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Background: The primary objective of this study was to ascertain the risk factors associated with hardware complications following segmental mandibular reconstruction in head and neck cancer patients. Additionally, we sought to develop a nomogram model that enables accurate risk prediction., Methods: Patients who underwent segmental mandibulectomy with immediate free or local regional tissue transfer between January 2016 and December 2020 were reviewed. Hardware complications were defined. Patient demographics and perioperative parameters were analyzed., Results: A total of 510 patients were analyzed. Postoperative radiation therapy (OR = 2.296, 95% CI = 1.339-3.938, p = 0.003), postoperative wound infection (OR = 2.367, 95% CI = 1.472-3.806, p < 0.001), and debridement for flap-related complications (OR = 5.484, 95% CI = 3.269-9.199, p < 0.001) were identified as independent risk factors. The nomogram model demonstrated good discriminatory ability., Conclusion: This comprehensive analysis identified three independent risk factors, and the nomogram provides a valuable tool for predicting the risks. Further research is needed to validate these findings and explore preventive strategies., (© 2024 Wiley Periodicals LLC.)

In this paper, a method of automatic surgical planning for mandibular osteotomy based on automatic identification of mandibular landmark points was proposed with facial skeletal contour surgery. A mandibular osteotomy plane optimization model was established, allowing key anatomical measurement parameters to be obtained. The analysis of the preoperative CT images of 100 patients with mandibular osteotomy showed that the average RMS error of the automatic identification algorithm was 1.87 ± 0.33 mm. To verify the effectiveness of the mandibular angle osteotomy surgical planning system on real cases, three clinical trials were conducted, and the results of the surgical planning scheme could meet the clinical needs., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethical approval: The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Shanghai Ninth People’s Hospital. Informed consent: Informed consent was obtained from all subjects involved in the study. Written informed consent was obtained from the patient(s) to publish this paper., (© 2025. The Author(s).)

Background: Many studies have compared lip-splitting mandibulotomy (LSM) and lip-mandible preservation (LMP) techniques in oral and oropharyngeal cancer (OOPC) patients with inconsistent conclusions. Evidence-based recommendations for the optimal surgical approach for treating OOPC are lacking., Methods: The Cochrane Library, Pubmed, Embase, Web of Science, WAN-FANG, CQVIP, and China National Knowledge Infrastructure were systematically searched to identify studies that compared LSM versus LMP for OOPC. An additional search of the gray literature was performed using Google Scholar, OpenGrey and ProQuest Dissertations & Theses Global. Survival rate, recurrence rate, surgical margin, perioperative outcomes, postoperative complications and functional status were assessed. The standard mean difference (SMD) and odds ratio (OR) with a 95% CI were pooled using fixed-effect or random-effect models., Results: Four randomized controlled trials, five case-control studies, and twenty cohort studies including a total of 2622 patients were identified. The LSM approach significantly increased postoperative complications such as mandibular osteomyelitis/osteoradionecrosis (OR = 4.57; 95% CI = 1.20-17.39; P = 0.026), fistula (OR = 1.5; 95% CI = 1.05-2.15; P = 0.027), and flap infection (OR = 2.96; 95% CI = 1.49-5.87; P = 0.002), while LMP improved facial appearance (SMD = -0.65; 95% CI = -1.05 to -0.25; P = 0.002). Meta-analyses showed no significant difference in survival rate (OR = 1.07; 95% CI = 0.83-1.38; P = 0.59), total recurrence (OR = 1.15; 95% CI = 0.87-1.52; P = 0.325), local recurrence (OR = 1.39; 95% CI = 0.88-2.19; P = 0.163), operation duration (SMD = 0.19; 95% CI = -0.75 to 1.13; P = 0.688), length of hospital stay (SMD = 0.48; 95% CI = -0.27 to 1.22; P = 0.208), volume of blood loss (SMD = 0.43; 95% CI = -0.17 to 1.03; P = 0.156), surgical margin (OR = 1.01; 95% CI = 0.72-1.41; P = 0.947), hematoma/seroma (OR = 1.01; 95% CI = 0.46-2.25; P = 0.972), wound infection (OR = 1.28; 95% CI = 0.92-1.79; P = 0.145), swallowing (SMD = -0.33; 95% CI = -0.91 to 0.24; P = 0.428) and speech (SMD = -0.14; 95% CI = -0.44 to 0.17; P = 0.381) between the LSM and LMP groups., Conclusion: These findings suggest that LMP may be a safe and efficient alternative to LSM for treating OOPC patients with decreased mandibular osteomyelitis/osteoradionecrosis, fistula, flap infection, and a better aesthetic outcome., (Copyright © 2025 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: This study aimed to assess patient satisfaction regarding facial appearance and quality of life pre- and post-reduction mandibuloplasty. In addition, it sought to investigate the factors influencing patient satisfaction., Methods: Conducted as a prospective cohort study spanning from November 2020 to October 2023, participants were required to complete the FACE-Q assessment both before and one year following reduction mandibuloplasty. Normative FACE-Q values from individuals aged over 18 years were employed for comparison. A multivariate linear regression model was used to evaluate the impact of various factors on FACE-Q outcomes., Results: Statistically significant enhancements in patient satisfaction were observed with overall appearance, lower face and jawline, and quality of life post-surgery. When compared to normative data, preoperative scores were significantly lower, yet postoperative scores reach levels comparable to those of the normative population. Moreover, patients generally perceived themselves as looking approximately 0.75 years younger post-surgery. Notably, patients aged 30 and younger experienced more pronounced improvements than those above 30., Conclusion: Reduction mandibuloplasty significantly contributes to the enhancement of facial appearance and quality of life, achieving results representative of the general population. Moreover, it positively influences the perception of apparent facial age. The extent of improvement varies among distinct age groups, emphasizing the recommendation for reduction mandibuloplasty at earlier ages, as older patients tended to exhibit less improvement., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no conflict of interest to disclose. Ethical Approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of the clinical research committee of plastic surgery hospital (12100000400266049B) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed Consent: Informed consent was obtained from all patients and can be seen by the editors., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Background: This study assesses the feasibility of real-time surgical navigation to plan and guide sequential steps during mandible reconstruction on a series of cadaveric specimens., Methods: An image-guided surgical (IGS) system was designed including customized mandible and fibula fixation devices with navigation reference frames and an accompanied image-guided software. The mandibular and fibular segmental osteotomies were performed using the IGS in all five cadaveric patients. Procedural time and cephalometric measurements were recorded., Results: Five real-time IGS mandibulectomy and fibular reconstruction were successfully performed. The mean Dice score and Hausdorff-95 distance between the planned and actual mandible reconstructions was 0.8 ± 0.08 and 7.29 ± 4.81 mm, respectively. Intercoronoid width, interangle width, and mandible projection differences were 1.15 ± 1.17 mm, 0.9 ± 0.56 mm, and 1.47 ± 1.62 mm, respectively., Conclusion: This study presents the first demonstration of a comprehensive image-guided workflow for mandibulectomy and fibular flap reconstruction on cadaveric specimens and resulted in adequate cephalometric accuracy., (© 2024 The Author(s). Head & Neck published by Wiley Periodicals LLC.)

Background: Planning of surgical procedures in patients suffering from oropharyngeal cancer requires appropriate imaging, particularly in consideration of the spatial relationship to the mandible. Resection of portions of the mandible (box, marginal, or segmental resection) is often necessary, while simultaneously avoiding overtreatment. Typically, a computed tomography (CT) scan is initially performed. However, the question arises of whether CT alone is adequate for reliable assessment of mandibular involvement., Materials and Methods: A patient cohort of 25 individuals aged 44-79 years (mean 62 years) undergoing partial oropharyngeal resection with segmental mandibular resection was examined. The indication for segmental resection was based on the close relationship of the tumor to the mandible observed in imaging. Reconstruction was consistently carried out with a reconstruction plate and free or pedicled flaps. Preoperative radiological findings were compared with histopathology results after decalcification of the mandibular bone., Results: Cortical tumor infiltration was observed in the mandible in 9 patients (36%). Preoperatively, clear bone infiltration had been identified in CT in only 2 of these 9 patients; in the remaining 7, only direct tumor contact with the mandible was evident. Magnetic resonance imaging (MRI) revealed bone infiltration in 1 of these 7 patients., Discussion: Adhering to safety margins requires a radical surgical approach and reliable intraoperative frozen section analysis. However, at the bone level, intraoperative frozen section analysis is technically impractical due to the required decalcification. Only after decalcification can the entire specimen be assessed for tumor infiltration. In our cohort, a significant discrepancy in terms of bone infiltration was noted between preoperative imaging assessments and postoperative histopathology. CT preoperatively identified bone infiltration in only 8% of our patients. In two thirds of the specimens, no bone infiltration was evident after decalcification and histopathological processing, retrospectively indicating overtreatment by segmental resection; box or marginal resections may have been sufficient in these cases. Therefore, when tumors are adjacent to the bone in CT, MRI should also be performed preoperatively to more reliably detect bone infiltration., Competing Interests: Einhaltung ethischer Richtlinien. Interessenkonflikt: S. Herberhold, S. Greschus, H. Kußmann, F. Bootz, R.H. Reich und F. Far geben an, dass kein Interessenkonflikt besteht. Für diesen Beitrag wurden von den Autor/-innen keine Studien an Menschen oder Tieren durchgeführt. Für die aufgeführten Studien gelten die jeweils dort angegebenen ethischen Richtlinien., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

This study aimed to develop a novel reconstruction method for segmental mandibulectomy. In the authors' opinion, reconstruction of the anterior border of the mandibular ramus using a double-arm vascularized fibular flap is important to prevent deformity due to buccal depression and the accumulation of food debris, thereby eliminating masticatory dead space that cannot be filled with prostheses such as implants or dentures. Using conventional reconstruction plates, the reconstructed bone positioned at the anterior border of the mandibular ramus required either fixing with only 1 screw or using 2 plates for stable fixation, making it difficult to position the plates stably. The TriLock Bridging Plate System (Medartis AG, Switzerland) has 2 arms on the distal side of the plate, which enables stable fixation of the reconstructed bone placed at the anterior border of the mandibular ramus. This innovation has made it possible to securely place the fibula in the ideal position., Competing Interests: The authors report no conflicts of Interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Rationale: Orthognathic surgery cases are inherently challenging to treat with lingual appliances due to the complexities of orthodontic management and difficulties in achieving intermaxillary fixation during surgery. This challenge is further amplified in cases involving asymmetric space closure, such as those with a missing molar on one side and a premolar on the other, a scenario not yet documented in the literature. This case report presents the orthodontic-orthognathic management of an adult patient requiring space closure of asymmetric missing lower teeth., Patient Concerns: A 30-year-old female patient presented with a severe skeletal Class II patient with a retruded mandible, hyperdivergent facial pattern, excessive overjet and overbite, and asymmetric missing lower teeth., Diagnosis: The patient was diagnosed with a Class II malocclusion and asymmetric missing mandibular posterior teeth on a skeletal hyperdivergent Class II relationship., Interventions and Outcomes: The treatment involved orthodontic decompensation with fixed lingual appliances in combination with mandibular advancement osteotomy and genioplasty. Mini-screws were utilized for anchorage control during asymmetric space closure in the presurgical stage and entire lower arch distalization in the postsurgical stage. A significant facial esthetic and functional improvement was achieved posttreatment., Lessons: The combination of mini-screws and lingual appliances may offer effective anchorage management in both presurgical and postsurgical orthodontic stages for optimal orthodontic-orthognathic treatment outcomes. This approach allows for precise tooth movement and control during space closure in the presence of challenging asymmetric missing tooth patterns., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Importance: Reconstructive stability after mandibulectomy with osseous autogenous transplant is influenced by masticatory forces and the resulting stress on the titanium plate., Objective: To determine an optimal geometry of mandibular osteotomy that minimizes undesirable loading of the reconstruction plate., Design, Setting, and Participants: In this combined in silico and in vitro basic science study, segmented computed tomography images of an adult male human mandible downloaded from the Visible Human Project were analyzed. Data were collected from July to November 2023., Exposures: Four posterolateral mandibular resections and bony transplants were modeled following (1) vertical, (2) angled, (3) step, and (4) sagittal osteotomies. Using SOLIDWORKS software, mastication was simulated under (1) incisal, (2) ipsilateral molar, and (3) contralateral molar loading. Mandible models were then 3-dimensionally printed, osteotomized, and plated. Masticatory loads were simulated using pulleys, and strains were measured using strain gauges., Main Outcomes and Measures: On the reconstruction plate, von Mises stresses were measured in silico, and strains were measured using strain gauges in vitro. Stress and strain are reactions of a material to loading that can result in irreversible deformation or fracture., Results: In silico, maximum plate stress was highest with the vertical osteotomy, followed by the angled osteotomy (median difference vs vertical: ipsilateral molar loading, 126 MPa; 95% CI, 18-172; incisal loading, -24 MPa; 95% CI, -89 to 31; contralateral molar loading, 91 MPa; 95% CI, 23-189), step osteotomy (median difference vs angled: ipsilateral molar loading, 168 MPa; 95% CI, 112-235; incisal loading, 80 MPa; 95% CI, 15-140; contralateral molar loading, -17; 95% CI, -115 to 83), and sagittal osteotomy (median difference vs step: ipsilateral molar loading, 122 MPa; 95% CI, 102-154; incisal loading, 197 MPa; 95% CI, 166-230; contralateral molar loading, 161 MPa; 95% CI, 21-232). An angled osteotomy had the lowest stress at 30° of angulation (median difference vs contralateral molar loading at 40° of angulation: 111 MPa; 95% CI, 4-186). In vitro, the vertical osteotomy had the highest maximum strain, followed by the angled osteotomy (mean difference vs vertical: incisal loading, 0.021 mV/V; 95% CI, 0.014-0.027; contralateral molar loading, 0 mV/V; 95% CI, -0.004 to 0.005), step osteotomy (mean difference vs angled: incisal loading, 0.015 mV/V; 95% CI, 0.003-0.028; contralateral molar loading, 0.021 mV/V; 95% CI, 0.016-0.027), and sagittal osteotomy (mean difference vs step: incisal loading, 0.006 mV/V; 95% CI, -0.006 to 0.018; contralateral molar loading, 0.020 mV/V; 95% CI, 0.015-0.026)., Conclusions and Relevance: In this study, the traditional vertical osteotomy resulted in less favorable plate stresses in all loading scenarios compared with angled, step, or sagittal osteotomies, in silico and in vitro. Future clinical studies analyzing the impact of varying osteotomy geometries are warranted to translate these findings to the operating room.

Background: Numerous surgical options for correcting prominent mandibular angles in East Asian patients have been reported. The objective of this study was to investigate the importance of remodeling physiological mandibular angle by comparing the surgical effects and complications of mandibular V-line ostectomy and long curved ostectomy., Methods: A retrospective study was conducted on patients who underwent either mandibular V-line ostectomy (group 1) or long curved ostectomy (group 2). The outcomes were evaluated using computed tomography images in combination with medical records and photographs. Data were collected preoperatively and at 6- to 12-month intervals postoperatively. Mandibular angle, posterior mandibular ramus height, radian of the ostectomy line, and mandibular symmetry, as well as complications, were investigated. FACE-Q reports of facial appearance and psychosocial measures were also compared between the 2 groups., Results: All 106 patients showed improved lower facial contours. Although the postoperative mandibular angle (116.67 ± 7.14 versus 118.31 ± 6.80 degrees; P = 0.233) and mandibular symmetry (2.36 ± 1.21 mm versus 2.56 ± 1.19 mm; P = 0.395) were similar in the 2 groups, larger postoperative posterior mandibular height and lower radian of the ostectomy line were observed in group 1 ( P < 0.001). Physiological mandibular angle was also remodeled in group 1. The gonial deficiency, more soft-tissue sagging, and significantly lower FACE-Q scores for facial appearance were observed in group 2 ( P < 0.001)., Conclusions: V-line ostectomy is better suited for achieving a more physiological mandibular angle with fewer complications compared with mandibular long curved ostectomy. V-line ostectomy may be the preferred option for mandibular contouring., Clinical Question/level of Evidence: Therapeutic, III., (Copyright © 2023 by the American Society of Plastic Surgeons.)

Objectives: Microvascular free tissue transfer (MVFTT) for head and neck reconstruction is infrequently performed in pediatric patients. There is a paucity of data on perioperative airway management in pediatric MVFTT, such as the need for tracheostomy, which can pose higher morbidity to young patients due to potential long-term effects on the softer, more pliable laryngotracheal cartilage. Our objective was to report airway outcomes on pediatric patients undergoing MVFTT after segmental mandibulectomy with or without tracheostomy., Methods: Retrospective chart review of pediatric patients who underwent MVFTT reconstruction after segmental mandibulectomy at a tertiary care center from 2014 to 2023. Demographic variables, surgical characteristics, and hospital clinical outcomes were recorded. Statistical analyses were performed with JMP Pro, Version 16.0.0 (2021) SAS Institute Inc., Cary, NC, 1989-2021., Results: Ten patients (median age 11.5 years old, IQR: 9.0-13.3) underwent fibular free flap reconstruction. Mandibular pathologies included 3 ameloblastoma, 2 mesenchymal chondrosarcoma, 2 desmoplastic fibroma, 1 Ewing sarcoma, 1 chondroblastic osteosarcoma, and 1 desmoid tumor. Two patients received upfront tracheostomy at time of initial surgery for a subtotal mandibulectomy and a sub-hemimandibulectomy, respectively. Both patients were decannulated within 1 week after surgery and prior to discharge. The median ICU and hospital length of stay for patients who underwent tracheostomy was 3.5 days [IQR: 3.0-4.0] and 8.5 days [IQR: 8.0-9.0] respectively. Of the remaining 8 patients without tracheostomy, surgical defects were hemimandibulectomy and anterior subtotal mandibulectomy. Median intubation duration was 1.0 day [IQR: 1.0-2.5]. The median ICU and hospital length of stay for these patients were 3.0 days [IQR: 2.0-6.3] and 8.5 days [IQR: 7.3-13.0], respectively. No patient had to be reintubated for respiratory failure following extubation or had long-term airway complications during the follow-up period., Conclusions: Fibular free flap reconstruction without tracheostomy can be feasible in pediatric patients with mandibular defects, which can potentially reduce hospital resources required for fresh tracheostomy care needs and avoid additional surgical morbidity. Further studies in larger populations and prospective approaches are warranted., 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 B.V. All rights reserved.)

Background: The pathological evaluation of cancellous bone at resection margins of mandibular osteoradionecrosis (ORN) has not been well elucidated. Here, we developed a unique classification system for evaluating the degree of bone marrow fibrosis, one of most common pathological features, in patients with mandibular ORN, based on which we investigated its relationship with treatment outcome., Methods: This study included 15 patients who underwent mandibulectomy and free fibula osteocutaneous flap reconstruction. The extent of mandibulectomy was determined, with safety margins of approximately 10 mm from the apparent osteolytic areas on preoperative computed tomography image. Special staining was performed on thin sections from center of the osteolytic areas (medial area) and bilateral resection margins, and the degree of bone marrow fibrosis was evaluated and investigated its relationship with presence of bone union as a treatment outcome., Results: The degree of bone marrow fibrosis of medial area was significantly higher than those of resection margins. Although most resection margins had collagen fibers which indicate severe fibrosis, all transferred fibula flaps achieved bone union., Conclusion: When mandibulectomy is performed with safety margins of approximately 10 mm from the apparent osteolytic areas, all transferred fibula flaps achieved bone union regardless of the degree of bone marrow fibrosis at resection margin. In other words, the association between severe bone marrow fibrosis at resection margins and treatment outcome was not seen., Clinical Relevance: Setting safety margins of approximately 10 mm may achieve bone union, but further study is needed., (© 2024. The Author(s).)

Surgery is the first line of treatment in gingival cancers of the mandible, and bone resection is necessary in the majority of cases. In the less extensive surgical option, marginal mandibulectomy (MM), the mandibular base is preserved. In contrast, in a segmental mandibulectomy (SM) the mandible is divided and the continuity is not preserved. If MM can be performed with comparable oncological results to SM, it is the preferred method. The aim of the present study was to identify preoperative predictors for local recurrence (LR), to support the selection of candidates for MM. Outcome measures were local recurrence free survival (LRFS) and disease specific survival (DSS). 67 patients treated with MM between 2008 and 2021 were included. Cox regression analyses of LR with hazard ratios and adjustments for postoperative radiotherapy, pathological T-stage (pT) and soft tissue margins were performed. 5-years LRFS was 63% (95% CI 46.9-75.5) and DSS 80.6% (95% CI 64.7-89.9). In conclusion we found that edentulous patients, more advanced pT-stage and positive soft tissue margins had increased risk for LR. Future studies of the correlation between cT and pT would be important to provide more robust preoperative support in the selection between MM and SM., (© 2024. The Author(s).)

This clinical report summarizes a workflow that introduces two approaches for fabricating a metal framework removable partial denture for a marginal mandibulectomy patient. First, the pre-existing denture was adjusted according to the piezographic technique to determine the optimal configuration for adhering to the available denture space. Second, computer-aided design-computer-aided manufacturing (CAD-CAM) technology was used to fabricate a new removable partial denture by digitally scanning the oral condition and the well-adjusted denture and then using the obtained data to design and fabricate the new denture. These two approaches can help to reduce chair time not only for maxillofacial prosthetic treatment but also for other denture cases.

Background: In very rare cases, patients who have undergone surgery-first approach with intraoral vertical ramus osteotomy (IVRO) exhibit unusual downward movements of mandible even up to 1-year post surgery, which makes it difficult for orthodontists to stabilize the occlusion during the postoperative orthodontic period. The aim of this study was to identify factors affecting the unusual downward movement of the mandible 1-year after the surgery-first approach using IVRO, while focusing on cephalometric values., Methods: This retrospective cohort study sample was divided into two groups based on the amount of vertical movement of the B-point 1-year post surgery (Group S, predictable upward movement; Group U, unpredictable downward movement greater than 2 mm). To evaluate cephalometric changes between the two groups, cephalograms were obtained before surgery, 1 day after surgery, 1 month after surgery, and 1 year after surgery. The data were analyzed using the independent t-test, Mann-Whitney U test with Bonferroni correction, Pearson correlation analysis, and multiple regression analysis., Results: At the initial examination, Group U showed a shallower anterior overbite. The vertical surgical change in the B-point was statistically different between the two groups (p < 0.001), indicating that group U exhibited more upward movement of the mandible during surgery. Group U showed significant downward movement of the mandible 1 month after surgery, and this finding persisted until 1 year postoperatively. Clockwise rotation of the mandible was also observed. Surgical vertical movement of the B-point showed a strong correlation with postoperative vertical movement of mandible (r = -0.674; p < 0.001) along a linear relationship, indicating that the amount of postoperative vertical downward movement of the mandible increased as the amount of surgical upward movement of the B-point increased (R 2  = 0.449; p < 0.001)., Conclusions: This study revealed that unusual downward movement of the mandible after a surgery-first approach using IVRO is correlated with the amount of upward movement during the surgery. When planning surgery, in cases in which a significant upward movement of the mandible is anticipated, orthodontists should prepare for the possibility of subsequent unusual downward movement and a tendency for the anterior overjet to decrease during the postoperative orthodontic period., (© 2024. The Author(s).)

A 7-year-old French Bulldog presented with an acanthomatous ameloblastoma affecting approximately 30% of the right mandibular body. We utilized a patient-specific 3D-printed surgical template to perform lateral fenestration of the mandible and elevation of the inferior alveolar nerve (IAN), facilitating nerve preservation during subsequent segmental mandibulectomy. The resulting critical-sized bone defect was anatomically stabilized using a patient-specific polyetheretherketone (PEEK) bridging plate. The recovery process was uneventful, with maintained occlusion and orofacial sensitivity.Similar to cases in humans with ameloblastoma, preserving orofacial sensitivity through the preservation of the inferior alveolar nerve seems feasible in dogs. Consequently, potential negative consequences of permanent regional denervation, which are unavoidable in traditional mandibulectomy, can be avoided. Bridging the ostectomy with a PEEK plate, offering advantages such as radiolucency, absence of imaging artifacts, and a modulus of elasticity similar to bone, proved to be functional in this canine patient, with no signs of complications observed up to the latest follow-up at 6 months., Competing Interests: The authors declare no conflict of interest., (Thieme. All rights reserved.)

Background: Segmental mandibulectomy and reconstruction of resulting defect can be performed via intraoral approach (IOA) or extraoral approach (EOA). Both approaches have advantages, disadvantages, indications, and contraindications to consider during their selection., Objective: To compare IOA vs EOA of segmental mandibulectomy and microvascular reconstruction with fibula free flap (FFF)., Methods: We conducted a retrospective cohort study in which 51 patients who underwent segmental mandibulectomy and microvascular reconstruction with FFF from 2020 to 2024 were included, especially 17 patients by IOA and 34 patients by EOA, representing both groups of this study. Clinical characteristics, surgery parameters, and patients' prognosis were evaluated. Patients' satisfaction and Derriford Appearance Scale (DAS59) were assessed during follow-up., Results: Ameloblastoma was the most frequent diagnosis (52.9% managed by IOA vs 70.6% by EOA); FFF was frequently positioned as double barrel (94.1% managed by IOA vs 88.2% by EOA). Compared with EOA group, IOA group had less intraoperative blood loss (mean difference [MD] = -112.2, 95% confidence interval [CI]: -178.9 to -45.5, p = 0.001), higher satisfaction score (MD = 1.3, 95% CI: 0.9 to 1.7, p ˂ 0.001), and lower DAS59 score (MD = -0.5, 95% CI: -0.7 to -0.2, p ˂ 0.001)., Conclusion: Both IOA and EOA were found safe and feasible, presenting similar perioperative features and postoperative outcomes. Patients managed with IOA were more satisfied with aesthetic outcomes than patients managed with EOA. In the absence of simultaneous immediate implant during mandibular FFF reconstruction, after stability of FFF on the defect site, patients should always be referred to an implantologist and/or prosthodontist for teeth restoration to improve functional and aesthetic outcomes., Competing Interests: Conflict of interest Chunjie Li had collaboration with Chengdu Bangmeite Trade Co., Ltd, who provided BioMet titanium plates for our hospital. The collaboration project aimed to improve the side wall screw system. The other 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 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Mandibular angle osteotomy with outer cortex grinding is an effective cosmetic procedure for correcting square faces. However, morphological changes in the mandible may also cause temporomandibular joint (TMJ) disorders. This retrospective study aimed to investigate the morphological stabilization of the TMJ and changes in masseter muscle thickness after mandibular angle osteotomy to evaluate the safety of the procedure. Data from patients who underwent mandibular angle osteotomy with outer cortex grinding between January 2016 and January 2019 were retrospectively reviewed. Preoperative and long-term follow-up (~1 y) computed tomography data were collected from these patients, and morphological changes in the TMJ and masseter muscle were analyzed. The results from the computed tomography data showed that the condylar length and condylar height were significantly reduced 1 year after the operation ( P < 0.05). In addition, the morphology of the TMJ was stable, and the distance between the mandibular condyle and the glenoid fossa did not change significantly. No significant difference was observed in masseter muscle thickness before and after the operation. After mandibular angle osteotomy with outer cortex grinding, the length and height of the mandibular condyle were functionally restored without any disorders of the TMJ. Moreover, the masseter muscle exhibited stable function. In conclusion, the procedure is safe for occlusal function and suitable for popularization., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Objective: The aim of the study was to develop and evaluate an automated preoperative planning algorithm based on anatomical landmark point recognition for enhancing the efficiency and intelligence of preoperative planning for mandibular angle osteotomy., Methods: A retrospective cohort of 34 patients underwent preoperative planning with this algorithm. The present algorithm was developed using a method based on anatomical marker point recognition. The efficiency, symmetry, and safety of the automated preoperative planning and esthetics were statistically analyzed by paired t test and χ2 test., Results: The results showed that the automated planning algorithm was able to achieve a great improvement in preoperative planning efficiency as well as safety and symmetry. A prospective case report of 2 patients is then reported, illustrating the safety and esthetics of the algorithm with 1-year postoperative follow-up and postoperative esthetic scores., Conclusion: This algorithm can help to improve the efficiency of preoperative planning for surgeons while ensuring safety and esthetics and can be further applied to other craniomaxillofacial personalized design surgeries in the preoperative design in the future., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Introduction: Innovative technologies from other fields of science are constantly being introduced in medicine. Research works on animals strongly confirm the belief in better results following ultrasound and laser surgery. The main conclusions are based on observations from different animal species, whose biological characteristics differ from those of humans. This requires scientific experiments to be performed and confirmed in humans., Material & Methods: Human mandible specimens harvested in vivo by a conventional low-speed rotary device, an ultrasonic unit, or an Er: YAG laser were studied and analyzed to compare their effects on bone morphology and tissue response following surgery., Results: The cutting surface of eighty biopsies was studied, as well the facial edema, pain levels, and jaw dysfunction were followed up in the same eighty patients from whom the slices were obtained. In the piezosurgery and drill groups, the borders exhibited irregular edges full of bone fragments and debris. Thermal alterations within the superficial surface in all bone samples were generally minimal. In all specimens, intact osteocytes were detectable away from the area of direct action of the bone-cutting device. It was established, that the reactive facial edema, pain levels, and jaw disfunction were with milder values following in vivo osteotomy by an ultrasonic unit and Er: YAG laser compared to the conventional drilling. Moreover, the recovery of the patients in these two groups was more pronounced. The observed tissue changes proved to affect the follow-up tissue reactions in the postoperative period (p ≤ 0.05)., Discussion: Based on the established effects on human bone by its in vivo cutting, it can be concluded that laser and ultrasonic bone surgery was a superior alternative osteotomy method in humans to conventional drilling., Competing Interests: Declaration of competing interest None., (Copyright © 2023. Published by Elsevier Masson SAS.)

Background: Patients with micrognathia undergoing mandibular distraction osteogenesis (MDO) for functional and aesthetic improvement are at significant risk for dental complications. The authors investigated the association of 2 osteotomy patterns-oblique and inverted-L-with risk to developing dentition., Methods: A senior orthodontist (H.D.N.) performed a retrospective review of dental radiographs of patients undergoing MDO with confirmed oblique or inverted-L osteotomies between 2012 and 2022. Images were assessed for evidence of missing, damaged, or displaced teeth, and proportion of affected hemimandibles by injury type and median number of affected teeth per hemimandible were compared between groups using appropriate statistical methodology., Results: Analysis included 44 patients (23 oblique, 21 inverted-L) and 85 hemimandibles (45 oblique, 40 inverted-L). Mean age at surgery was 3.1 ± 4.6 years, and mean time to imaging was 4.9 ± 4.1 years; there was no difference between groups ( P = 0.23, P = 0.34, respectively). Oblique osteotomy was associated with greater odds of missing teeth (odds ratio [OR], 13.3, P < 0.001), damaged teeth (OR, 3.2; P = 0.02), and any dental injury (OR, 39.9; P < 0.001) compared with inverted-L, as well as greater number of missing teeth (β = 0.6; P < 0.01), damaged teeth (β = 0.3; P = 0.02), and total number of affected teeth (β = 0.9; P < 0.001). There was no difference in incidence ( P = 0.5) or number ( P = 0.4) of displaced teeth between groups., Conclusions: Inverted-L osteotomies were associated with fewer dental complications compared with oblique osteotomy at all ages studied. Although longer-term follow-up and prospective data are needed before definitive recommendations can be made, these data are helpful to surgeons as they plan MDO., Clinical Question/level of Evidence: Therapeutic, III., (Copyright © 2023 by the American Society of Plastic Surgeons.)

We are grateful to the authors of the study by Castagnola et al., which sought to ascertain the prevalence of tooth necrosis in patients undergoing mandibulotomy or mandibulectomy for head and neck cancer. In order to prevent surgical problems, the researchers suggested doing root canal therapy on the teeth next to the surgical site prior to surgery. Although the results offer insightful information about tooth necrosis in patients with head and neck cancer who have had mandibulotomies or mandibulectomy, we would like to voice our concerns about the reported data in order to give a stronger basis for future studies in this field., (© 2024. The Author(s).)

Objective: The purpose of this study was to quantify the spontaneous new bone formation and bony bridge formation by 3-dimensional analysis of cone-beam computed tomography (CBCT) after segmental mandibulectomy reconstruction using an R-plate without any graft material in patients with medication-related osteonecrosis of the jaw (MRONJ)., Study Design: 15 MRONJ patients (13 females and 2 males) were selected based on the inclusion criteria. Data on new bone formation, bony bridge formation, R-plate fracture, patient age, and type and duration of medication were collected. Panoramic and CBCT scans were obtained at 1 day, 6, 12, and 24 months postoperatively. CBCT images of each period were transferred to a personal computer using MIMICS 21.0 for volumetric analysis. After quantifying the volume of new bone formation, we calculated the percentage of the volume of new bone to the segmentally resected necrotic bone volume (%NB)., Results: All patients showed spontaneous new bone formation with the average of 20.69% within a year and 28.52% within 2 years, and 80.0% showed bony bridge formation within a year., Conclusions: The R-plate reconstruction in patients with MRONJ showed significant amount of spontaneous new bone formation within 2 years after segmental mandibulectomy., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A calcifying epithelial odontogenic tumor is a rare, benign odontogenic neoplasm. Surgical treatment is the option, and late recurrence is very rare. Radiologically, the lesions are commonly present scattered calcifications. This case report details a 64-year-old female patient with a recurrence of a right mandibular calcifying epithelial odontogenic tumor 2 decades after successful initial surgical removal. A segmental mandibulectomy and immediate reconstruction were performed using a planned vascularized free fibula flap with virtual surgery, custom reconstruction plate, and intraoperative computed tomography. Modifications were made to the design of the reconstruction plate to improve the cervicofacial profile and subsequent rehabilitation with dental implants. Fully guided implant surgery with point-of-care manufacturing protocol was done to improve prosthetically driven implant planning. The case presented highlights the usefulness of new technologies for mandibular reconstruction with the free fibula flap and the concept of point-of-care with technical notes that increase precision and reduce morbidity in implant-supported rehabilitation., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Statement of Problem: Several mandibular defect classifications after oncological resection have been proposed with no universal acceptance among surgeons and prosthodontists. Established criteria for describing these mandibulectomy defects are lacking., Purpose: The purpose of this systematic review was to analyze the classification systems of mandibular defects available in the scientific literature, provide a critical appraisal, and identify the criteria necessary for a universal description of mandibular discontinuity defects., Material and Methods: An electronic search of the English language literature between 1971 and 2020 was performed on 2 electronic databases (PubMed and Cochrane Library). The search was conducted using MeSH terms and free text words: Mandible neoplasm AND Mandibular reconstruction OR Mandible resection OR Mandible defect AND classification, followed by the application of inclusion and exclusion criteria. Studies describing the classification of osteoradionecrosis of the mandible, mandibular fracture, impacted mandibular third molar, and mandibular endodontic or periodontal treatment were not included. The full texts of selected articles were reviewed in depth to provide a critical appraisal. The various descriptive factors of each classification system were tabulated to identify criteria suitable for the universal description of mandibular discontinuity defects., Results: The electronic search yielded a total of 239 titles and abstracts. Of these, 52 titles relevant to the review were identified by the 2 reviewers independently. Those studies that did not match the predetermined inclusion criteria and duplicates were excluded. By reviewing the 21 selected studies and applying exclusion criteria, 12 studies were selected for full-text reading. A manual search in the references of the selected publications was performed, which yielded 1 additional article that satisfied the inclusion criteria. Thus, a total of 13 full-text articles were included in the final review. After further qualitative analysis and tabulation of relevant information from selected classification systems, the 8 descriptive criteria and a pyramidal hierarchical chart were proposed that included the extent of bony defect, soft tissue defect, dental status, mandibular function, neurological status, condyle status, type of reconstruction, and combined resection., Conclusions: The spectrum of patients with mandibulectomy defects following resection varies greatly. The question of the most ideal classification system remains unresolved. Eight different criteria for the description of mandibular discontinuity defects and the pyramidal hierarchical chart proposed will allow surgeons and prosthodontists to better communicate and conceptualize an individualized surgical and prosthetic treatment plan., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: This study aims to evaluate the factors most associated with early and late complications following microvascular free tissue transfer (MVFTT) after mandibulectomy., Methods: A retrospective review of patients undergoing MVFTT after segmental mandibulectomy from September 2016 to February 2021 was performed across a single academic institution. Surgical variables were collected, including the location of the resultant mandibular defect (anterior vs posterior) and flap type (osseous or non-osseous). The primary outcome variables included postoperative complications (early, <90 days; and late, >90 days) and the patients' functional status (return to oral intake). Descriptive statistics, chi-square test, Fischer's exact test, and 2-sample t tests were used to analyze differences among variables., Results: We analyzed a cohort of 114 consecutive patients with mandibular defects, comprising 57 anterior and 57 posterior defects. Bony free flaps with hardware were used to reconstruct 98% of anterior defects compared to 58% of posterior defects ( P  < .001). All soft tissue only flaps did not utilize any hardware during the reconstruction. Anterior defects demonstrated more late complications requiring additional surgery (30% vs 9%, P  = .04). A secondary analysis of posterior mandibular reconstructions compared soft tissue only flaps and bony free flaps with hardware and showed equivalent rates of early (12% vs 13%, P  > .99) and late (9% vs 8%, P  > .99) complications requiring additional surgery while demonstrating a similar return to full oral competence (55% vs 46%, P  = .52) and recovery of a 100% oral diet (67% vs 54%, P  = .53)., Conclusion: Osseous free tissue transfer for segmental mandibular defects remains the gold standard in reconstruction. In our patient cohort, anterior mandibular defects are associated with greater late (>90 day) complications requiring additional surgery. Comparable outcomes may be achieved with soft tissue only versus osseous free flap reconstruction of posterior mandibular defects., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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.)

Objective: To assess submental-cervical soft tissue changes after en bloc mandibular U-shaped osteotomy and examine alterations in the anterior belly of digastric muscle (ABDM)., Methods: A retrospective study analyzed 20 patients who underwent en bloc mandibular U-shaped osteotomy from 2018 to 2023. Preoperative (Tp) and long-term follow-up (Tf) CT data were collected for analysis, measuring mandibular volume, soft tissue thickness at menton (Mes) and cervicale (C), and ABDM parameters (length, cross-sectional area (CSA), volume, distance from centroid point to the mandibular margin). Correlation analyses were performed to investigate the connection between soft tissue thickness changes, ABDM changes, and mandibular osteotomy volume., Results: Long-term follow-up revealed a significant increase in soft tissue thickness at the Mes and C points after U-shaped mandibular osteotomy, especially at the C point. The adaptive length of ABDM decreased, CSA increased, and volume decreased, but the ABDM centroid point shifted downward relative to the mandibular margin, indicating drooping protrusion. The increment of soft tissue thickness was moderately positively correlated with the amount of osteotomy, and the decrement of ABDM length and volume were slightly positively correlated with the amount of osteotomy., Conclusion: The degree of soft tissue relaxation after U-shaped osteotomy is related to the extent of osteotomy. Notably, the protrusion of ABDM relative to the mandibular margin affects submental-cervical contour aesthetics. Prior to U-shaped osteotomy, it is crucial to assess the soft tissue condition of the patient's lower face, and the individualized design of the osteotomy volume should be carried out cautiously and safely., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

For radical treatment of malignancies in the posterior region of the oral cavity and oropharynx, surgical exposure of the tumor by mandibulotomy is often required. Midline or paramedian vertical mandibulotomies are commonly performed in clinical practice, but these can damage the suprahyoid musculature and genioglossus, and weaken the swallowing and speech function of patients. Stair-stepped mandibulotomy is a new procedure, developed on the principles of functional surgery, that preserves the structure and function of the mandible whilst providing a clear field and avoiding damage to critical muscle attachments. Stair-stepped mandibulotomy is suitable for patients whose primary tumor is located in the middle and posterior part of the tongue or oropharynx, especially if the lesion involves extrinsic tongue muscles. In this case report, we draw on 2 cases of typical patients in our center to elaborate the surgery program design, operation points, advantages and disadvantages of stair-stepped mandibulotomy., 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: The adequacy of the cut end of the mandible following a segmental mandibulectomy done for oral cancer intraoperatively is at times assessed using a frozen section (FS) of the bone marrow (BM) at the cut ends. The study aimed to assess its utility to guide the intraoperative decision on the adequacy of bony margins., Materials and Methods: All patients with oral squamous cell carcinoma (OSCC) who underwent segmental mandibulectomy from January 2012 to December 2021 at our institute and for whom intraoperative FS of BM was utilized were included. We analyzed the sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of this in predicting positive bone margins., Results: A total of 457 patients were included in the study. The majority of the cases were per premium cases (n = 372, 81.4%). The median age of the cohort was 52 years (range: 22-80 years). Most patients had T4 disease (n = 406, 88.8%). On FS, BM was positive in only 18 patients (3.9%) for whom the bone margin was revised. BM biopsy report in the final histopathology was positive in 12 patients (2.2%). The sensitivity, specificity PPV, and NPV were 52.3%, 98.65%, 64.7%, and 97.7% respectively. No factors predicting BM positivity on FS could be identified in this cohort., Conclusions: The BM FS was positive in only a small percentage of patients, and it helped in reducing the bone margin positivity rate from 3.9% to 2.2% only. Hence the intraoperative BM FS seems to have limited utility as seen from our study., (© 2024 Wiley Periodicals LLC.)

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.)

Objective: The risk that mandibular distraction osteogenesis (MDO) poses to the developing mandibular dentition is well-known; however, less is understood about how the choice of instrumentation used for mandibular osteotomy might affect the development of permanent molars., Methods: Retrospective chart review examining infants with micrognathia who underwent MDO from 2010 to 2018 at a single tertiary care children's hospital using external, multivector devices. The first and second permanent mandibular molars were radiographically examined years after surgery to determine whether osteotomy cutting techniques affect the risk of injury to the permanent dentition., Results: Thirty-seven infants and children underwent MDO from 2010 to 2018. Follow-up dental radiographs were available for 17 patients; 6 patients were excluded based on the use of preoperative computed tomography, utilization of virtual surgical planning technology, use of buried internal distractors, or older age at the time of distraction surgery. This yielded a total of 11 patients who underwent MDO with external hardware without virtual surgical planning representing 22 osteotomies. Sixteen osteotomies were performed using a side-cutting burr and 6 with a piezoelectric saw. The median age at distraction surgery was 3 weeks. The rate of an abnormal permanent first or second mandibular molar finding per osteotomy was 88% (14/16) in the side-cutting group versus 17% (1/6) with the piezoelectric technique (P = 0.004)., Conclusion: Mandibular distraction osteogenesis risks injury to the mandibular molars; however, this study suggests a significant risk reduction in molar injury if the piezoelectric device is utilized., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Background: Post-traumatic mandibular malocclusion is a complex condition that poses a significant challenge to reconstructive surgeons. The malocclusion that ensues from bilateral condylar and parasymphseal fractures presents a particular challenge as it leads to bilateral posterior shortening and lingual tilting of dental arch leading to a combination of open anterior bite, crossbite, overbite, underbite, and/or facial asymmetry. The complexity of such malocclusion requires intricate freedom of movement of the mandibular arch that can be achieved by performing a 5-segment mandibular osteotomy., Method: This is a case series of 9 adult patients with significant post-traumatic mandibular malocclusion who were treated with 5-segment mandibular osteotomy technique. This article details the demographics, surgical technique and outcomes in this cohort of patients., Results: All 9 patients in this series had condylar fracture as part of the index mandibular trauma. They have a common post-traumatic deformity of the mandibular arch due to shortening of the vertical mandibular height in the fracture site and variable degrees of lingual tilting leading to crossbite. The 5-segment mandibular osteotomy provided an adequate correction of dental and facial deformities in all 9 patients. One patient had a relapse of the dental malocclusion that required postoperative rescue orthodontics. Furthermore, one patient had a significant postoperative hemorrhage that required a facial artery ligation., Conclusion: Post-traumatic mandibular malocclusion is a complex deformity that poses a great challenge to practicing surgeons. Five-segment mandibular osteotomy is a technique that provides ample degrees of movement of mandibular segments that is necessary to correct such deformity., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 by Mutaz B. Habal, MD.)

Background: Mandibular reconstruction has historically been challenging due to the complex, highly functional, and esthetic nature of the anatomy. The most common etiologies of these defects requiring resection include trauma, benign tumors, and malignant pathology. Mandibular defects have been treated with little consideration for neural reconstruction, leaving patient's orally incompetent with associated social stigma. Although recent advances in reconstructive techniques improve oral rehabilitation, immediate inferior alveolar nerve (IAN) reconstruction has not been widely adapted., Objective: Here-in we seek to discuss the innovations of neural reconstruction of large segment mandibular defects and associated IAN defects and present an example case performed at Naval Medical Center San Diego (NMCSD)., Methods: Pertinent literature discussing maxillofacial reconstruction and nerve repair using autogenous nerve harvest and allograft was queried from available online resources., Results: Six patients have received immediate reconstruction of the IAN using processed nerve allograft over the past three years. All obtained sensation to S3 within six months of surgery., Conclusion: IAN repair using nerve allografts in conjunction with free flap reconstruction for large mandibular defects is a viable treatment and should be the new paradigm in maxillofacial reconstruction as it provides substantial quantifiable and qualitative improvements in social, functional, and esthetic outcomes of care.

Background: The current absence of a standardized mandibular body osteotomy design poses challenges in surgical planning. Traditional approaches may not suit patients with wider anterior mandibles, potentially resulting in unsatisfactory outcomes. Addressing this issue requires a rational design that combines mandibular angle and body osteotomies for improved clinical practice., Objectives: In this retrospective cohort study we aimed to analyze mandibular computed tomography (CT) data with digital methods. The goal was to establish an integrated osteotomy design for both mandibular angle and body procedures and classify prevalent mandibular types in the Chinese Han population for surgical guidance., Methods: Included were 89 patients who underwent mandibular angle osteotomy without genioplasty between 2016 and 2022 at Peking University Third Hospital. Mimics 21.0 software facilitated CT data reconstruction and osteotomy planning. Postoperative effects were assessed through imaging, complications, and surveys, leading to mandibular type classification., Results: Mandibular angles were categorized by 3 types, based on osteotomy range. Type I involved mandibular body osteotomy only, type II mandibular angle osteotomy only, and type III both mandibular angle and body osteotomies. Distribution within the cohort was 2.25%, 8.99%, and 88.76% for types I, II, and III respectively. Patient satisfaction was high, with minor and major complications at 47.19% and 1.12% by Clavien-Dindo classification., Conclusions: Utilizing Mimics software, we established an integrated osteotomy design and categorized mandibular types. Findings offer valuable guidance for mandibular angle surgery and contribute to understanding of Asian mandibular morphology., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Aesthetic Society.)

Background: Mandibular angle osteotomy (MAO) is a frequently described technique in Eastern females. The success hinges on the precise positioning of the osteotomy line. The geometric mathematical method is viable. Therefore, we explored the impact of mandibular angle osteotomy using aesthetic standards and printed digital osteotomy templates (DOTs) on the aesthetic osteotomy line., Methods: This retrospective observational study included female patients with prominent mandibular angle (PMA) who underwent MAO at our hospital between January 2020 and March 2021. Thirty-three female patients were included, 22 in the DOTs group using new DOTs, and 11 in the traditional group using traditional free-hand techniques., Results: Regarding the width of the excised bone, the postoperative deviation from the preoperative plan was not significant in the DOTs group (0.5 ± 0.3 mm, P > 0.05), while the deviation was significant for the traditional group (2.5 ± 1.2 mm, P<0.05). The preparation time was longer in the DOTs group than in the traditional group (82 ± 11 vs. 53±4 min, P < 0.001). The osteotomy time and the operation time were shorter in the DOTs group than in the traditional group (osteotomy: 54 ± 5 vs. 73 ± 6 min; preparation: 124 ± 10 vs. 169 ± 13 min; both P < 0.001). The Likert (4.0 ± 0.5 vs. 1.0 ± 0.6, P = 0.006) and FACE-Q scores (17.5 ± 1.7 vs. 15.6 ± 1.3, P = 0.029) were higher in the DOTs group., Conclusions: The new method of positioning the new aesthetic osteotomy line based on geometric analysis might provide a possible osteotomy method that strongly suggests effectiveness, safety, individualization, and accuracy, with a shorter operation and higher patient satisfaction., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Background: Reconstruction of continuity defects following osteonecrosis in multimorbid patients is challenging. In all cases of the predescribed palliative treatment method for alloplastic mandible reconstruction, plate fractures were detected in follow-up. We hypothesized that a modification could avoid these fractures, leading to stable long-term results., Methods: This retrospective study compares the original method with a modification using single, laser-sintered CAD-CAM plates instead of manually bent miniplates. The predescribed shuttering technique was used to reconstruct the mandible in its original shape with bone cement., Results: Uneventful wound healing was observed in 86% of the cases after modification of the method. No implant or plate fracture occurred., Conclusions: The presented method should be considered as a treatment option for mandible reconstruction in elderly, multimorbid patients in palliative situations. The results of this study suggest that the modification of the method leads to significantly improved long-term stability. Donor site morbidity is avoided with this method of palliative surgery., (© 2023 The Authors. Head & Neck published by Wiley Periodicals LLC.)

With the advancement of digital technology over the last few decades, the use of virtual surgical planning and fabrication of surgical guides have tremendously improved the outcomes of various maxillofacial surgical procedures. The intraoral vertical ramus osteotomy (IVRO) is an orthognathic surgical procedure largely employed for mandibular setback in correcting dentofacial deformities. This study describes the design and application of a surgical cutting guide for IVRO. The guide can also be used to facilitate the placement of miniplate fixation. The initial experience at the authors' centre suggests that the guide has allowed the osteotomy to be performed with increased precision and confidence. Furthermore, the use of miniplate fixation decreased the period of maxillomandibular fixation. However, a larger series is required to evaluate the utility of this system more thoroughly., (Copyright © 2022 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: In east Asia, lower face contouring surgeries including reduction mandibuloplasty and genioplasty are the most popular aesthetic craniofacial surgeries. Conventional selection of surgical strategies mainly relied on the visual judgment of the mandibular angle, without overall assessment of the mandibular sub-units. Furthermore, only a few studies offered quantitative assessment of the mandibular shape., Methods: From 2010 to 2021, 1241 patients diagnosed with square faces and received customized lower face contouring surgeries by the senior author were reviewed and analyzed to propose an "ABC" classification system for facilitating surgical planning., Results: Among them, 998 (80.42%) received bilateral mandible reshaping, 155 (12.49%) underwent bilateral mandible reshaping combined with genioplasty, and 88 (7.09%) received asymmetric mandible reshaping. A modified classification system composed of three critical parameters (height, morphology/thickness, divergence) in three aesthetic zones (mandibular angle, mandibular body, chin) was proposed based on quantitative summarization of the CT database and the senior author's 12-year experience. The way to facilitate surgical planning with this classification was demonstrated., Conclusions: This modified classification system ushered a decision-making process that prioritized several critical measurements and proposed an operative planning form. Meanwhile, it can also be cooperated into the three-dimensional virtual surgical plan., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 ., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Porcine mandibular defect models are commonly used for the preclinical evaluation of reconstruction techniques. Existing studies vary in technique, complexity, and postoperative outcomes. The procedures are complex and often described without sufficient detail. We describe in detail a simple and reproducible method for creating a critical-size mandibular defect in a porcine model. Seven hemimandibular critical size defects were created in five male Yorkshire-Landrace pigs, three with unilateral defects and two with bilateral defects. A transverse incision was made over the mandibular body. Periosteum was incised and elevated to expose the mandibular body and a critical-size defect of 30 × 20 mm created using an oscillating saw. The implant was inserted and fixed with a titanium reconstruction plate and bicortical locking screws, and the wound closed in layers with resorbable sutures. Intraoral contamination was avoided. Dentition was retained and the mental nerve and its branches preserved. The marginal mandibular nerve was not encountered during dissection. All pigs retained normal masticatory function, and there were no cases of infection, wound breakdown, haematoma, salivary leak, or implant-related complications. The procedure can be performed bilaterally on both hemimandibles without affecting load-bearing function. All pigs survived until the end point of three months. Postoperative computed tomographic scans and histology showed new bone formation, and a three-point bend test showed the restoration of biomechanical strength. Straight-segment mandibulectomy is a simple and reproducible method for the creation of critical-size mandibular defects in a porcine model, simulating a load-bearing situation., (Copyright © 2022 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Background: The procedure of mandibular angle osteotomy (MAO) via an intraoral approach is challenging and experience-dependent due to the limited field of view and inadequate operational space. Uncertainty about the osteotomy line and plane can lead to severe complications. A three-dimensional printed guidance template based on a computer-assisted preoperative simulation is a potential solution to this problem. The current study aims to retrospectively investigate the feasibility and accuracy of using a custom-made segmented template to guide the osteotomy plane during the procedure., Methods: Sixty patients who had segmented template-guided MAO were included in the study. Preoperative simulation using the custom-designed template and postoperative computed tomography were collected and parameters, including mandibular angle, gonion distance, and the mandibular plane angle were measured. A paired t tests and intraclass correlation coefficients (ICCs) were used to evaluate the efficacy, accuracy, and symmetry of the results. All complications were reviewed., Results: The patients had a significantly larger mandibular angle and narrower gonion distance postoperatively. Preoperative simulations and postoperative outcomes were compared; ICCs were larger than 95% indicating significant agreement. Bilateral postoperative comparisons of the mandible also demonstrated excellent agreement (ICC > 95%). Numbness in the chin area was the most frequent complication but all recovered by 3 months postoperatively., Conclusions: The custom-made template can guide the osteotomy plane during the MAO procedure and achieve favorable accuracy and symmetry. Direct contact of the saw with the guidance template not only facilitates control of the osteotomy line but also the oblique angle of the osteotomy plane. This methodology may be a feasible and effective tool for mandibular contouring., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by Mutaz B. Habal, MD.)

Abstract: This study presents an innovative surgery that successfully improved the facial profile and occlusal function of a patient with a skeletal Class III malocclusion and posterior hypodontia. The patient had chief complaints of missing teeth and a protrudedjaw. A novel 1-stage surgery referred to as posterior mandibular segmental split osteotomy combined with Le Fort i osteotomy and BSSRO was used because the patient wanted to save time and was worried about periodontal complications associated with other treatment methods. As a result, a satisfying facial profile and a Class I occlusion with a normal position of the posterior dentoalveolar segment of the mandible were achieved with no adverse effects. Thus, posterior mandibular segmental split osteotomy can be considered an effective treatment for skeletal Class III malocclusion with posterior hypodontia., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by Mutaz B. Habal, MD.)

Clear cell odontogenic carcinoma (CCOC) is a rare malignant odontogenic tumor. It is characterized by showing, on histopathological examination, clusters of vacuolated and clear tumor cells with epithelial differentiation surrounded by fibrocollagenous stroma and fibroblasts. The present study presents a rare clinical case of mandibular CCOC associated with an impacted tooth in a 26-year-old woman surgically treated with mandibulectomy and reconstruction with iliac crest bone graft. The patient has been followed up for 22 months without signs of recurrence. A search for case report/case series was carried out in the PUBMED database, as well as in the references of relevant previously published literature reviews. Ninety-six publications were identified, totaling 136 distinct cases reported. Female sex was the most affected (63.1%) with 63.3% of cases occurring in patients in the fifth, sixth, or seventh decades of life. The mandible was more affected than the maxilla (74.2%). Association of CCOC with impacted teeth was found in 2.4% of cases, thus rendering it a rare occurrence. The present case report corroborates the results of the survey regarding sex and anatomical location of the tumor; however, it contradicts the findings regarding age predilection. The case described is the fourth known occurrence of tooth impaction associated with the tumor and the first in a female. In conclusion, CCOC should be considered, as well as other malignancies, as a possible diagnosis of maxillary or mandibular intraosseous lesions even in unusual circumstances such as in association with impacted teeth and in young patients., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: In this study, an AI osteotomy software was developed to design the presurgical plan of mandibular angle osteotomy, which is followed by the comparison between the software-designed presurgical plan and the traditional manual presurgical plan, thus assessing the practicability of applying the AI osteotomy software in clinical practices., Methods: (1) Develop an AI osteotomy software: design an algorithm based on convolutional neural networks capable of learning feature point and processing clustering segmentation; then, select 2296 cases of successful 3D mandibular angle osteotomy presurgical plans, followed by using those 2296 cases to train the deep learning algorithm; (2) compare the osteotomy presurgical plan of AI osteotomy software and that of manual: first step: randomly selecting 80 cases of typical female head 3D CTs, and designing those 80 cases by means of AI osteotomy software designing (group A) and manually designing (group B), respectively; second step: comparing several indexes of group A and those of group B, including the efficiency index (time from input original CT data to osteotomy presurgical plan output), the safety index (the minimum distance from the osteotomy plane to the mandibular canal), the symmetry indexes (bilateral difference of mandibular angle, mandibular ramus height and mandibular valgus angle) and aesthetic indexes (width ratio between middle and lower faces (M/L), mandibular angle and mandibular valgus angle)., Results: The efficiency index: the design time of group A is 1.768 ± 0.768 min and that of group B is 26.108 ± 1.137 min, with P = 0.000; the safety index: The minimum distances from the osteotomy plane to the mandibular canal are 3.908 ± 0.361mm and 3.651 ± 0.437mm, p = 0.117 in groups A and B, respectively; The symmetry indexes: Bilateral differences of mandibular angle are 1.824 ± 1.834° and 1.567 ± 1.059° in groups A and B, respectively, with P = 0.278; bilateral differences of mandibular ramus height are 2.083 ± 1.263 and 2.965 ± 1.433, respectively, with P = 0.119 in groups A and B; Aesthetic indexes: M/L in groups A and B is 1.364 ± 0.074 and 1.371 ± 0.067, respectively, with P = 0.793; mandibular angles in groups A and B are 127.724 ± 5.800° and 127.242 ± 5.545°, respectively, with P = 0.681; Valgus angles in groups A and B are 11.474 ± 5.380 and 9.743 ± 4.620, respectively, with P = 0.273., Conclusions: With high efficiency, as well as safety, symmetry and aesthetics equivalent to those of a manual design, the AI osteotomy software designing can be used as an alternative method for manual osteotomy designing., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Purpose: We present our experience with transoral segmental mandibulectomy, in conjunction with vascularized osseous mandibular reconstruction, utilizing an intraoral anastomosis and free of extraoral incisions. Virtual surgical planning and intraoperative navigation were used to help achieve this minimally invasive and scar-free approach., Methods: A retrospective study was performed on 9 patients who underwent transoral segmental mandibulectomy followed by vascularized osseous reconstruction using an intraoral anastomosis between January 2018 and October 2018. The anastomotic recipient vessels were the facial artery and vein. The outcome variable was defined as the flap survival. Postoperative panoramic radiographs and computed tomography images were obtained for assessment of the neo-mandible. In addition, we performed a cadaver dissection to highlight relevant anatomic details of the facial artery and vein., Results: Successful transoral segmental mandibulectomy was achieved in 9 patients, with an intraoral anastomosis successfully achieved in 8 patients. In one patient, an extraoral anastomosis was required because of challenging facial vein anatomy. Both recipient and donor sites healed uneventfully with a 100% successful rate of flap survival. In all cases, a well-positioned neo-mandible with good occlusion was demonstrated on postoperative imaging and examination. A symmetric facial appearance with no restrictions in mouth opening was also achieved in each case. In our cadaver dissection, we describe the anatomical course of the facial artery and vein. An average angle of 30° between these vessels is identified., Conclusions: Transoral segmental mandibulectomy combined with intraoral microvascular mandibular reconstruction is a surgically achievable technique with the benefit of being scar free., (Copyright © 2022 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To compare the masseter muscle changes and bone regeneration between reduction mandibuloplasty along with partial masseter muscle resection and reduction mandibuloplasty alone., Methods: Forty-seven patients who complained of prominent mandibular angle and hypertrophy masseter muscles (MMH) were divided into group 1 treated with reduction mandibuloplasty along with partial masseter muscle resection, and group 2 treated with reduction mandibuloplasty alone. Pre-5 days and long-term postoperative computed tomography data were collected, and the masseter muscle volume, hemi-mandible volume, and unilateral lower face width were measured. Patient satisfaction and complication were also evaluated., Results: At long-term follow-up, group 1 showed a greater decrease in masseter volume (p < 0.001), and lower face width (p < 0.001), and less bone regeneration (p < 0.001) than group 2. Furthermore, patients in group 1 had higher satisfaction with the surgical outcome (p < 0.05)., Conclusion: Reduction mandibuloplasty along with partial masseter muscle resection can achieve a slender frontal appearance and significantly decrease bone generation. For patients with MMH, reduction mandibuloplasty along with partial masseter muscle resection is an effective and predictable lower face reshaping surgery., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 ., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Objectives/hypothesis: Despite considerable effort being dedicated to contouring reconstruction plates, there remains limited evidence demonstrating an association between contour and reconstructive outcomes. We sought to evaluate whether optimizing mandibular reconstruction plate contouring is associated with reduced postoperative hardware complications., Study Design: Retrospective cohort study., Methods: A cohort study was performed with adult patients (age ≥18 years) who underwent mandibulectomy and osseous free flap reconstruction following oncologic ablation at the University Health Network in Toronto, Canada, between January 1, 2003 and December 31, 2014. Patients with computed tomography scans performed within 1 year of reconstruction were included. Computer-based three-dimensional models were generated and used to calculate the mean plate-to-bone gap (mm). The primary outcome was plate exposure. Secondary outcome included a composite of plate exposure or intraoral dehiscence. Logistic regression models were fitted for each outcome accounting for other patient and surgical characteristics associated with the primary outcome., Results: Ninety-four patients met inclusion criteria, with a mean age of 60.4 (standard deviation [SD] 14.9). The mean follow-up time was 31.4 months (range 3-94). Reconstruction was performed with fibular (57%) and scapular free flaps (43%). In the multivariable model, small mean plate-to-bone gap (<1 mm) was independently associated with 86% reduced odds of plate exposure (odds ratio [OR] 0.12; 95% confidence interval [CI] 0.02-0.55). Mean plate-to-bone gap less than 1 mm was also independently associated with reduced odds of developing a composite of plate exposure or intraoral dehiscence (OR, 0.29; 95%CI, 0.11-0.75)., Conclusion: Optimizing plate contouring during mandibular reconstruction may decrease the development of postoperative hardware complications., Level of Evidence: 4 Laryngoscope, 132:61-66, 2022., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Digital technology has been widely used in mandibular curved osteotomy to improve accuracy. However, the planning process still highly dependent on the experience and judgement of the surgeon. This study describes an automatic method to design the new gonion and osteotomy line based on the aesthetic standards in attractive women, and assesses its clinical outcomes., Methods: An automatic surgical planning method for mandibular curved osteotomy was developed based on our previous research of mandibular angle aesthetics. A prospective clinical study was conducted from April 2016 to April 2018. Twenty-five female patients with prominent mandibular angle were enrolled. Pre- and postoperative skull computed tomography (CT) was performed. Three-dimensional (3D) CT data were obtained and processed by Mimics 18.0. Surgical templates were designed according to the automatic surgical planning method and 3D printed for the surgery. Preoperative measurements, surgical simulation and postoperative measurements were taken to evaluate the surgical outcomes., Results: There were significant differences between the preoperative and the postoperative groups' results (p < 0.01). There was no difference between the surgical simulation and the postoperative results. All postoperative measurements were consistent with aesthetic features of mandibles. Patients were satisfied with their outcomes in terms of outline, symmetry and lower facial width., Conclusions: Our study developed an automatic method to position the new aesthetic gonion and osteotomy line for prominent mandibular angle patients. We proved that this method is safe, effective and reliable., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2021 Elsevier Ltd. All rights reserved.)