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Background Recently, medical rapid prototyping (MRP) models, fabricated with computer-aided design and computer-aided manufacture (CAD/CAM) techniques, have been applied to reconstructive surgery in the treatment of head and neck cancers. Here, we tested the use of preoperatively manufactured reconstruction plates, which were produced using MRP models. The clinical efficacy and esthetic outcome of using these products in mandibular reconstruction was evaluated. Methods A series of 28 patients with malignant oral tumors underwent unilateral segmental resection of the mandible and simultaneous mandibular reconstruction. Twelve patients were treated with prebent reconstruction plates that were molded to MRP mandibular models designed with CAD/CAM techniques and fabricated on a combined powder bed and inkjet head three-dimensional printer. The remaining 16 patients were treated using conventional reconstruction methods. The surgical and esthetic outcomes of the two groups were compared by imaging analysis using post-operative panoramic tomography. Results The mandibular symmetry in patients receiving the MRP-model-based prebent plates was significantly better than that in patients receiving conventional reconstructive surgery. Conclusions Patients with head and neck cancer undergoing reconstructive surgery using a prebent reconstruction plate fabricated according to an MRP mandibular model showed improved mandibular contour compared to patients undergoing conventional mandibular reconstruction. Thus, use of this new technology for mandibular reconstruction results in an improved esthetic outcome with the potential for improved quality of life for patients.

Background According to the AJCC third to seventh edition staging manuals (1988–2010), the presence of through cortex and/or skin invasion in oral cavity squamous cell carcinoma (OCSCC) identifies T4a tumors. The AJCC eighth edition (2018) introduced a depth of invasion (DOI) > 20 mm as a criterion for pT4a. Subsequently, a revision maintained that tumors > 4 cm with a DOI > 10 mm should be classified as pT4a. We sought to analyze the prognostic impact of the three distinct criteria identifying pT4a disease. Methods We examined 667 consecutive patients with pT3-4 buccal/gum/hard palate/retromolar SCC who underwent surgery between 1996 and 2016. pT1/pT2 ( n  = 108/359) disease were included for comparison purposes. Results The 5-year outcomes of patients with pT1/pT2/without ( n  = 406)/with tumor > 4 cm/DOI > 10 mm ( n  = 261), pT1/pT2/DOI ≤ 20 mm ( n  = 510) / > 20 mm ( n  = 157), and pT1/pT2/without ( n  = 305) / with through cortex/skin invasion ( n  = 362) were as follows: disease-specific survival (DSS), 98%/89%/79%/65%, p  < 0.001, 98%/89%/78%/59%, p  < 0.001, and 98%/89%79%/69%, p  < 0.001; overall survival (OS), 90%/79%/63%/51%, p  < 0.001, 90%/79%/63%/42%, p  < 0.001, and 90%/79%/65%/52%, p  < 0.001. In pT3-4 disease, a tumor > 4 cm/DOI > 10 mm was an independent adverse prognosticator for 5-year DSS rate, DOI > 20 mm was an independent adverse prognosticator for 5-year DSS and OS rates, whereas through cortex/skin invasion independently predicted 5-year OS rates. Conclusions All of the three criteria (tumor > 4 cm/DOI > 10 mm, DOI > 20 mm, and through cortex/skin invasion) identify high-risk patients, which should be reflected in further revisions of pT4a classification in OCSCC.

Background Mandibular tumors significantly impact patient health and quality of life. Surgical resection is the primary treatment, often necessitating reconstruction to restore appearance and function. Traditional surgical methods rely heavily on surgeon experience, posing risks such as excessive blood loss and facial paralysis. The advent of digital and robotic-assisted surgical technologies offers improved precision and outcomes. Methods The study included five pairs of models with mandibular tumors, divided into a control group (traditional surgery) and an experimental group (robot-assisted surgery). In the experimental group, procedures were performed using a robot-assisted electromagnetic surgical navigation system, following alignment with the preoperative design under robotic guidance. Conversely, the control group underwent traditional surgery, where osteotomy positions were estimated empirically based on the preoperative design. Postoperative CT scans were used to compare the actual outcomes with the preoperative plans. The osteotomy accuracy and reconstruction outcome were evaluated by measuring the positional and angular errors between the preoperatively designed and actual postoperative data. Results The robot-assisted group demonstrated significantly lower osteotomy distance and angle errors compared to the control group. The reconstruction outcomes in the experimental group also showed superior alignment with preoperative plans, indicating better aesthetic and functional results. Conclusion Robotic-assisted surgery for mandibular tumor resection and reconstruction enhances surgical precision and improves reconstructive outcomes compared to traditional methods. Further research with larger sample sizes and clinical settings is necessary to confirm these findings and expand clinical applications.

Background Intraosseous myofibroma of the jaw is a rare neoplasm of mesenchymal origin with limited comprehensive understanding. It typically affects patients in the first two decades of life with a male predilection. Case presentation This study presents a rare case of myofibroma mimicking an odontogenic lesion in a 2-year-old boy. The patient presented with an incidental finding of a painless swelling of the right mandibular ramus of unknown etiology. Imaging analysis revealed a solid, expansile lesion adjacent to the germinal zone of the right mandibular first molar. Histopathologic analysis and immunohistochemistry after incisional biopsy suggested a possible central odontogenic fibroma, and the patient underwent total enucleation, leading to the final diagnosis of intraosseous myofibroma. Follow-up examinations showed no evidence of recurrence. Conclusions This report contributes to the understanding of myofibroma in pediatric patients and underscores the critical role of meticulous histopathologic examination for effective surgical planning and optimal patient outcomes.

To investigate the feasibility of establishing a mandibular osteosarcoma model in Sprague-Dawley (SD) rats using tissue block transplantation, providing a foundational model for osteosarcoma research. Fourteen male SD rats, 3 weeks old and SPF grade, were randomly divided into a control group (n=4) and a mandibular osteosarcoma group (n=10). Using tissue block transplantation, UMR106 cell-induced tumor tissues were transplanted subcutaneously into the left mandibular marrow cavity of the SD rats. Observations included behavioral changes, weight variations, tumor growth, and tumor formation rate. Bone changes were monitored via micro-CT scanning, and histological analysis was conducted using HE staining. Two weeks post-transplantation, the mandibular osteosarcoma group exhibited significant left facial swelling, malocclusion, eating difficulties, and weight loss compared to the control group. The tumor formation rate was 80% (8/10). Micro-CT scans indicated significant bone destruction in the osteosarcoma group. HE staining revealed high cellular atypia and pathological mitoses in both subcutaneous and mandibular osteosarcoma cells, with no notable abnormalities in lung tissues. Tissue block transplantation is a viable method to establish a mandibular osteosarcoma model in SD rats. This method is simple, with a high tumor formation rate, providing an ideal animal model for mandibular osteosarcoma research.

Our report details an unusual case of chondrosarcoma in a man in his late 50s who presented with symptoms of pain, swelling and trismus. He was initially diagnosed with temporomandibular joint disorder (TMD) and managed conservatively. With time, symptoms progressed, so a cone beam CT scan was advised. The scan revealed an expansile lytic lesion in the condylar region with cortical erosion. It showed heterogeneous density with ring arch calcification around the condylar head, which was suggestive of the cartilaginous lesion. Microscopic examination showed a tumour composed of lobules of atypical chondrocytes with increased cellularity and hyperchromatic nuclei infiltrating the surrounding fibrous tissue. A confirmed diagnosis of grade I chondrosarcoma was made. The patient underwent surgical resection of the tumour with wide, clear margins. Follow-up care involved regular monitoring for any potential recurrence. This case highlights the rarity of chondrosarcoma, which presents with no specific symptoms or signs that can lead to a delay in diagnosis.

Mandibular tumor surgery necessitates precise osteotomies based on tumor boundaries; however, conventional osteotomies often lack accuracy in predicting osteotomy positions and planes, potentially leading to excessive resection of normal bone tissues or residual tumors, thus compromising postoperative quality of life and clinical outcomes. Robotic-assisted surgery (RAS) augmented with artificial intelligence (AI) offers precise localization capabilities, aiding surgeons in achieving accurate osteotomy positioning. This study aimed to evaluate the feasibility and accuracy of a robotic magnetic navigation system for positioning and osteotomy in an intraoral surgical trial of a mandibular tumor model. Patient computed tomography (CT) imaging data of mandibular chin and body tumors were utilized to create 3D printed models, serving as study subjects for mandibular tumor resection. Ten pairs of models were printed for the experimental and control groups. The experimental group (EG) underwent osteotomy using a robot-assisted surgical navigation system, performing osteotomy under robotic navigation following alignment based on preoperative design. The control group (CG) underwent traditional surgery, estimating osteotomy position empirically according to preoperative design. Postoperative CT scans were conducted on both models, and actual postoperative results were compared to preoperative design. Osteotomy accuracy was evaluated by positional and angular errors between preoperatively designed and actual osteotomy planes. For ten randomly selected spots on the left and right sides, respectively, the EG group had mean distance errors of 0.338 mm and 0.941 mm. These values were obtained from the EG group. In the EG group, on the left side, the mean angular errors were 14.741 degrees, while on the right side, they were 13.021 degrees. For the 10 randomly selected spots on the left and right sides, respectively, the CG had mean distance errors of 1.776 mm and 2.320 mm. This is in contrast to the results obtained by the EG. It was determined that the left side had a mean angle error of 16.841 degrees, while the right side had an error of 18.416 degrees in the CG group. The above results indicated significantly lower point errors of bilateral osteotomy planes in the experimental group compared to the control group. This study demonstrates the feasibility of electromagnetic navigation robot-assisted intraoral osteotomy for mandibular tumors and suggests that this approach can enhance the precision of clinical surgery.

This is the first study to investigate the impact of a second fibula flap or a soft tissue flap combined with bridging plate for a repeated segmental mandibulectomy reconstruction on flap outcomes in head and neck cancer patients. A retrospective comparative analysis (2007–2016) of 61 patients who underwent a second segmental mandibulectomy was performed. 20 patients underwent a fibula flap reconstruction whereas 41 had a soft tissue flap and plate reconstruction. No significant difference was seen in the operative time, total hospital stay, flap loss, re-exploration rates, plate exposure rate, or recipient site infection rate. On multivariate analysis, patients reconstructed with a soft tissue flap and bridging plate (odds ratio (OR) 3.997; 95% confidence interval (CI), 1.046–15.280, p  = 0.043) and complications developed in previous surgery (OR 4.792; 95% CI, 1.120–20.493, p  = 0.035) were shown to be independent predictors of a prolonged nasogastric tube dependence. The utilization of a soft tissue flap with plate is associated with comparative results of acute complication rate within 1 week, recipient site infection rate, and plate exposure rate to free fibula flaps alone. Free fibula flaps may result in a decreased risk for prolonged tube dependence compared to free soft tissue flap reconstructions.

Background Metastasizing ameloblastoma is a rare, distinct entity under the World Health Organization classification. It is a unique tumor in which metastasis can occur but remains benign. Incidence is considered to be around 2% of reported cases of ameloblastoma, but it could be much lower. Case presentation A 30-year-old South Indian woman of Dravidian ethnicity presented in the year 2020 with swelling over the right side of the face. She had a history of recurrent ameloblastoma on the left side of the mandible, for which she underwent multiple surgeries in the past 8 years. A right hemimandibulectomy with a patient-specific implant was performed, and the patient recovered well. She developed hypersensitivity to the implant, which was subsequently removed in 2021. In 2024, she developed a persistent cough with blood-tinged sputum. This did not subside with conservative management and hence was further evaluated. Imaging revealed multiple small, well-defined nodules in both lungs and a branching tubular hypodense lesion in the right parahilar region. Bronchoscopy-guided biopsy was done on the lesion. This was reported as metastatic ameloblastoma. The case was discussed in the multidisciplinary tumor board. It was decided to start the patient on a multikinase inhibitor. However, the patient refused further treatment. The patient is reported to be symptomatically better. Conclusion Ameloblastoma is a benign but locally aggressive odontogenic tumor that rarely metastasizes. We report a case with multiple local recurrences over 12 years, currently with pulmonary metastasis. Pulmonary metastasis may be indolent and hence could be misdiagnosed or missed altogether. The degree of suspicion should be higher for patients with recurrences.

Objectives The purpose of this study was to evaluate the incidence of complications following mandibular reconstruction and to analyse possible contributing factors. Materials and methods Clinical data and computed tomography scans of all patients who needed a mandibular reconstruction with a reconstruction plate, free fibula flap (FFF) or iliac crest (DCIA) flap between August 2010 and August 2015 were retrospectively analysed. Results One hundred and ninety patients were enrolled, encompassing 77 reconstructions with reconstruction plate, 89 reconstructions with FFF and 24 reconstructions with DCIA flaps. Cutaneous perforation was most frequently detected in the plate subgroup within the early interval and overall (each p = 0.004). Low body mass index (BMI) and total radiation dosage were the most relevant risk factors for the development of analysed complications. Conclusions Microvascular bone flaps have overall less skin perforation than reconstruction plates. BMI and expected total radiation dosage have to be respected in choice of reconstructive technique. Clinical relevance A treatment algorithm for mandibular reconstructions on the basis of our results is presented.