[Mandibular osteotomy, a simpler and safer method of osteosynthesis]. / Ostéotomie mandibulaire, une méthode plus simple et plus sûre d'ostéosynthèse.

Bilateral sagittal split osteotomy (BSSO) is a surgical procedure to treat mandibular malpositions. However, this surgery is associated with a risk of recurrence. Osteosynthesis techniques may be the cause of early recurrences. This study aims to demonstrate the efficiency and stability of osteosynthesis with two bicortical screws placed with a transjugal approach. We included patients who benefited from a BSSO alone, between May 2020 and August 2021. We performed the osteosynthesis using two bicortical screws placed with a transjugal approach. All the patients underwent lateral X-rays before the surgery, one week after and minimum six months after the intervention. These medical images allowed to study the mandibular movements during the intervention and the osteosynthesis stability. Twenty-five patients benefited from a BSSO alone. Patients obtained a satisfactory occlusal result. The results showed good stability of the two fragments, after surgery, during the studied period (average follow up of 8 months). Two bicortical screws osteosynthesis placed with a transjugal approach is a simple, effective and stable method for osteosynthesis in case of BSSO.

Les ostéotomies sagittales bilatérales mandibulaires (OSBM) sont des procédures chirurgicales utilisées pour traiter les malpositions mandibulaires. Toutefois, cette chirurgie présente un risque de récidive. Les techniques d'ostéosynthèse pourraient être la cause de récidives précoces. Cette étude vise à démontrer l'efficacité et la stabilité de l'ostéosynthèse à l'aide de deux vis bicorticales placées par voie transjugale. Nous avons inclus les patients ayant bénéficié d'une OSBM seule, entre mai 2020 et août 2021. Nous avons réalisé les ostéosynthèses à l'aide de deux vis bicorticales placées par voie transjugale. Tous les patients ont réalisé des clichés radiologiques de profil avant l'intervention, une semaine après et minimum six mois après. Ces imageries ont permis d'étudier les mouvements mandibulaires durant l'intervention et la stabilité de l'ostéosynthèse. Vingt-cinq patients ont bénéficié d'une OSBM seule. Les patients ont obtenu un résultat occlusal satisfaisant. Les résultats ont montré une bonne stabilité des deux fragments après la chirurgie durant la période étudiée (en moyenne, recul de 8 mois). En conclusion, l'ostéosynthèse à l'aide de deux vis placées par voie transjugale est une méthode simple, efficace et stable d'ostéosynthèse d'OSBM.

Postoperative Radiotherapy and Survival in Oral Cavity Squamous Cell Carcinoma With Mandibulectomy.

Importance: Oral cavity squamous cell carcinoma (SCC) tumors with mandibular invasion are upstaged to pT4a regardless of their size. Even small tumors with boney invasion, which would otherwise be classified as pT1-2, are recommended for the locally advanced treatment pathway to receive administration of postoperative radiotherapy (PORT). Objective: To evaluate the association of PORT with overall survival according to tumor size among patients who received mandibulectomy for pT4aN0 oral cavity SCC. Design, Setting, and Participants: This was a retrospective analysis using data from the US National Cancer Database from January 1, 2004, through December 31, 2019. All patients who received mandibulectomy for treatment-naive pT4aN0 oral cavity SCC with negative surgical margins were included. Data analyses were performed in January 2023 and finalized in July 2023. Exposure: PORT vs no PORT. Main Outcomes and Measures: Entropy balancing was used to balance covariate moments between treatment groups. Weighted multivariable Cox proportional hazards regression was used to measure the association of PORT with overall survival associated with tumor size. Results: Among 3268 patients with pT4aN0 oral cavity SCC (mean [SD] age, 65.9 [12.1] years; 2024 [61.9%] male and 1244 [38.1%] female), 1851 (56.6%) received PORT and 1417 (43.4%) did not receive PORT. On multivariable analysis was adjusted for age, insurance status, Charlson Comorbidity Index score, tumor site, tumor grade, tumor size, and PORT. Findings indicated that PORT was associated with improved overall survival and that this relative survival advantage trended upwards with increasing tumor size. That is, the larger the tumor, the greater the survival advantage associated with the use of PORT. For the 1068 patients with tumors greater than 4 cm, the adjusted hazard ratio (aHR) in favor of PORT was 0.63 (95% CI, 0.48-0.82); for the 1774 patients with tumors greater than 2 cm but less than or equal to 4 cm, the aHR was 0.76 (95% CI, 0.62-0.93); and for 426 patients with tumors less than 2 cm, the aHR was 0.81 (95% CI, 0.57-1.15). Conclusions and Relevance: In this retrospective analysis of patients who received mandibulectomy for pT4aN0 oral cavity SCC, PORT was associated with improved overall survival, the benefit of which improved relatively with increasing tumor size. These findings suggest that tumor size should be considered in guidelines for PORT administration in this patient population.

Case report of a patient with mandibulectomy followed up for 11 years.

Mandibular deviation and rotation following mandibulectomy can significantly impact oral function and quality of life. The postoperative course of a 57-year-old patient who underwent mandibulectomy for oral cancer and findings over 11 years of follow-up observation to monitor changes in the mandibular position are described here. Based on the observations, it is important to raise awareness regarding the necessity of continued monitoring of mandible position and regular adjustments of prostheses for patients who have undergone mandibulectomy.

Management of Through-and-Through Oromandibular Defects after Segmental Mandibulectomy with Fibula Osteocutaneous Flap.

BACKGROUND: Oromandibular defects involving the external skin are a reconstructive challenge. This study aimed to evaluate the use of the fibula osteocutaneous free flap (FOCFF) for through-and-through oromandibular defects by comparing the surgical outcomes and complications of different techniques to close the external skin defect. METHODS: A retrospective analysis was conducted of patients who underwent reconstruction of through-and-through oromandibular defects after oncologic segmental mandibulectomy between January 2011 and December 2014. Five groups were analyzed according to the method of external skin coverage: primary closure, locoregional flaps, deepithelialized double-skin paddle FOCFF (deEpi-FOCFF), division of the skin paddle for double-skin paddle FOCFF (div-FOCFF), and a simultaneous second free flap. Intraoperative and postoperative outcomes along with complications were analyzed between groups. RESULTS: A total of 323 patients were included. The mean total defect area requiring a simultaneous second free flap was larger in comparison to other groups (p < 0.001). Reconstructions performed with div-FOCFF had a higher number of perforators per flap when compared with deEpi-FOCFF (p < 0.001). External defects closed with another free flap exhibited higher intraoperative time for the reconstructive segment in comparison to other groups (p < 0.05). The overall rate of complications was comparable between groups (24%, p = 0.129). CONCLUSION: The FFOCF is a reliable alternative to harvesting multiple simultaneous free flaps for through-and-through oromandibular defects. The authors recommend appropriate curation of the surgical plan based on individual patient characteristics and reconstructive requirements.

A screw and wire assisted coronoidectomy procedure: A technical note.

Temporomandibular joint (TMJ) ankylosis and oral submucous fibrosis (OSMF) often exhibit elongated hyperplastic coronoid processes with fibrous attachments to the temporalis muscle. In managing this condition, a vital step involves performing a coronoidotomy or coronoidectomy alongside the primary surgical procedure. While coronoidectomy is preferable due to reattachment issues, its complexity arises from the thickened and elongated coronoid process. Our technical note introduces a screw and wire assisted coronoidectomy method, found to be efficient, replicable, and time-saving.

Clinicopathologic Profile and Surgical Modalities in Mandibular Ameloblastoma: A Descriptive Study.

BACKGROUND: Ameloblastoma is a benign neoplasm composed of epithelial tissue with invasive and infiltrative behavior at the local level and a high recurrence rate, with various histopathologic patterns and clinical forms. Approximately 85% of conventional ameloblastomas occur in the mandible, most often in the body, angle, and ascending ramus area. The treatment modalities include both conservative and radical treatments. Postoperative follow-up is most important in the treatment of ameloblastoma. AIMS AND OBJECTIVES: To describe the clinicopathologic profile of mandibular ameloblastoma in patients undergoing different surgical modalities. The primary objective was to describe the clinicopathologic profile and surgical management of mandibular ameloblastoma in patients aged ≥18 years, who had reported to a tertiary dental care center for follow-up during the study period. The secondary objective was to describe the distribution of comorbidities associated with different surgical modalities and reconstructive methods. SUBJECTS AND METHODS: A total of 34 patients with mandibular ameloblastoma who underwent various surgical modalities between 2011 and 2021 were studied. Information was collected using a predesigned proforma and statistically analyzed. RESULTS: Thirty-four review cases of ameloblastoma were included in the study. The patients were analyzed concerning age, sex, site, size, clinical presentation, radiographic pattern, histopathologic subtype, type of surgery, and associated comorbidities. Most cases of mandibular ameloblastoma involve the age of 16 to 55 years. The mean age of occurrence was found to be 35.5±13.2. A female preponderance, a tumor size range of 2 to 4 cm, a multicystic variant, involvement of the mandibular body in the premolar-molar area, root resorption, cortical perforation, and a follicular type of histopathologic pattern were the common presentations. Isolated anterior tumors restricted to the incisor/canine region were not found. The common surgical modalities undertaken were conservative methods such as enucleation, and chemical cauterization, and radical methods such as marginal mandibulectomy and segmental resection. Reconstruction using a titanium plate or free fibular graft was performed in the indicated cases. The common comorbidities included difficulty in chewing and loss of facial contour. Recurrence after surgical treatment was rare. Only 9% of cases developed a recurrence within 5 years. No recurrence was noted in cases treated with radical treatment, whereas 50% of cases treated with conservative methods showed recurrence. CONCLUSION: The age of occurrence, site, and size of the tumor, cortical perforation, root resorption, histopathologic type, and radiographic patterns are widely considered factors in devising a treatment plan for mandibular ameloblastoma. However, there may be rare instances where these tumors behave differently regardless of their innocuous clinicopathologic presentation. Surgical procedures such as segmental resection and marginal mandibulectomy were found to be promising for the eradication of the tumor, and prevention of recurrences and metastasis. However, conservative measures such as enucleation and chemical cauterization were fraught with an increased risk of tumor recurrence and metastasis. Future studies with a larger sample size should focus on the clinicopathologic characteristics of ameloblastoma to elucidate its varied behavior and develop newer and advanced treatment modalities that would provide better surgical and postsurgical outcomes in affected patients.

Accuracy of computer-assisted design and manufactured three-dimensional device for condylar positioning in mandibular bilateral sagittal split osteotomy (clinical trial).

INTRODUCTION: Aligning dental arches in orthognathic treatment after undergoing LeFort I osteotomy or bilateral sagittal split osteotomy (BSSO) relies on occlusal splints, which do not provide precise control over the condylar head. AIM OF THE STUDY: To clinically and radiographically assess the accuracy of computer-assisted design and manufactured (CAD/CAM) surgical guide for condylar positioning in a BSSO. MATERIALS AND METHODS: The study recruited 8 patients with a non-syndromic dentofacial deformity who underwent a BSSO. Surgery was planned according to CAD/CAM technology. After osteotomy, a pre-operative guide was used, followed by a repositioning guide. Computed tomography scans were conducted on all patients 1 week pre-operatively, immediately, and 3 months postoperatively. RESULTS: The data are presented as median values with the 25th and 75th percentiles. Eight patients (37.50% females and 62.50% males) between the ages of 19 and 24 underwent BSSOs. The surgical procedure successfully corrected their skeletal deformities. The absolute change between immediate postoperative and pre-operative condylar angle was 0.15 (0.00-0.3). The absolute change between 3 months postoperative and pre-operative condylar angle was 0.20 (0.00-0.30). CONCLUSION: The stability of the condylar head in position is well assessed by 3-dimensional condylar positioning devices designed and manufactured by CAD/CAM technology in the mandibular BSSO.

Modified submandibular mandibulotomy approach versus lip-splitting approach in tongue cancer surgery: a retrospective paired-cohort study.

OBJECTIVES: The surgical approach for resection and reconstruction of tongue cancer (TSCC) with or without the lip-splitting incision is controversial. This study introduced a modified approach without lip-splitting and the clinical results were assessed. METHODS: Sixty-eight TSCC patients underwent surgery using the modified submandibular mandibulotomy (MSMM) approach without lip-splitting, and another matched 68 patients using lip-splitting mandibulotomy (LSM) approach were enrolled in this study. The clinical results including intraoperative relevance and surgical morbidities, survival status, facial appearance and scar scores, function of lower lip, and quality of life (QOL) were evaluated. RESULTS: The primary tumors were en bloc resected through the MSMM approach with excellent tumor exposure and R0 resection margins as LSM approach. The survival status and complications were similar in both groups. The function of lower lip was better in patients of MSMM group at 1 month after surgery. The MSMM approach was associated with significantly better facial appearance and recreation compared to LSM approach by scar scores and QOL assessment. CONCLUSION: The MSMM approach without lip-splitting achieves similar tumor control, better aesthetic results, and QOL compared to LSM approach. It is a safe and effective surgical approach for patients with TSCC. CLINICAL RELEVANCE: The MSMM approach without lip-splitting is oncological safety in tongue cancer surgery and is scrutinized as one part of the treatment concept for better aesthetic results.

Does mandibular osteotomy affect the infraorbital nerve? a prospective study.

OBJECTIVES: The aim of this study was to evaluate the sensory function of the infraorbital nerve after orthognathic surgery (OS). MATERIALS AND METHODS: Patients who underwent Le Fort I osteotomy with or without BSSO for dentofacial deformity treatment were studied. Two groups were created according to whether BSSO was performed. Class A tests were performed to determine the degree of peripheral nerve damage. The Class B test was performed if decreased sensation was detected in at least one of these tests. A Class C test was performed if abnormal sensation was detected. RESULTS: Twenty-eight patients (n=56) who underwent OS were included in this prospective study. Of the patients, 57.1% were female, 42.9% were male, and the mean age was 24.6 (±3.8). Seven patients were in group 1 (n=14), and 21 patients were in group 2 (n=42). In both groups, there were statistically significant differences between T1 and T2 (p<0.001), and the mean NSD score at T2 was higher than that at T1. The mean NSD score in the single jaw group was higher than that in the double jaw group at all time points. CONCLUSIONS: Bimaxillary surgeries had a negative effect on the somatosensory changes that developed in the early period. The upper lip's somatosensorial recovery was faster than IOR and single jaw recovery was faster than double jaw. CLINICAL RELEVANCE: Maxillofacial surgeons performing orthognathic surgery should be aware that in double jaw operations, changes in the somatosensory function of the ION are more severe.

Mandibular small cell osteosarcoma: a case report and review of literature.

BACKGROUND: Small cell osteosarcoma is an extremely rare histopathological variant of conventional osteosarcoma. Due to nonspecific symptoms, most osteosarcomas of the jaws are misdiagnosed as periapical abscesses and mistreated by teeth extraction and drainage. CASE PRESENTATION: We report, to our knowledge, the seventh case of small cell osteosarcoma in gnathic sites affecting the mandible of an old female with history of a large painful swelling related to the right mandibular molar area for 2 months. Cone-beam computed tomography scan showed an osteolytic lesion related to the lower molar area with involvement of the inferior alveolar nerve. An incisional biopsy was taken, and after histopathological examination and immunohistochemical staining, a diagnosis of small cell osteosarcoma was reached. Hemi-mandibulectomy was performed by a maxillofacial surgeon. No clinical evidence for recurrence was noted until manuscript writing. CONCLUSION: Accurate diagnosis is very important, and general practitioners should be aware of this entity considering that small cell osteosarcoma has a poor prognosis when compared to conventional osteosarcoma.

Aesthetic Enhancement of the Gonial Angle and Inferior Mandibular Border in the Chinese Population.

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.

Alloplastic reconstruction of the mandible after subtotal mandibulectomy for medication-related osteonecrosis of the jaw: An update of the method.

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.

Occlusal Plane Angle as a Key Factor for Chin Protrusion After Mandibular Osteotomy in Skeletal Class III.

There is no treatment algorithm to decide whether maxillomandibular or mandibular osteotomy alone should be performed in borderline cases. This study assessed the factors that affect the changes in soft tissue after mandibular setback. Patients who underwent mandibular osteotomy alone to correct mandibular protrusion were included in this study. Hard and soft tissue analyses were performed on lateral cephalograms before and 12±3 months after surgery. The popular points were set for referencing hard and soft tissues on the lateral cephalogram. Nasolabial, labiomental, and soft tissue facial plane angles were measured for the soft tissue assessment. To assess the mandibular setback amount, SNB was calculated. Twenty-one patients were included in this study. The nasolabial angle was increased after surgery and its change significantly correlated with the change in SNB ( P =0.00815). The change in soft tissue facial plane angle after surgery per change in SNB significantly correlated with the occlusal plane angle ( P =0.0009). An occlusal plane angle of at least 15.45 degrees was required for the SNB and soft tissue facial plane angle to change to the same degree. The occlusal plane angle (whether or not it was ≥15.45 degrees) may help in determining the surgical approach in borderline cases, specifically on whether maxillomandibular or mandibular osteotomy alone should be performed if the mandibular setback is simple.

A novel simulation module for segmental mandibulectomy and mandible reconstruction using 3D models.

INTRODUCTION: Mandibular resection and reconstruction are common but complex procedures in head and neck surgery. Resection with adequate margins is critical to the success of the procedure but technical training is restricted to real case experience. Here we describe our experience in the development and evaluation of a mandibular resection and reconstruction simulation module. METHODS: 3D printed (3DP) models of a mandible with a pathologic lesion were developed from imaging data from a patient with an ameloblastoma. During an educational conference, otolaryngology trainees participated in a simulation in which they reviewed a CT scan of the pathologic mandible and then planned their osteotomies before and after handling a 3DP model demonstrating the lesion. The adequacy of the osteotomy margins was assessed and components of the simulation were rated by participants with pre- and post-training surveys. RESULTS: 52 participants met criteria. After reviewing the CT scan, 34 participants (65.3 %) proposed osteotomies clear of the lesion. This proportion improved to 48 (92.3 %, p = 0.001) after handling the 3D model. Among those with initially adequate margins (n = 33), 45.5 % decreased their margins closer to the ideal, 27.2 % made no revision, 21.2 % widened their margins. 92 % of participants found the simulation beneficial for surgical planning and technical training. After the exercise, the majority of participants had increased confidence in conceptualizing the boundaries of the lesion (69.2 %) and their abilities to ablate (76.5 %). CONCLUSIONS: The structured mandibulectomy simulation using 3DP models was useful in the development of trainee experience in segmental mandible resection. LAY SUMMARY: This study presents the first mandibulectomy simulation module for trainees with the use of 3DP models. The use of a 3DP model was also shown to improve the quality of surgical training.