Uso de enxerto autógeno não vascularizado associado à Oxigenoterapia Hiperbárica nas reconstruções mandibulares

Reconstruction of mandibular defects caused by tumor resection is a challenge for the maxillofacial surgeon. The size of the bone defect, the type of graft used (vascularized or non-vascularized), the soft tissue conditions of the recipient area, are factors that directly influence the success of the treatment. The use of vascularized bone grafts presents a good prognosis for the treatment of large mandibular defects; however, they present some difficulties, since it requires a team of microvascular surgery, longer hospitalization time and high costs. An alternative is the use of nonvascularized grafts such as those of iliac crest, however, due to the lack of vascularization, neoangiogenesis is sometimes difficult, and may result in reduction of the incorporated graft volume or even in the non-union of the grafts. Several studies have reported the effects of neoangiogenesis and neo-osteogenesis using Hyperbaric Oxigen Therapy (HBO). Hyperbaric oxygen therapy consists of administering pure oxygen at an atmospheric pressure of 2.5 ATA (absolute atmosphere). The patient is placed in a camera where they breathe pure oxygen for a period of 90 minutes. The objective of this research is to evaluate the effects of hyperbaric oxygen therapy on autogenous bone grafts used for mandibular reconstruction in patients affected by bone neoplasms, through computerized microtomographies and histologic analysis of biopsies from each patient. This study was divided into four specific objectives; Specific objective 1: To evaluate the effects of hyperbaric oxygen therapy on the remodeling of autogenous bone grafts obtained from iliac crest and used for the reconstruction of extensive mandibular defects of patients submitted to resection, through computerized microtomography, immunohistochemistry and histologic analysis of Trephined bone tissue; Specific objective 2: The objective of this study was to describe a series of cases of patients submitted to the installation of implants in provisional immediate load in mandible reconstructed with iliac crest grafts, discussing the clinical aspects and the feasibility to apply this type of treatment; Specific objective 3: The objective of this study was to describe a treatment protocol for patients with odontogenic tumors undergoing mandibulectomy and subsequent mandibular reconstruction with nonvascularized iliac crest grafting associated with hyperbaric oxygen therapy; Specific objective 4: The objective of this study was to report a clinical case with a mandibular tumor submitted to bone resection, mandibular reconstruction using free iliac crest grafting associated with hyperbaric oxygen therapy, followed by the installation of implants with immediate loading.Tese (Doutorado)A reconstrução dos defeitos mandibulares causados por ressecção de tumores é um desafio para o cirurgião maxilofacial. O tamanho do defeito ósseo, o tipo de enxerto utilizado (vascularizado ou não vascularizado), as condições do tecido mole da área receptora, são fatores que influenciam diretamente no sucesso do tratamento. A utilização de enxertos ósseos vascularizados apresenta bom prognóstico para o tratamento dos defeitos mandibulares de grandes dimensões, no entanto, apresentam algumas dificuldades, pois exige uma equipe de cirurgia microvascular, maior tempo de internação e custos elevados. Uma alternativa é a utilização de enxertos não vascularizados como os de crista ilíaca, no entanto, devido à falta de vascularização, a neoangiogênese por vezes é dificultada, podendo resultar em redução do volume do enxerto incorporado ou ate mesmo na não união dos enxertos. Diversos estudos têm reportado os efeitos de neoangiogênese e neo- osteogênese a partir da Oxigenoterapia Hipebárica (OHB). A oxigenoterapia hiperbárica consiste na administração de oxigênio puro a uma pressão atmosférica de 2,5 ATA (atmosfera absoluta). O paciente é colocado numa câmera onde respira oxigênio puro por um período de 90 minutos. Os objetivos desta pesquisa foram avaliar os efeitos da oxigenoterapia hiperbárica sobre grandes enxertos ósseos autógenos usados para reconstrução mandibular em pacientes acometidos por neoplasias ósseas, através de microtomografias computadorizadas e análise histológica de biópsias provenientes de cada paciente. Este estudo foi dividido em quatro objetivos específicos; objetivo específico 1: Avaliar os efeitos da oxigenoterapia hiperbárica sobre a remodelação de enxertos ósseos autógenos obtidos de crista ilíaca e utilizados para a reconstrução de extensos defeitos mandibulares de pacientes submetidos à resseção, através de análise por microtomografia computadorizada, e análises histológicas de amostras do tecido ósseo trefinado; objetivo específico 2: O objetivo deste trabalho foi descrever uma série de casos de pacientes submetidos à instalação de implantes em carga imediata provisória em mandíbulas reconstruídas com enxertos de crista ilíaca, discutindo os aspectos clínicos e a viabilidade para aplicação deste tipo de tratamento; objetivo específico 3: O objetivo deste estudo foi descrever um protocolo de tratamento para pacientes portadores de tumores odontogênicos submetidos à mandibulectomia e posterior reconstrução mandibular com enxerto não vascularizado de crista ilíaca associado à Oxigenoterapia hiperbárica; objetivo específico 4: O objetivo deste estudo foi relatar um caso clínico portador de tumor mandibular submetido à ressecção óssea, de reconstrução mandibular utilizando enxerto livre de crista ilíaca associado à Oxigenoterapia hiperbárica, seguida de instalação de implantes com carregamento imediato

Drilling dimension effects in early stages of osseointegration and implant stability in a canine model

Background: This study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols. Material and Methods: Forty dental implants (4.1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrilling-group) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent. Results: The insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs ( p <0.001). No significant differences were de - tected between implant designs for each drilling technique ( p >0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique ( p <0.03) only, but not for those placed in the 3.75 mm drilling sites ( p >0.32). Conclusions: Despite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevaile

Long-term follow-up of a case of multicystic ameloblastoma treated with curettage: case report / Acompanhamento a longo prazo de um caso de ameloblastoma multi-cístico tratado com curetagem: relato de caso

The conventional or multicystic solid ameloblastoma is the most common type with the majority of cases affecting the posterior region of the mandible and occurring between the third and fourth decades of life. The present study aims to report a case of multicystic ameloblastoma in which treatment by means of curettage was chosen and no evidence of recurrence was noted over 7 years of follow-up. Although the literature indicates aggressive surgical therapy as the best form of treatment for multicystic ameloblastoma, factors such as the clinical, radiographic and histopathological aspects of the lesion, patient age, postoperative morbidity, possibilities for aesthetic and functional changes must be evaluated together during treatment planning. In some cases, as in the report presented, conservative therapies such as aggressive curettage of the lesion can be effective in the long term, with no recurrence of the lesion and providing quality of life to the patient

Concepts in Management of Advanced Craniomaxillofacial Injuries

The authors present a sequencing assessment of patients who were victims of traumatic deformities of the craniomaxillofacial complex. To that end, the authors highlight the eight steps worthy of particular attention, namely (1) clinical history and photographic documentation; (2) clinical assessment; (3) assessment through image and diagnostic exams; (4) planning of the treatment; (5) bases for the three-dimensional reconstruction of the face; (6) reconstruction sequence of multiple facial fractures; (7) support measures; and (8) complications. The proposed assessment sequence allows the oral and maxillofacial surgeon or craniomaxillofacial surgeon to assess the degree of impairment of traumatic deformity, which contributes in a significant way to the decision-making process of the treatment

Avaliação in vitro e in vivo do efeito da cobertura de biossilicato aplicado sobre a superfície de titânio durante a osseointegração

The aim of this study was to evaluate in vivo, using beagle dog model, the effect of incorporation of biossilicato (highly bioactive glass) on the process of osteogenesis through the bone-implant contact and evaluate in vitro using model cell culture, the influence of the incorporation of biossilicato the rough surface on titanium discs adhesion and cell viability. The implants used for the in vivo study (n = 32) were 10 mm long and 3.5 mm in diameter and having surface treated with double etching. Half of these implants (n = 16) received the incorporation of biossilicato on its surface roughened (Group AA + BIO), while the other half only with rough surfaces (n = 16) was used as control group (group AA). The in vitro assays used commercially pure titanium disks grade IV 8.0 mm diameter by 4.0 mm in height with the same characteristics of implants used in in vivo tests. The assessment from scanning electron microscopy revealed that about 25% of the implant surface was covered by highly bioactive glass so homogeneous. Surface double etching associated biossilicato (AA + BIO) also showed a lower contact angle (α10s = 5.3 ± 1.7 °) compared with the AA surface. The adhesion test used to verify the stability of highly bioactive glass particles embedded on both disks as implants, demonstrate adequate stability, with no disruption of the interface bond between the particle and the surface of titanium. The results of in vitro through cell culture, showed that the percentage of viable cells adhered to the roughened surface covered with biossilicato (AA + BIO) was significantly lower (p <0.001) than the group with surface - AA (P = 0.004). The cell viability test showed that there were no statistically significant differences between groups AA and AA + BIO in any of the periods analyzed. The histomorphological results suggest that the initial repair is not affected by surface AA + BIO compared with the surface only with double etching.Mestre em OdontologiaO objetivo deste estudo foi avaliar in vivo, utilizando modelo de implantação em mandíbula de cães, o efeito da incorporação de biossilicato (vidro bioativo) sobre o processo de neosteogênese por meio do contato osso-implante e, avaliar in vitro, utilizando modelo de cultura de células, a influência da incorporação do biossilicato na superfície rugosa de discos de titânio sobre a adesão e viabilidade celular. Os implantes usados para o estudo in vivo (n=32) eram de 10 mm de comprimento e 3,5 mm de diâmetro e conexão cone Morse apresentando superfície tratada com duplo ataque ácido. Metade desses implantes (n=16) recebeu a incorporação de biossilicato em sua superfície rugosa (Grupo AA+BIO), enquanto a outra metade apenas com superfícies rugosa (n=16) foi utilizada como grupo controle (Grupo AA). As análises in vitro utilizaram discos de titânio comercialmente puro grau IV de 8,0 mm de diâmetro por 4,0 mm de altura com as mesmas características dos implantes utilizados nos testes in vivo. A avaliação a partir de microscopia eletrônica de varredura revelou que cerca de aproximadamente 25% da superfície dos implantes foi coberta pelo vidro bioativo de forma homogenea. Superfície com duplo ataque ácido associado ao biossilicato (AA+BIO) também apresentou um menor ângulo de contato (α10s=5,3±1,7º) quando comparada com a superfície AA. Os testes de adesão utilizados para verificar a estabilidade das partículas do vidro altamente bioativo incorporado tanto aos discos quanto aos implantes, demostraram uma adequada estabilidade, não havendo rompimento da interface de união entre a partícula e a superfície de titânio. Os resultados in vitro, por meio de cultura de células, demostraram que a percentagem de células viáveis aderidas à superfície rugosa coberta com biossilicato (AA+BIO) foi significativamente menor (p <0,001) do que o grupo com superfície - AA (P = 0,004). O teste de viabilidade celular demonstrou que não houve diferenças estatisticamente significativas entre os grupos AA e AA+BIO em nenhum dos períodos analisados. Os resultados histomorfológicos sugerem que a fase inicial do reparo não é afetada pela superfície com AA+BIO quando comparada com a superfície apenas com duplo ataque ácido

Recurrent condylar luxation after third molar extraction: an uncommon condition treated by eminectomy

INTRODUCTION: Extraction of third molars can rarely provoke post-operative complications, such as temporomandibular joint disorders (TMDs). OBJECTIVE: Although the literature presents a series of discussions of the clinical evidence related to this subject, in this report, we present an uncommon case of a patient submitted for the extraction of third molars who presented, in postoperative monitoring, with recurrent bilateral condylar luxation. CONCLUSION: Due to this critical condition, the patient was successfully treated by bilateral eminectomy

Failure of dental implants in cemento-osseous dysplasia: a critical analysis of a case

Introduction: Osseointegrated dental implants have been routinely used in oral rehabilitation. Patients with dysplastic bone diseases represent a particular challenge for oral rehabilitation with dental implants. Nevertheless, the installation of implants in patients with cemento-osseous dysplasia (COD) has been reported with apparent success. Objective: In this paper, we present a case of a patient with COD in which a dental implant had been installed and lost six months later. In this regard, we analyzed pertinent aspects of the indications for dental implants in patients with COD considering the pathogenesis, dysplastic nature, and behavior of the disease. Conclusion: The present case report illustrates that COD can be considered a limiting factor in the recommendation for a dental implant. Because of this, it is imperative to inform the patient about the risks of surgically manipulating the diseased bone

Oral Manifestations of Secondary Syphilis

Known as “the great imitator,” secondary syphilis may clinically manifest itself in myriad ways, involving different organs including the oral mucosa, and mimicking, both clinically and histologically, several diseases, thereby making diagnosis a challenge for clinicians. We highlight the clinical aspects of oral manifestation in 7 patients with secondary syphilis. Clinicians should consider secondary syphilis in the differential diagnosis of ulcerative and/or white oral lesions