This study presents a digital surgical planning method for long-curve mandibular angle osteotomy based on three-dimensional (3D) symmetry principles. The authors retrospectively analyzed 30 patients with mandibular angle hypertrophy who had previously undergone conventional long-curve osteotomy. Many reported postoperative dissatisfaction due to visible bilateral mandibular margin asymmetry from the submental view. Preoperative CT data were reconstructed into 3D models, to which a symmetry-guided osteotomy protocol was applied. By integrating sagittal, coronal, and axial planes with dynamic bilateral point adjustments, the protocol identified asymmetries often overlooked by traditional methods. Quantitative analyses confirmed these discrepancies. The proposed approach achieved bilateral mandibular margin symmetry in frontal, lateral, and submental views. This reproducible and clinically applicable 3D planning method may reduce revision rates and improve patient satisfaction, particularly among populations with aesthetic preferences for a slender V-line contour.

Background: Mandibular advancement is a commonly performed surgical procedure for the treatment of mandibular retrognathia and Class II dentofacial deformities; however, large advancements impose increased mechanical demands on fixation systems. Despite the availability of various fixation strategies, standard straight plate systems remain widely used worldwide due to their availability, cost-effectiveness, and clinical familiarity. Continuous biomechanical evaluation of these systems is therefore required to optimize stability and performance under demanding conditions. Objectives: The aim of this study was to evaluate the influence of plate design, plate thickness, and fixation architecture on the mechanical stability of mandibular advancement using finite element analysis. Methods: A three-dimensional finite element model simulating a unilateral mandibular osteotomy with a 10 mm gap was generated as mandibular advancement was developed. Fifteen fixation configurations were analyzed, including variations in plate design (simple and reinforced plates with partial or total inferior mesh extension), plate thickness (0.8 mm and 1.0 mm), and fixation architecture using independent plate systems (LN) or integrated fixation systems (FM). A vertical load was applied to the lower central incisor to simulate functional loading. Outcome measures included global equivalent stress considering screws and plate, equivalent stress within the plate, and global deformation of the fixation system. Results: The analyses demonstrated distinct mechanical behaviors among the evaluated configurations. Differences in stress distribution and deformation were observed according to plate design, thickness, and fixation architecture. Reinforced designs, increased plate thickness, and integrated fixation systems showed reduced deformation and more favorable stress distribution when compared with simple plate configurations. Conclusions: Plate design, thickness, and fixation architecture influenced the mechanical stability of mandibular advancement, supporting the importance of biomechanical optimization of standard fixation systems, particularly in large mandibular advancements.

Mandibular symphysis segmentation for the correction of transverse deformities has been recently described in the literature, highlighting its potential in the management of dentofacial deformities. However, the use of osteosynthesis systems in this context has not yet been fully standardized, mainly due to the difficulty of obtaining standard plates with specific designs for these procedures. The aim of this report is to present a solution to this limitation using a standard plate that provides adequate spacing and 3-dimensional stability. This approach optimizes the osteosynthesis stage, reduces the amount of material required, and shortens surgical time.

Asymmetric Mandibular Osteotomies in Hemimandibular Hyperplasia Associated with Osteochondroma: A Novel Surgical Proposal in Cases of Sagittal Class I Relationship

The aim of the current study is to compare the skeletal stability of single-plate versus double-plate osteosynthesis in anterior mandibular osteotomies. A prospective case-control trial was planned, enrolling all the patients who reported to us for the correction of anterior mandibular issues, including patients planned for lower anterior sub-apical osteotomies and genioplasties. The patients were randomly allocated to two groups Group I (single plate fixation) and Group II (two plate fixation) based on the Lot method. The patients in each group were further divided into subgroups, with Subgroup A undergoing subapical setback and Subgroup B undergoing advancement genioplasty. All the patients underwent preoperative clinical and cephalometric evaluation (T1) to assess the magnitude of movement of the anterior mandibular segments. All the patients had an immediate post-operative cephalogram done (T2). They were under follow-up for 6 months to 3 years (T3), and the post-operative skeletal stability was assessed using COGS analysis on a lateral cephalogram between T3 and T2. Intraoperative time and postoperative neurosensory disturbances were the secondary outcomes that were measured. G power analysis was used to calculate the sample size, and statistical analysis used SPSS (version 23.0), employing ANCOVA for non-parametric tests (Quade's approach) with significance set at P<0.05. Twenty-six patients within the age group of 15 to 35 years (14 females, 12 males) were enrolled in the study. Thirteen patients were allocated to each group. Seven patients underwent genioplasty in group I and seven in group II, and six underwent subapical osteotomy in groups I and six in group II, respectively. The mean magnitude of subapical setback was 7 mm, while the magnitude of chin advancement was 8 mm, and this was comparable among the groups. The cephalometric evaluation involved the evaluation of vertical and horizontal distances of points B, Pog, and menton from the true horizontal and true vertical of COGS analysis. These parameters showed no statistically significant differences in the follow-up period (T3-T2) between single-plate and double-plate osteotomy groups for subapical osteotomies and genioplasties between age and sex-matched control groups. However, secondary outcomes, including neurosensory disturbances, intraoperative time, differed significantly (P<0.05) between groups and favored the use of single plate fixation. This clinical trial suggests that the choice between single-plate and double-plate osteosynthesis does not significantly affect skeletal stability following anterior mandibular osteotomies. However, significant differences were observed in secondary outcomes, indicating potential considerations for surgical approach in orthognathic procedures.

ABSTRACTBackgroundIn our previous study, the minor T allele of the rs7858836 C/T single‐nucleotide polymorphism (SNP) in the ASTN2 gene, which encodes astrotactin 2, was associated with reduced fentanyl requirements after laparoscopic‐assisted colectomy and after mandibular osteotomy. In this study, we investigated the effects of this SNP on pain‐related phenotypes in patients who underwent laparoscopic gynecologic surgery (LGS).MethodsWe studied 333 Japanese women, 21–69 years, who underwent LGS at Juntendo University Hospital between 2017 and 2019. We evaluated associations between SNP genotypes and postoperative pain‐related phenotypes, including fentanyl requirements, rescue analgesic requirements, and the average pain scores on an 11‐point Numeric Rating Scale (NRS) during the 24‐h postoperative period. Patients with the TT or CT genotype were compared with those with the CC genotype using the Mann–Whitney test or χ2 test. Values of p < 0.05 were considered statistically significant.ResultsThe minor T allele frequency was 34.1%. Patients with the CT or TT genotype reported significantly lower average NRS pain scores (median, 1.6 vs. 2.0; p = 0.031) and required fewer rescue analgesics (5.5% vs. 15.0%; p = 0.003) compared to those with the CC genotype. Postoperative fentanyl requirements did not differ between the two groups (p = 0.940).ConclusionThe minor T allele of the rs7858836 SNP was significantly associated with lower postoperative pain intensity, albeit only slightly, and decreased the need for rescue analgesics under comparable fentanyl dosing conditions, potentially reflecting lower pain sensitivity. However, the magnitude of the effect was less than our previous findings.

This study investigates the impact of ramus-sparing mandibular angle ostectomy on mandibular contour morphology and lower facial soft tissue laxity. A total of 104 patients who underwent surgery at Shanghai Ninth People's Hospital affiliated with Shanghai Jiao Tong University School of Medicine between January 2018 and December 2023 were included. Comprehensive three-dimensional facial data acquisition using 3DMD imaging systems and computed tomography scans were performed preoperatively and at 6-month follow-up. Quantitative assessments included: 1) comparative analysis of hard and soft tissue ramus heights, 2) Merz aesthetic scale evaluation, and 3) cervical-mental angle measurements. No statistically significant differences were observed in ramus height measurements between osseous and soft tissue components (p>0.05), demonstrating proportional soft tissue adaptation to skeletal reduction (mean bone resection: 17.1±4.5 mm vs soft tissue change: 15.9±4.3 mm). Both Merz scale assessments (preoperative: 1.94 vs postoperative: 1.79) and cervical-mental angles (preoperative: 114.62° vs postoperative: 111.52°) showed no statistically significant differences at 6-month follow-up (p>0.05). The ramus-sparing mandibular angle ostectomy effectively contours the mandible without inducing significant lower facial soft tissue relaxation in short-term evaluation, demonstrating its clinical reliability for facial aesthetic surgery.

Patients with cleft lip and palate (CL/P) often require Le Fort I maxillary advancement for correction of maxillary hypoplasia. Because of scar tissue formation, aberrant anatomy, and diminished vascularity, these patients may be at higher risk for complications, compared with patients without CL/P. The objective of this study was to evaluate 90-day postoperative complications of Le Fort I osteotomy in patients with CL/P compared with patients without CL/P. The secondary objective was to evaluate differences in reoperation and readmission rates between cohorts. A retrospective cohort study was conducted using the PearlDiver Mariner national database. Inclusion criteria were patients older than or equal to 12 years of age who underwent Le Fort I osteotomy between the years 2010 and 2022. Exclusion criteria were patients with craniofacial syndromes or those who underwent concomitant mandibular osteotomy. The primary outcome was 90-day complications. Secondary outcomes were reoperation and readmission rates. A total of 7053 patients were included, and 717 (10.2%) had an associated CL/P diagnosis. Patients in the CL/P group had higher risk of surgical site infection (OR: 1.20; 95% CI: 1.00-1.42, P=0.046), hardware removal (OR: 3.43; 95% CI: 2.81-4.19; P<0.001), revision Le Fort I osteotomy (OR: 2.68; 95% CI: 1.61-4.35; P<0.001), and readmission (OR: 3.20; 95% CI: 1.59-6.18; P<0.001). Patients with CL/P had a significantly higher risk of postoperative infection, reoperation, and readmission than patients without CL/P. These results highlight the elevated postoperative risk profile for patients with CL/P. Furthermore, there is a need to develop perioperative protocols to minimize preventable complications and improve outcomes for patients with CL/P undergoing Le Fort I osteotomy.

ABSTRACT Purpose To investigate short-term changes in sleep respiratory status and respiratory disturbance index (RDI) pre- and post-orthognathic surgery and determine the period during which morphological changes in the airway and surgical invasion affect postoperative sleep dynamics. Materials and Methods This study enrolled patients with skeletal mandibular prognathism who underwent mandibular ramus sagittal split osteotomy alone (mandible-only group, n = 10) or mandibular and maxillary surgery (two-jaw surgery group, n = 13). Simplified sleep tests were conducted pre-orthognathic surgery (T0) and at 7 (T1), 14 (T2), and 21 (T3) days postoperatively. Correlations between inflammation status at the surgical site before and during the postoperative management period were analysed Results RDI values at T0, T1, T2, and T3 were 3.5 ± 2.1, 5.0 ± 3.1, 4.3 ± 2.7, and 3.2 ± 1.4 in the mandible-only group, and 2.9 ± 2.0, 4.7 ± 2.5, 4.4 ± 2.4, and 2.8 ± 0.9 in the two-jaw surgery group, respectively. In the two-jaw surgery group, the RDI increased significantly between T0 and T1. The RDI in both groups exhibited a declining trend between T1 and T2 and decreased significantly between T2 and T3. C-reactive protein levels and white blood cell counts increased significantly between T0 and T1 and decreased significantly between T1 and T2 in both groups. The airway area was reduced significantly in the mandible-only group. Conclusion Temporary swelling of tissues around the osteotomy site increases the RDI in orthognathic surgery. Airway management for approximately 3 weeks is important until postoperative recovery is complete.

Application of a new synthetic bone graft material in the bone junction at mandibular osteotomy

Anatomical and surgical insights into double mandibular osteotomy with segmental rotation for parapharyngeal space and infratemporal fossa access.

Mandibular osteotomies are known to widen the mandibular angles by increasing the bigonial distance (BGD). Previous studies have highlighted the relationship between the extent of mandibular movement and the increase in BGD, both for cutaneous bigonial distance (CBGD) and osseous bigonial distance (OBGD). However, the relationship between changes in OBGD, CBGD and mandibular advancement remains to be fully established. The aim of this study was to compare changes in OBGD and CBGD using adapted three-dimensional examination techniques in patients who underwent mandibular osteotomies. Preoperative and postoperative computed tomography scans and stereophotogrammetry were used to measure mandibular advancement, OBGD and CBGD before and after surgery. Of the 77 patients included, 93.5% underwent bilateral sagittal split osteotomy, and 79.2% had received patient-specific guided surgery. Of these, 53 patients had mandibular advancement and 24 underwent mandibular setback. In all cases, a significant increase in both OBGD and CBGD was found after surgery. The extent of mandibular advancement was significantly associated with a greater increase in both OBGD and CBGD.

Bilateral sagittal split osteotomy of the mandible (BSSO) is the most common orthognathic surgery procedure. The use of bone grafting seems widely used whereas its interest has not been shown to date. The aim of this study was to describe the current state of practice of bone graft in BSSO in France. An online survey was used to collect data about the use of bone grafting in BSSO procedures among French maxillofacial surgeons. One hundred and forty-eight surgeons responded to the survey, mostly maxillo-facial surgeons (96 %). Only 31.8 % of participants had already performed grafts in BSSO and the majority did it in less than 10 % of cases. The main grafting indication was the degree of advancement especially for advances over 10 mm. Different types of grafts were used, mainly: autologous bone grafting (mandibular or hip) or other bone grafting (xenograft, allograft). This survey shows the diversity of practices in France regarding the use of grafting in BSSO. Further studies are needed to investigate prospectively the utility of such procedures.

Orthognathic surgery practices depend on patient characteristics, which may vary from one country to another, and they may also evolve with new techniques and developments. The aim of this study is to describe the epidemiological characteristics of patients and orthognathic surgical procedures performed in the maxillofacial surgery department at Pitié-Salpêtrière University Hospital (Paris, France). This was a retrospective study covering the period from January 2017 to December 2020. All patient records from this period were reviewed. The following data were collected: demographic characteristics (age at the time of surgery, gender), type of dentofacial deformity (Angle class I, II, or III, transverse and vertical facial dimensions), and type of surgical procedure. A total of 667 patient records were included. Analysis of the parameters studied showed a female predominance (60.82%) with a mean age of 27.9 years. The most common Angle dental class was class II (56.4%) followed by class III (35.4%). Long-face patients accounted for 47.86% of the sample, short-face 41.61%, and balanced-face 10.53%, with 44.4% exhibiting facial asymmetry. A reduced transverse dimension was observed in 22.12% of cases. The most common orthognathic procedure was maxillomandibular osteotomy (56.08%), followed by mandibular osteotomy (20.7%), and maxillary osteotomy (19.12%). Overall, 23.4% of patients underwent dental extractions during surgery and 4.4% of records reported reinterventions (revision surgery, hardware removal, or pseudarthrosis repair). Class II malocclusion is common in the French population and is frequently encountered in orthodontic-surgical protocols. According to the literature, maxillomandibular surgery appears to be on the rise. The results of this four-year retrospective study reveal a predominance of young, female patients. Class II malocclusion was the most frequent, and maxillomandibular surgery was the most commonly performed procedure. Given the lack of epidemiological data, further studies should be conducted to assess variations in surgical practices across different geographic regions and types of institutions (private, public, etc.).

This study aimed to evaluate the incidence of neurosensory disturbance (NSD) following two modifications of bilateral sagittal split mandibular osteotomy (BSSO)—low medial cut (Posnick modification) and high medial cut (standard)— in the immediate postoperative period and after a minimum follow-up of six months. Twenty patients with skeletal Class III deformity requiring mandibular setback were randomly divided into two equal groups. Subjective and objective testing for inferior alveolar nerve function was performed. The results showed that all patients (except four in the Posnick group) exhibited some degree of NSD immediately postoperatively. However, at the 6-month follow-up, a complete recovery of NSD was reported in 74% of the low medial cut group and 35% of the high medial cut group. The low medial cut (Posnick) osteotomy demonstrated a shorter average osteotomy duration (20.30 minutes) compared to the high medial cut (27.21 minutes) and allowed for better visualization of the inferior alveolar nerve with decreased medial dissection.. The study concludes that the low medial cut (Posnick) SSO is a valuable osteotomy technique, offering shorter osteotomy duration, decreased incidence of bad split, and better neurosensory recovery in the extended followup period compared to the traditional BSSO.

This study aimed to evaluate the incidence of neurosensory disturbance (NSD) following two modifications of bilateral sagittal split mandibular osteotomy (BSSO)—low medial cut (Posnick modification) and high medial cut (standard)— in the immediate postoperative period and after a minimum follow-up of six months. Twenty patients with skeletal Class III deformity requiring mandibular setback were randomly divided into two equal groups. Subjective and objective testing for inferior alveolar nerve function was performed. The results showed that all patients (except four in the Posnick group) exhibited some degree of NSD immediately postoperatively. However, at the 6-month follow-up, a complete recovery of NSD was reported in 74% of the low medial cut group and 35% of the high medial cut group. The low medial cut (Posnick) osteotomy demonstrated a shorter average osteotomy duration (20.30 minutes) compared to the high medial cut (27.21 minutes) and allowed for better visualization of the inferior alveolar nerve with decreased medial dissection.. The study concludes that the low medial cut (Posnick) SSO is a valuable osteotomy technique, offering shorter osteotomy duration, decreased incidence of bad split, and better neurosensory recovery in the extended follow- up period compared to the traditional BSSO.

This case report presents a rare use of mandibular sagittal split osteotomy (MSSO) for the extraction of an impacted third molar, aided by virtual surgical planning. A 32-year-old male presented for third molar removal, but clinical examination revealed the right third molar was not visible intraorally, and access was limited due to restricted mouth opening and tongue mobility. Cone-beam computed tomography confirmed a horizontally impacted right mandibular third molar. Due to the tooth's position and proximity to the inferior alveolar nerve, MSSO was selected. Virtual surgical planning and a 3D-printed surgical guide were used to plan and execute the procedure. The molar was successfully extracted while preserving the nerve, and the osteotomy was stabilized with a 2.0 4-hole miniplate. The patient experienced no postoperative complications or occlusal changes. This case supports MSSO, combined with virtual planning, as a safe and effective option for extracting impacted teeth in complex anatomic locations.

BackgroundOral and maxillofacial tumors, particularly those requiring mandibular reconstruction, present significant clinical challenges due to the complexities involved in achieving precise surgical outcomes and ensuring post-operative stability. Traditional methods for mandibular reconstruction, such as freehand bending of titanium plates, often result in errors in osteotomy and reconstruction, compromising both the precision and stability of the procedure.MethodsThis study initially developed the Robot-assisted Augmented Reality Osteotomy Navigation System (RARONS) and constructed a virtual surgical plan using imaging data. In this robot-assisted cadaveric osteotomy study, 20 Non-Flap Fibulas (NFFs) and 9 Free Flap Fibulas (FFFs) were included to evaluate the impact of pedicle factors on osteotomy precision. Augmented Reality technology enabled surgeons to intuitively perform procedures according to the virtual plan during the robot-assisted osteotomy process. Additionally, in the mandibular reconstruction experiments using cadavers, 11 NFFs and 9 FFFs were included to assess the influence of pedicle factors on reconstruction accuracy. 11 fibulas were reconstructed using surgical guide-plate methods, while 9 fibulas were reconstructed using freehand methods to evaluate the impact of surgical guide plates on reconstruction precision. Finally, an evaluation framework was established to quantify the precision of osteotomy and reconstruction, with osteotomy errors measured in terms of length, angle, and volume, and mandibular reconstruction errors assessed based on width, height, anteroposterior diameter, and symmetry.ResultsIn the osteotomy experiments, the Non-Flap Fibula group demonstrated higher accuracy compared to the Free Flap Fibula group, with mean errors in osteotomy length, angle, and volume recorded as 1.08 ± 1.57 mm, 11.78° ± 5.72°, and 10.76 ± 5.94%, respectively. Similarly, in the mandibular osteotomy experiment, the errors in osteotomy length were within clinically acceptable ranges, with mean errors in length, angle, and volume reported as 1.75 ± 1.32 mm, 6.32° ± 2.71°, and 10.61 ± 5.29%, respectively. In the reconstruction experiments, the presence of a pedicle fibula did not significantly affect the error rate in mandibular reconstruction. Additionally, the personalized surgical guide-plate reconstruction group showed superior accuracy in width, anteroposterior diameter, and symmetry compared to the traditional freehand reconstruction group. The posterior mandibular angle and anterior mandibular angle for the personalized group were 1.57° ± 1.07° and 1.16° ± 1.31°, respectively.ConclusionsThis study demonstrated that RARONS significantly improved osteotomy accuracy and enhanced mandibular reconstruction precision using personalized pseudo-titanium plates and guide-plates. These advancements lay the foundation for integrating digital osteotomy navigation and personalized surgical guide-plate technology into clinical maxillofacial surgery.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12903-025-06566-2.

Facial deformities are treated with various osteotomies; one of them is the median osteotomy of the mandibular symphysis. The combined use of other osteotomies offers advantages in addressing different anatomic alterations. This study aimed to analyze the performance of the mandibular midline osteotomy in a series of cases, used in conjunction with other mandibular osteotomies. A series of 9 cases was evaluated, including patients of both sexes, excluding those with incomplete records. Preoperative and postoperative variables were examined to determine indications and surgical sequence characteristics. Two patients presented temporomandibular joint symptoms in the postoperative phase and received minimally invasive treatment. No periodontal alterations were observed at the osteotomy sites, and all cases showed occlusal stability, concluding with standard orthodontic treatment. The results suggest that the described technique allows for predictable and stable occlusal outcomes in the treatment of facial deformities, making it a versatile tool with low complication rates.

Elective tracheostomy is commonly performed to secure the airway following major oncologic and reconstructive head and neck procedures, though it carries risks of additional morbidity and may not be necessary in all cases. The purpose of this study was to evaluate the association between elective tracheostomy and postoperative airway complications. This was a retrospective cohort study of all patients undergoing resection and free flap reconstruction of an oral cavity cancer from 2012 to 2022 in the American College of Surgeons National Surgical Quality Improvement Program databases. The primary predictor was elective tracheostomy. The primary outcome was the occurrence of any airway complication within 30 days of surgery. Secondary outcomes included adverse discharge disposition, extended length of hospital stay, 30-day mortality, and readmission. A total of 2722 subjects (mean age 62.4±13.1y, 66.2% male) were included, with 195 experiencing an airway complication (7.16%). In adjusted analysis, longer operative time (P<0.001) and mandibular osteotomies (P=0.050) were the only independent predictors of airway complications. Elective tracheostomy was not associated with airway complications or secondary outcomes, but was independently associated with a 75% reduction in the odds of 30-day mortality (P=0.001). These findings suggest that while elective tracheostomy is not required in every case, it may confer a survival benefit in select patients. Decisions regarding tracheostomy should be individualized based on patient characteristics, anatomy, and surgical complexity.