Are Cellular Bone Matrix Allografts a Viable Option for Mandibular Tissue Engineering and Reconstruction?

BACKGROUND: Traditional mandibular reconstruction has relied on the use of vascularized and non-vascularized autografts. The use of allografts and tissue engineering modalities has risen as an alternative. PURPOSE: The purpose of this study was to determine the success of a cellular bone matrix (CBM) allograft composed of lineage committed bone forming cells for mandibular tissue engineering and reconstruction. STUDY DESIGN, SETTING, SAMPLE: A retrospective cohort study was implemented using data from subjects treated with a CBM at the University of Louisville from 2019 to 2023. Subjects were excluded if they were not treated with a CBM, data were not complete, or postoperative follow-up time was less than 3 months. PREDICTOR VARIABLES: The predictor variables were composed of heterogenous variables grouped into the following categories: demographics (age, sex), medical history (history of penicillin [PCN] allergy, history of diabetes mellitus [DM] and tobacco use), etiology (benign tumor, ballistic trauma, nonballistic trauma, odontogenic cyst, osteomyelitis/ medication-related osteonecrosis of the jaw), mandibular resection length (cm) and type (marginal, segmental), delayed versus immediate reconstruction, and whether an autograft (proximal tibia) with platelet-rich fibrin was used in combination with the CBM. MAIN OUTCOME VARIABLE: The primary outcome variable was graft success (yes or no). Success was defined as bony union and defect fill (demonstrated on panoramic radiograph) and mandibular stability (based on postoperative clinical examination at 3 months). COVARIATES: Not applicable. ANALYSES: Descriptive statistics were calculated for each variable. To measure the associations between the risk factors and graft success, Fisher's exact test for categorical variables and the Wilcoxon rank sum test for numeric data were used. A P value of <.05 was considered significant. RESULTS: The sample included 38 subjects. The median age of all subjects was 46 (interquartile range 32.6) years. Overall, 28 (73.7%) cases were successful. Subjects with a reported PCN allergy or a history of DM had significantly lower success (2, 7.1% with PCN allergy or DM) compared to those who did not (P = .008, PCN allergy; P = .03, DM). CONCLUSIONS AND RELEVANCE: This is the largest case series of CBM based mandibular reconstruction relative to the available maxillofacial surgery literature. The clinician should consider confirmation of PCN allergy so PCN-type antibiotics can be used. CBMs may be an alternative to autografts.

Can a Point-of-Care 3D Printing Workflow Produce Accurate and Successful Results for Craniomaxillofacial Trauma?

BACKGROUND: Computer-aided design and manufacturing (CAD/CAM) is having a profound impact on craniomaxillofacial surgery, and point-of-care (POC) solutions for repairing facial trauma are starting to emerge. PURPOSE: The purpose of this study was to demonstrate the success and accuracy of a POC 3D printing workflow for craniomaxillofacial trauma. STUDY DESIGN, SETTING, SAMPLE: A retrospective cohort study was undertaken to analyze subjects presenting to a level 1 trauma center after sustaining facial trauma and were then treated using the POC 3D printing workflow. Subjects were excluded if they were not treated with the POC 3D printing workflow, were lost to follow-up, or if clinical data were incomplete. PREDICTOR VARIABLE: Predictor variables included the cause of trauma (mechanism), location of the mandibular fracture, type of fracture, mandibular severity score, and repair error (ie, root mean square error (RMSE) value for planned vs actual outcome). MAIN OUTCOME VARIABLE(S): The primary outcome variables were case success and case error. Success was defined as clinical and radiographic evidence of bony stability at 3 months. Case accuracy was calculated overlaying preoperative plan data to postoperative data generating a numerical value (RMSE value, mm). COVARIATES: Covariates included age (years), gender (male/female), surgery time (mins), and CAD/CAM time (preoperative). ANALYSES: Descriptive statistics were calculated for each variable. Dependence between rates or counts was established using the Wilcoxon rank sum or Fisher's exact test. Linear regression model was computed to discern how predictor variables influence RMSE. A P value < .05 was considered statistically significant. RESULTS: The sample included 27 subjects (19 male/8 female). The average age of all subjects was 46.4 ± 18.0 years. Common mechanisms of injury were assault (33%) and self-inflicted gunshots (SIGSW; 30%), and the average severity score for mandible injury was (13.5 ± 3.3). Ninety-three percent of cases were deemed successful. The average repair accuracy (RMSE value) was 3.4 ± 1.8 mm. A linear regression model indicated those injured by a fall (ß-coefficient 1.99; P = .010), motor vehicle collision (ß-coefficient 1.49; P = .043), or SIGSW (ß-coefficient 2.82; P < .001) correlated with RMSE. CONCLUSION AND RELEVANCE: In-house CAD/CAM technologies can be utilized at the POC to repair complex facial trauma accurately and successfully.

Intermaxillary Fixation in the Primary and Mixed Dentition.

Anatomic differences of the primary dentition may hinder traditional methods of intermaxillary fixation. Furthermore, the presence of both the primary and permanent dentition can complicate establishing, and maintaining, the preinjury occlusion. The treating surgeon must be aware of these differences for optimal treatment outcomes. This article discusses and illustrates methods that facial trauma surgeons can use to establish intermaxillary fixation in children aged 12 years and younger.

Immediate Reconstruction of Segmental Mandibular Defects With Nonvascular Bone Grafts: A 30-Year Perspective.

PURPOSE: The use of nonvascular bone grafts for immediate mandibular reconstruction has remained a controversial topic. The purpose of the present study was to investigate the variables that might influence graft survival examining the outcomes from 30 years of experience. MATERIALS AND METHODS: We designed a retrospective cohort study to analyze the data from patients at a tertiary university medical center who had undergone segmental mandibular resection with immediate reconstruction with a nonvascularized free bone graft with or without adjuncts from 1989 to 2019. The predictor variables recorded included general demographic data, pathologic diagnosis, resection length, reconstruction modality, bone graft type, and inferior alveolar nerve procedures. The primary outcome variable was graft success, defined as bony union demonstrated on panoramic radiographs and mandibular stability demonstrated on clinical examination at 4 months postoperatively. Descriptive, bivariate, and linear regression models were computed. RESULTS: The sample included 47 subjects with a mean age of 43 ± 16 years; 51.1% were men. Of the 47 patients, 25 had a tissue diagnosis of benign tumor, most of which were ameloblastoma (n = 16) or ossifying fibroma (n = 6), and 22 had a tissue diagnosis of osteomyelitis or medication-related osteonecrosis of the jaw (MRONJ). The average resection size for all the patients was 6.9 ± 2.5 cm and was 6.1 ± 1.5 cm for those with a benign tumor and 7.8 ± 3.1 cm for those with osteomyelitis or MRONJ. The mean defect size of grafts that failed was 10.7 ± 3.5 cm and 6.5 ± 2.0 cm for those that succeeded (P ≤ .001). A linear regression model revealed that graft length correlated significantly with graft outcome (ß-coefficient, -0.548; 95% confidence interval, 0.905 to 1.542; P ≤ .001). CONCLUSIONS: The results of our study have shown that nonvascular bone grafts can be used to immediately reconstruct mandibular defects greater than 6 cm from benign pathologic lesions; however, larger grafts are more likely to fail.

In-House Digital Workflow for the Management of Acute Mandible Fractures.

Computer-aided design and additive manufacturing are revolutionizing oral and maxillofacial surgery. Current methods use virtual surgical planning sessions and custom plate milling via third-party vendors, which is costly and time-consuming, negating the effectiveness in acute facial trauma. This technical note describes a state-of-the-art in-house expedited digital workflow for computer-aided virtual fracture reduction, 3-dimensional printing, and preoperative reconstruction plate adaptation for the management of an acute mandible fracture. This process uses the computed tomographic scan a patient receives in the emergency department or clinic. The DICOM (Digital Imaging and Communications in Medicine) data are transferred into US Food and Drug Administration-approved software, in which the fracture is segmented and virtually reduced based on condylar position, midline symmetries, and occlusion if present. The reduced mandible is then printed, which serves as a template for preoperative reconstruction plate adaptation. This method facilitates a virtually reduced fractured mandible, 3-dimensionally printed model, and ideally adapted plates ready for sterilization before surgery within 2 hours after DICOM upload.

Management of Mandibular Osteomyelitis With Segmental Resection, Nerve Preservation, and Immediate Reconstruction.

PURPOSE: The purpose was to present our experience with management of mandibular osteomyelitis with segmental resection, nerve preservation, and immediate reconstruction with nonvascularized bone grafts. PATIENTS AND METHODS: We completed a retrospective analysis of 18 cases overseen by a single practitioner at a university medical center from June 2011 to July 2018. All patients had osteomyelitis and were treated with segmental mandibular resection, inferior alveolar nerve (IAN) preservation, and immediate reconstruction with autogenous bone graft from the tibia. Data obtained from medical records included the chief complaint at initial presentation, resection size, and IAN neurosensory recovery at 6 months, as well as descriptive statistics of the patient cohort. The university institutional review board granted this study exempt status. RESULTS: The patient cohort had a mean age of 50.9 years, ranging from 29 to 70 years, and included 11 female and 7 male patients. The mean follow-up time was 15 months. The most common chief complaint at initial presentation was pathologic fracture (39%), followed closely by abscess (33%). The average mandibular resection size of all patients was 8.1 cm (standard deviation [SD], 3.3 cm). The resection size measured 7.1 cm (SD, 2.6 cm) in patients with successful bone grafts (n = 15) and 13.1 cm (SD, 2.0 cm, P = .0016) in those with graft failure (n = 3). IAN neurosensory testing showed that 54% of patients had no meaningful recovery at 6 months, 25% had partial recovery, and 21% had full recovery. Finally, osteomyelitis was eliminated in all patients. CONCLUSIONS: Segmental mandibular resection is an effective method for eradicating mandibular osteomyelitis. Furthermore, immediate reconstruction via nonvascularized grafts is successful in cases with large defects, with a mean defect size of 7.1 ± 2.6 cm. However, IAN-sparing surgery is not effective for preserving patient IAN function. Taken together, our findings show that mandibular resection with immediate reconstruction is a viable method in the treatment of mandibular osteomyelitis. This method removes infection and shortens the disease course.

Dental Problems in Primary Care.

Oral health directly affects overall health and quality of life. More Americans lack dental insurance than medical insurance. Patients with poor oral health are more likely to have respiratory and cardiovascular diseases, adverse pregnancy outcomes, and diabetes mellitus. Early childhood caries is the most common chronic condition in American children. Certain illicit and prescription drugs increase the risk of enamel erosion and caries formation in adults. Incision and drainage is the treatment of choice for dental abscess. Risk factors for periodontal disease include smoking, diabetes, human immunodeficiency virus infection, use of certain medications, and genetic susceptibility. Patients with gingivitis typically present with swollen, erythematous gum tissue that bleeds easily with brushing or flossing. One in three children will have an injury to the primary teeth, and one in five 12-year-old children will have an injury to the permanent teeth. All dental fractures should be evaluated with imaging and managed in conjunction with a dental professional. Immediate reimplantation is the preferred treatment for avulsed permanent teeth. Primary care clinicians are well positioned to reduce rates of oral disease. Family physicians can incorporate oral health into routine practice through counseling about diet, oral hygiene, smoking cessation, and fluoride supplementation; application of fluoride varnish; and screening for dental disease.

Aggressive histologic features do not predict biologic behavior in melanotic neuroectodermal tumor of infancy.

While generally benign, occasional aggressive histologic features in the melanotic neuroectodermal tumor of infancy (MNTI) have been used to justify a diagnosis of malignancy; this could lead to overtreatment. We report a case with presumed aggressive histologic features that did not recur following conservative treatment. This adds evidence that histologic features are not predictive of clinical behavior in MNTI.

Topical application of a mucoadhesive freeze-dried black raspberry gel induces clinical and histologic regression and reduces loss of heterozygosity events in premalignant oral intraepithelial lesions: results from a multicentered, placebo-controlled clinical trial.

PURPOSE: Approximately 30% higher grade premalignant oral intraepithelial neoplasia (OIN) lesions will progress to oral cancer. Although surgery is the OIN treatment mainstay, many OIN lesions recur, which is highly problematic for both surgeons and patients. This clinical trial assessed the chemopreventive efficacy of a natural product-based bioadhesive gel on OIN lesions. EXPERIMENTAL DESIGN: This placebo-controlled multicenter study investigated the effects of topical application of bioadhesive gels that contained either 10% w/w freeze-dried black raspberries (BRB) or an identical formulation devoid of BRB placebo to biopsy-confirmed OIN lesions (0.5 g × q.i.d., 12 weeks). Baseline evaluative parameters (size, histologic grade, LOH events) were comparable in the randomly assigned BRB (n = 22) and placebo (n = 18) gel cohorts. Evaluative parameters were: histologic grade, clinical size, and LOH. RESULTS: Topical application of the BRB gel to OIN lesions resulted in statistically significant reductions in lesional sizes, histologic grades, and LOH events. In contrast, placebo gel lesions demonstrated a significant increase in lesional size and no significant effects on histologic grade or LOH events. Collectively, these data strongly support BRB's chemopreventive impact. A cohort of very BRB-responsive patients, as demonstrated by high therapeutic efficacy, was identified. Corresponding protein profiling studies, which demonstrated higher pretreatment levels of BRB metabolic and keratinocyte differentiation enzymes in BRB-responsive lesions, reinforce the importance of local metabolism and differentiation competency. CONCLUSIONS: Results from this trial substantiate the LOH reductions identified in the pilot BRB gel study and extend therapeutic effects to significant improvements in histologic grade and lesional size.

Role of nuclear medicine imaging in recognizing different causes of osteonecrosis of the jaw.

The incidence of osteonecrosis of the jaw (ONJ) among patients with cancer and metastatic bone disease being treated with bisphosphonates is as high as 10%, which dictates that an understanding of the risk factors, preventative measures, means of early diagnosis, and treatment is critical. Despite ONJ occurring in the clinical setting of intravenous bisphosphonates, there are other causes associated with higher risk of ONJ, such as multiple dental extractions. Overall, it is important for imaging health care professionals to recognize, describe, and understand ONJ to help minimize biopsies and allow proper treatment to begin as soon as possible.

Facial skeletal trauma in the growing patient.

The management of pediatric craniomaxillofacial trauma requires the additional dimension of understanding growth and development. The surgeon must appreciate the considerable influence of the soft tissue envelope and promote function when possible. Children heal well but with an exuberant tissue response that may contribute to greater scarring, therefore, careful and prudent attention given to meticulous soft tissue repair and support is critical. Support must also be given and sought from the family of the injured child. Follow-up management of children must continue to ensure that the growth of the craniomaxillofacial skeleton continues within the normal parameters of development.

Bisphosphonate-related osteonecrosis of the jaws.

PURPOSE OF REVIEW: The purpose of this article is to review a new pathologic entity named bisphosphonate-related osteonecrosis of the jaws (BRONJ). RECENT FINDINGS: BRONJ was observed and first reported in 2001-2002 when clinicians noticed cases of refractory osteomyelitis after simple dental procedures such as dental extractions in patients who had received bisphosphonate therapy. The condition was initially seen in patients who received i.v. bisphosphonates for malignancies such as multiple myeloma and metastatic breast cancer. However, with the use of bisphosphonate therapy for osteoporosis, BRONJ is seen in patients without a cancer diagnosis. SUMMARY: The incidence of BRONJ remains unclear. Treatment recommendations based on sound scientific data are sparse. The management of BRONJ remains a difficult and controversial situation that continues to challenge the clinician.

Failed Fixation in Atrophic Mandibular Fractures: The Case against Miniplates.

Despite advances in the treatment of the fractured atrophic edentulous mandible, treatment continues to be difficult. Patient management is more complicated due to patients often being elderly with more complex medical problems. Rigid internal fixation has greatly improved outcomes with shorter treatment times, yet a consensus has yet to be reached regarding which method yields the most predictable results. Options include using small miniplates to larger reconstruction plates. Although each method has advantages, we present our experience with retreatment of failed miniplate fixation using load-bearing reconstruction plates of fractured atrophic edentulous mandibles.

Management of comminuted fractures of the mandible.

Comminuted fractures of the mandible are unusual but not rare. They are complex injuries with a high complication rate. Gunshot wounds are a frequent cause. Traditional management with closed techniques is noted for good long-term results, but may involve an extended period of treatment. Treatment with open reduction and rigid internal fixation significantly shortens the course of treatment and simplifies the convalescence.

Fractures of the growing mandible.

Oral and maxillofacial surgeons must constantly weigh the risks of surgical intervention for pediatric mandible fractures against the wonderful healing capacity of children. The majority of pediatric mandibular fractures can be managed with closed techniques using short periods of maxillomandibular fixation or training elastics alone. Generally, the use of plate- and screw-type internal fixation is reserved for difficult fractures. This article details general and special considerations for this surgery including: craniofacial growth & development, surgical anatomy, epidemiology evaluation, various fractures, the role rigid internal fixation and the Risdon cable in pediatric maxillofacial trauma. It concludes with suggestions concerning long-term follow-up care in light of the mobility, insurance obstacles, and family dynamics facing the patient population.

Contemporary management of infected mandibular fractures.

The treatment of infected mandibular fractures has advanced rather dramatically over the past 50 years. Immobilization with maxillomandibular fixation and/or splints, removal of diseased teeth in the fracture line, external fixation, use of antibiotics, debridement, and rigid internal fixation has played a role in management. Perhaps the most important advance was the realization that infected fractures also result from moving fragments and nonvital bone, not just bacteria. Controlling movement and eliminating the dead bone allowed body defenses to also eliminate bacteria. The next logical step in the evolution of treatment was primary bone grafting of the resulting defect following application of rigid internal fixation and debridement of the dead bone. We offer our results with this treatment in 21 infected fractures, 20 of which achieved primary union.

Lag screw fixation of anterior mandibular fractures: a retrospective analysis of intraoperative and postoperative complications.

PURPOSE: To review, retrospectively, the outcomes of 102 patients who underwent lag screw technique fixation of fractures of the anterior mandible. PATIENTS AND METHODS: A total of 102 consecutive, skeletally mature patients who have undergone open reduction internal fixation for fractures of the anterior mandible utilizing the lag screw technique were reviewed. All patients had a clinically mobile fracture between the mental foramina of the mandible. The patients were followed at usual postoperative intervals with shortest long-term follow-up of 2 months. Intraoperative and long-term postoperative outcomes including status of union, infection, and intraoperative surgical misadventure were recorded. RESULTS: Data from the 102 patients showed that there was 1 fixation failure due to inappropriate patient selection, 1 nonunion requiring bone grafting, 1 with infected screws but with union, 1 with an infected screw and delayed union treated conservatively, and 6 with broken drills from intraoperative surgical misadventures. CONCLUSIONS: Lag screw osteosynthesis of anterior mandibular fractures is a sensitive, facile, predictable, and relatively inexpensive method for internal fixation of indicated fractures. As with all methods of rigid internal fixation, most failures or complications are the result of operator judgment or technique.

Cone beam computed tomographic findings in refractory chronic suppurative osteomyelitis of the mandible.

AIMS: To report the imaging features of osteomyelitis of the mandible in various two-dimensional multiplanar and three-dimensional reformations using cone beam computed tomography (CBCT). METHODS: The images were 12-bit DICOM files acquired with a 10cm field of view and voxel resolution of 0.4mm. Two-dimensional multiplanar reformatted reconstructions included coronal, "panoramic" (variable thickness), and serial cross-sections. Three-dimensional reconstructions included surface renderings. Images were presented to referring oral and maxillofacial surgeons in "real time" immediately after acquisition. RESULTS: The features of mandibular osteomyelitis seen on CBCT included: a peripheral sclerotic rim, cortical layering (involucrum), central loss of trabecular pattern with internal round radiolucent resorptive tracts, minimal jaw expansion, and reduction of the alveolar cortex. Sequestra were occasionally evident. The history and presentation of each case on CBCT were consistent with osteomyelitis of the mandible; however, the clinical differential diagnosis in each case had included malignancy. The definitive diagnosis was confirmed by histological examination of biopsy specimens. Two of the three cases were patients who had been treated with bisphosphonates. CONCLUSION: CBCT facilitated comprehensive and dynamic imaging of the jaws based on surgical consultation, rather than inflexible imaging protocols. CBCT images guided operative planning.

Maxillary sinus augmentation.

Attention to the principles of bone grafting, bone healing, and maxillary sinus physiology as well as anatomy is critical to the successful placement of dental implants in the posterior maxilla. The integration of these principles must take into account the restorative dental requirements and the patient's autonomy in guiding implant reconstruction. As in so many clinical disciplines, additional research is needed to provide better guidance for clinicians. Despite some gaps in our knowledge, however, sinus augmentation procedures have proven to be safe and effective and have permitted the placement of implants in sites that would have otherwise been impossible to treat. This article summarizes techniques and technologies related to maxillary sinus augmentation.