Análise comparativa entre técnicas cirúrgicas de enxertia óssea em reabilitação de maxila atrófica: transplante celular odontológico (TCO) e técnica convencional de enxertia óssea ­ relato de caso clínico / Comparative analysis between surgical techniques of bone grafting in rehabilitation of atrophic maxilla: dental cell transplantation (OCT) and conventional bone grafting technique - a case report

A reabilitação de maxila atrófica se apresenta ainda nos dias de hoje como um desafio anatômico/fisiológico para os profissionais da área odontológica que visam buscar a instalação de implantes para futuras reabilitações protéticas, tendo em vista o grau de dificuldade de reconstituição do rebordo alveolar perdido. Com o intuito de reabilitar essas maxilas frente às adversidades, diferentes técnicas são propostas tais como enxertos ósseos autógenos, homógenos, substitutos ósseos alógenos, xenógenos e aloplásticos e suas respectivas técnicas. O objetivo deste trabalho foi apresentar um relato de caso clínico, no qual duas técnicas de reconstituição de rebordo alveolar de hemi-arco foram realizadas na mesma maxila utilizando biomaterial em bloco, visando comparar os resultados histológicos e clínicos. Após 5 meses da realização da enxertia, foi coletado material dos enxertos alveolares bilateralmente utilizando-se brocas trefinas para estudo histológico. Através da metodologia empregada, pode-se observar maior formação de estrutura óssea no lado em que foi praticada a metodologia transplantes celular odontológico (TCO), que preconiza a associação de sangue medular mandibular ao biomaterial, em relação a técnica contralateral em que utilizou a metodologia convencional, que preconiza a associação ao biomaterial do sangue periférico. Pode-se observar através da metodologia empregada que a utilização de biomateriais potencializados com sangue medular mandibular apresentou maior crescimento de estrutura óssea, incrementando em torno de 35% a mais na neoformação.de osso vital.

The rehabilitation of atrophic maxilla is still presented today as an anatomical/physiological challenge for professionals in the dental field who aim to seek the installation of implants for future prosthetic rehabilitations, in view of the degree of difficulty in reconstituting the lost alveolar ridge. In order to rehabilitate these jaws in the face of adversity, different techniques are proposed such as autogenous, homogenous bone grafts, allogeneic, xenogenous and alloplastic bone substitutes and their respective techniques. The aim of this study was to present a clinical case report, in which two hemi-arch alveolar ridge reconstruction techniques were performed in the same maxilla using biomaterial en bloc, in order to compare the histological and clinical results. After 5 months of grafting, material was collected from the alveolar grafts bilaterally using trephine burs for histological study. Through the used methodology, it was possible to see greater bone formation of structure on the side in which the dental cell transplantation (TCO) methodology was practiced, which advocates the association of mandibular medullary blood to the biomaterial, in relation to the contralateral technique in which the methodology was used conventional method, which advocates the association with peripheral blood biomaterial. It can be observed through the used methodology that the use of biomaterials potentiated with mandibular medullary blood showed greater growth of bone structure, increasing around 35% more in the neoformation of vital bone.

Histologic and Histometric Analysis of Bone Repair at the Site of Mandibular Body Osteotomy and at the Bone-Screw Interface After Using a Biodegradable 2.0-mm Internal Fixation System.

The aim of the study was to evaluate histologically and histometrically the bone repair at the mandibular body osteotomy and at the bone-screw interface after using a biodegradable 2.0-mm internal fixation system. Six dogs were subjected to an osteotomy in the mandibular body, which was stabilized by applying a fixation device manufactured with poly-L-DL-lactic acid (70:30). The dogs were euthanized at 2 and 18 weeks. Each screw was sectioned along its long axis, and the osteotomy sites were divided into 3 parts: the upper part was labeled the tension third (TT); the lower part, compression third (CT); and the part between the TT and CT, intermediary third (IT). Histologic analysis showed areas of direct contact between the screw surface and the parent lamellar bone at 2 weeks. At 18 weeks, 3 microscopically distinct layers at the bone-screw interface were noted. At the osteotomy sites, union between the bone fragments was observed at 18 weeks. Statistically significant differences in the newly formed bone among TT, IT, and CT (P = 0.019) were observed. In conclusion, the biomechanical environment created by the biodegradable IF system used in this study facilitated bone repair at the osteotomy site.

Focal osteoporotic bone marrow defect mimicking a mandibular cystic lesion.

An unusual presentation of a focal osteoporotic bone marrow defect (FOBMD) of the mandible mimicking a cystic lesion is documented. A definitive diagnosis could be established only on the basis of the histopathologic evaluation. A 66-year-old Brazilian woman was referred by her dentist for well-defined radiolucency of the mandibular molar region suggesting a cystic lesion of odontogenic origin. The computed tomography scan confirmed that the lesion did not affect the corticals. The biopsy confirmed the diagnosis of FOBMD. The diagnostic difficulty in the current case is obvious, because FOBMD, usually exhibiting an ill-defined radiolucency, is seldom suspected preoperatively when a differential diagnosis is considered for focal well-defined radiolucent areas in the jaws.

Nanotopography directs mesenchymal stem cells to osteoblast lineage through regulation of microRNA-SMAD-BMP-2 circuit.

The aim of this study was to investigate if chemically produced nanotopography on titanium (Ti) surface induces osteoblast differentiation of cultured human bone marrow mesenchymal stem cells (hMSCs) by regulating the expression of microRNAs (miRs). It was demonstrated that Ti with nanotopography induces osteoblast differentiation of hMSCs as evidenced by upregulation of osteoblast specific markers compared with untreated (control) Ti at day 4. At this time-point, miR-sequencing analysis revealed that 20 miRs were upregulated (>twofold) while 20 miRs were downregulated (>threefold) in hMSCs grown on Ti with nanotopography compared with control Ti. Three miRs, namely miR-4448, -4708, and -4773, which were significantly downregulated (>fivefold) by Ti with nanotopography affect osteoblast differentiation of hMSCs. These miRs directly target SMAD1 and SMAD4, both key transducers of the bone morphogenetic protein 2 (BMP-2) osteogenic signal, which were upregulated by Ti with nanotopography. Overexpression of miR-4448, -4708, and 4773 in MC3T3-E1 pre-osteoblasts noticeably inhibited gene and protein expression of SMAD1 and SMAD4 and therefore repressed the gene expression of key bone markers. Additionally, it was observed that the treatment with BMP-2 displayed a higher osteogenic effect on MC3T3-E1 cells grown on Ti with nanotopography compared with control Ti, suggesting that the BMP-2 signaling pathway was more effective on this surface. Taken together, these results indicate that a complex regulatory network involving a miR-SMAD-BMP-2 circuit governs the osteoblast differentiation induced by Ti with nanotopography. J. Cell. Physiol. 229: 1690-1696, 2014. © 2014 Wiley Periodicals, Inc.

Accidents and complications associated to third molar surgeries performed by dentistry students.

OBJECTIVE: The aim of this work is to demonstrate the accidents and complications rates on third molars surgeries performed by senior dentistry students. METHODS: A retrospective study of 122 patient charts submitted to third molars surgeries was done. Patient age, gender, dental in arch position, and accidents/complications were considered with the charts presenting incomplete dates being excluded from the study. After all, 88 patients (210 surgeries) were included. RESULTS: The majority of the patients were female (70.4 %), with the average age of 24 years. Mandibular molars represented more than half of the surgical procedures (56.2 %), with teeth at vertical position the most found (60.3 %). The cases of accidents and complications totalized 10.4 % of all performed procedures, being hemorrhage (1.9 %), root fractures (1.9 %), and maxillary tuberosity fracture (1.9 %) the most found. Suture dehiscence (1.4 %), dry socket (1.4 %), oroantral communications (0.9 %), paresthesia (0.9 %), and infection (0.4 %) were also observed. CONCLUSIONS: Surgeons' inexperience was not considered a determinant factor to modify the rates of accidents and complications at third molars surgeries when compared to previous works developed by experienced surgeons. It is important to highlight the necessity of the students' knowledge of the most adequate treatments of each of the accidents and complications.

Mandibular bisphosphonate-related osteonecrosis after dental implant rehabilitation: a case report.

It has been a matter of debate as to whether dental implant therapies are suitable for patients subjected to long-term use of bisphosphonates (BPs). This report presents a case of a 76-year-old woman who developed BPs-related osteonecrosis of the jaw (BRONJ) in the left hemimandible after dental implant exposure. The implants and the necrotic crestal bone were removed, and postoperatively, a delay in tissue healing with bone exposure was noticed. The histologic analysis of the block biopsies revealed a lamellar bone tissue exhibiting necrotic areas and bacterial colonies associated with the bone outer surface. The bone-implant interface showed viable lamellar bone with enlarged vascular spaces in the areas between the implant threads. The possible mechanisms for the loss of implants in BRONJ patients are discussed, and the potential protocols for dental implant rehabilitation for patients under BP therapies are presented.

Acidentes e complicações associadas à cirurgia dos terceiros molares realizada por alunos de odontologia / Accidents and complications associated to third molar surgeries performed by dentistry students

O objetivo deste artigo é o de demonstrar as taxas de acidentes e complicações nas cirurgias de terceiros molares realizadas por alunos do último ano do curso de graduação em Odontologia. METODOLOGIA: a análise retropectiva do prontuário de 122 pacientes submetidos à extração dos terceiros molares foi realizada. A idade dos pacientes, o gênero, a posição do dente no arco e os acidentes e complicações decorrentes das cirurgias foram considerados. Prontuários com dados incompletos foram excluídos do estudo. Do total, 88 pacientes foram incluídos, totalizando 210 extrações. RESULTADOS: A maioria dos pacientes era do gênero feminino (70,47%), com idade média de 24 anos. Os molares inferiores corresponderam a mais da metade dos procedimentos cirúrgicos (56,2%), senda a posição vertical (60,37%) a mais encontrada. Os casos de acidentes e/ou complicações totalizaram 10,47% dos procedimentos, sendo a hemorragia (2,38%), as fraturas radiculares (1,90%) e as fraturas da tuberosidade maxilar (1,90%) as mais encontradas. Outros acidentes/complicações encontrados foram deiscência de sutura (1,45%), comunicação buco-sinusal (0,95%), parestesia (0,95%), alveolite (0,47%) e infecção (0,47%). CONCLUSÕES: a inexperiência do cirurgião não pôde ser considerada como um fator determinante para o aumento das taxas de acidentes e complicações em exodontias dos terceiros molares, tendo em vista a semelhança dos resultados deste trabalho com estudos desenvolvidos por cirurgiões experientes. É importante salientar a necessidade do conhecimento por parte dos alunos dos tratamentos mais adequados para os diferentes acidentes e complicações encontradas.

The aim of this work is to demonstrate accidents and complications rates on third molars surgeries performed by senior dentistry students. METHODS: a restrospective study of 122 patient charts submitted to third molars surgeries was done. Patient age, gender, dental in arch position, and accidents/complications were considered with the charts presenting incomplete dates being excluded from study. After all, 88 patients (210 surgeries) were included. RESULTS: the majority of the patients were female (70,47%), with average age of 24 years old. Mandibular molars represented more than half of the surgical procedures (56,2%), with teeth at vertical position the most found (60,37%). The cases of accidents and complications totalized 10,47% of all performed procedures, being bleeding (2,38%), root fractures (1,90%) and maxilar tuberosity (1,90%) the most found. Suture dehiscence (1,45%), oro-antral comunications (0,95%), paresthesia (0,95%), alveolitis (0,47%) and infection (0,47%) were also observed. CONCLUSIONS: surgeons inexperience was not considered a determinant factor to modify the rates of accidents and complications at third molars surgeries when compared to previous works developed by experienced surgeons. Is important to highlight the necessity of the students knowledge of the most adequate treatments of each of the accidents and complications.