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Direct and rapid analysis of cholesterol was accomplished in the ambient environment using reactive desorption electrospray ionization (DESI) mass spectrometry. This was achieved by electrospraying reagent solutions in the form of high velocity charged droplets at surfaces such as dried serum samples and animal tissue sections. Betaine aldehyde, incorporated into the spray solvent, reacts selectively and rapidly with the alcohol group of cholesterol by nucleophilic addition, forming a hemiacetal salt. Limits of detection for pure cholesterol and related compounds were ∼1 ng when a solution of cholesterol of 1 μg/mL was spotted onto the surface. Quantitative analysis of free cholesterol in serum using reactive DESI was demonstrated using cholesterol-d7 as internal standard. High throughput analysis of small volumes of serum spotted onto a suitable substrate was achieved at an analysis rate of ∼14 a per sample, with a relative standard deviation (RSD) of ca. 6%. Use of reactive DESI in te imaging mode allowed 2D spatial distributions of phospholipids and cholesterol to be recorded simultaneously in rat brain tissues. [ABSTRACT FROM AUTHOR]

Purpose: Diffuse deep neck space infection (DDNSI) is an emergent condition that requires efficient surgical and airway management. A novel surgical approach has been developed to enhance access and improve visualization of the involved deep neck spaces, which allows for better evaluation of the extent of tissue necrosis. This study will compare the treatment of DDNSI with traditional incision and drainage with drain placement (Conventional) versus the new incision and drainage design with the use of a wound vacuum (VAC)., Methods: This retrospective cohort study was performed on DDNSI cases treated with the VAC versus Conventional techniques from July 2014 to September 2020 at Memorial Hermann Hospital by the oral and maxillofacial surgery service. To be categorized as a DDNSI, the patient had to demonstrate radiographic evidence of an infection bilaterally in a minimum of four spaces, such as bilateral submandibular, sublingual, and submental spaces. Primary predictor variable was treatment method for DDNSI, Conventional versus VAC. Primary outcome variables were hospital length of stay (LOS), number of washouts, and days of intubation. Covariates were age, sex, number of spaces involved, presence of necrotic tissues, comorbidities, and mortality. Appropriate uni- and bi-variate statistics were calculated. Statistical significance was set at P < .05., Results: Fifty-one patients (17 female and 34 male) aged 18 to 65 years were treated for DDNSI. Twenty-eight patients were treated using the VAC approach and 23 patients were treated with the conventional approach. The average LOS 8.3 ± 0.8 days (P-value = .0001), number of days intubated 3 ± 0.3 (P-value = .0001), and number of required washouts 2 ± 0.2 (P-value = .004) were statistically lower in the VAC group compared to the Conventional group., Conclusions: There were significant improvements encountered with overall length of hospital stay, number of days intubated, and the number of required wash outs. There were significant differences in outcomes between patients with comorbidities when compared to those who had none., (Copyright © 2022 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Craniofacial defects require a treatment approach that provides both robust tissues to withstand the forces of mastication and high geometric fidelity that allows restoration of facial architecture. When the surrounding soft tissue is compromised either through lack of quantity (insufficient soft tissue to enclose a graft) or quality (insufficient vascularity or inducible cells), a vascularized construct is needed for reconstruction. Tissue engineering using customized 3D printed bioreactors enables the generation of mechanically robust, vascularized bony tissues of the desired geometry. While this approach has been shown to be effective when utilized for reconstruction of non-load bearing ovine angular defects and partial segmental defects, the two-stage approach to mandibular reconstruction requires testing in a large, load-bearing defect. In this study, 5 sheep underwent bioreactor implantation and the creation of a load-bearing mandibular defect. Two bioreactor geometries were tested: a larger complex bioreactor with a central groove, and a smaller rectangular bioreactor that were filled with a mix of xenograft and autograft (initial bone volume/total volume BV/TV of 31.8 ± 1.6%). At transfer, the tissues generated within large and small bioreactors were composed of a mix of lamellar and woven bone and had BV/TV of 55.3 ± 2.6% and 59.2 ± 6.3%, respectively. After transfer of the large bioreactors to the mandibular defect, the bioreactor tissues continued to remodel, reaching a final BV/TV of 64.5 ± 6.2%. Despite recalcitrant infections, viable osteoblasts were seen within the transferred tissues to the mandibular site at the end of the study, suggesting that a vascularized customized bony flap is a potentially effective reconstructive strategy when combined with an optimal stabilization strategy and local antibiotic delivery prior to development of a deep-seated infection., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Watson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Most literature regarding traumatic Le Fort or maxillary fractures exists in the adult population, with limited information regarding the epidemiology and management of pediatric fractures. The purpose of this study was to evaluate fracture mechanism, surgical management, and associated injuries in pediatric patients with Le Fort fractures., Methods: A retrospective chart analysis of all pediatric patients age ≤18 years diagnosed with facial fractures at a single level 1 trauma center over a 10-year period (January 2006-December 2015) was performed. Demographics, fracture location, mechanism of injury, and hospital course were abstracted as well as associated injuries and need for operative management., Results: A total of 1274 patients met inclusion criteria. Sixty-nine (5.4%) presented with Le Fort fractures. Factors associated with Le Fort fractures included motor vehicle collisions (P < 0.001), increased age (P < 0.001), and traumatic brain injury (P < 0.04). Patients with Le Fort fractures were more likely to need intensive care unit admission (P < 0.001), surgical management (P < 0.001), transfusions (P < 0.001), secondary fixation surgery (P < 0.001), and have a longer length of stay (P < 0.001). Multivariate showed increased odds for increased age (OR 1.1; 95%CI 1.04-1.17) and concomitant orbit fractures (OR 8.33; 95%CI 4.08-19.34). Decreased odds were associated for all mechanisms of injury other than motor vehicle collisions (Other blunt trauma: OR 0.36; 95%CI 0.2-0.6. Penetrating trauma: OR 0.13; 95%CI 0.01-0.6)., Conclusion: Maxillary or Le Fort fractures represent a small portion of pediatric facial fractures but require high rates of operative management. The high velocity required to create this fracture type is associated with significant traumatic comorbidities, which can complicate the hospital course., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

Mandibular reconstruction requires functional and aesthetic repair and is further complicated by contamination from oral and skin flora. Antibiotic-releasing porous space maintainers have been developed for the local release of vancomycin and to promote soft tissue attachment. In this study, mandibular defects in six sheep were inoculated with 10 6 colony forming units of Staphylococcus aureus; three sheep were implanted with unloaded porous space maintainers and three sheep were implanted with vancomycin-loaded space maintainers within the defect site. During the same surgery, 3D-printed in vivo bioreactors containing autograft or xenograft were implanted adjacent to rib periosteum. After 9 weeks, animals were euthanized, and tissues were analyzed. Antibiotic-loaded space maintainers were able to prevent dehiscence of soft tissue overlying the space maintainer, reduce local inflammatory cells, eliminate the persistence of pathogens, and prevent the increase in mandibular size compared to unloaded space maintainers in this sheep model. Animals with an untreated mandibular infection formed bony tissues with greater density and maturity within the distal bioreactors. Additionally, tissues grown in autograft-filled bioreactors had higher compressive moduli and higher maximum screw pull-out forces than xenograft-filled bioreactors. In summary, we demonstrated that antibiotic-releasing space maintainers are an innovative approach to preserve a robust soft tissue pocket while clearing infection, and that local infections can increase local and remote bone growth., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Addressing access to oral health care in many low- to middle-income countries is a complicated issue. Oral and maxillofacial surgeons may help engage with vulnerable populations through carefully planned dentoalveolar mission trips. The process of planning a mission includes selecting a population and identifying their unique needs, designing clinic layouts and workflows, team preparation, collection of supplies, fundraising, and advertising. During the mission, methods for protecting privacy, delivering treatment that is standard of care, and sanitation/sterilization options are reviewed. Ethical considerations include avoiding exploitation of vulnerable populations, offending local hosts, need for data collection, and long-term mission sustainability., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The aim of this study is to assess if there is an increase in postoperative venous thromboembolism (VTE) or bleeding complications in patients who received perioperative chemical thromboprophylaxis compared with patients in whom chemical thromboprophylaxis was held during periorbital trauma surgery. This is a retrospective chart review of patients undergoing periorbital surgery treated in three different city hospitals, by the Department of Oral and Maxillofacial Surgery, University of Texas, between August 2014 and December 2016. A total of 237 patients were included in this study. None of these patients suffered a postoperative VTE. A total of 102 patients received perioperative pharmacologic thromboprophylaxis in the form of enoxaparin or heparin. In this group, one patient suffered a buccal space hematoma. Chemical thromboprophylaxis was held in 135 patients preoperatively and for at least 24 hours postoperatively. In this group, one patient suffered a retrobulbar hematoma after repair of an orbital floor fracture. The rate of postoperative bleeding complications was compared by the chi-square test and was not statistically significant ( p  = 0.8417)., Competing Interests: Conflicts of Interest No disclosures or conflicts of interest to report., (© Thieme Medical Publishers.)

This article reviews the basic setup and function of surgical navigation and displays a variety of applications in oral and maxillofacial surgery. The use of surgical navigation for dental implant placement is discussed elsewhere in this issue., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: Pediatric facial fractures due to intentionally violent mechanisms represent a unique subset of facial fractures. The objective of our research is to identify how violence affects patterns of facial fractures and their management in pediatric patients., Methods: An IRB approved, retrospective study of our institution's pediatric patients ≤18 years of age who presented with ≥1 facial fracture due to violence from January 2006 to December 2015 was performed. Violence was defined as trauma intended to hurt another or self. Demographics, fractures, mechanism, concomitant injuries, and management were analyzed., Results: The 1274 patients were diagnosed with facial fractures, with 235 of these due to violence (18%). These patients of violence (POV) had 332 fractures, with an average fracture per patient of 1.4 ± .0.8. The majority (86%) were male, Non-Hispanic African American (35%), and the average age was 15.9 ± 2.8 years. The most common fracture was the mandible (50% of patients) and most common mechanism was assault (76%). The POV were older, male, and of minority race/ethnic groups when compared to patients of non-violence (PONV) (P <0.01). The POV presented with fewer concomitant injuries, were less likely to be admitted to the intensive care unit, and more often surgically managed when compared to the PONV (P <0.01)., Conclusion: This study represents the largest US, single institution, Level 1 trauma center study of pediatric facial fractures. Pediatric patients with facial fractures due to a violent mechanism represent a distinct category of trauma patients with a unique profile of injuries.

Background: Dislocation of the mandibular condyle into the middle cranial fossa is a rare injury that can be seen after facial trauma. Early identification of condyle dislocation into the middle cranial fossa was difficult until the development of computed tomography, and diagnosis was often significantly delayed after the initial trauma., Case Description: We present a rare case of a young woman who presents after a mechanical fall resulting in facial trauma with an avulsion condyle fracture with dislocation of the mandibular condyle into the middle cranial fossa., Conclusions: To our knowledge, this complete avulsion of the condyle into the middle cranial fossa requiring an intracranial approach for condylectomy is extremely rare. We discuss the surgical management options for reduction and fixation accomplished in a multidisciplinary approach involving neurosurgery and oral maxillofacial surgery., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Pediatric facial fractures present and are managed differently than the adult population. This study describes the pattern and mechanism of facial fractures in children and identifies factors associated with need for surgical management. An IRB-approved retrospective chart analysis of all pediatric patients age ≤ 18 years diagnosed with facial fractures at our level 1 trauma center over a 10-year period (January 2006-December 2015) was performed. Demographics, fracture location, mechanism of injury, concomitant head and neck injuries, and surgical management were reviewed. Statistical analysis was then performed comparing surgical and nonsurgical cohorts using univariate and multivariate analyses. One thousand two hundred seventy-four patients were diagnosed with facial fractures. Five hundred seventeen (40.6%) underwent surgical management. Two thousand one hundred seventy-two total facial fractures were recorded. Orbit fractures (29%) were the most commonly recorded, observed in 49% of patients presenting. Increased age was associated with increased odds of surgical management (OR 1.13; 95% CI 1.09-1.16). Mandible (OR 9.28; 95% CI 6.88-12.51) and Le Fort fractures (OR 19.73; 95% CI 9.78-39.77) had increased odds of surgical management. Patients with traumatic brain injury had reduced odds (OR 0.54; 95% CI 0.35-0.83) of surgical management for their facial fractures. Older pediatric patients may be more likely to require surgical management of their facial fractures, especially those with mandible or Le Fort fractures. Patients with traumatic brain injury are likely to sustain life threatening injuries, deferring repair of their facial fractures. Patient education and counseling, as well as predictive models, can be improved to reflect these data.

Large mandibular defects are clinically challenging to reconstruct due to the complex anatomy of the jaw and the limited availability of appropriate tissue for repair. We envision leveraging current advances in fabrication and biomaterials to create implantable devices that generate bone within the patients themselves suitable for their own specific anatomical pathology. The in vivo bioreactor strategy facilitates the generation of large autologous vascularized bony tissue of customized geometry without the addition of exogenous growth factors or cells. To translate this technology, we investigated its success in reconstructing a mandibular defect of physiologically relevant size in sheep. We fabricated and implanted 3D-printed in vivo bioreactors against rib periosteum and utilized biomaterial-based space maintenance to preserve the native anatomical mandibular structure in the defect site before reconstruction. Nine weeks after bioreactor implantation, the ovine mandibles were repaired with the autologous bony tissue generated from the in vivo bioreactors. We evaluated tissues generated in bioreactors by radiographic, histological, mechanical, and biomolecular assays and repaired mandibles by radiographic and histological assays. Biomaterial-aided mandibular reconstruction was successful in a large superior marginal defect in five of six (83%) sheep. Given that these studies utilized clinically available biomaterials, such as bone cement and ceramic particles, this strategy is designed for rapid human translation to improve outcomes in patients with large mandibular defects., Competing Interests: The authors declare no conflict of interest.

Background: There were 2 main purposes of this retrospective chart review study. The first was to describe the demographic, social, and financial characteristics of patients with severe odontogenic infections. The second was to assess the relationships among several demographic, social, and treatment variables and length of stay (LOS) in the hospital and hospital bill (charges)., Methods: The authors conducted a retrospective chart review for patients admitted to the hospital and taken to the operating room for treatment of severe odontogenic infections at 3 hospitals in Houston, TX (Ben Taub, Memorial Hermann Hospital, and Lyndon B. Johnson) from January 2010 through January 2015., Results: The authors included data from severe odontogenic infections in 298 patients (55% male; mean age, 38.9 years) in this study. In this population, 45% required admission to the intensive care unit, and the mean LOS was 5.5 days. Most patients (66.6%) were uninsured. The average cost of hospitalization for this patient population was $13,058, and the average hospital bill was $48,351. At multivariable analysis, age (P = .011), preadmission antibiotic use (P = .012), diabetes mellitus (P = .004), and higher odontogenic infection severity score (P < .001) were associated with increased LOS. Higher odontogenic infection severity score, diabetes mellitus, and an American Society of Anesthesiologists score of 3 or more were associated with an increased charge of hospitalization., Conclusions: Severe odontogenic infections were associated with substantial morbidity and cost in this largely unsponsored patient population. The authors identified variables associated with increased LOS and charge of hospitalization., Practical Implications: Clinicians should consider these findings in their decision-making processes and prioritize early treatment of odontogenic infections potentially to decrease the number of patients admitted to the hospital, LOS, and overall costs of treatment for these infections., (Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Reconstruction of large mandibular defects is clinically challenging due to the need for donor tissue of appropriate shape and volume to facilitate high fidelity repair. In order to generate large vascularized tissues of custom geometry, bioreactors were implanted against the rib periosteum of 3-4year-old sheep for nine weeks. Bioreactors were filled with either morcellized autologous bone, synthetic ceramic particles, or a combination thereof. Tissues generated within synthetic graft-filled bioreactors were transferred into a large right-sided mandibular angle defect as either avascular grafts (n=3) or vascularized free flaps (n=3). After twelve additional weeks, reconstructed mandibular angles were harvested and compared to contralateral control angles. Per histologic and radiologic evaluation, a greater amount of mineralized tissue was generated in bioreactors filled with autologous graft although the quality of viable bone was not significantly different between groups. Genetic analyses of soft tissue surrounding bioreactor-generated tissues demonstrated similar early and late stage osteogenic biomarker expression (Runx2 and Osteocalcin) between the bioreactors and rib periosteum. Although no significant differences between the height of reconstructed and control mandibular angles were observed, the reconstructed mandibles had decreased bone volume. There were no differences between mandibles reconstructed with bioreactor-generated tissues transferred as flaps or grafts. Tissues used for mandibular reconstruction demonstrated integration with native bone as well as evidence of remodeling. In this study, we have demonstrated that synthetic scaffolds are sufficient to generate large volumes of mineralized tissue in an in vivo bioreactor for mandibular reconstruction., Statement of Significance: A significant clinical challenge in craniofacial surgery is the reconstruction of large mandibular defects. In this work, we demonstrated that vascularized tissues of large volume and custom geometry can be generated from in vivo bioreactors implanted against the rib periosteum in an ovine model. The effects of different bioreactor scaffold material on tissue ingrowth were measured. To minimize donor site morbidity, tissues generated from bioreactors filled with synthetic graft were transferred as either vascularized free flaps or avascular grafts to a large mandibular defect. It was demonstrated that synthetic graft in an in vivo bioreactor is sufficient to produce free tissue bone flaps capable of integrating with native tissues when transferred to a large mandibular defect in an ovine model., (Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The reconstruction of large craniofacial defects remains a significant clinical challenge. The complex geometry of facial bone and the lack of suitable donor tissue often hinders successful repair. One strategy to address both of these difficulties is the development of an in vivo bioreactor, where a tissue flap of suitable geometry can be orthotopically grown within the same patient requiring reconstruction. Our group has previously designed such an approach using tissue chambers filled with morcellized bone autograft as a scaffold to autologously generate tissue with a predefined geometry. However, this approach still required donor tissue for filling the tissue chamber. With the recent advances in biodegradable synthetic bone graft materials, it may be possible to minimize this donor tissue by replacing it with synthetic ceramic particles. In addition, these flaps have not previously been transferred to a mandibular defect. In this study, we demonstrate the feasibility of transferring an autologously generated tissue-engineered vascularized bone flap to a mandibular defect in an ovine model, using either morcellized autograft or synthetic bone graft as scaffold material.

This study investigated the use of injectable poly(propylene fumarate) (PPF) formulations for mandibular fracture stabilization applications. A full factorial design with main effects analysis was employed to evaluate the effects of the PPF:N-vinyl pyrrolidone (NVP, crosslinking agent) ratio and dimethyl toluidine (DMT, accelerator) concentration on key physicochemical properties including setting time, maximum temperature, mechanical properties, sol fraction, and swelling ratio. Additionally, the effects of formulation crosslinking time on the mechanical and swelling properties were investigated. The results showed that increasing the PPF:NVP ratio from 3:1 to 4:1 or decreasing the DMT concentration from 0.05 to 0.01 v/w % significantly decreased all mechanical properties as well as significantly increased the sol fraction and swelling ratio. Also, increasing the crosslinking time at 37°C from 1 to 7 days significantly increased all mechanical properties and decreased both the sol fraction and swelling ratio. This study further showed that the flexural stiffness of ex vivo stabilized rabbit mandibles increased from 1.7 ± 0.3 N/mm with a traditional mini-plate fixator to 14.5 ± 4.1 N/mm for the 4:1 (0.05 v/w % DMT) PPF formulation at day 1. Overall, the formulations tested in this study were found to have properties suitable for potential further consideration in mandibular fracture fixation applications., (© 2014 Wiley Periodicals, Inc.)

A case is presented of a unique presentation and treatment of a mandibular nerve schwannoma. Its uniqueness stems from the fact that it consisted of 2 distinct tumors along the same nerve: one within the body of the mandible and the other within the ipsilateral pterygomandibular space. Rather than the standard approach of lip split and hemimandibulectomy, a unique approach of a sagittal split ramus osteotomy was used that allowed access to the 2 lesions and avoided the added morbidity of the former approach. The 2 portions of the lesion were successfully removed and the patient was satisfied with the result. Recurrence has not been detected after 6 months., (Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

This study evaluated the in vitro and in vivo performance of antibiotic-releasing porous polymethylmethacrylate (PMMA)-based space maintainers comprising a gelatin hydrogel porogen and a poly(dl-lactic-co-glycolic acid) (PLGA) particulate carrier for antibiotic delivery. Colistin was released in vitro from either gelatin or PLGA microparticle loaded PMMA constructs, with gelatin-loaded constructs releasing colistin over approximately 7 days and PLGA microparticle-loaded constructs releasing colistin for up to 8 weeks. Three formulations with either burst release or extended release at different doses were tested in a rabbit mandibular defect inoculated with Acinetobacter baumannii (2×10(7) colony forming units ml(-1)). In addition, one material control that released antibiotic but was not inoculated with A. baumannii was tested. A. baumannii was not detectable in any animal after 12 weeks on culture of the defect, saliva, or blood. Defects with high dose extended release implants had greater soft tissue healing compared with defects with burst release implants, with 8 of 10 animals showing healed mucosae compared with 2 of 10 respectively. Extended release of locally delivered colistin via a PLGA microparticle carrier improved soft tissue healing compared with implants with burst release of colistin from a gelatin carrier., (Copyright © 2013 Acta Materialia Inc. All rights reserved.)

Reconstruction of composite defects involving bone and soft tissue presents a significant clinical challenge. In the craniofacial complex, reconstruction of the soft and hard tissues is critical for both functional and aesthetic outcomes. Constructs for space maintenance provide a template for soft tissue regeneration, priming the wound bed for a definitive repair of the bone tissue with greater success. However, materials used clinically for space maintenance are subject to poor soft tissue integration, which can result in wound dehiscence. Porous materials in space maintenance applications have been previously shown to support soft tissue integration and to allow for drug release from the implant to further prepare the wound bed for definitive repair. This study evaluated solid and low porosity (16.9% ± 4.1%) polymethylmethacrylate space maintainers fabricated intraoperatively and implanted in a composite rabbit mandibular defect model for 12 weeks. The data analyses showed no difference in the solid and porous groups both histologically, evaluating the inflammatory response at the interface and within the pores of the implants, and grossly, observing the healing of the soft tissue defect over the implant. These results demonstrate the potential of porous polymethylmethacrylate implants formed in situ for space maintenance in the craniofacial complex, which may have implications in the potential delivery of therapeutic drugs to prime the wound site for a definitive bone repair., (Copyright © 2012 Wiley Periodicals, Inc.)

An antibiotic-releasing porous polymethylmethacrylate (PMMA) construct was developed to maintain the bony space and prime the wound site in the initial step of a two-stage regenerative medicine approach toward reconstructing significant bony or composite craniofacial tissue defects. Porous PMMA constructs incorporating gelatin microparticles (GMPs) were fabricated by the sequential assembly of GMPs, the antibiotic colistin, and a clinically used bone cement formulation of PMMA powder and methylmethacrylate liquid. PMMA/gelatin/antibiotic constructs with varying gelatin incorporation and drug content were investigated to elucidate the relationship between material composition and construct properties (porosity and drug release kinetics). The porosity of PMMA/gelatin/antibiotic constructs ranged between 7.6±1.8% and 38.4±1.4% depending on the amount of gelatin incorporated and the drug solution added for gelatin swelling. The constructs released colistin over 10 or 14 days with an average release rate per day above 10 μg/ml. The porosity and in vitro colistin release kinetics of PMMA/gelatin/antibiotic constructs were tuned by varying the material composition and fabrication parameters. This study demonstrates the potential of gelatin-incorporating PMMA constructs as a functional space maintainer for both promoting tissue healing/coverage and addressing local infections, enabling better long-term success of the definitive regenerated tissue construct., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Current treatment of traumatic craniofacial injuries often involves early free tissue transfer, even if the recipient site is contaminated or lacks soft tissue coverage. There are no current tissue engineering strategies to definitively regenerate tissues in such an environment at an early time point. For a tissue engineering approach to be employed in the treatment of such injuries, a two-stage approach could potentially be used. The present study describes methods for fabrication, characterization, and processing of porous polymethylmethacrylate (PMMA) space maintainers for temporary retention of space in bony craniofacial defects. Carboxymethylcellulose hydrogels were used as a porogen. Implants with controlled porosity and pore interconnectivity were fabricated by varying the ratio of hydrogel:polymer and the amount of carboxymethylcellulose within the hydrogel. The in vivo tissue response to the implants was observed by implanting solid, low-porosity, and high-porosity implants (n = 6) within a nonhealing rabbit mandibular defect that included an oral mucosal defect to allow open communication between the oral cavity and the mandibular defect. Oral mucosal wound healing was observed after 12 weeks and was complete in 3/6 defects filled with solid PMMA implants and 5/6 defects filled with either a low- or high-porosity PMMA implant. The tissue response around and within the pores of the two formulations of porous implants tested in vivo was characterized, with the low-porosity implants surrounded by a minimal but well-formed fibrous capsule in contrast to the high-porosity implants, which were surrounded and invaded by almost exclusively inflammatory tissue. On the basis of these results, PMMA implants with limited porosity hold promise for temporary implantation and space maintenance within clean/contaminated bone defects.

Purpose: The aim of this study was to determine the rate of postoperative infection and the efficacy of removing teeth in the line of mandibular angle fractures treated with 2.0-mm 8-hole titanium curved strut plates. Our understanding is that this method of repair is currently being used only in a few centers in the United States., Materials and Methods: A retrospective review of mandibular angle fractures treated with a 2.0-mm 8-hole strut plate during a 4-year period. Postoperative antibiotics were given for 1 week. Follow-up appointments were 4 weeks or longer. A nonchewing diet was instructed for 6 weeks. Data for all selected patients include the information such as age, gender, etiology of injuries, medical history, concurrent injuries, nerve deficits, pre- and postoperative antibiotic administration, postop infection, a presence or absence of teeth in the line of fractures, and whether these teeth were removed., Results: Four patients (4 of 49 or 8.2%) developed infections. Two of those patients had a tooth in the line of a fracture that was retained (2 of 14 or 14%). The third had a tooth in the line of a fracture that was extracted (1 of 18 or 5.6%). The fourth patient was 1 of the 17 patients who did not have teeth in the line of fracture and developed infection (1 of 17 or 5.9%). None of the patients developed failed hardware, malunion, nonunion, malocclusion, or iatrogenic nerve injury., Conclusions: The use of a 2.0-mm 8-hole strut plate is associated with a low infection rate (8.2%). The infection rate for those mandibular angle fractures with teeth in the line of fracture retained was 14% compared with 5.6% for those fractures with the teeth in the line of fracture extracted.

In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion. To test this hypothesis, healing bone was investigated within a rabbit incisor extraction socket, a subcritical size bone defect that resists significant soft tissue invasion by virtue of its conformity. After removal of the incisor teeth, one tooth socket was left as an empty control, one was filled with crosslinked polymer networks formed from the hydrophobic polymer poly(propylene fumarate) (PPF), and one was filled with a hydrogel formed from the hydrophilic oligomer oligo(poly(ethylene glycol) fumarate) (OPF). At five different times (4 days as well as 1, 2, 4, and 8 weeks), jaw bone specimens containing the tooth sockets were removed. We analyzed bone healing by histomorphometrical analysis of hematoxylin and eosin stained sections as well as immunohistochemically stained sections. The proposed hypothesis, that a hydrophilic material would hinder bone healing, was supported by the histomorphometrical results. In addition, the immunohistochemical results reflect molecular signaling indicative of the early invasion of platelets, the vascularization of wound-healing tissue, the differentiation of migrating progenitor cells, and the formation and remodeling of bone tissue. Finally, the results emphasize the need to consider biomaterial properties and their differing effects upon endogenous growth factors, and thus bone healing, during the development of tissue engineering devices., (Copyright 2003 Wiley Periodicals, Inc.)