surgery planning (143 patients) and virtual planning (209 patients)., Results: The reoperation rate was 7.69% for conventional surgery patients and 3.82% for virtual planning patients. Malocclusion was the most common reason for reoperation in both groups. Bilateral sagittal split ramus osteotomies (BSSO) and genioplasty were the most frequently performed revision procedures., Conclusion: Virtual planning in orthognathic surgery may lead to a reduced reoperation rate compared with conventional planning methods. The accuracy, visualization, and interdisciplinary collaboration offered by virtual planning can improve surgical outcomes., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Background: This study was conceived to assess the postoperative stability of condylar position following fixation with miniplates and lag screws after bilateral sagittal split osteotomy (BSSO)., Methods: This retrospective study included a cohort of 20 patients undergoing BSSO using the Obwegeser-Dal Pont modification. The bony segments were stabilized using either miniplates with two 2.0-mm monocortical screws per segment or three 2.0-mm bicortical lag screws along the mandible's superior border. Pre- and postoperative (7-day interval) spiral computed tomography scans were conducted to assess skeletal changes across both groups. Data analysis employed Wilcoxon signed-rank and Wilcoxon rank-sum tests (α = 0.05)., Results: No statistically significant difference was observed between the pre-and postoperative condylar position parameters (P>0.05). However, the lag screw group showed a marginal significant increase in the left condyle's angulation (preoperative: 24.83 ± 6.37 vs. postoperative: 32.5 ± 4.93; P = 0.04). Changes in condylar height, length, and width were not statistically significant before and after BSSO in either groups (P>0.05). Nor was any statistically significant difference found between the miniplates and lag screws groups regarding condylar position parameters (P>0.05)., Conclusion: The results indicated that both lag screw and miniplate fixation methods can be effectively employed in BSSO procedures without impacting condylar position parameters. Thus, either fixation method can be chosen depending on factors such as the surgeon's preference and clinical outcomes., (© 2024. The Author(s).)

Objectives: To establish an analysis pipeline for the volumetric evaluation of the osteotomy site after bilateral sagittal split osteotomy (BSSO)., Patients and Methods: Cone-beam computed tomography (CBCT) was performed before, directly after BSSO, and 6-12 months after surgery. Image segmentations of each osteotomy gap data set were performed manually by four physicians and were compared to a semi-automatic segmentation approach., Results: Five patients with a total of ten osteotomy gaps were included. The mean interclass correlation coefficient (ICC) of individual patients was 0.782 and the standard deviation 0.080 when using the manual segmentation approach. However, the mean ICC of the evaluation of anatomical sites and time points separately was 0.214, suggesting a large range of deviation within the manual segmentation of each rater. The standard deviation was 0.355, further highlighting the extent of the variation. In contrast, the semi-automatic approach had a mean ICC of 0.491 and a standard deviation of 0.365, which suggests a relatively higher agreement among the operators compared to the manual segmentation approach. Furthermore, the volume of the osteotomy gap in the semi-automatic approach showed the same tendency in every site as the manual segmentation approach, but with less deviation., Conclusion: The semi-automatic approach developed in the present study proved to be valid as a standardised method with high repeatability. Such image analysis methods could help to quantify the progression of bone healing after BSSO and beyond, eventually facilitating the earlier identification of patients with retarded healing., (© 2024. The Author(s).)

This study presents a combination of 2 different surgery procedures performed on the mandible as part of the treatment aiming to improve the facial profile and occlusal function of patients with severe skeletal class Ⅲ malocclusion and bilateral edentulous gaps. The teeth next to the edentulous gaps were found to be ankylosed. Mandibular setback by bilateral sagittal split ramus osteotomies and mandibular body osteotomies, combined with Le Fort Ⅰ level maxillary advancement were performed, since the chief complaint of the patient was a concave profile. As a result, the skeletal class Ⅲ malocclusion had been corrected, a satisfying facial profile had been achieved, and no apparent adverse effect was found. Thus, it has been proved that the combination of sagittal split ramus osteotomy and mandibular body osteotomy is available for correcting skeletal class Ⅲ malocclusion., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

There are several treatment options to treat a class II dentofacial deformity with a pronounced chin. A total subapical osteotomy is one of these options. This type of osteotomy was refined to total subapical and ramus (TSAR) osteotomy. In this technical note, a detailed and schematic presentation of the TSAR osteotomy is presented step by step. The surgical approach to the TSAR osteotomy is divided into three parts. The first part consists of the horizontal osteotomy at the level of the ramus, the second part approaches the corticotomy to release and protect the mental nerve and the third part consists of connecting the horizontal ramus osteotomy and the local corticotomy around the mental nerve. In this third part, it is important that the inferior alveolar nerve (IAN) is actively sought and protected., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

This study aimed to evaluate maxillary bone healing and computed tomography (CT) values after Le Fort I osteotomy with sagittal split ramus osteotomy in patients with class II and III malocclusion. Four absorbable plates and screws were used to fix the maxillary segments in all patients. For 112 sides (58 patients), the bone defect areas at the anterior and posterior sites between the maxillary segments were measured using 3-dimensional CT views reconstructed over a constant CT value at 1 week and 1 year postoperatively. Subsequently, CT values at the upper, middle, and lower sites around the osteotomy line in the medial, middle, and lateral regions were measured. The bone defect area after 1 year increased at the anterior site in class III and at both the anterior and posterior sites in class II (P < 0.05). This study suggests that the increase in bone defect area was affected by lower CT values at the middle site of the middle and lateral regions in class II, and that bony defects between fragments in the maxilla could partially remain in both classes II and III within 1 year after Le Fort I osteotomy., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

To minimize condylar positional and morphological changes after mandibular advancement through bilateral sagittal split ramus osteotomy (BSSRO), surgeons add either a bicortical screw or a two-hole plate distal to the conventional single miniplate. Since there have been no previous studies investigating the effect of this combination, our study aimed to evaluate the short- and long-term effects of these adjunctive fixation methods (AFM) on condylar positional and morphological changes after mandibular advancement through BSSRO. This retrospective cohort study included consecutive patients with retruded mandibles who were treated in the Department of Orthognathic and TMJ Surgery at West China Hospital of Stomatology, Sichuan University. The patients were divided into two groups based on the primary predictor variable, which was the addition of AFM - either a single bicortical screw or a two-hole plate in addition to the single miniplate. The primary outcome variable was the condylar positional and morphological changes after mandibular advancement through BSSRO. Three-dimensional facial CT scans were obtained at three different time points (preoperatively - T0, 1 week postoperatively - T1, and 1 year postoperatively - T2) and analyzed using ITK-SNAP, 3D Slicer, and SlicerSALT software. Intergroup comparisons were conducted with an independent t-test, with a p-value of <0.05 considered significant. Correlations between the variables were estimated by Pearson correlation. The study comprised 51 patients (32 females, 19 males; mean age 25.13 ± 4.24 years), involving a total of 81 condyles (21 unilateral and 60 bilateral). There was a significant difference in long-term condylar displacement in favor of AFM along with a single miniplate (p < 0.001). The bicortical screw group recorded less condylar displacement than the two-hole plate group horizontally (0.11 mm vs 0.22 mm) and sagittally (0.03 mm vs 0.17 mm), but more vertically (0.85 mm vs 0.03 mm). Bone formation associated with AFM occurred on all condylar surfaces, compared with only three surfaces in the single miniplate group. The adjunctive method in addition to the single miniplate fixation method showed less condylar displacement and more bone apposition after mandibular advancement through BSSRO. The follow-up duration variable was the only significant determinant for volumetric changes in the condyle., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: The change of condyle position following orthognathic surgery affects the stability of treatments. This study aims to assess the correlation between the amount of condyles' position change and the severity of mandibular asymmetry following BSSO., Materials and Methods: This is a cross-sectional study. Subjects with asymmetric mandibular prognathism following BSSO were studied. Subjects were classified into 2 groups: group 1, subjects had mandibular asymmetry without occlusal cant and underwent BSSO. Group 2, subjects had mandibular asymmetry with occlusal cant and underwent BSSO+ Lefort I osteotomy. The condyle position was evaluated using cone-beam computer tomography (CBCT). Pearson's correlation test was used to assess any correlation between the condyle changes and the change in the mandible in sagittal and anterior-posterior directions., Results: A total of 44 subjects were studied. In group 1, the condyle tilted outward in the deviated condyle and inward in the non-deviated condyle immediately after osteotomy. After 12 months, both condyles showed a rotation relative to the original position. In group 2, the condyles of the deviated sides and non-deviated sides moved inferiorly after surgery (condylar sagging), which was more significant in the non-deviated sides. The condyle rotation was similar to group 1. The severity of asymmetry and occlusal cant correlate with the condylar position change in the two groups., Conclusion: The severity of mandibular asymmetry correlates with the amount of condyles' position change immediately after BSSO. However, the condyles tend to return to their original position 12 months later., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Introduction: Orthognathic surgery has the potential to compromise the vitality of the teeth. This paper aims to assess changes in pulp blood flow (PBF) and pulp sensibility (PS) of the anterior dentition following orthognathic surgery and to assess the influence of the proximity of the surgical osteotomy on the PBF and/or PS., Methods: Twenty-six patients undergoing orthognathic surgery (Le Fort I or bilateral sagittal split osteotomy [BSSO]) were compared to sixteen control patients treated by fixed appliances only using Laser Doppler flowmeter (LDF) and thermal testing (CO2 snow). Surgery patients were tested at T1 (presurgery), T2 (4-5 weeks postsurgery), T3 (3 months postsurgery), and T4 (6 months postsurgery). Control patients were tested at T1 (pretreatment), T2 (6 months posttreatment), T3 (12 months posttreatment), and T4 (18 months posttreatment). Differences between the maxilla and mandible were assessed., Results: No differences in PBF or PS were recorded in the control group. In the surgery group, both jaws followed the same pattern after surgery, an initial decrease at T2 followed by a gradual recovery to pretreatment PBF levels with no significant difference between T1 versus T4 in both jaws. No difference in PBF was observed between the maxilla and mandible at any testing time interval., Conclusions and Clinical Implications: PBF and PS of the anterior dentition was severely affected immediately postsurgery, followed by a gradual increase to full recovery. This pattern of recovery was exhibited in both jaws. A negative sensibility response or discoloration should not be seen as an indication of irreversible ischemic pulp changes. Monitoring for at least 6 months or using LDF as a confirmatory test is required before any irreversible endodontic treatment is to be considered., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Background: Computer-assisted surgical simulation (CASS) allows more precise orthognathic surgery. However, few studies have evaluated associations between CASS-designed bilateral sagittal split osteotomy (SSO) and bone contact surface in class II mandibular asymmetry. This study aims to evaluate the effects of using computer-assisted simulation and design modification of SSO to improve bony contact in skeletal class II asymmetry., Methods: This retrospective analysis reviewed 28 patients with class II asymmetry who underwent orthognathic surgery, including 15 with modified SSO (group CS) and 13 with conventional SSO (group C). Modified SSO was designed under CASS. Operative characteristics, postoperative outcomes, and complications were collected and compared between the two groups., Results: Bony contact was found at the distal end of the proximal segment in all group CS patients, while bone gap was noted in all group C patients ( P < 0.05). Moreover, bone graft was used in four group C patients but was not used in all cases in group CS patients ( P < 0.05). A trend toward lower operative time or perioperative bleeding was noted in group CS, but without statistical significance. After 1-year follow-up, inferior alveolar nerve disturbances were noted in two group CS patients and one group C patient. Palpable bone gap with uneven jaw line was noted in two group C patients 1 year after surgery and one patient received fat graft treatment., Conclusion: The simulation-based SSO modification provides appropriate contact surface and eliminates the bone gap between proximal and distal segments in class II asymmetry., Clinical Question/level of Evidence: Therapeutic, III., (Copyright © 2023 by the American Society of Plastic Surgeons.)

The purpose of this study was to elucidate the effects of mandibular anatomy and osteotomy technique on lingual fracture patterns in SSRO. The predictor variables were: length of horizontal medial osteotomy; type of border osteotomy; buccolingual width; and vertical length of the basal cortex. The outcome variable was the type of lingual split pattern. This was categorized into four types according to a lingual split scale (LSS): LSS 1, true Hunsuck; LSS 2, fracture line to posterior border of the ramus; LSS 3, through to mandibular canal; LSS 4, unfavorable fracture pattern. Data were analyzed using analysis of variance and the Pearson χ 2 test. Values of p < 0.05 were considered statistically significant. The study sample comprised 312 lingual split patterns in 156 patients. The most common type of lingual split pattern was LSS 1 (n = 204). There was a significant relationship between inferior border osteotomy type and LSS type (p = 0.001). Whilst LSS 1 was the most common among all border osteotomy types. LSS 4 was most frequently observed in cases where the lower border osteotomy remained in the buccal surface. According to the results of this study, the likelihood of an unfavorable split pattern increases when the lower border osteotomy remains in the buccal surface., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest in regard to this work., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: To three-dimensionally evaluate post-operative mandibular stability following bilateral sagittal split ramus osteotomies between hybrid and non-hybrid rigid internal fixation techniques., Materials and Method: Seventy adults with skeletal class II deformity who underwent bilateral split sagittal osteotomy with mandibular advancement were included. Patients were divided into four groups based on their fixation techniques: hybrid technique (HT) groups I, II, and IV received a 4-hole 2 mm miniplate with either a bicortical screw (BS), additional 2 mm 4-hole miniplate, or two-hole miniplate, while non-HT group III received a 4-hole 2 mm miniplate with four mini-screws (MS). Measurements were taken pre-operatively (T0), immediately postoperatively (T1), and ≥1 year after surgery (T2) using 3D Slicer software., Results: Age, sex, and follow-up period did not correlate significantly with postoperative relapse or stability. Significant differences were observed in the advancement on the right side between groups II, III, and IV and on the left side between groups I, III, and IV. However, the type of surgical intervention showed no significant effect on postoperative relapse and stability. All groups of fixations showed satisfactory stability with irrelevant relapse (< 2 mm or 2°)., Conclusion: The study demonstrated satisfactory and comparable stability among different fixation groups on patients undergoing mandibular advancement following bilateral split sagittal osteotomy. The results highlighted the importance of considering the degree of advancement when planning orthognathic surgery and managing postoperative outcomes., Competing Interests: Declaration of Competing Interest The authors declared no potential conflicts of interest concerning this article's research, authorship, and publication., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

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 ., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Objective: The objective of this study was to evaluate the effect of orthognathic surgery on taste sensation., Materials and Methods: Thirty-five patients scheduled to undergo Le Fort I osteotomy (LFIO), sagittal split ramus osteotomy (SSRO), and bimaxillary surgery (BMS) were evaluated by administering localized and whole-mouth taste tests preoperatively and postoperatively at months 1, 3, and 6. The patients were asked to identify the quality of four basic tastes applied to six locations on the palate and tongue and to rate the taste intensities they perceived. Taste recognition thresholds and taste intesity scores were evaluted according to operation groups and follow-ups., Results: There were significant decreases in the quinine HCl recognition thresholds at the postoperative follow-ups compared to the preoperative in LFIO patients (p = 0.043). There were significant decreases in sucrose taste intensity scores in the right posterolateral part of the tongue at months 3 and 6 compared to preoperative in SSRO patients (p = 0.046), and significant increases in quinine HCL taste intensity scores in the right and left anterior parts of the tongue at month 6 compared to preoperative in LFIO patients (p < 0.05)., Conclusion: Taste perception is affected due to potential damage to the chemosensory nerves during orthognathic surgical procedures. Generally, non-significant alterations have been observed in taste perception after orthognathic surgery, except for significant alterations in bitter and sweet taste perceptions., Clinical Relevance: Maxillofacial surgeons should be aware of taste perception change after orthognathic surgery procedures and patients should be informed accordingly., The Trial Registration Number (trn): NCT06103422/Date of registration: 10.17.2023 (retrospectively registered)., (© 2024. The Author(s).)

The treatment of mandibular deformities with an anterior open bite is challenging. In this study, skeletal stability after mandibular osteotomies was evaluated to determine the best treatment for mandibular prognathism with an anterior open bite in three procedures: intraoral vertical ramus osteotomy (IVRO), conventional sagittal split ramus osteotomy (conv-SSRO), and SSRO without bone fixation (nonfix-SSRO). Patients who underwent mandibular osteotomy to correct skeletal mandibular protrusion were included. Changes in skeletal and soft tissues were assessed using lateral cephalograms taken before (T1), 3 ± 2 days (T2), and 12 ± 3 months (T3) after surgery. Thirty-nine patients were included: nine in the IVRO group and 11 and 19 in the conv- and nonfix-SSRO groups, respectively. The mandibular plane angles (MPAs) of the T2-T1 were - 2.7 ± 2.0 (p = 0.0040), - 3.7 ± 1.7 (p < 0.0001), and - 2.3 ± 0.7 (p < 0.0001) in the IVRO, conv-SSRO, and nonfix-SSRO groups, respectively. The skeletal relapse of the MPAs was not related to the MPA at T2-T1, and it was approximately 1.3° in the conv-SSRO group. The skeletal relapse of the MAPs was significantly correlated with the MPA of T2-T1 in the IVRO (p = 0.0402) and non-fix-SSRO (p = 0.0173) groups. When the relapse of the MPAs was less than 1.3°, the MPA of T2-T1 was calculated as 2.5° in the nonfix-SSRO group. When the MPA of T2-T1 is less than 2.5°, non-fix SSRO may produce a reliable outcome, and when it is more than 2.5°, conv-SSRO may produce better outcomes., (© 2023. The Author(s), under exclusive licence to The Society of The Nippon Dental University.)

Introduction: Aligning dental arches in orthognathic treatment after undergoing LeFort I osteotomy or bilateral sagittal split osteotomy (BSSO) relies on occlusal splints, which do not provide precise control over the condylar head., Aim of the Study: To clinically and radiographically assess the accuracy of computer-assisted design and manufactured (CAD/CAM) surgical guide for condylar positioning in a BSSO., Materials and Methods: The study recruited 8 patients with a non-syndromic dentofacial deformity who underwent a BSSO. Surgery was planned according to CAD/CAM technology. After osteotomy, a pre-operative guide was used, followed by a repositioning guide. Computed tomography scans were conducted on all patients 1 week pre-operatively, immediately, and 3 months postoperatively., Results: The data are presented as median values with the 25th and 75th percentiles. Eight patients (37.50% females and 62.50% males) between the ages of 19 and 24 underwent BSSOs. The surgical procedure successfully corrected their skeletal deformities. The absolute change between immediate postoperative and pre-operative condylar angle was 0.15 (0.00-0.3). The absolute change between 3 months postoperative and pre-operative condylar angle was 0.20 (0.00-0.30)., Conclusion: The stability of the condylar head in position is well assessed by 3-dimensional condylar positioning devices designed and manufactured by CAD/CAM technology in the mandibular BSSO., Competing Interests: Declaration of interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85-1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff., Competing Interests: Declaration of competing interest All authors have no competing interests to declare. All authors have read and approved the manuscript and it in not under consideration for publication elsewhere., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The precise location of the mandibular lingual (ML) and foramen (MF) is clinically significant because they are crucial anatomic markers for the inferior alveolar nerve protection in sagittal split ramus osteotomy. To determine the position of the ML and MF among subjects with class I, class II, and class III skeletal patterns to obtain information that could be useful for interventions in mandibular ramus. A retrospective study of 324 mandibular ramus from 162 patients was performed to evaluate the distance from the MF to the occlusal plane (OP) and the distance of the ML to the MF, OP, and the margin of the mandible ramus. The MF was more often located below the OP in class III (55.1%), compared with class I (29.0%) and class II (45.3%) patients (P<0.05). The distance from the ML to the MF in skeletal Class III patients (10.15 ± 1.56 mm) was found to be greater than class I (9.25 ± 1.52 mm) and class II (8.34 ± 1.79 mm) patients (P<0.001). And the distance from the ML to the OP was shown to be longer in class III (9.40 ± 2.53 mm) than in class I (6.85 ± 2.55 mm) and class II (6.99 ± 2.53 mm) patients (P<0.001). Therefore, we believe that a low medial horizontal cut at the height of OP is dangerous for Class III patients. And the safe zone for the high medial horizontal cut over the ML should be determined according to the patient's skeletal patterns., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Purpose: To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars., Material and Methods: A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique., Results: A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020)., Conclusion: The results obtained support concomitant molar extraction with BSSO as a feasible option., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study aimed to assess the correlation between temporomandibular joint (TMJ) disc position and skeletal stability and identify the cephalometric measurements associated with relapse after bimaxillary surgery., Methods: The participants were 62 women with jaw deformities (124 joints) who underwent bimaxillary surgery. The TMJ disc position was classified into four types (anterior disc displacement (ADD), anterior, fully covered, and posterior) using magnetic resonance imaging, and cephalometric analysis was performed preoperatively and 1 week and 1 year postoperatively. The differences between pre- and 1-week postoperative values (T1) and 1-week and 1-year postoperative value (T2) were calculated for all cephalometric measurements. Moreover, the relationship between skeletal stability using cephalometric measurements, skeletal class, and TMJ disc position was analyzed., Results: The participants included 28 patients in class II and 34 in class III. There was a significant difference in T2 in SNB between class II mandibular advancement cases and class III mandibular setback cases (P = 0.0001). In T2, in ramus inclination, there was a significant difference between the ADD and posterior types (P = 0.0371). Stepwise regression analysis revealed that T2 was significantly correlated with T1 for all measurements. However, the TMJ classification was not applied to all measurements., Conclusion: This study suggested that TMJ disc position, including ADD, could not affect skeletal stability, including the maxilla and distal segment after bimaxillary osteotomy, and short-term relapse could be related to the movement amount or angle change by surgery for all measurements., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: The present study aims to assess the impact of bilateral and high oblique sagittal split osteotomy (BSSO/HSSO), as well as displacement distances and directions on the expected and achievable bone contact area (BCA) and changes in the intercondylar distance (ICD). The primary question addressed is whether mandibular splitting through BSSO results in a greater BCA and/or ICD when compared to splitting through HSSO., Materials and Methods: Totally 80 mandibular displacements were performed on 20 fresh cadavers, for each subject, four splints were produces to facilitate mandibular advancement as well as setbacks of 4 and 8 mm. Pre- and postoperative CBCT scans were performed to plan the surgical procedures and to analyze the expected and achieved BCA and ICD., Results: Regarding the maximum mandibular displacement, the expected BCA for HSSO/BSSO were 352.58 ± 96.55mm 2 and 1164.00 ± 295.50mm 2 , respectively, after advancement and 349.11 ± 98.42mm 2 and 1344.70 ± 287.23mm 2 , respectively, after setback. The achieved BCA for HSSO/BSSO were 229.37 ± 75.90mm 2 and 391.38 ± 189.01mm 2 , respectively, after advancement and 278.03 ± 97.65mm 2 and 413.52 ± 169.52 mm 2 , respectively after setback. The expected ICD for HSSO/BSSO were 4.51 ± 0.73 mm and 3.25 ± 1.17 mm after advancement and - 5.76 ± 1.07 mm and - 4.28 ± 1.58 mm after setback. The achieved ICD for HSSO/BSSO were 2.07 ± 2.9 mm and 1.7 ± 0.60 mm after advancement and - 2.57 ± 2.78 mm and - 1.28 ± 0.84 mm after setback. Significant differences between the BCA after HSSO and BSSO were at each displacement (p < 0.001), except for the achieved BCA after 8-mm setback and advancement (p ≥ 0.266). No significant differences were observed regarding ICD, except for the expected ICD after 8-mm setback and advancement (p ≤ 0.037)., Conclusions: Compared to the virtual planning, the predictability regarding BCA and ICD was limited. ICD showed smaller clinical changes, BCA decreased significantly in the BSSO group., Clinical Relevance: BCA and ICD might have been less important in choosing the suitable split technique. in orthognathic surgery., (© 2024. The Author(s).)

Objectives: This study aims to evaluate the potential benefits of combining tongue reduction with mandibular setback surgery in patients undergoing class III orthognathic surgery. Specifically, we investigated whether this combined approach reduced the risk of surgical relapse, condylar resorption, and airway space reduction by mitigating tongue pressure on the mandible., Material and Methods: The study retrospectively enrolled patients who had undergone bilateral sagittal split ramus osteotomy (BSSRO) with at least 5 mm of setback and met the criteria of a body mass index > 20 kg/m 2 and tongue volume > 100 mm 3 . The study included 20 patients with 10 in the tongue reduction group (TR, n = 10) and 10 in the BSSRO only group (SO, n = 10)., Results: The volumetric changes of the total airway space were significantly different between the TR and SO groups (p = 0.028). However, no significant differences were observed in the condylar resorption and postoperative relapse between the groups (p = 0.927 and 0.913, respectively). The difference between the resorption of the anterior and posterior segments of the condyle was also statistically insignificant (p = 0.826). Postoperative counterclockwise rotation of the proximal segment only demonstrated a significant correlation with postoperative relapse (p = 0.048)., Conclusions: The reduction in tongue volume demonstrated a preventive effect on the reduction of the airway space after mandibular setback, although it did not yield statistical significance concerning surgical relapse and condylar volume. The counterclockwise rotation of the proximal segment might be responsible for the forward displacement of the distal segment and postoperative relapse. However, the clinical implications of this finding should be interpreted with caution owing to the limited sample size CLINICAL RELEVANCE: Tongue reduction could potentially serve as a preventive measure in preserving the airway space and might be beneficial in mitigating the risk of obstructive sleep apnea in patients with class III deformity., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Unilateral temporomandibular joint ankylosis with jaw deformity (UTMJAJD) may require simultaneous total joint prosthesis (TJP) reconstruction, sagittal split ramus (SSRO), and Le Fort I osteotomies. The purpose of this study was to evaluate outcomes in patients treated with these procedures., Methods: Patients diagnosed UTMJAJD between 2016 and 2018 were selected for the study. Mandible-first procedure was performed after ankylosis release with TJP on the ankylosed side and SSRO on the contralateral side. Le Fort I osteotomy with and without genioplasty was lastly performed. Maximal incisor opening (MIO), facial symmetry, and jaw and condyle stability were compared before, after operation, and during follow-ups., Results: Seven patients were included in the study. Their average chin deviation was 9.5 ± 4.2 mm, and maxillary cant was 5.1 ± 3.0°. After operation, jaw deformity significantly improved, with chin deviation corrected 7.6 ± 4.1 mm (p = 0.015) and advanced 5.9 ± 2.5 mm (p = 0.006). After an average follow-up of 26.6 ± 17.1 months, MIO significantly increased from 11.4 ± 9.3 to 35.7 ± 2.6 mm (p = 0.000). The occlusion was stable with no significant positional or rotational changes of the jaw (p > 0.05). There was no obvious condylar resorption during follow-ups., Conclusion: Simultaneous TJP reconstruction, SSRO, and Le Fort I osteotomy are reliable and effective methods for the treatment of UTMJAJD., (© 2024. The Author(s).)

Objective: To compare the difference between virtual surgical planning (VSP) position and postoperative real position of maxilla and condyle, and to explore the degree of intraoperative realization of VSP after orthognathic surgery., Methods: In this study, 36 patients with mandibular protrusion deformity from January 2022 to December 2022 were included. All the patients had been done bilateral sagittal split ramus osteotomy (SSRO) combined with Le Fort Ⅰ osteotomy under guidance of VSP. The VSP data (T 0 ) and 1-week postoperative CT (T 1 ) were collected, the 3D model of postoperative CT was established and segmented into upper and lower jaws in CCMF Plan software. At the same time, accor-ding to the morphology of palatal folds, the virtual design was registered with the postoperative model, and the unclear maxillary dentition in the postoperative model was replaced. Then the postoperative model was matched with VSP model by registration of upper skull anatomy that was not affected by the operation. The three-dimensional reference plane and coordinate system were established. Selecting anatomical landmarks and their connections of condyle and maxilla for the measurement, we compared the coordinate changes of marker points in three directions, and the angle changes between the line connecting the marker points and the reference plane to analyze the positional deviation and the angle deviation of the postoperative condyle and maxilla compared to VSP., Results: The postoperative real position of the maxilla deviates from the VSP by nearly 1 mm in the horizontal and vertical directions, and the anteroposterior deviation was about 1.5 mm. In addition, most patients had a certain degree of counterclockwise rotation of the maxilla after surgery. Most of the bilateral condyle moved forward, outward and downward (the average distance deviation was 0.15 mm, 1.54 mm, 2.19 mm, respectively), and rotated forward, outward and upward (the average degree deviation was 4.32°, 1.02°, 0.86°, respectively) compared with the VSP., Conclusion: VSP can be mostly achieved by assistance of 3D printed occlusal plates, but there are certain deviations in the postoperative real position of maxilla and condyle compared with VSP, which may be related to the rotation axis of the mandible in the VSP. It is necessary to use patient personalized condylar rotation axis for VSP, and apply condylar positioning device to further improve surgical accuracy.

Objective: To establish and assess the precision of pre-surgical condyle position planning using mandibular movement trajectory data for orthognathic surgery., Methods: Skull data from large-field cone beam computed tomography (CBCT) and dental oral scan data were imported into IVSPlan 1.0.25 software for 3D reconstruction and fusion, creating 3D models of the maxilla and mandible. Trajectory data of mandibular movement were collected using a mandibular motion recorder, and the data were integrated with the jaw models within the software. Subsequently, three-dimensional trajectories of the condyle were obtained through matrix transformations, rendering them visually accessible. A senior oral and maxillofacial surgeon with experience in both diagnosis and treatment of temporomandibular joint disease and orthognathic surgery selected the appropriate condyle position using the condyle movement trajectory interface. During surgical design, the mobile mandibular proximal segment was positioned accordingly. Routine orthognathic surgical planning was completed by determining the location of the mandibular distal segment, which was based on occlusal relationships with maxilla and facial aesthetics. A virtual mandible model was created by integrating data from the proximal and distal segment bone. Subsequently, a solid model was generated through rapid prototyping. The titanium plate was pre-shaped on the mandibular model, and the screw hole positions were determined to design a condylar positioning guide device. In accordance with the surgical plan, orthognathic surgery was performed, involving mandibular bilateral sagittal split ramus osteotomy (SSRO). The distal segment of the mandible was correctly aligned intermaxillary, while the proximal bone segment was positioned using the condylar positioning guide device and the pre-shaped titanium plate. The accuracy of this procedure was assessed in a study involving 10 patients with skeletal class Ⅱ malocclusion. Preoperative condyle location planning and intraoperative positioning were executed using the aforementioned techniques. CBCT data were collected both before the surgery and 2 weeks after the procedure, and the root mean square (RMS) distance between the preope-rative design position and the actual postoperative condyle position was analyzed., Results: The RMS of the condyle surface distance measured was (1.59±0.36) mm (95% CI : 1.35-1.70 mm). This value was found to be significantly less than 2 mm threshold recommended by the expert consensus ( P < 0.05)., Conclusion: The mandibular trajectory may play a guiding role in determining the position of the mandibular proximal segment including the condyle in the orthognathic surgery. Through the use of a condylar positioning guide device and pre-shaped titanium plates, the condyle positioning can be personalized and customized with clinically acceptable accuracy.

Background: Neurosensory disturbance (NSD) is a common complication after sagittal split ramus osteotomy (SSRO) due to inferior alveolar nerve (IAN) injury. The impact of intraoperative nerve manipulation on NSD remains debated., Purpose: The purpose of this study was to evaluate the influence of IAN exposure and manipulation during SSRO on functional sensory recovery (FSR)., Study Design: This was a single-center, prospective cohort study of 40 patients undergoing SSRO at Mahidol University from December 2020 to December 2021. The inclusion criteria were patients aged 20-34, ASA Class I-II. The exclusion criteria were patients with systemic bone disease, history of head and neck or neurological pathology, previous SSRO, or incomplete data collection., Predictor Variable: Degree of intraoperative nerve manipulation was divided by the attending surgeon as follows; 1) Nerve fully encased in distal segment and not visible (NS); 2) Nerve encased in distal segment but partially visible (DS); and 3) Nerve partially encased in proximal segment and fully dissected free (PS)., Outcome Variables: The area of interest was divided into the lip and chin. The primary outcome was time to FSR. The secondary outcome was subjective patient report, using a visual analogue scale, compared to FSR., Covariates: The covariates were sex, age, skeletal diagnosis, degree of movement, and concomitant genioplasty/subapical procedure., Analyses: Kaplan-Meier survival analysis, Cox proportional hazards regression, and Mcnemar test were utilized. P-value < .05 was significant., Results: In the lip, the median times to FSR were NS, 2 days; DS, 45 days; PS, 102 days. (Interquartile range: 77,127, 114, respectively) In the chin, the median times to FSR were NS, 23 days; DS, 92 days; PS, 87 days. (Interquartile range: 77, 161, 101, respectively.) Nerve manipulation significantly affected FSR in the lip and chin (P = .001, <0.001, respectively. Cox hazard ratios for DS and PS were lower compared to NS. Patients consistently reported more NSD compared to FSR as per Mcnemar test., Conclusion and Relevance: After SSRO, FSR in the lip is prolonged when the IAN is partially encased in the proximal segment and released. This raises the question of the efficacy of surgically releasing a partially encased IAN., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The anatomical position of the lingula is clinically very important to prevent injuries during sagittal split ramus osteotomy. Our study aims to evaluate the localisation of the lingula by cone beam computed tomography (CBCT) and to compare the localisation of the lingula between malocclusion, gender, and lingula types., Methods: A retrospective study was conducted to evaluate the shape and location of the lingula using CBCT. A total of 250 CBCT images were included in this study. The lingula was classified as nodular, assimilated, truncated, or triangular type. Six defined distances from the top of the lingula were measured: anterior border of the ramus (L-A), posterior border of the ramus (L-P), internal oblique ridge (L-IOR), mandibular notch (L-N), and distal surface of the mandibular second molar (L-M2) and occlusal plane (L-OP). The measured distances were compared between gender, malocclusion, and lingula types., Results: The most common type of lingula was nodular (32.4%). The L-N, L-P, L-M2, and L-OP distances between genders were statistically higher in male patients than in female patients. The L-IOR, L-M2, and L-OP distances exhibited statistically significant differences found between malocclusions. No statistically significant difference was found when the distances of the lingula to the anatomical points were compared between the lingula types., Conclusion: These variations in positioning of the lingula depending on the dysmorphoses are developing towards a systematic 3D examination before any mandibular osteotomy to precisely visualize the position and shape of the lingula., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Maintaining condyle position following bilateral sagittal split ramus osteotomy (BSSO) is crucial to minimizing postoperative relapse. However, the impact of BSSO on the articular disc position remains inconclusive., Purpose: This study aimed to investigate the changes in articular disc position following setback BSSO surgery., Study Design, Setting, and Sampling: In this prospective cohort study, subjects with mandibular prognathism requiring setback BSSO were enrolled between August 2021 and June 2022 at the Oral and Maxillofacial Surgery Clinic, Faculty of Dentistry, Chiang Mai University, Thailand. Patients with surgical complications, loss of follow-up, or significant artifacts in their MR images were excluded., Predictor/exposure/independent Variables: The predictor variable was time. The articular disc position was assessed at 3 time points, preoperatively (T0), 3 months postsurgery (T1), and 6 months postsurgery (T2)., Main Outcome: The primary and secondary outcome variables were the changes in articular disc position between T0-T2 and T0-T1, respectively. Articular disc position was coded as normal, anterior disc displacement with reduction (ADDwR), anterior disc displacement without reduction (ADDwoR), and anterior disc displacement without reduction and degenerative joint disease (ADDwoR + DJD)., Covariates: Covariate variables collected included age (years), sex (male or female), asymmetry (present or absent), surgical procedure (single jaw (BSSO) or bimaxillary surgery), and setback distance (millimeters)., Analyses: Friedman's test with 80% power and a significance level of 0.05 was employed. Pairwise comparisons were performed using the Dunn-Bonferroni posthoc test to identify statistically significant differences., Results: The study included 16 subjects, 6 females and 10 males, with a total of 32 TMJs. Subjects had a mean age of 23.75 (4.57) years. The proportion of TMJs with normal disc position postoperatively increased from 3 (9.4%) to 19 (59.4%). Statistically significant differences were found in the changes in disc position over time (P < .001)., Conclusions: Following setback BSSO, the articular discs underwent changes, with a majority of ADDwR cases transitioning to a normal position. Cases with ADDwoR also demonstrated disc reduction capability after surgery. The combined orthodontic treatment and setback BSSO appear to have an effect on articular disc position in skeleton class III patients., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The purpose of this study was to evaluate the accuracy and stability of condylar positioning in patients treated with bimaxillary procedures compared with patients treated with maxillary procedures alone. All patients had undergone treatment at Odense University Hospital and were treated with inferior maxillary procedures. The primary outcome was changes in condyle position and the primary predictor variable was time: pre-operative (T 0 ) measurements to 1-week post-operative (T 1 ) and 1-year post-operative (T 2 ) measurements. Condyle movement was measured using dual voxel-based alignment. Sixteen patients were included. Seven patients underwent solitary maxillary procedure and 9 patients bimaxillary procedure. Bimaxillary procedures overall showed a condyle positional change in pitch from T 0 to T 1 and T 1 to T 2 compared to maxillary procedures alone. Condylar translation was stable despite large differences in positioning. Compared to solitary maxillary procedures, bimaxillary procedures showed a statistically significant anterocranial rotation at 1-week follow-up movement (3.95° vs. -0.95°; SD 3,74 vs 1,05; P value = 0.000) and an additional statistically significant anterocranial movement at 1 year after surgery (4.89° vs 0.60°; SD 3,82 vs 0,92; P value = 0.000). In conclusion a need for greater anterocranial stability of the sagittal split osteotomy than that provided by 3 bicortically fixated screws alone might be indicated., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The aim of the study was to compare the stability of the virtual surgical planning (VSP) and computer-aided design accompanied by patient-specific implants (PSIs) and conventional mini-plates in mandible advancement with bilateral sagittal split osteotomy (BSSO). This retrospective study evaluates the clinical and cephalometric records of 53 patients (12 male, 41 female) treated with BSSO in Helsinki University Hospital. Subjects were divided into two groups: VSP-PSI (21 patients: 4 male and 17 female; mean age 38 years, range 25-53 years); and conventional wafer-based repositioning with mini-plate fixation (32 patients: 8 male and 24 female; mean age 39 years, range 21-56 years). The effect of the amount and direction of the advancement on the stability was also analysed individually. The standardized lateral cephalometric radiographs in three time points were analysed to compare the groups. After surgery (T2), there were no differences between groups in cephalometric variables. During follow-up (T2-T3), the cephalometric variables in both Groups A and B were stable, so there was no difference in stability between the VSP-PSI and the conventional mini-plate groups. During follow-up, the mandibles rotated clockwise or counterclockwise, relapsed towards their original direction, and the changes were statistically significant (jaw relationship; p = 0.018, soft tissue profile; p = 0.025); when the advancement of mandible was >6 mm, the increase in gonial angle compared to mandibles advanced ≤6 mm was statistically significant (p = 0.03). VSP-PSI and conventional mini-plate fixation can be considered equally stable. Large advancements with counterclockwise rotation regardless of fixation method are more susceptible to relapse. VSP-PSI alone cannot solve the relapse-related concerns in mandible osteotomy., Competing Interests: Declaration of competing interest J.S. has participated in congresses where attendance fees were in part or in total supported by DePuy Synthes or KLS Martin. Planmeca has provided materials and intelligent support for in vitro studies free of charge., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Impaired bony healing following bilateral sagittal split osteotomy (BSSO) is a major unmet medical need for affected patients, and rare occurrences can hinder the identification of underlying risk factors. We hypothesised that osseous union following BSSO can be quantified using volumetric analysis, and we aimed to identify the risk factors for impaired bone healing. The percentage change in bony volume was measured in orthognathic patients following BSSO using two consecutive postoperative cone-beam computed tomography scans. Patients' characteristics and treatment parameters were documented, and correlation and regression analyses of these variables performed. Thirty-six patients (23 men and 13 women) with a mean (SD) age of 33.28 (11.86) years were included. The gap site (lingual versus buccal) (p < 0.01) had a significant impact on the change in volume. Age (p = 0.06) showed a trend towards significance. Initial width of the osteotomy gap, sex, and indication for surgery did not influence osseous healing. Increased age at surgery and the side of the buccal osteotomy are independent risk factors for impaired osseous healing following BSSO., (Copyright © 2023 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: The purpose of this study is to assess the impact of Sagittal Split Ramus Osteotomy (SSRO) on the alignment of the condyle and orientation of the Ramal segment following surgery in patients operated for the correction of mandibular asymmetry., Methods: A total of 27 patients who underwent SSRO were enrolled in this study, and study groups were defined as asymmetric (study group) and symmetric (control group) using linear measurements from the dental midline based on a three-dimensional coordinate system. Differences on preoperative and postoperative values of anterior (AJS), posterior (PJS) and superior joint spaces (SJS), condylar axial angle (CAA), Sagittal Ramal Angle (SRA), and Coronal Ramal Angles (CRA) of study and control groups were measured and compared. The data was analyzed using the "Wilcoxon signed-ranks test" to identify differences between groups., Results: Differences between preoperative and postoperative values of CRA and SRA of the contralateral group showed statistically significant results with p-values of 0.007 and 0.005, respectively. A statistically significant change in CAA angle was found in the control and deviation groups (p = 0.018 and p = 0.010, respectively)., Conclusions: SSRO has inevitable effects on the condylar and ramal orientation. Individuals with asymmetry require particular attention throughout the planning process and beyond. Conjunctive modalities and modifications should be considered and utilized when necessary. Future studies with larger sample sizes, homogenous follow-up periods, and more comprehensive clinical data are needed to substantiate understanding of the response of the condylar segment., Clinical Relevance: Orthognathic surgeries inevitably alter the alignment and harmony of temporomandibular structures and may result in change of AJS, PJS, SJS, CAA, SRA, and LRA, which may change the biomechanics of joint and lead to several complications like temporomandibular disorders. Especially in cases with midline asymmetry needs special consideration from planning till the end of the treatment to achieve best results. In severe cases, conjunctive modalities and modifications and other alternatives such as inverted-L osteotomies should be considered., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Defects in the lower border of the mandible may represent an aesthetic problem after mandibular advancement in orthognathic surgery. The use of bone grafts has been reported in the literature as a possibility to reduce these defects in the postoperative period., Objective: The objective of this systematic review is to answer the following research question: Is it necessary to use bone grafts to prevent defects at the lower border of the mandible after mandibular advancement?, Methods: The literature search was conducted on MEDLINE via PubMed, Scopus, Central Cochrane, Embase, LILACS, and Sigle via Open Gray up until December 2020. Five studies were eligible for this systematic review, considering the previously established inclusion and exclusion criteria., Results: 1340 mandibular osteotomies were evaluated, with a mean advance of 8 mm, being 510 with bone graft (42 defects), 528 without graft (329 defects), and 302 with an alternative technique (32 defects). Regarding the type of bone graft used, three articles used xenogenous or biomaterial grafts and two allogenous bone grafts. The results of the meta-analysis showed a reduction in the presence of defects in the bone graft group: OR 0.04, 95% CI = 0.01, 0.19; p = 0.0005, (I2 = 87%; p < 0.0001)., Conclusion: The use of bone grafts seems promising in reducing defects in the lower border of the mandible after mandibular advancement. New controlled prospective studies with a larger number of participants are needed to ensure the effectiveness of this procedure., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: The purpose of this study was to evaluate the effect of adding a fourth osteotomy at the lower border of the mandible on the lingual cortical fracture pattern in bilateral sagittal split ramus osteotomies., Patients and Methods: The sample of the study consisted of 20 patients (12 male and 8 female, with a mean age of 26.79 ± 7.12 years) with mandibular deformities who needed bilateral sagittal split ramus osteotomy. One side underwent a traditional sagittal split ramus osteotomy, and the procedure was modified on the other side by adding a 1 cm horizontal osteotomy at the lower border of the mandible, just distal to the caudal end of the vertical buccal osteotomy cut. A 3D CBCT was used to identify the split pattern., Results: In the total sample, 40% of the lingual splits ran vertically toward the lower border of the mandible (LSS1), 20% of the splits passed horizontally to the posterior border of the mandible (LSS2), 32.5% of the splits took place along the inferior alveolar canal (LSS3), and 7.5% of the splits were unfavourable fractures (LSS4). On the inferior border osteotomy sides, the distribution of LSS1, LSS2, LSS3, and LSS4 was 10 (25%), 6 (15%), 4 (10%), and 0 (00), respectively. Their distribution on the sides without inferior border osteotomy was 6 (15%), 8 (20%), 13 (32.5%), and 3 (7.5%), respectively. Statistical analysis revealed a significant difference between the two groups (p < 0.05)., Conclusion: Inferior border osteotomy tends to direct the lingual split fracture line toward the lower and posterior borders of the mandible and minimizes bad splits; however, further studies are needed to confirm our findings., (© 2023. The Author(s).)

Introduction: This study aimed to compare postsurgical stability between conventional (CSA) and surgery-first (SFA) approaches and investigate its prognostic factors in patients with a skeletal Class Ⅲ extraction., Methods: Twenty and 19 patients treated with LeFort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) with premolar extraction were enrolled in SFA and CSA groups, respectively. Serial cone-beam computed tomography images obtained before surgery, immediately after surgery (T1), 3 months after surgery, and 12 months after surgery were used for 3-dimensional quantitative analysis. The condyle was segmented for analyzing volumetric changes. Repeated measures analysis of variance, independent t test, and chi-square test were used to compare time-course and intergroup differences. Pearson and Kendall correlation and multivariate linear regression analyses were used to explore prognostic factors affecting skeletal stability., Results: In both CSA and SFA, postsurgical relapse mainly occurred in the mandible sagittal and vertical dimensions and during the first 3 months after surgery. Stability in SFA was significantly less than that in CSA. Intraoperatively, inferolateral condylar displacement with proximal segment inwards, clockwise rotation, and return movements after surgery were observed regardless of the treatment approach. The condylar volume remained stable over time. Multivariate regression analysis showed that posterior vertical dimension (VD) at T1 (-1.63 mm), surgical amount of mandibular setback (-10.33 mm), surgical condylar downwards displacement (-1.28 mm), and anterior overjet at T1 (6.43 mm) were the most important predictors of early mandibular relapse (r 2  = 0.593)., Conclusions: The risk of early relapse could be reduced by controlling the anterior, middle, and posterior constraints provided by the prediction model., (Copyright © 2023 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)