Preservation of the inferior alveolar vasculonervous bundle in mandibular resective therapies: systematic review and report of two cases

Background: Segmental surgical resection is a frequently indicated procedure to treat aggressive mandibular tumors. One of the most important complications derived from this technique is permanent paresthesia of the inferior alveolar nerve (IAN), which significantly affects the quality of life of patients who experience it. This could be avoided through maneuvers that preserve the IAN. The objective of this paper is to review the main techniques for IAN preservation and to present 2 cases with the technique used by the author. Material and Methods: A systematic review was performed according to the PRISMA guidelines, apropos of two clinical cases reported in this study. The MEDLINE/PubMed and Scopus databases were searched. Several variables were considered and are presented in detail in the form of tables and figures. In addition, 2 case reports with NAI preservation techniques are presented. Results: 13 articles were finally obtained for analysis. 127 patients were evaluated, reporting mandibular resections associated with various pathologies. Various surgical techniques were used, all with the same goal of maintaining the IAN. In most of the patients, the maintenance of sensitivity was achieved, which was verified with different methods. Conclusions: Preservation of the IAN in maxillofacial surgical procedures where surgical resection of the mandibular bone has been performed is an alternative that has demonstrated successful results in terms of reducing postoperative sequelae and is currently positioned as a necessary and feasible procedure. (AU)

Classification of unusual fracture patterns of the mandible: A retrospective study.

The aim of this study is to devise and summarize a classification of fracture patterns involving multiple anatomical sites of the mandible. A retrospective study was conducted by reviewing clinical case records, imaging records, and the surgical management of patients presenting with mandibular fracture. Demographic data were collected and causes of the fractures were studied. Following radiological evaluations based on the courses of fracture lines, these fractures were categorized into three components: horizontal (H), vertical (V), and sagittal (S). In case of horizontal components, the mandibular canal was used as a reference. For vertical components, the fracture lines were classified according to where they terminated. With sagittal components, the direction of the bicortical split at the base of mandible was used as a reference. Out of a total of 893 mandibular trauma patients, 30 unusual fractures were identified (21 in males and nine in females), which do not fit into existing classifications. These were mainly due to road traffic accidents. Horizontal components of fractures were classified as H-I, H-II, and H-III, and vertical components as V-I, V-II, and V-III. For sagittal components, two types were identified - S-I and S-II - resulting in a bicortical split of the mandible. This classification is proposed to help understanding the complex fractures and to allow standardized communication among clinicians. Moreover, it is designed in such a way that aids in the choice of fixation technique. Further studies are needed to establish standardized treatment algorithms for efficient management of these unusual fractures.

Conhecimento e atitudes de indivíduos leigos sobre avulsão de dentes permanentes / Knowledge and atitudes of lay individuals about avulsion of permanente teeth / Conocimientos y actitudes de los legos sobre la avulsión de los dientes permanentes

Introdução: A avulsão dentária é caracterizada pelo deslocamento total do elemento dentário para fora do alvéolo em decorrência de um trauma externo e as medidas emergenciais prestadas ainda no local do acidente são imprescindíveis para um bom prognóstico. Objetivo: Investigou-se o nível de conhecimento e atitudes de leigos sobre possíveis condutas frente à avulsão de dentes permanentes. Métodos: A coleta de dados foi realizada a partir de um questionário contendo perguntas sobre características gerais da lesão e as atitudes que os pacientes tomariam em um caso de avulsão. Os dados foram analisados pelo teste de Mann Whitney, considerando um nível de significância de 5% (p <0,05). Resultados: Questionários foram respondidos por 120 pacientes enquanto aguardavam atendimento. A média geral de respostas corretas / atitudes esperadas foi de 3,74. Os participantes que possuíam informação prévia acerca do tema, obtiveram médias significativamente maiores, o mesmo não foi verificado com aqueles que possuíam experiência prévia com trauma. Conclusão: Conclui-se que o conhecimento sobre avulsão dentária dos pacientes é baixo e que a educação em saúde, através da informação da população pode ser um fator relevante para a melhora da conduta emergencial no local do trauma pela população leiga... (AU)

Introduction: Tooth avulsion is characterized by the total displacement of the tooth out of the socket as a result of an external trauma and emergency measures provided at the accident site are essential for a good prognosis. Objective: We investigated the level of knowledge and attitudes of lay people about possible behaviors in the face of avulsion of permanent teeth. Methods: Data collection was performed using a questionnaire containing questions about general characteristics of the lesion and the attitudes that patients would take in a case of avulsion. Data were analyzed using the Mann-Whitney test, considering a significance level of 5% (p <0,05). Results: Questionnaires were answered by 120 patients while waiting for care. The overall average of correct answers/expected attitudes was 3.74. Participants who had previous information on the subject had significantly higher averages, the same was not verified with those who had previous experience with trauma. Conclusion: It is concluded that the knowledge about dental avulsion of patients is low and that health education, through population information can be a relevant factor for the improvement of emergency management at the trauma site by the lay population... (AU)

Introducción: La avulsión dentaria se caracteriza por el desplazamiento total del diente fuera del alvéolo como consecuencia de un traumatismo externo y las medidas de urgencia en el lugar del accidente son fundamentales para un buen pronóstico. Objetivo: Indagamos el nivel de conocimientos y actitudes de los legos sobre posibles comportamientos ante la avulsión de dientes permanentes. Métodos: La recolección de datos se realizó mediante un cuestionario que contenía preguntas sobre las características generales de la lesión y las actitudes que tomarían los pacientes en caso de avulsión. Los datos fueron analizados mediante la prueba de Mann-Whitney, considerando un nivel de significación del 5% (p<0,05). Resultados: Los cuestionarios fueron respondidos por 120 pacientes en espera de atención. La media global de aciertos/ actitudes esperadas fue de 3,74. Los participantes que tenían información previa sobre el tema tuvieron promedios significativamente más altos, lo mismo no se verificó con aquellos que tenían experiencia previa con el trauma. Conclusión: Se concluye que el conocimiento sobre la avulsión dentaria de los pacientes es bajo y que la educación en salud, a través de la información poblacional, puede ser un factor relevante para la mejora del manejo de la emergencia en el sitio del trauma por parte de la población no especializada... (AU)

Tratamento cirúrgico em fratura de mandíbula atrófica: uma revisão de literatura / Surgical treatment of atrophic jaw fracture: a literature review

Analisar o manejo de fraturas em mandíbula atrófica voltado para a abordagem cirúrgica com ênfase na melhor técnica indicada. A perda óssea alveolar tem sido uma das consequências do edentulismo, que tem o potencial de levar a atrofia óssea. As fraturas de mandíbulas atróficas, normalmente são consideradas um procedimento desafiador, devido ser encontrada em pacientes idosos ou em virtude da perda dentária precoce resultando em um reparo dessas fraturas mais complexo. Os principais fatores etiológicos têm sido os acidentes automobilísticos, seguidos de queda e agressão. Geralmente, as causas das quedas decorrem de desequilíbrio, fraqueza muscular, tontura, e uso crônico de medicamentos como sedativos. As opções terapêuticas objetivam restaurar forma, função e imobilização apropriada desse possível evento. A individualização do tratamento de escolha é de grande importância, pois geralmente o paciente apresenta alterações fisiológicas decorrentes do envelhecimento e ossos mais fragilizados com potencial osteogênico reduzido, que dificultam a abordagem cirúrgica. Entretanto, deve ser considerado para o manejo dessas fraturas, a idade do paciente, as condições e quantidade de tecido ósseo e tecido mole. Porém, vale ressaltar que o envelhecimento não apresenta contraindicação, apenas exige condições especiais que devem ser consideradas. Nesse sentido, quando há oportunidade de dispositivos tecnológicos, como os biomodelos que contribuem significativamente para procedimentos cirúrgicos bucomaxilofaciais, esses fornecem maior previsibilidade de resultados, bem como redução do tempo cirúrgico.

To analyze the management of fractures in atrophic mandible aimed at the surgical approach, emphasizing which technique is best indicated. Alveolar bone loss has been one of the consequences of edentulism, which has the potential to lead to bone atrophy. Atrophic jaw fractures are usually considered a challenging procedure, as they are found in elderly patients or due to early tooth loss, resulting in a more complex repair of these fractures. The main etiological factors have been described as car accidents, followed by falls and aggression. Commonly, the causes of falls stem from imbalance, muscle weakness, dizziness, and chronic use of medications such as sedatives. The therapeutic options aim to restore form, function and appropriate immobilization of this possible event. The individualization of the treatment of choice is of great importance, as the patient usually presents physiological changes resulting from aging and more brittle bones and a reduced osteogenic potential, which makes the surgical approach difficult. However, the patient's age, conditions and amount of bone and soft tissue must be taken into consideration for the management of these fractures. However, it is noteworthy that aging has no contraindication, it only requires special conditions that must be considered. In this sense, when there is an opportunity for technological devices, such as biomodels that significantly contribute to maxillofacial surgical procedures, it provides greater predictability of results, as well as reduced surgical time.

Leukocyte-platelet rich fibrin on the treatment of a large paradental cyst: a novel regenerative approach.

Leukocyte-platelet rich fibrin (PRF) is an autologous biomaterial formed by platelets, cytokines, growth factors and cells imprisoned on a fibrin mesh, produced according to Choukroun's protocol. The aim of the present article was to report the use of PRF, associated with a bone substitute, on the regenerative treatment of a large bone defect resulting from the enucleation of a paradental cyst involving the posterior mandible. The treatment resulted in the maintenance of the bone volume, and radiographic evaluation showed new bone formation after 40 days, suggesting an osteogenic and osteoinductive effect. Also, the current literature was reviewed.

Updates in Management of Craniomaxillofacial Gunshot Wounds and Reconstruction of the Mandible.

This article includes updates in the management of mandibular trauma and reconstruction as they relate to maxillomandibular fixation screws, custom hardware, virtual surgical planning, and protocols for use of computer-aided surgery and navigation when managing composite defects from gunshot injuries to the face.

Proposal for a preventive protocol for medication-related osteonecrosis of the jaw / Propuesta de protocolo preventivo para la osteonecrosis de la mandíbula relacionada con medicamentos

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse reaction experienced by somepatients exposed to certain drugs (antiresorptives such as bisphosphonates or denosumab, and antiangiogenic drugs).From a review of the literature it appears that there is no uniform criterion when selecting preventive measures;these vary according to author. Likewise, the measures recommended are usually general, so that in few cases theyresult in specific actions to be applied depending on the different variables involved such as the type of drug used,the duration of its application, the underlying pathology, the presence or absence of risk factors, etc. The aim of thisstudy has been to design a preventive protocol which can be easily applied in any clinic or by any dental care service.Material and Methods: We undertook an exhaustive literature review to find any articles related to the topic of study,namely, preventive measures for medication-related osteonecrosis of the jaw, on the one hand generically and on theother focusing on dental implant treatment. The most part the criteria of the Preferred Reporting Items for SystematicReviews and Meta-Analyses (PRISMA) guidelines were followed. From 3946 items, we selected a total of 21 items.Results: From the analysis of the selected articles, several protocols have been developed that are easy to applyin a dental clinic.: Protocol 1. Before starting treatment with antiresorptives (Patients who are going to be treatedfor osteoporosis / Patients who are going to be treated for cancer). Protocol 2. Once treatment is initiated withantiresorptives (Patients being treated for osteoporosis / Patients being treated for cancer)...(AU)

Local administration of HMGB-1 promotes bone regeneration on the critical-sized mandibular defects in rabbits.

Reconstruction of a critical-sized osseous defect is challenging in maxillofacial surgery. Despite novel treatments and advances in supportive therapies, severe complications including infection, nonunion, and malunion can still occur. Here, we aimed to assess the use of a beta-tricalcium phosphate (ß-TCP) scaffold loaded with high mobility group box-1 protein (HMGB-1) as a novel critical-sized bone defect treatment in rabbits. The study was performed on 15 specific pathogen-free New Zealand rabbits divided into three groups: Group A had an osseous defect filled with a ß-TCP scaffold loaded with phosphate-buffered saline (PBS) (100 µL/scaffold), the defect in group B was filled with recombinant human bone morphogenetic protein 2 (rhBMP-2) (10 µg/100 µL), and the defect in group C was loaded with HMGB-1 (10 µg/100 µL). Micro-computed tomography (CT) examination demonstrated that group C (HMGB-1) showed the highest new bone volume ratio, with a mean value of 66.5%, followed by the group B (rhBMP-2) (31.0%), and group A (Control) (7.1%). Histological examination of the HMGB-1 treated group showed a vast area covered by lamellar and woven bone surrounding the ß-TCP granule remnants. These results suggest that HMGB-1 could be an effective alternative molecule for bone regeneration in critical-sized mandibular bone defects.

Effectiveness of Prophylactic Preoperative Antibiotics in Mandible Fracture Repair: A National Database Study.

OBJECTIVE: This is the first database study to assess the effectiveness of prophylactic preoperative antibiotics (PPAs) in mandible fracture repair. STUDY DESIGN: Retrospective cohort. SETTING: Database study using US inpatient and outpatient insurance claims submitted from July 2006 to March 2015. METHODS: The IBM MarketScan Commercial Database was queried for adults aged 18 to 64 years who had undergone first-time mandible fracture repair according to Current Procedural Terminology codes for open and closed repair. Primary outcomes included surgical revision, local infection, and osteomyelitis. Rates were compared between cohorts based on whether or not patients had filled antibiotic prescriptions during the preoperative period alone. The effects of drug abuse and type of mandible repair (open vs closed) were explored. Multivariate Poisson regression models were used to calculate adjusted relative risk estimates, and 95% CIs were used to determine statistically significant differences. RESULTS: A total of 2676 patients were included, with 847 (31.7%) filling PPAs and 1829 (68.3%) filling no antibiotics. Rates were 38.9% for revision, 5.8% for local infection, and 2.1% for osteomyelitis. After multivariate analysis, exposure to PPAs was not associated with surgical revision (adjusted relative risk, 1.04; 95% CI, 0.94-1.15), local infection (1.16; 0.82-1.64), or osteomyelitis (1.21; 0.68-2.14). Patients were more likely to fill PPAs if they underwent open repair (35.3%) versus closed (26.6%) (proportion difference, 8.7%; 95% CI, 5.2%-12.2%), but exposure to antibiotics did not predict outcomes on subgroup analysis. CONCLUSION: PPAs do not improve mandible repair outcomes, regardless of repair type.

Comparative analysis of plasma-derived albumin scaffold, alveolar osteoblasts and synthetic membrane in critical mandibular bone defects: An experimental study on rats.

Repair of bone deficiencies in the craniofacial skeleton remains a challenging clinical problem. The aim of this study was to evaluate and compare the effects of a plasma-derived albumin scaffold, alveolar osteoblasts and synthetic membrane implanted into experimental mandibular defects. Bilateral mandibular defects were created in twelve immunodeficient rats. The bone defect was filled with serum scaffold alone in left sides and scaffold combined with human alveolar osteoblast in right side defects. Implanted areas were closed directly in Group 1 (n = 6) and covered by a resorbable polyglycolic-polylactic acid membrane in Group 2 (n = 6). Bone regeneration was determined at 12 weeks as measured by and exhaustive multiplanar computed tomography analysis and histological examination. No significant differences in bone density were observed between defects transplanted with scaffold alone or scaffold seeded with osteoblasts. The use of membrane did not result in a determining factor in the grade of bone regeneration between Groups 1 and 2. Based on these results, it could be concluded that the albumin scaffold alone has osteoinductive capacity but presence of seeded ostogenic cells accelerates defect repair without being significantly influenced by covering the defect with a resorbable membrane.

Effects of exogenous nerve growth factor on the expression of BMP-9 and VEGF in the healing of rabbit mandible fracture with local nerve injury.

BACKGROUND: Mandibular fracture healing is a complex process involving nerves and growth factors. Nerve growth factor (NGF) not only facilitates the maintenance of sympathetic neurite growth but also stimulates other growth factors that can promote the essential osteogenesis and angiogenesis for fracture healing. Therefore, it is necessary to analyze the combined effects of NGF, bone morphogenic protein-9 (BMP-9), and vascular endothelial growth factor (VEGF) to accelerate the healing of mandible fractures. METHODS: The models of mandible fracture with local nerve injury established in 48 rabbits were randomly divided into nerve growth factor group (NGF group), gelatin sponge group (GS group), blank group, and intact group. The recovery of nerve reflex was assessed by observing the number of rabbits with lower lip responses to acupuncture. The fracture healing was observed with visual and CBCT, and then callus tissues from the mandibular fracture area were collected for hematoxylin and eosin (HE) staining observation, and the expression of BMP-9 and VEGF in callus at different stages was detected by quantitative real-time PCR (qRT-PCR). RESULTS: Needling reaction in the lower lip showed the number of animals with nerve reflex recovery was significantly higher in the NGF group than that in the GS and blank groups at the 2nd and 4th weeks after the operation. The combined results of macroscopic observation, CBCT examination, and histological analysis showed that a large number of osteoblasts and some vascular endothelial cells were found around the trabecular bone in the NGF group and the amount of callus formation and reconstruction was better than that in the GS group at the 2nd week after the operation. The qRT-PCR results indicated that the expression levels of BMP-9 and VEGF in the four groups reached the highest values at the 2nd week, while the expression levels of both in the NGF group were significantly higher than that in the GS group. CONCLUSION: The exogenous NGF could accelerate the healing of mandible fractures. This work will provide a new foundation and theoretical basis for clarifying the mechanism of fracture healing, thereby promoting fracture healing and reducing the disability rate of patients.

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.

Concordancia clínica e histopatológica de lesiones óseas orales. Estudio retrospectivo / Clinical and Histopathological Concordance of oral Bone Lesions. Retrospective Study

Resumen Las lesiones óseas de los maxilares tienen su origen a partir de estructuras odontogénicas y no odontogénicas. Pueden ser benignas o malignas, asintomáticas, pueden ubicarse alrededor de la raíz del diente, alrededor de la corona y en el área interradicular o pueden no tener relación con los dientes. OBJETIVO: determinar la frecuencia de las diferentes lesiones óseas y la concordancia existente entre el diagnóstico clínico e histopatológico, en el internado clínico de la Facultad de Odontología de la Universidad de Costa Rica (UCR). METODOLOGÍA: estudio retrospectivo de lesiones óseas recuperados del archivo de biopsias de la Facultad de Odontología de la UCR del 2008 a 2015. Se evaluaron y analizaron de forma descriptiva y cualitativa información sobre el sexo, edad, localización de la lesión, diagnóstico clínico y diagnóstico histopatológico. La concordancia entre el diagnóstico clínico e histopatológico fue verificada mediante el test Kappa. RESULTADOS: los 77 casos de lesiones óseas orales afectaron preferentemente a los hombres 53.8 % (n=41), el promedio de edad fue 34.7±19.6 años y con lesiones predominantemente localizadas en mandíbula posterior 36.4 % (n=28) y maxila anterior 35.1% (n=27). Los quistes odontogénicos (QO) 42.9% (n=33), diagnóstico no específico o sin clasificación 28.6% (n=22) y lesiones inflamatorias de origen pulpar y periapical 14.2% (n=11). Los TO representaron el 7.8% (n=6) de las lesiones. Las cuatro lesiones más predominantes fueron el quiste radicular, diagnóstico inespecífico, quiste dentígero y granuloma periapical. La concordancia con la primera hipótesis diagnóstica se presentó en 24 (31.2%) casos, el valor de Kappa fue de 0.274 (concordancia discreta) y un 20,8 % sin diagnóstico clínico solo una descripción de la lesión. CONCLUSIONES: Los QO fueron los predominantes; siendo en forma individual el quiste radicular la lesión más frecuente. La concordancia clínica e histopatológica fue discreta.

Abstract Bone lesions of the jaws have their origin from odontogenic and non- odontogenic structures. They can be benign or malignant, asymptomatic, they can be located around the root of the tooth, around the crown and in the interradicular area or they may not be related to the teeth. OBJECTIVE: to determine the frequency of the different bone lesions and the concordance between the clinical and histopathological diagnosis, in the clinical internship of the Faculty of Dentistry of the University of Costa Rica (UCR). METHODOLOGY: retrospective study of bone lesions recovered from the biopsy archive of the Faculty of Dentistry of the UCR from 2008 to 2015. Information on sex, age, location of the lesion, clinical diagnosis and diagnosis were evaluated and described. The agreement between the clinical and histopathological diagnosis was verified by the Kappa test. RESULTS: The 77 cases of oral bone lesions preferentially affected men 53.8% (n=41), the average age was 34.7 years (s.d.±19.6) and with lesions predominantly located in the posterior jaw 36.4% (n=28) and anterior maxilla 35.1% (n=27). Odontogenic cysts (OC) 42.9% (n=33), non-specific or unclassified diagnosis 28.6% (n=22) and inflammatory lesions of pulp and periapical origin 14.2% (n=11). TOs accounted for 7.8% (n=6) of the lesions. The four most predominant lesions were the radicular cyst, nonspecific diagnosis, dentigerous cyst and periapical granuloma. Concordance with the first diagnostic hypothesis was presented in 24 (31.2%) cases, the value of Kappa was 0.274 (discrete concordance) and 20.8% without clinical diagnosis only a description of the lesion. CONCLUSIONS: The OC were the predominant; being individually the radicular cyst the most frequent lesion. The clinical and histopathological concordance was discrete.

Reconstruction Of Segmental Mandibular Loss With Vascularized Free Fibula Flapsn.

BACKGROUND: Various methods for mandibular reconstruction have been demonstrated in literature from autogenous bone graft to free flaps and more recently tissue engineered materials. We share our experience of mandibular reconstruction with free fibular flap and evaluate its efficiency as a viable option for mandibular reconstruction. METHODS: It was a cross-sectional study, conducted at Plastic surgery department combined military hospital, Rawalpindi. Study was carried out over a period of two years from November 2016 to November 2018. The data of demography, mode of presentation, pattern of reconstruction and procedural complications of the patients who underwent free fibula flap for segmental mandibular loss, were collected and analysed. Patients with segmental loss of mandible ranging from 6 to 15 cm and those who could sustain surgery were included in the study, while the patients with metastatic malignancy and recurrent disease were excluded from the study. Each patient was called for first follow up after 2 weeks then subsequent follow up after 1 month. Descriptive statistics were done with the help of SPSS-20. RESULTS: A total of 57 patients with segmental mandibular loss treated with free fibula flap, fulfilling inclusion and exclusion criteria were included in this study. Thirtyeight patients were male while 19 were female with mean age 56±3 years. Cause of mandibular loss was malignancy in 52 (91.2%), trauma in 3 (5.2%), and ameloblastoma in 2 (3.5%) patients. Major complications like flap failure was seen in one (1.75%), bone exposure in 1 (1.75%) and recurrence was observed in 1 (1.75%) patient. Minor complications like hematoma, wound dehiscence and oro-cutaneous fistula were seen in 2, 1 and 3 patients respectively. CONCLUSIONS: Free fibular flap shows good functional results with a high degree of consistency, and acceptable complications rate, so it should be the first choice for mandibular reconstruction.

Design and Fabrication of Implants for Mandibular and Craniofacial Defects Using Different Medical-Additive Manufacturing Technologies: A Review.

Mandibular and craniofacial bone defects can be caused by trauma, inflammatory disease, and benign or malignant tumors. Patients with bone defects suffer from problems with aesthetics, speech, and mastication, resulting in the need for implants. Conventional methods do not always provide satisfactory results. Most of the techniques proposed by researchers in the field of biomedical engineering use reverse engineering, computer-aided design (CAD), and additive manufacturing (AM), whose implementation can improve the outcomes of reconstructive surgeries. Several literature reviews on this particular topic have been conducted. However, they provide mostly overviews of AM technologies for general biomedical devices. This paper summarizes the use of existing medical AM techniques for the design and fabrication of mandibular and craniofacial implants, and then discusses their advantages and disadvantages in terms of accuracy, costs, energy consumption, and production rate. The aim of this study is to present a comparative review of the most commonly used AM technologies to aid researchers in selecting the best possible AM technologies for medical use. Studies included in this review contain CAD designs of mandibular or cranial implants, as well as their fabrication using AM technologies. Special attention is paid to PolyJet technology, because of its high accuracy, and economical efficiency.

Teriparatide (recombinant parathyroid hormone 1-34) enhances bone allograft integration in a clinically relevant pig model of segmental mandibulectomy.

Massive craniofacial bone loss poses a clinical challenge to maxillofacial surgeons. Structural bone allografts are readily available at tissue banks but are rarely used due to a high failure rate. Previous studies showed that intermittent administration of recombinant parathyroid hormone (rPTH) enhanced integration of allografts in a murine model of calvarial bone defect. To evaluate its translational potential, the hypothesis that rPTH would enhance healing of a mandibular allograft in a clinically relevant large animal model of mandibulectomy was tested. Porcine bone allografts were implanted into a 5-cm-long continuous mandible bone defect in six adult Yucatan minipigs, which were randomized to daily intramuscular injections of rPTH (1.75 µg/kg) and placebo (n = 3). Blood tests were performed on Day 56 preoperation, Day 0 and on Day 56 postoperation. Eight weeks after the surgery, bone healing was analyzed using high-resolution X-ray imaging (Faxitron and micro computed tomography [CT]) and three-point bending biomechanical testing. The results showed a significant 2.6-fold rPTH-induced increase in bone formation (p = 0.02). Biomechanically, the yield failure properties of the healed mandibles were significantly higher in the rPTH group (yield load: p < 0.05; energy to yield: p < 0.01), and the post-yield displacement and energy were higher in the placebo group (p < 0.05), suggesting increased mineralized integration of the allograft in the rPTH group. In contrast to similar rPTH therapy studies in dogs, no signs of hypercalcemia, hyperphosphatemia, or inflammation were detected. Taken together, we provide initial evidence that rPTH treatment enhances mandibular allograft healing in a clinically relevant large animal model.

Epidemiological analysis of 736 patients who suffered facial trauma in Brazil / Análisis epidemiológico de 736 pacientes que sufrieron trauma facial en Brasil

The etiology of facial fractures is directly related to the studied country, varying according to the socioeconomic, cultural condition of the population, besides the period of investigation. The objective of the present study is to evaluate the epidemiological characteristics of the prevalence, treatment modalities and complications rates of maxillofacial fractures in a hospital in the state of Espírito Santo, over a period of 5 years. A total of 428 patients presented a facial fracture, with a prevalence of males (436), with a mean age of 40 years. Regarding the number of fractures, 291 individuals suffered fractures only in the fixed skeleton, 97 only in the mandible, and 48 suffered fractures in both fixed and mandibular skeletons. The predominant anatomical site in fixed skeletal fractures was zygomatic complex (56.6 %), orbit (31.9 %) and nose (29.2 %); while in the mandible the condyle (33.8 %), body (17.9 %) and angle (13.1 %). The frequent etiology was falls, physical aggression, sports accidents. Regarding the type of treatment, in fixed skeleton 192 fractures were treated conservatively and 303 by surgery. Already in the mandible, the numbers were 43 and 143, respectively. In addition, 24 patients progressed with some type of complication in one or more operated sites. It is worth mentioning that epidemiological assessments provide important support in the creation of legislation in the attempt to reduce important for the establishment of clinical and research priorities, since risk factors and patterns of presentation can be identified. Accordingly in an attempt to reduce these rates.

La etiología de las fracturas faciales está directamente relacionada con el país estudiado, variando según la condición socioeconómica y cultural de la población, además del período de investigación. El objetivo del presente estudio fue evaluar las características epidemiológicas de la prevalencia, las modalidades de tratamiento y las tasas de complicaciones de las fracturas maxilofaciales en un hospital en el estado de Espírito Santo, durante un período de 5 años. Un total de 428 pacientes presentaron fractura facial, con una prevalencia de varones (436), con una edad media de 40 años. Con respecto al número de fracturas, 291 individuos sufrieron fracturas solo en el esqueleto fijo, 97 solo en la mandíbula y 48 sufrieron fracturas tanto en el esqueleto fijo como en el mandibular. El sitio anatómico predominante en las fracturas esqueléticas fijas fue el complejo cigomático (56,6 %), la órbita (31,9 %) y la nariz (29,2 %); mientras que en la mandíbula el cóndilo (33,8 %), el cuerpo (17,9 %) y el ángulo (13,1 %). La etiología frecuente fue caídas, agresión física, accidentes deportivos. En cuanto al tipo de tratamiento, en el esqueleto fijo se trataron 192 fracturas de forma conservadora y 303 mediante cirugía. Ya en la mandíbula, los números eran 43 y 143, respectivamente. Además, 24 pacientes progresaron con algún tipo de complicación en uno o más sitios operados. Cabe mencionar que las evaluaciones epidemiológicas brindan un apoyo importante en la creación de legislación en estos casos, para establecer prioridades clínicas y de investigación, debido a que se pueden identificar factores de riesgo y patrones de presentación. En consecuencia, en un intento de reducir estas tasas.

Human amnion-derived mesenchymal stem cells promote osteogenic differentiation of human bone marrow mesenchymal stem cells via H19/miR-675/APC axis.

Bone volume inadequacy is an emerging clinical problem impairing the feasibility and longevity of dental implants. Human bone marrow mesenchymal stem cells (HBMSCs) have been widely used in bone remodeling and regeneration. This study examined the effect of long noncoding RNAs (lncRNAs)-H19 on the human amnion-derived mesenchymal stem cells (HAMSCs)-droved osteogenesis in HBMSCs. HAMSCs and HBMSCs were isolated from abandoned amniotic membrane samples and bone marrow. The coculture system was conducted using transwells, and H19 level was measured by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). The mechanism was further verified. We here discovered that osteogenesis of HBMSCs was induced by HAMSCs, while H19 level in HAMSCs was increased during coculturing. H19 had no significant effect on the proliferative behaviors of HBMSCs, while its overexpression of H19 in HAMSCs led to the upregulated osteogenesis of HBMSCs in vivo and in vitro; whereas its knockdown reversed these effects. Mechanistically, H19 promoted miR-675 expression and contributed to the competitively bounding of miR-675 and Adenomatous polyposis coli (APC), thus significantly activating the Wnt/ß-catenin pathway. The results suggested that HAMSCs promote osteogenic differentiation of HBMSCs via H19/miR-675/APC pathway, and supply a potential target for the therapeutic treatment of bone-destructive diseases.

Preauricular Swelling Mimicking a Tumour: Dissolution of Mandibular Capitulum Following Trauma in a 15-Year Old Child.

AIM: The report is about diagnosis, therapy, and follow-up of a 15-year old boy, who experienced facial swelling and impaired mouth opening after a sport accident. CASE REPORT: Diagnosis of mandibular damage was delayed due to inadequate clinical investigation and radiography after trauma and only became clear after a parotid swelling occurred sometime later resulting from the dissolution of the upper part of the articular process. Follow-up control over a period of three years showed a partial restoration of the articular process but some inhibition of mouth opening combined with slight deviation of the mandible to the affected side remained over the years. CONCLUSION: This report reminds us that parotid swelling can be the result of mandibular trauma without a recent history of physical injury to this region. Therefore, the basic standards of radiologic diagnosis should be maintained and the limited restoring capacity of the condylar process in adolescence should be acknowledged.

Aesthetic management of a fractured mandibular central incisor with two canals using fibre post.

Mandibular incisors show variations in their root canal anatomy from regular pattern in some cases. Magnification plays a vital role to identify those unusual canal morphologies. A certain modification in access cavity preparation is required to locate those extra canals. Not only the functional restoration but also aesthetic harmony should be restored while treating anterior teeth. In these cases, post space preparation should be done with extra care to prevent vertical root fracture. This case report illustrates the importance of proper radiograph and magnification in the successful identification and management of complex canal systems in mandibular incisors.