Use of Virtual Surgical Planning and Virtual Dataset With Intraoperative Navigation to Guide Revision of Complex Facial Fractures: A Case Report.

The use of intraoperative navigation has become prevalent in multiple surgical fields, including neurosurgery, orthopedic surgery, spine surgery, and head and neck surgery. In the past decade, its use also has become popular in oral and maxillofacial surgery. Previous studies have suggested the use of intraoperative navigation improves surgical precision and accuracy and decreases intraoperative risks and postsurgical morbidity. This report presents a case in which intraoperative navigation was used for revision and secondary reconstruction of multiple facial fractures. Preoperative virtual surgical planning allowed customization of osteotomies of multiple bony segments and virtual reduction of these segments to their anatomically correct position. Then, the newly reconstructed 3-dimensional virtual computed tomographic dataset was used as a template in the navigation system to guide the osteotomies and precisely reposition bony fragments during surgery. This report describes the workflow necessary to use this technology.

Evaluation of the Safety and Efficacy of Soft Tissue Augmentation With a Compressive-Resistant Collagen Matrix in a Nonhuman Primate Model.

PURPOSE: The purpose of the present study was to evaluate the safety and efficacy of the compression-resistant collagen-based cross-linked matrix for augmentation of maxillary and mandibular soft tissue defects in an animal model. MATERIALS AND METHODS: Six rhesus macaque monkeys were subjected to soft tissue grafting in 4 sites intraorally; the anterior maxilla was subjected to hard and soft tissue grafting with implant placement. Each site was randomly assigned 1 of 3 treatments: a compressive-resistant collagen matrix membrane (CM), a subepithelial connective tissue autograft (SCTG), or sham treatment, in which a partial-thickness flap was elevated and then sutured closed with no further treatment (control). The following methods were used for data collection: in vivo evaluation by periodontal probing, ultrasound, shear modulus elasticity, polyether impressions for volumetric analysis, and in vitro analysis by histologic biopsy examinations. In vitro analysis provided by histologic measurements and evaluations was performed on nondecalcified sections. The follow-up period was 6 months. RESULTS: The SCTG and CM showed favorable tissue integration. No adverse reaction to or deviation from the normal healing processes was detected. The CM integrated well in all sites, with a variable range of soft tissue volume increases. Volumetric discrepancies were appreciated in the histologic analyses and differences were found when the CM and SCTG were applied in the anterior maxilla in combination with hard tissue grafting and implant placement. Histologic evaluation showed favorable integration, no immunogenic response to the CM, and stable volumetric retention in autograft and CM sites during the experimental period. CONCLUSION: The compressive-resistant CM could be a safe and efficacious alternative for soft tissue augmentation by obviating a donor site and the consequent morbidity. Although a similar performance between the CM and SCTG was observed, further studies will be necessary to estimate the clinical potentiality and describe the limits of the technique.

What Name Best Represents Our Specialty? Oral and Maxillofacial Surgeon Versus Oral and Facial Surgeon.

PURPOSE: To determine whether changing "oral and maxillofacial surgeon" (OMS) to "oral and facial surgeon" improves the perception and awareness of the OMS's role and surgical scope of practice in undergraduate biomedical and dental students. MATERIALS AND METHODS: This cross-sectional study requested undergraduate and dental students to select 1 of 5 specialists to treat 21 conditions. Two different surveys were presented: 1 designating specialists as "oral and maxillofacial surgeons" and 1 designating specialists as "oral and facial surgeons." The independent variable was the specialist "oral and maxillofacial surgeon" or "oral and facial surgeon." The dependent variables included specialists chosen for the procedure (ear, nose, and throat surgeon; OMS vs oral and facial surgeon; plastic surgeon; periodontist; and "other"). The test of proportions (z test) with the Yates correction was performed. RESULTS: The sample was composed of 1,671 undergraduate upper division science students and 568 senior dental students. Results showed that undergraduate students' perception of an OMS's surgical scope increased significantly from 28 to 33% when "oral and facial surgeon" was used instead of "oral and maxillofacial surgeon." Dental students' perception of an OMS's surgical scope remained the same whether "oral and maxillofacial surgeon" or "oral and facial surgeon" was used. CONCLUSION: The results of this study suggest that using "oral and facial surgeon" instead of "oral and maxillofacial surgeon" increases awareness of an OMS's surgical scope of practice in undergraduate upper division science students, which could be an important step toward increasing the recognition of the profession by the general public and other non-dental medical colleagues.

Primordial Odontogenic Tumor: Report of a Case.

Primordial odontogenic tumor (POT) was first described in 2014. It typically presents in the posterior mandible of a child or adolescent as a "dentigerous cyst-like" well-circumscribed radiolucency associated with an unerupted molar. POT consists of an ellipsoidal mass of dental papilla-like myxoid connective tissue entirely enveloped in a delicate membrane of ameloblastic epithelium. It shows features of a developing tooth with a huge dental papilla, and because it is devoid of dental hard tissue, it could be regarded a soft tissue odontoma. The lesion histologically mimics early (primordial) stages of tooth development. This report describes a case of POT and POT-like proliferations in an unrelated complex odontoma.

Immediate Versus Delayed Treatment of Mandibular Fractures: A Stratified Analysis of Complications.

PURPOSE: To analyze the rate of complication outcomes of mandibular fracture repairs across different injury-to-repair time spans. PATIENTS AND METHODS: We conducted a retrospective cohort study of patients with repaired mandibular fractures. The independent variable was the time span from injury to surgical repair. The primary outcome variable was the rate of complications measured postoperatively during the follow-up appointments. Other variables were grouped for performance of a stratified analysis: favorability of the fracture, patient compliance, substance abuse, and fracture location. Descriptive and bivariate statistics were computed. RESULTS: The final sample was composed of 505 patients, and the time span from injury to repair ranged from 0 to 90 days. The total number of patients from the sample with reported complications was 124. There was no statistical significance correlating the time spans and complication rates (P = .796). The variables for the stratified analysis also showed no significant correlations except for fracture location. Body fractures resulted in the highest rate of complications (33%; P = .041). Of the noncompliant patients (n = 144), 28.5% presented with complications (P = .352). No significance was seen in unfavorable fractures (n = 283), with a rate of complications of 28.6%. No significance could be correlated with substance abuse (n = 107, 29.9% with complications; P = .262). CONCLUSIONS: The results of this study suggest that although time from injury to repair does not affect the rate of complications, the global standard of care for the management of non-emergent mandibular fractures should consider the cost-effectiveness of delaying treatment while exercising a reasonable length of delay for the comfort of the patient.

The case for advanced physics topics in oral and maxillofacial surgery.

Research in oral and maxillofacial surgery has focused mainly on principles founded in the biological and chemical sciences, which have provided excellent answers to many questions. However, recent technologic advances have begun to gain prominence in many of the medical sciences, providing clinicians with more effective tools for diagnosis and treatment. The era of modern physics has led to the development of diagnostic techniques that could provide information at a more basic level than many of the current biochemical methods used. The goal of this report is to introduce 2 of these methods and describe how they can be applied to oral and maxillofacial surgery.

Closure of large palatal defect using a tongue flap.

The aim of this study is to report the effectiveness of a tongue flap for covering a large hard and soft tissue defect following cleft of the palate. A young patient diagnosed with acute lymphoblastic leukemia underwent a surgical reconstruction of the cleft palate by Le Fort I osteotomy and palatal closure utilizing a tongue flap. The flap provided sound and lasting closure after the surgery, and the patient successfully healed. Our goal is to present this unique case and highlight how postoperative results were good, safe, and predictable. We also hope to show that tongue transplantation as flap for hard and soft tissue reconstruction represents a valuable option in reconstruction, given the proper circumstances.

Treatment of severe frontobasilar fractures in growing patients: a case series evaluation.

OBJECTIVE: The treatment of frontobasilar fractures is a demanding aspect of craniofacial fracture management. A sequel of inadequate or improper fracture management presents cosmetic and functional problems which are very difficult to correct. The aim of this manuscript was to examine a group of growing patients treated for frontobasilar fractures and provide clinicians a possible therapeutic option for the treatment of these challenging fractures. METHODS: In this investigation, 12 patients under the age of 16 years treated for severe injuries to the frontobasilar region were included. Their records were reviewed to evaluate the clinical diagnosis, preoperative findings, hospital course, postoperative results, and long-term follow-up. Preoperative and postoperative CT scans were performed in all children treated. Postoperative complications were reviewed in detail. Surgical procedures were evaluated for type and location of fixation. All complications and treatments were recorded. RESULTS: Three of the patients presented with a cerebrospinal fluid (CSF) leak and required pericranial flaps. Only 3 patients underwent removal of plates and screws due to palpability in 1 patient, loose hardware in 1 patient, and limited disturbance on growth in the rest patient. Seven patients underwent open reduction and internal fixation with resorbable plates, 4 patients with titanium plates, and 1 patient with a combination. Follow-up ranged from 6 months to 5 years. No patients with a preoperative CSF leak developed any recurrence of the leak. CONCLUSION: According to basic craniofacial principles, reducing and stabilizing the fractures should reconstruct the anterior cranial base. However, the treatment of paediatric maxillofacial trauma requires the evaluation of several factors. The facial skeleton of a child is constantly evolving and its growth depends on the balance of basal bone and soft tissues.

Osteoplasty flap technique for repair of latent (30-year) post-traumatic frontal sinus mucocele: case report and review of the literature.

Mucoceles are benign, slow-growing lesions defined as mucus-filled pseudocystic formations. Paranasal mucoceles predominantly affect the frontal sinus (60% to 65%), followed in frequency by the ethmoidal (20% to 30%), maxillary (10%), and sphenoid (2% to 3%) sinuses. Mucoceles usually arise because of sinus ostium obstruction, preceded by infection, fibrosis, inflammation, trauma, surgery or tumors such as osteomas. Mucoceles arising from the frontal sinus present with a variety of clinical signs, including decreased visual acuity, visual field abnormalities, proptosis, ptosis, periorbital swelling, displacement of the globe, restricted ocular movements, and choroidal folds. We describe a case of orbital involvement from a mucocele of the frontal sinus 30 years after the initial trauma, with a review of the published data concerning the etiology, diagnosis, and treatment planning.

Recombinant human bone morphogenetic protein 2 combined with an osteoconductive bulking agent for mandibular continuity defects in nonhuman primates.

PURPOSE: Recombinant human bone morphogenetic protein 2 (rhBMP-2) is an option for reconstructing mandibular continuity defects. A challenge of this technique is the need to maintain sufficient space to avoid compression of the defect. A compression-resistant matrix (CRM) provides a bulking agent that provides support during the bone formation phase. MATERIALS AND METHODS: Thirteen Rhesus Macaque monkeys were used to evaluate different forms of an osteoconductive bulking agent compared with an absorbable collagen alone placed into a critical-sized mandibular defect. A total of 5 groups (26 defects) were evaluated: group A, rhBMP-2/absorbable collagen sponge (ACS) (1.5 mg/mL); group B, rhBMP-2/ACS with ceramic granules (15% hydroxyapatite/85% ß-tricalcium phosphate) at 1.5 mg/mL; group C, rhBMP-2 (2.0 mg/mL) with a CRM; group D, rhBMP-2 (0.75 mg/mL) with a CRM; and group E, a CRM alone. RESULTS: Histology and micro computed tomography were used to evaluate and compare new bone formation in the defects. The reconstructed bone was evaluated with regard to the new bone formation, residual voids, and density. Animals treated with the CRM and rhBMP-2 at 2.0 mg/mL (group C) showed significantly higher amounts of new bone formation, bone density, and reduced voids when compared with rhBMP-2 and ACS (1.5 mg/mL) (P < .05). CONCLUSION: The carrier system CRM combined with rhBMP-2 and a reconstruction plate results in significantly higher bone density and better space maintenance than rhBMP-2 combined with ACS in a nonhuman primate mandibular bone repair model.

Neurotrophin Pathway Receptors NGFR and TrkA Control Perineural Invasion, Metastasis, and Pain in Oral Cancer.

Oral squamous cell carcinoma (OSCC) patients suffer from poor survival due to metastasis or locoregional recurrence, processes that are both facilitated by perineural invasion (PNI). OSCC has higher rates of PNI than other cancer subtypes, with PNI present in 80% of tumors. Despite the impact of PNI on oral cancer prognosis and pain, little is known about the genes that drive PNI, which in turn drive pain, invasion, and metastasis. In this study, clinical data, preclinical, and in vitro models are leveraged to elucidate the role of neurotrophins in OSCC metastasis, PNI, and pain. The expression data in OSCC patients with metastasis, PNI, or pain demonstrate dysregulation of neurotrophin genes. TrkA and nerve growth factor receptor (NGFR) are focused, two receptors that are activated by NGF, a neurotrophin expressed at high levels in OSCC. It is demonstrated that targeted knockdown of these two receptors inhibits proliferation and invasion in an in vitro and preclinical model of OSCC, and metastasis, PNI, and pain. It is further determined that TrkA knockdown alone inhibits thermal hyperalgesia, whereas NGFR knockdown alone inhibits mechanical allodynia. Collectively the results highlight the ability of OSCC to co-opt different components of the neurotrophin pathway in metastasis, PNI, and pain.

Vascularized connective tissue flap for bone graft coverage.

Alveolar defects are characterized by missing soft and hard tissues. It is often necessary to combine secondary procedures to address the soft-tissue component. The authors describe a technique that uses a split-thickness flap design that is placed over the crest of the remaining ridge and extends in a palatal direction. This allows advancement of the flap with its exposed connective tissue over the bone graft and provides restoration of both bone and keratinized tissue. Seventeen patients with defects involving the anterior maxilla who required grafting procedures were including in this study. All patients had an autogenous bone graft (n  =  17) combined with osseointegrated implants (n  =  41). A split-thickness flap design was used at the time of bone graft placement (primary) in 9 patients and at the time of implant uncovering (secondary) in 8 patients. There were no cases of flap necrosis or dehiscence with exposure of the bone graft. All patients demonstrated an increase in keratinized tissue involving the peri-implant area. An apical repositioned split-thickness flap provides an increased zone of keratinized tissue with improved esthetics and implant maintenance. This technique can be performed simultaneously with the grafting procedure, thus avoiding extensive undermining of the adjacent soft tissue.

Brush swab as a noninvasive surrogate for tissue biopsies in epigenomic profiling of oral cancer.

BACKGROUND: Oral squamous cell carcinoma (OSCC) has poor survival rates. There is a pressing need to develop more precise risk assessment methods to tailor clinical treatment. Epigenome-wide association studies in OSCC have not produced a viable biomarker. These studies have relied on methylation array platforms, which are limited in their ability to profile the methylome. In this study, we use MethylCap-Seq (MC-Seq), a comprehensive methylation quantification technique, and brush swab samples, to develop a noninvasive, readily translatable approach to profile the methylome in OSCC patients. METHODS: Three OSCC patients underwent collection of cancer and contralateral normal tissue and brush swab biopsies, totaling 4 samples for each patient. Epigenome-wide DNA methylation quantification was performed using the SureSelectXT Methyl-Seq platform. DNA quality and methylation site resolution were compared between brush swab and tissue samples. Correlation and methylation value difference were determined for brush swabs vs. tissues for each respective patient and site (i.e., cancer or normal). Correlations were calculated between cancer and normal tissues and brush swab samples for each patient to determine the robustness of DNA methylation marks using brush swabs in clinical biomarker studies. RESULTS: There were no significant differences in DNA yield between tissue and brush swab samples. Mapping efficiency exceeded 90% across all samples, with no differences between tissue and brush swabs. The average number of CpG sites with at least 10x depth of coverage was 2,716,674 for brush swabs and 2,903,261 for tissues. Matched tissue and brush swabs had excellent correlation (r = 0.913 for cancer samples and r = 0.951 for normal samples). The methylation profile of the top 1000 CpGs was significantly different between cancer and normal samples (mean p-value = 0.00021) but not different between tissues and brush swabs (mean p-value = 0.11). CONCLUSIONS: Our results demonstrate that MC-Seq is an efficient platform for epigenome profiling in cancer biomarker studies, with broader methylome coverage than array-based platforms. Brush swab biopsy provides adequate DNA yield for MC-Seq, and taken together, our findings set the stage for development of a non-invasive methylome quantification technique for oral cancer with high translational potential.

Immediate loading of two freestanding implants retaining a mandibular overdenture: 1-year pilot prospective study.

PURPOSE: The aim of this 1-year pilot prospective study was to evaluate the implant success rate, peri-implant tissue response, and complications associated with the immediate loading of two freestanding implants retaining mandibular overdentures. MATERIALS AND METHODS: Ten adults with a mean age of 59.7 years (range, 43 to 78 years) underwent treatment that included a maxillary removable complete denture opposing a mandibular removable overdenture retained by two freestanding, threaded, titanium oxide-surface implants with a 3-mm machined collar (n = 20 implants). The success of each implant was evaluated clinically and radiographically. Marginal bone levels and changes were evaluated using sequential standardized periapical radiographs. Surgical and prosthetic complications were recorded. RESULTS: Two patients, one with one failed implant, dropped out prior to completion of the study. The failed implants were included in the evaluation of cumulative implant success. The cumulative implant success rate at 1 year was 94% (16/17). The mean marginal bone loss was 1.12 ± 1.10 mm at 12 months. However, if the expected bone loss of 0.39 mm above the smooth-rough implant surface junction was considered, the mean marginal bone loss was only 0.73 mm. Mean Periotest values of -4.25 ± 0.93 at 1 year implied that osseointegration had been achieved for all successful implants. Modified Plaque Index scores of 0 and 1 were recorded throughout the duration of the study. No irreversible surgical and/or prosthetic complications were observed. CONCLUSIONS: In this 1-year pilot prospective study, two immediately loaded unsplinted mandibular symphyseal implants retaining an overdenture resulted in favorable implant success and peri-implant tissue response.

Use of a porcine collagen matrix as an alternative to autogenous tissue for grafting oral soft tissue defects.

PURPOSE: Soft tissue grafting is often required to correct intraoral mucosal deficiencies. Autogenous grafts have disadvantages including an additional harvest site with its associated pain and morbidity and, sometimes, poor quality and limited amount of the graft. Porcine collagen matrices have the potential to be helpful for grafting of soft tissue defects. PATIENTS AND METHODS: Thirty consecutive patients underwent intraoral grafting to re-create missing soft tissue. Defects ranged in size from 50 to 900 mm(2). Porcine collagen matrices were used to reconstruct missing tissue. Indications included preprosthetic (22), followed by tumor removal (5), trauma (2), and release of cheek ankylosis (1). RESULTS: The primary efficacy parameters evaluated were the degree of lateral and/or alveolar extension and the evaluation of re-epithelialization and shrinkage of the grafted area. Overall, the percentage of shrinkage of the graft was 14% (range, 5%-20%). The amount of soft tissue extension averaged 3.4 mm (range, 2-10 mm). The secondary efficacy parameters included hemostatic effect, pain evaluation, pain and discomfort, and clinical evaluation of the grafted site. All patients reported minimal pain and swelling associated with the grafted area. No infections were noted. CONCLUSION: This porcine collagen matrix provides a biocompatible surgical material as an alternative to an autogenous transplant, thus obviating the need to harvest soft tissue autogenous grafts from other areas of the oral cavity.

Recombinant human bone morphogenetic protein type 2 jaw reconstruction in patients affected by giant cell tumor.

Giant cell tumor (GCT) is a relatively common skeletal tumor. Mandibular localization of this tumor is usually treated with resection of the tumor area. Several autogenous bone-grafting techniques are available for the restoration of large continuity defects of the mandible. However, these procedures are associated with limitations involving postoperative morbidity, difficulty in ambulation (hip graft), and pain. The development of a technique of surgical reconstruction not involving autogenous bone would offer new opportunities for facial bone reconstruction, particularly of the mandible. This study aims to underline the effect of recombinant human bone morphogenetic protein type 2 (rhBMP-2) in a collagen carrier with concomitant bone grafting material in the restoration of continuity critical-size defects after GCT resection in the mandible. The rhBMP-2 was used with absorbable collagen sponge. A total dose of 4 to 8 mg of rhBMP-2 was delivered to the surgical site in concentrations of 1.5 mg/mL. The patient was followed up over a period from 6 to 18 months. Occlusal function was initially restored with conventional prosthesis. Bone formation in the surgical area could be palpated at the end of 3 to 4 months and identified radiographically at the end of 5 to 6 months. The results clearly indicated that the use of rhBMP-2 without concomitant bone grafting materials in large critical-size mandibular defects secondary to GCT produced excellent regeneration of the area, establishing the basis for the return of prosthodontic function.

Traumatic eyelid defects: a review of reconstructive options.

PURPOSE: Reconstruction of eyelid defects sustained from trauma can cause significant morbidity if not properly treated. Various local flaps are available to aid in this reconstruction. PATIENTS AND METHODS: Two hundred twelve patients sustained facial lacreations. Of these, 33 patients sustained injury to the eyelids. Six patients had significantly missing tissue, which required treatment with flaps. RESULTS: All patients had reconstruction of their eyelid defects. Three of the 6 patients (50%) with avulsive-type defects required a staged approach. CONCLUSIONS: For large avulsive eyelid defects, local and rigid flaps provide adequate reconstruction. For very large defects, a staged approach is recommended.

Implant success in distracted bone versus autogenous bone-grafted sites.

Endosseous implants are the treatment of choice for restoring function and reconstructing most edentulous areas of the maxilla and mandible. In general, alveolar bone defects can be reconstructed by either distraction osteogenesis or autogenous bone grafting. After alveolar reconstruction, endosseous implants are used to support and retain the prosthesis for restoration of form and function. Eighty-two consecutive patients requiring alveolar augmentation prior to implant placement were evaluated. All patients were given treatment options for reconstructing their alveolar defects, which included autogenous bone grafting vs distraction osteogenesis. Sixty-five patients received autogenous grafts (anterior iliac crest: 44; retromolar: 17; tibia: 2; chin: 2), and 17 patients underwent distraction osteogenesis prior to implant placement. A total of 184 implants were placed in the autogenous bone-grafted sites and 56 implants in the distracted bone sites. Implants placed in sites restored with autogenous bone grafts had an implant success rate of 97% (178/184), whereas implants placed in distracted bone sites had a success rate of 98% (55/56). In the autogenous grafted group, 3 implants failed in the posterior mandible, one in the anterior maxilla, one in the anterior mandible, and one in the posterior maxilla. In the distraction group, one implant failed in the posterior mandible. Both techniques are associated with good success rates. There was no statistical difference between implant success in autogenous bone vs distracted bone sites in this group of patients.

Titanium Mesh Grafting Combined with Recombinant Human Bone Morphogenetic Protein 2 for Alveolar Reconstruction.

There are several methods of regenerating the maxillary and mandibular ridge to achieve orthoalveolar form with bone grafting procedures, including block onlay grafting and guided bone regeneration. Traditionally, guided bone regeneration has focused on creating a space for bone regeneration to occur. The use of a formed titanium mesh to regenerate alveolar defects was popularized in the 1980s. With the advent of other adjuncts, such as resorbable membranes, and growth factors, such as recombinant human bone morphogenetic protein 2, the predictability of the procedure has increased and a wide variety of defects can be restored using this technology.