A rare case report of extensive mandibular osteoma corrected by unilateral mandibulectomy: Cytological, radiological, and pathological investigation.

Background: Osteoma is a benign bone tumor that rarely affects animals. The most common bones involved with this tumor included the mandible, maxillofacial bones, and nasal sinuses. Definitive diagnosis is based on pathology findings which allow for differentiation with other bone lesions. Case Description: The patient, a 5-year-old intact male Mongrel dog presented with a huge mandibular mass that involved both the right and left mandible, and led to dental occlusion. The radiography was performed and depicted the intense mass with a well-demarcated edge, a short transitional zone between normal and abnormal bone, and a smooth rounded radiopaque appearance. The investigation according to the fine needle aspiration showed the presence of oval to spindle shape cells with poorly malignancy criteria, fatty cells, reactive osteoblasts, and osteoclasts based on a population of spindle-shaped cells, and low numbers of degenerated neutrophils, bacteria, and few macrophages. Then, the radiographic assessments and cytology findings demonstrated the osteoma and were referred for surgical intervention. A unilateral mandibulectomy was performed, and the lesion was sent to the histopathology laboratory. The histopathology evaluation showed osteocyte proliferation without malignancy features. The osteoblast cells also showed no atypical proliferation that endorses the osteoma tumor. Conclusion: Although mandibular and maxillofacial bone resection in small animals have different tolerations, this patient became a candidate for surgery for future better nutrition and prevention of facial deformity and dental malocclusion. Follow-up after osteoma is one of the most necessary post-operation treatments to check the regeneration of the mass. There are considerable data in this report that should regard this tumor as a possible differential diagnosis for mandibular tumors.

A viable method to replace the metal trocar drill guide in the inaccessibility of the long sagittal drill for mandibular fixation in BSSO.

The bilateral sagittal split osteotomy requires many specific instruments. Many of them are not used by any surgical team other than the maxillofacial surgery team. The absence of some of these materials makes it practically impossible to perform or continue the operation, with a negative impact on the outcome. The present report aims to discuss an alternative in cases where long drills for drilling mandibular sagittal osteotomies are not available. An inexpensive method, available in all surgical centers.

A Comparison Study of Outcomes and Complications Between Marginal Mandibulectomy With or Without Additional Mandibulotomy in Tongue Cancers.

BACKGROUND: Marginal mandibulectomy with or without additional mandibulotomy could represent the alternatives to avoid segmental mandibulectomy in carefully selected tongue cancers. AIM AND OBJECTIVES: This study investigated a subgroup of tongue cancers with suspected involvement to the alveolar bone because of the shallow and deformed mouth floor. We aimed to compare the functional outcomes, postoperative complications, and disease control efficacy between the 2 different marginal mandibulectomy approaches, with or without additional mandibulotomy. MATERIALS AND METHODS: A retrospective study of 29 marginal mandibulectomies and 26 combined mandibulotomies for tongue cancer wide excisions and flap reconstruction at Chang Gung Memorial Hospital Linkou Branch during 2014 to 2019 was performed. RESULTS: The combined mandibulotomy group had more advanced T-status ( P < 0.001) and greater tumor diameters ( P < 0.001) but not increased preexisting trismus, bone invasions, or positive margins. The additional mandibulotomy increased flap necrosis ( P = 0.044), late infections ( P = 0.004), and tongue movement limitations ( P = 0.044) but not osteoradionecrosis. Osteoradionecrosis was unrelated to the resected mandibular length or the mandibulotomy sites. Feeding tube dependence was greater in the combined group at discharge ( P = 0.014), but no long-term differences were noted. Kaplan-Meier overall survival ( P = 0.052) and disease-free survival ( P = 0.670) were both comparable between the 2 groups. CONCLUSIONS: The combined procedure of mandibulotomy and marginal mandibulectomy in large tongue cancers without bone invasions is associated with increased soft tissue-related complications but not bone-related complications. However, comparable disease control, survival, and long-term tube feeding outcomes were noted.

What are the surgical risks and 2-year stability of mandibular anterior subapical osteotomy in the treatment of dentoalveolar protrusion?

OBJECTIVE: To investigate the stability and complications of mandibular anterior subapical osteotomy (ASO) in the treatment of bimaxillary dentoalveolar protrusion by way of a retrospective study. MATERIALS AND METHODS: One hundred and twenty patients who received orthognathic surgery at a single center between 2008 and 2017 were included. Relapse was assessed by serial tracings of lateral cephalograms which were obtained pre-operatively (T1), within 6 weeks after surgery (T2) and at 2 years after surgery. The changes between T2 and T3 represented stability and were tested using the paired t test. The relationship between the extents of surgical repositioning (T2-T1) and relapse (T3-T2) was investigated using the Pearson correlation coefficient. The associations between the variables and the occurrence of relapse and complications identified the risk factors and were evaluated using the χ2 test or Fisher's exact test. When r > 0.80, clinical correlation was considered significant; and statistical significance was set at P < 0.05, while confidence interval was set at 95%. RESULTS: There was a mean uprighting of L1-MP by 12.7°. At 2 years after surgery, 96.7% of the patients experienced a mean relapse of L1-MP by 2.9°. The extent of surgical repositioning was only weakly correlated with that of relapse and no specific factor that increased the risk of relapse could be identified. The most frequent complications were blood loss requiring transfusion, wound dehiscence or infection, gingival recession, and periodontal bone loss, involving 25.8 to 43.3% of the patients. The remaining complications included tooth root damage, fixation hardware exposure or infection, lingual mucosal laceration, and tooth devitalization. There were no cases of avascular necrosis or nonunion. CONCLUSIONS: Although relapse occurred in most of the patients after 2 years, the actual extent was small (2.9°) which was not likely to be clinically significant. TRIAL REGISTRATION: HKUCTR-2964 CLINICAL RELEVANCE: Although ASO may be valuable in correcting mandibular dentoalveolar protrusion, the procedure brings with it risks and complications and should be reserved for severe deformities.

Quality of life after segmental mandibulectomy and free flap for mandibular osteonecrosis: Systematic review.

OBJECTIVE: Review QOL outcomes among patients undergoing segmental mandibulectomy and bony free flap reconstruction for ONJ. DATA SOURCES: PubMed was searched for MeSH terms "Quality of life," "Osteonecrosis," "Osteoradionecrosis," "Bisphosphonate-associated osteonecrosis of the jaw," "Free tissue flaps," and "Mandibular reconstruction." REVIEW METHODS: English language studies with QOL outcomes data for patients undergoing free flap reconstruction for advanced ONJ were included. 197 records were initially screened; 18 full texts assessed; 10 full texts included. PRISMA guidelines were followed. RESULTS: Ten studies were included in this systematic review: six retrospective, three retrospective with comparison groups, and one prospective. In studies with comparison groups, ONJ patients have worse self-reported QOL than the general population as well as head and neck cancer patients without ONJ. Nearly all patients with QOL measurements (220/235 patients) had ONJ from prior radiation. Segmental mandibulectomy and bony free flap improved overall QOL in over half of patients, as well as pain associated with ONJ in 70-75 % of patients. Surgery did not improve long-term effects of radiation such as chewing, swallowing, and salivary production. Donor site morbidity rarely affects QOL. CONCLUSIONS: Osteonecrosis of the jaw (ONJ) worsens quality-of-life, and advanced disease often requires segmental mandibulectomy and bony free flap reconstruction. Patients and surgeons may expect improvement in some, but not all, domains of patient-reported QOL by the use of segmental mandibulectomy and reconstruction for advanced ONJ.

Safety of Mandibular Osteotomies in Infants with Pierre Robin Sequence: Computer-Aided Modeling to Characterize the Risks of Various Techniques.

BACKGROUND: Mandibular distraction osteogenesis is effective for the correction of severe tongue-based airway obstruction in infants with Pierre Robin sequence. Involved osteotomies may damage developing tooth buds and/or the inferior alveolar nerve. The authors evaluated the theoretical safety of various osteotomy techniques to better define infantile mandibular anatomy using computer-aided modeling. METHODS: Seven mandibular osteotomy techniques (oblique, inverted-L, multiangular, walking stick, high oblique, vertical/high inverted-L, and horizontal) were simulated using computed tomography studies from infants with Pierre Robin sequence and without other associated conditions. Software was used to manually segment the mandibular bone, inferior alveolar nerve, and tooth buds. RESULTS: Sixty-five computed tomography scans were included, yielding 130 hemimandibles. The horizontal osteotomy pattern had significantly lower theoretical risk of tooth bud (p < 0.001) and inferior alveolar nerve involvement (p < 0.001) than all other patterns. Osteotomies with high vertical components (i.e., vertical, walking stick, and multiangular) had lower theoretical tooth bud involvement than the more proximal oblique and inverted-L osteotomies (p < 0.001). Average lingula location was measured at a point 65 percent of the mandibular width from anterior mandibular border and 63 percent of the mandibular height from the inferior mandibular border. CONCLUSIONS: Surgical planning with computed tomography scans can help evaluate an infant's mandibular anatomy to select an osteotomy that reduces morbidity risks. Regardless of technique, tooth buds and the inferior alveolar nerve are often included in osteotomies. The lingula location in this study demonstrates a position more superior and posterior than that previously described. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Morbidity related to the lip-split mandibulotomy approach: a systematic and narrative review.

The lip-split mandibulotomy (LSMA) is an access procedure that has been used in head and neck (H&N) surgery as an aid to surgical resection of inaccessible tumours of the postertior oral cavity and oropharynx. Anecdotal evidence suggests that it has significant morbidity. Voices of concern within the H&N surgical community suggest that it has been abandoned in favour of technological advances such as robotic surgery. We report here the first (to our knowledge) registered systematic review of its kind, documenting the safety and efficiency of LSMA in H&N surgery. We performed a PRISMA-guided systematic review (PROSPERO-registered) and identified reports using a search algorithm in MEDLINE/EMBASE. LSMA-related surgical complications were recorded using the Clavien-Dindo classification. Secondary outcomes included swallowing dysfunction, facial cosmesis, and patient satisfaction recorded in health-related quality of life questionnaires (HRQoL). From 125 studies identified, 54 met the inclusion criteria (3872 patients). The LSMA mortality rate was 0%; we did not identify a single case of perioperative death. The median rate of osteoradionecrosis was 5.4%, whereas fistula formation was 5.7%. Malunion was noted in 4.9%. Other complications (surgical site infection, plate exposure) were around 5%. There was significant between-study variation with regards to swallowing assessment tools, but overall there was no significant difference in outcomes. This was also the case for the HRQoL questionairres. LSMA is a safe procedure with an acceptable rate of complications, and should definitely remain in the armamentarium of H&N surgery.

Survival analysis of segmental mandibulectomy with immediate vascularized fibula flap reconstruction in stage IV oral squamous cell carcinoma patients.

PURPOSE: This study aims to assess the survival rate of oral squamous cell carcinoma (OSCC) patients following immediate mandibular reconstruction with vascularized fibula flap (VFF) and to identify risk factors influencing the overall survival rate and postoperative outcomes. PATIENTS AND METHODS: Patients suitable for the inclusion criterion diagnosed and treated between January 1996 till June 2019 for OSCC were retrospectively reviewed (n = 74). Potential risk factors and postoperative outcomes were recorded and analyzed. RESULTS: The overall cumulative survival rate of patients was 0.52 at the end of 5th year. Overall, advanced pN stage (p = 0.0422), poor tumor differentiation (p < 0.0001), positive/close surgical margins (p = 0.0209), vascular invasion (p = 0.0395), perineural invasion (p = 0.0022) and tumor recurrence (p = 0.0232) were significantly related to a decreased cumulative survival. Tumor recurrence was significantly correlated with involvement of positive/close surgical margins, moderate (p = 0.0488), poor-differentiated tumors (p = 0.202), extracapsular spread (p = 0.0465), computer-assisted surgery (p = 0.0014) and early complications (p = 0.0224). Pain was significantly associated with the extracapsular spread (p = 0.0353) and early complications (p = 0.0127). CONCLUSION: The five-year survival rate of advanced OSCC patients after segmental mandibulectomy with fibula free-flap reconstruction was 52.4%. Clinical/pathological risk factors such as the pN stage, tumor differentiation, surgical margins, vascular invasion, perineural invasion, tumor recurrence significantly influenced the overall cumulative survival rate.

Inferior alveolar nerve allogenic repair following mandibulectomy: A systematic review.

PURPOSE: Processed nerve allografts (PNA) are an alternative to nerve autografts to reconstruct the inferior alveolar nerve (IAN) when it is damaged. The purpose of this study was to report the results of IAN reconstruction using PNA in the context of aggressive benign mandibular pathology. MATERIAL AND METHOD: A systematic literature review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement through the MEDLINE (Pubmed) and SCOPUS (Elsevier) databases. Studies concerning reconstructive surgeries of IAN by PNA, performed at the same time as the surgical resection of the benign pathologies of the mandible were included. The following data were analyzed: gender and patient age, cause of mandibular resection, graft dimensions, sensory recovery at least 6 months after surgery according to the MRC scale, and adverse events related to the intervention. RESULTS: The initial search yielded 290 studies and 5 were included in the final review. A total of 33 patients underwent 36 IAN reconstructions; 14 patients were female (42.4%) and mean age was 30 years old. The mean length of graft used was 64.0 ± 9.1 mm. The most common pathology that led to nerve resection was ameloblastoma (52%). Among the reconstructions for which follow-up data were available, functional sensory recovery occurred in 92.9% of cases. CONCLUSION: PNA are a reliable, safe, and effective alternative to nerve autografts for the rehabilitation of the IAN with 92.9% of functional recovery according to the reported literature, avoiding any comorbidity associated with the use of a donor site.

Predictive factors of osteoradionecrosis necessitating segmental mandibulectomy: A descriptive study.

OBJECTIVE: The objective of this study was to assess characteristics of patients with mandibular osteoradionecrosis (ORN) of severity necessitating segmental mandibulectomy and osteocutaneous free flap reconstruction. STUDY DESIGN: This study is a retrospective review of patients who underwent free flap reconstruction of the mandible at the UCLA Medical Center between January 2016 and February 2020 secondary to ORN. RESULTS: Twenty-nine charts with detailed dental and medical records were identified. Hypertension was reported in 14 of 29 patients, diabetes in 2 of 29, osteoporosis in 2 of 29, antiresorptive use in 3 of 29, tobacco use in 15 of 29, and alcohol use in 19 of 29. Twenty-three patients initially had stage III-IV cancer. The median radiation dose was 68 Gy and median time to ORN was 5.2 years. Chemotherapy was given in 21 patients and 4 had previous mandibular surgery. Twelve of 29 patients had surgical procedures identified as the causative factor and 17 of 29 occurred spontaneously. Median decayed, missing, and filled teeth score was 17 and 17 of 29 patients had grade II-IV periodontitis. Periodontitis was present in 8 of 17 of spontaneous and 1 of 12 of surgery cases. Twenty-five of 29 cases occurred in the same oral sextant as the tumor. CONCLUSION: Severe ORN occurred at doses >60 Gy in most cases. Location of the primary tumor was predictive of site of ORN and only molars were involved when precipitated by tooth extraction. Risk of ORN persists indefinitely.

Prospective Phase II Open-Label Randomized Controlled Trial to Compare Mandibular Preservation in Upfront Surgery With Neoadjuvant Chemotherapy Followed by Surgery in Operable Oral Cavity Cancer.

PURPOSE: The objective of this study was to explore the potential role and safety of neoadjuvant chemotherapy (NACT) in tumor shrinkage and resultant mandibular preservation in oral cancers compared with conventional surgical treatment. METHODS: This study was a single-center, randomized, phase II trial of treatment-naive histologically confirmed squamous cell carcinoma of the oral cavity with cT2-T4 and N0/N+, M0 (American Joint Committee on Cancer, seventh edition) stage, necessitating resection of the mandible for paramandibular disease in the absence of clinicoradiologic evidence of bone erosion. The patients were randomly assigned (1:1) to either upfront surgery (segmental resection) followed by adjuvant treatment (standard arm [SA]) or two cycles of NACT (docetaxel, cisplatin, and fluorouracil) at 3-week intervals (intervention arm [IA]), followed by surgery dictated by postchemotherapy disease extent. All patients in the IA received adjuvant chemoradiotherapy, and patients in the SA were treated as per final histopathology report. The primary end point was mandible preservation rate. The secondary end points were disease-free survival and treatment-related toxicity. RESULTS: Sixty-eight patients were enrolled over 3 years and randomly assigned to either SA (34 patients) or IA (34 patients). The median follow-up was 3.6 years (interquartile range, 0.95-7.05 years). Mandibular preservation was achieved in 16 of 34 patients (47% [95% CI, 31.49 to 63.24]) in the IA. The disease-free survival (P = .715, hazard ratio 0.911 [95% CI, 0.516 to 1.607]) and overall survival (P = .747, hazard ratio 0.899 [95% CI, 0.510 to 1.587]) were similar in both the arms. Complications were similar in both arms, but chemotherapy-induced toxicity was observed in the majority of patients (grade III: 14, 41.2%; grade IV: 11, 32.4%) in the IA. CONCLUSION: NACT plays a potential role in mandibular preservation in oral cancers with acceptable toxicities and no compromise in survival. However, this needs to be validated in a larger phase III randomized trial.

Fibula Jaw-in-a-Day with Minimal Computer-Aided Design and Manufacturing: Maximizing Efficiency, Cost-Effectiveness, Intraoperative Flexibility, and Quality.

SUMMARY: The vascularized fibular flap has been the mainstay for mandibular reconstruction for over 30 years. Its latest evolutionary step is the jaw-in-a-day operation, during which the fibula flap and dental prosthesis restoration are performed in a single stage. Computer-aided design and manufacturing technology in mandibular reconstruction has gained popularity, as it simplifies the procedure and produces excellent outcomes. However, it is costly, time-consuming, and limited in cases that involve complex defects, including bone and soft-tissue coverage. Moreover, it does not allow for intraoperative changes in the surgical plan, including defect size and recipient vessel selection.The authors describe their approach, including a conventional technique for fibula osteoseptocutaneous flap harvest without the need for a premanufactured cutting guide, using bundled wooden tongue spatulas instead, a stereolithographic model to customize commercially ready-made reconstruction plates, and two pieces of resin to maintain occlusive alignment of the remaining jaw segments during mandibular osteotomy. Dental implants are inserted free-hand. Vector guides are then connected to the implants following insertion into the fibula to confirm acceptable alignment and subsequently replaced with scan sensors. An intraoperative digital scan is used to design and to produce a dental prosthesis by in-house milling of a polymethylmethacrylate block. From our 10-case experience over the past 3 years, we have found that our approach offers a reliable method that matches the excellent outcomes seen using full computer-assisted design and manufacturing technology. It is time- and cost-effective, not limited to relatively simple jaw defects, and can readily accommodate intraoperative changes of surgical plan.

Effects of rs958804 and rs7858836 single-nucleotide polymorphisms of the ASTN2 gene on pain-related phenotypes in patients who underwent laparoscopic colectomy and mandibular sagittal split ramus osteotomy.

BACKGROUND: Opioids are widely used as effective analgesics, but opioid sensitivity varies widely among individuals. The underlying genetic and nongenetic factors are not fully understood. Based on the results of our previous genome-wide association study, we investigated the effects of single nucleotide polymorphisms (SNPs) of the astrotactin 2 (ASTN2) gene on pain-related phenotypes in surgical patients. METHODS: We investigated the effects of two SNPs, rs958804 T/C and rs7858836 C/T, of the ASTN2 gene on eight and seven pain-related phenotypes in 350 patients who underwent laparoscopic colectomy (LAC) and 358 patients who underwent mandibular sagittal split ramus osteotomy (SSRO), respectively. In both surgical groups, intravenous fentanyl patient-controlled analgesia (PCA) was used for postoperative analgesia, and 24-hour postoperative PCA fentanyl use was the primary endpoint. RESULTS: The association analyses among the two SNPs and pain-related traits showed that 24-hour fentanyl use was significantly associated with the two SNP genotypes in both surgical groups. The Mann-Whitney test showed that 24-hour fentanyl use was lower in patients with the C allele than in patients with the TT genotype of the rs958804 T/C SNP (P = .0019 and .0200 in LAC and SSRO patients, respectively), and it was lower in patients with the T allele than in patients with the CC genotype of the rs7858836 C/T SNP (P = .0017 and .0098 in LAC and SSRO patients, respectively). CONCLUSION: The two SNPs of the ASTN2 gene were consistently associated with fentanyl requirements after two different types of surgery. These findings may contribute to personalized pain control.

Inferior alveolar nerve reconstruction in extensive mandibular resection: Technical notes.

The inferior alveolar nerve (IAN) is a sensitive branch of the mandibular nerve innervating the lower lip, the chin, the buccal mucosa and the teeths. Lesions of the IAN are reported to occur in the 64,4% of maxillo-facial procedures, leading to anesthesia, hypoestesia and/or neurogenic discomfort. An extensive segment of the nerve can be moreover removed during mandibular resection for benign or malignant pathologies. Nervous grafts can be used in these cases to restore the nerve continuity. In order to optimize the procedure and to allow a concomitant mandibular osseous reconstruction, the Authors identified several standardized steps. The technique described allows to perform confortable and safe nervous anastomoses and to reduce the risk of damage and tension during the flap insetting phases.

Double Mandibular Osteotomy for Access to High-Carotid Pathology.

BACKGROUND: Anecdotal experience demonstrates the existence of patients with superiorly located carotid stenosis, neoplasms, or aneurysms where the mandible obstructs effective surgical access using standard techniques. As carotid pathology extends anatomically beyond the limits of standard operative technique, additional exposure becomes paramount to safely and effectively address the lesion. Double mandibular osteotomy (DMO) is one of several techniques to obtain additional exposure to high-carotid pathology; however, there is no large series to address the outcomes of patients undergoing this procedure. METHODS: A retrospective case series was performed for all patients undergoing surgery for carotid pathology from 2011-2019 that could not be approached with standard cervical incision. The primary predictor variable was high-anatomic carotid pathology necessitating DMO. The primary outcome variable was early and late complications sustained by patients. RESULTS: Fifteen patients met study criteria and underwent 16 DMOs to access high-carotid pathology including carotid stenosis (n = 8 patients), carotid aneurysm (n = 2 patients), and carotid body tumor (n = 8 patients). Two patients had dual ipsilateral pathology with one patient having both carotid artery stenosis and aneurysm, and the other patient diagnosed with carotid artery stenosis and carotid body tumor. One patient had bilateral carotid artery stenosis, each requiring high anatomic exposure for treatment. Early complications occurred in 8 patients. Five patients experienced significant dysphagia requiring enteral feeding, and 2 patients developed malocclusion directly related to the double mandibular osteotomy. One patient experienced contralateral cortical watershed infarcts. Late complications included one patient developing osteomyelitis of the mandible, and this patient also developed distal mandibular segment screw exposure. The comparison of the outcome groups for categorical predictor variables using Fisher's exact test detected no statistically significant differences for gender, hypertension, hyperlipidemia, type 2 diabetes, chronic obstructive pulmonary disease, tobacco use, chronic kidney disease, or cerebrovascular disease. For the continuous variable comparisons, independent-samples t-tests detected no difference between the complication groups for age, operative time, or years of follow-up. No significant differences were found between the groups for body mass index or intraoperative blood loss. CONCLUSIONS: The double mandibular osteotomy provides excellent exposure and surgical access to the distal internal carotid artery for repair of vascular pathology with acceptable outcomes and long-term complications compared with previously reported techniques. Because of the early complications realized with the DMO, we recommend the procedure for symptomatic patients with a high risk of failing medical therapy alone and not appropriate for endovascular treatment as well as those patients with tumors requiring surgical intervention.

Cancellous Tibial Bone Graft for Malunion after Mandibular Reconstruction in Head and Neck Cancer.

OBJECTIVES/HYPOTHESIS: While nonunion after mandibular reconstruction for head and neck surgery is rare, literature exploring management is scarce. Our primary objective was to determine success rates of tibial bone graft (TBG) in achieving mandibular union. Secondary objectives include determining factors that contribute to failure of TBG. STUDY DESIGN: Retrospective Chart Review. METHODS: Retrospective chart review between January 1, 2008 and December 31, 2018. Patients who underwent a mandibulotomy or mandibulectomy with osteocutaneous free flap reconstruction were identified. Patients who were pursuing dental rehabilitation, subsequently diagnosed with mandibular nonunion and received a cancellous TBG were assessed. RESULTS: The 15 patients meeting inclusion criteria were mostly male (67%), white (87%), and nonsmokers (67%) with a median age of 64 (IQR = 60-73). Successful union occurred in 13 of 18 (72%) TBGs and the majority (63%) had a partial union documented at the time of surgery. Five patients (83%) who initially had a mandibulotomy achieved union compared to 78% of those with osteocutaneous reconstruction (P = 1.0). Postoperative radiation did not affect rates of union: 80% for both (P = 1.0). Patients with osteoradionecrosis (ORN) achieved union in 67% of cases compared to 75% of cases who did not have ORN (P = .86). There were similar rates of union for those who required perioperative antibiotics for infection and those without infection (67% vs. 75%, P = .86). Dental rehabilitation was achieved in 55% of patients, most commonly dentures. CONCLUSIONS: This study shows that TBG can be used to achieve union for patients with malunion after head and neck cancer reconstruction. We show its successful use within the reconstructive algorithm for patients regardless of postoperative radiation for very small defects. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:1291-1296, 2021.

Predictive Nomogram for the Necessity of Tracheotomy During Oral and Oropharyngeal Cancer Surgery.

OBJECTIVES/HYPOTHESIS: The individualized risk of airway obstruction after head and neck cancer surgery is unclear, especially oral and oropharyngeal cancer. The study aimed to establish an individualized predictive model for the necessity of temporary tracheotomy in these patients. METHODS: Patients who underwent oral and oropharyngeal cancer surgery from 1999 to 2019 were retrospectively reviewed. A nomogram was developed and validated in patients treated from 1999 to 2009 and 2010 to 2019, respectively. RESULTS: In total, 1551 patients were included. Oropharyngeal cancer, large tumor, midline crossing, preoperative radiation, mandibulectomy, flap reconstruction, and neck dissection were independent risk factors of postoperative airway obstruction in the training group (n = 707). A nomogram incorporating these factors had a C-index of 0.931 and was validated in the testing group (n = 844) (C-index, 0.918). Good calibration curves were observed in both groups. CONCLUSIONS: The nomogram successfully predicted the individual risk of postoperative airway obstruction for patients with oral and oropharyngeal cancer. LEVEL OF EVIDENCE: 4. Laryngoscope, 131:E1489-E1495, 2021.

Short-Term Outcomes following Virtual Surgery-Assisted Immediate Dental Implant Placement in Free Fibula Flaps for Oncologic Mandibular Reconstruction.

BACKGROUND: Despite reports demonstrating feasibility of immediate dental implant placement in mandibular reconstruction with free fibula flaps for benign disease, this practice is not routinely used in the oncologic setting. The authors aim to demonstrate the safety of immediate dental implant placement for oncologic mandible reconstruction. METHODS: In 2017, the authors' center began immediate dental implant placement in free fibula flaps for oncologic patients undergoing mandibulectomy reconstruction. Immediate dental implant placement patients were compared to a historical cohort also reconstructed with computer-aided design and manufacturing technology beginning in 2011 (n = 34) as a noninferiority study design. Primary outcomes of interest included 90-day complications, time to radiotherapy, and time to and number of patients achieving dental restoration. RESULTS: Sixty-one patients underwent free fibula flaps following mandibulectomy using computer-aided design and manufacturing. Seventy-two dental implants were placed in the immediate dental implant placement cohort (n = 27). No differences were noted in major or minor 90-day complications between groups (p > 0.05). Radiotherapy was required in 55 percent in the immediate dental implant placement cohort versus 62 percent in the historical cohort, with no significant difference in time to radiotherapy (67.6 days versus 62.2 days, respectively). One dental implant was removed for nonosseointegration noted during vestibuloplasty. Fourteen (51.8 percent) immediate dental implant patients had complete dental restoration at 90 days compared with none in the historical cohort (p < 0.05). CONCLUSIONS: Immediate dental implant placement is a safe procedure with an unchanged short-term complication profile and no delay in radiotherapy initiation. Patients undergoing immediate dental implant placement are more likely to complete full dental rehabilitation. Long-term and health-related quality-of-life outcomes remain to be determined. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Non-Autogenous Innovative Reconstruction Method Following Mandibulectomy.

BACKGROUND: Plexiform ameloblastoma is a locally aggressive odontogenic tumor, rare in the anterior mandible. The treatment of choice is resection with 1-3 cm free margins. In most of reported cases, the affected mandible is reconstructed by autogenic bone graft or osseocutaneous microvascular free flap in order to return function and esthetics. CASE DESCRIPTION: A 2 cm diameter exophytic ameloblastoma, located in the anterior mandible of a 50-year-old male was resected and reconstructed in a unique manner-allogenic bone block, recombinant human bone morphogenetic protein (rhBMP) and xenograft particles via transcutaneous submental approach. After bone maturation, dental implants were placed and restored by fixed prosthetics. PRACTICAL IMPLICATIONS: Mandible reconstruction modalities have a crucial influence on patient quality of life, function and esthetics. Allogenic bone block combined with rhBMP and xenograft particles can replace the traditional autogenous bone in certain circumstances. A submental transcutaneous "tent pole" approach can improve the success rate of the reconstruction procedure.

The Envelope of Segmental Movement and Airway Changes After Mandibular Anterior Subapical Osteotomy in Skeletal Class II Protrusion Patients.

INTRODUCTION: This study aimed to determine the envelope of anterior segmental movement and changes in the inferior pharyngeal airway space (IPAS) and position of the hyoid bone following mandibular anterior subapical osteotomy (ASO) under local anesthesia in skeletal Class II patients with protrusion. METHODS: The subjects were 33 skeletal Class II adult patients with lip protrusion. They were treated by extraction of 4 premolars and mandibular ASO under local anesthesia. Surgical movement of mandibular anterior segment and IPAS after surgery was evaluated by mandibular superimposition using lateral cephalograms between before and immediately after surgery. The depth of osteotomy and overlapping ratio were measured. RESULTS: The mean retraction of the mandibular incisor was 4.04 mm at the tip and 4.29 mm at the root apex. The mean vertical movement of the mandibular incisor was 3.33 mm intrusion at the tip and 3.42 mm at the root apex. The axis of the mandibular incisor did not change significantly. Patients with deep curve of Spee showed significantly more intrusion of incisors, whereas the incisor axis became more proclined. The IPAS became narrower, and the hyoid bone moved downward after surgery. The decreased IPAS was positively correlated with retraction of root apex and proclination of the mandibular incisors. CONCLUSION: To establish precise surgical treatment objectives, a balance between the amount of intrusion and changes in axis should be sought after considering anatomical limitations. Mandibular ASO should be performed with caution in skeletal Class II patients vulnerable to airway-related problems.