Immunohistochemical, tomographic, and histological study on onlay bone graft remodeling. Part III: allografts

Objective In the last decades aroused the interest for bone tissue bank as an alternative to autogenous grafting, avoiding donor sites morbidity, surgical time, and costs reduction. The purpose of the study was to compare allografts (ALg) with autografts (AUg) using histology, immunochemistry, and tomographic analysis. Material and methods Fifty-six New Zealand White rabbits were submitted to surgical procedures. Twenty animals were donors and 36 were actually submitted to onlay grafting with ALg (experimental group) and AUg (control group) randomly placed bilaterally in the mandible. Six animals of each group were sacrificed at 3, 5, 7, 10, 20, and 60 postoperative days. Immunolabeling was accomplished with osteoprotegerin (OPG); receptor activator of nuclear factor-k ligand (RANKL); alkaline phosphatase (ALP); osteopontin (OPN); vascular endothelial growth factor (VEGF); tartrate-resistant acid phosphatase (TRAP); collagen type I (COL I); and osteocalcin (OC). Density and volume of the grafts was evaluated on tomography obtained at the surgery and sacrifice. Results The ALg and AUg exhibited similar patterns of density and volume throughout the experiments. The intra-group data showed statistical differences at days 7 and 60 in comparison with other time points (P = 0.001), in both groups. A slight graft expansion from fixation until day 20 (P = 0.532) was observed in the AUg group and then resorbed significantly at the day 60 (P = 0.015). ALg volume remained stable until day 7 and decreased at day 10 (P = 0.045). The light microscopy analysis showed more efficient incorporation of AUg onto the recipient bed if compared with the ALg group. The immunohistochemical labeling picked: at days 10 and 20 with OPG in the AUg group and at day 7 with TRAP in the ALg group (P = 0.001 and P = 0.002, respectively). Conclusions ALg and AUg were not differing in patterns of volume and density during entire experiment. Histological data exhibit more efficient AUg incorporation into recipient bed compared with the ALg group. Immunohistochemistry outcomes demonstrated similar pattern for both ALg and AUg groups, except for an increasing resorption activity in the ALg group mediated by TRAP and in the AUg group by higher OPG labeling. However, this latter observation does not seem to influence clinical outcomes.

Reabilitação protética de mandíbula atrófica por meio de implantes curtos: relato de caso clínico com oito anos de acompanhamento

This case report shows how the prognosis of severe mandibular atrophy can be improved with the use of short dental implants. A Caucasian 54 years-old male patient received four dental implants in the anterior mandibular region. Four months later, the definitive prosthesis was delivered. At the 8-year follow-up period, no complaints or loss of integration were reported. Short dental implants with complete, fixed definitive prosthesis can be a successful treatment in the mandibular arch.

Reconstrução de maxila severamente atrófica via enxerto ósseo autógeno de calota craniana: descrição de técnica

Bone reconstructions are traditionally conducted with autogenous grafts harvested from intra- or extra-oral donor sites to reestablish the lost bone volume for further implant-prosthetic rehabilitation. The calvarial bone has been studied as an excellent donor site in large atrophic situations, presenting low resorption rates, as well as complications and minimal morbidity. The hospitalization time is short, with low pain levels, short functional limitations, and invisible scars. The skull microarchitecture is predominantly cortical in the presence of growth factors that demonstrate their osteogenic, osteoinductive, and osteoconductive abilities resulting in low resorption rate and high predictability when compared to the iliac crest. Dural lacerations, extra and subdural bleeding, cerebrospinal fluid leakage, and brain damage have been minimized due to the development of surgical technique. The delimitation of diploe, preserving the internal skull cortex before osteotomy at the donor made it possible to reduce accidents and complications. The aim of this paper is to show a technical and to discuss aspects of the use of calvarial bone in the reconstruction of severely atrophic maxilla for oral rehabilitation with osseointegrated implants.

Reconstruction of maxillary ridge atrophy caused by sequela of dentoalveolar trauma with autogenous bone graft harvested from mentum

Dentoalveolar traumatisms, particularly those that affect the anterior teeth, interfere adversely in the patient s life.Among them, tooth avulsion is pointed out because it is characterized as a complex injury that affects multiple tissues, andbecause there is no effective treatment available for its resolution with a stable long-term outcome.Aim/Hypothesis: The aim of the present study was to relate a clinical case of complete reconstruction of atrophy of the alveolarbone corresponding to tooth 11, lost by tooth resorption 10 years after the tooth reimplantation procedure.Material and methods: Reconstruction was performed with autogenous bone harvested from the mentum donor site. Surgicalaccess began in the receptor area with a Newman mucoperiosteal incision using a scalpel blade 15 mounted in a scalpel handlefor detachment and exposure of the receptor site. Extensive bone resorption was observed in the vestibular-palatine direction,proved by the thinness of the receptor bed. Decorticalization of the vestibular bone plate was performed. After preparing thereceptor bed, and incision was made in the mucosa in the depth of the anterior vestibular fornix, then a perpendicular muscleperiostealincision to detach and exposure the donor area. The bone graft necessary for reconstruction of the donor area wasdelimited, followed by monocortical osteotomy and the monocortical graft was removed. The next stage was to perform shapingfor passive graft accommodation and fixation by means of two bicortical screws. After fixation of the graft the sharp angles wererounded off in order to avoid possible exposure and/or fenestrations of the reconstructed area, then the receptor and donor areawere sutured. After the 6-month period to allow incorporation of the autogenous graft, an osseointegrated dental implant wasinserted. At the end of the 6-month period of waiting for osseointegration to occur, the process of fabricating the screw-retainedmetal ceramic

Particularities in the technique of calvaria graft

Calvaria grafts provide good bone quantity for the reconstruction of the atrophic maxilla, and have lower morbidity and resorption rates when compared to iliac crest. The aim of this paper is to present the technique for obtaining a graft of the skull. Initially, the depth of the osteotomy is determined by a manually conducted bur, which establishes the limits of the structures of the skull (outer table, diploe and inner table), making the removal of bone blocks easier and safer. Thus, osteotomies of the blocks are made with greater security, avoiding the complications inherent to surgical technique. The case that will be presented it is from a male patient of 65 years who refused to submit to the iliac crest graft, opting for the calvaria, despite being bald, that is a contraindication for this treatment modality. A delicate suture associated with placement of titanium mesh to maintain the conformation of the patient's skull in the region of the bone defect, created after removal of the graft, provided a good cosmetic result at the donor site. The use of titanium mesh for re-anatomization of bone defects created in the grafts is well indicated for bald patients.

Estudo retrospectivo de implantes osseointegrados instalados imediatamente após exodontias

Objectives: to evaluate implant survival immediately placed after tooth extraction considering different sites, prosthodontic modalities, and the need for biomaterials. Material and methods: dental records of 500 patients treated with dental implants between 2004 and 2011 were screened. Results: only 200 records (20%) corresponded to immediate implants. Reasons for tooth extraction included extensive caries, bone loss, and root fractures. From the 197 immediate dental implants, 86 were placed in the maxilla with a survival rate of 93.9% and 111 in the mandible (survival rate of 99.1%). The overall survival rate was 97.46%. Prosthodontic modalities identified were: Brånemark classic complete denture screwed prostheses (36%), overdentures (5.6%), fixed partial denture (31%), and single-tooth prostheses (27.4%). Also, it was observed that in 33% of cases there was a need for the use of grafts and/or biomaterials. Conclusion: it can be concluded that, when correctly indicated, immediate implants are an excellent choice. The anterior mandibular region, screwed and overdenture-type prostheses presented higher success rates when associated to immediate implant placement. The need for bone graft/biomaterial does not affect the clinical results.

Effect of framework soldering on the deformation of implant abutments after framework seating

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Osteologia craniana e aspectos evolutivos de Mycteria (Aves: Ciconiidae)

The genus Mycteria (Ciconiidae) is composed of species with controversial phylogenetic hypotheses of relationships. This study sought to describe the cranial osteology of the four species included in the genus Mycteria, comparing with representative species from other genera of the family. The monophyly of Mycteria coud be hypothesized based on the following cranial characters: 1) medial process of the mandible medially oriented and 2) pseudo temporal tubercle developed when compared to other species Ciconiidae. Mycteria ibis and M. leucocephala are sister groups supported by: 1) deep temporal fossa, 2) reduced “T” tubercle and 3) expansion of the caudal fossa coanalis relative to other species of Ciconiidae. Among the species studied, the most basal was M. cinerea and the taxon formed by M. ibis and M. leucocephala is sister group of M. americana, sustained by the presence of total fusion of lacrimal and frontal bones, whereas in remaining species of Ciconiidae the suture between these bones is visible.

Comparative analysis of the cranial osteology and evolutionary traits of micrastur gilvicollis, micrastur ruficollis and micrastur semitorquatus (aves: falconiformes)

The cranial osteology of Micrastur gilvicollis (Vieillot, 1817), Micrastur ruficollis (Vieillot, 1817) and Micrastur semitorquatus (Vieillot, 1817) is comparatively and meticulously described to characterize each of the species and to determine which traits the species have in common and which are distinct. These traits will be used a posteriori for phylogenetic analysis. Our results indicate that M. gilvicollis and M. ruficollis are closely related, as they share a large number of traits, including a lacrimal bone with a distal portion that is approximately half as long as the proximal portion and a parasphenoid rostrum that covers 50% of the distance between the occipital condyle and pterygoid. Similarly, M. gilvicollis and M. semitorquatus both have a partially fused craniofacial flexion zone. In both M. ruficollis and M. semitorquatus, the symphyseal region of the mandible is 1/5 the total length of the mandible. The diagnostic traits for each of these species are as follows: a) in M. gilvicollis, the interorbital distance is 1/3 the length of the parietal, and the zygomatic process stretches 1/5 of the distance from the orbital arch to the jugal arch; b) in M. ruficollis, the interorbital distance is 2/5 of the length of the parietal and the zygomatic process extends 1/4 of the distance from the orbital arch to the jugal arch; and c) in M. semitorquatus, the interorbital distance is 3/7 the length of the parietal and the distal portion of the lacrimal is 1/3 the length of the proximal portion. Among the three species, M. gilvicolis and M. ruficollis share the most traits, which leads us to infer that these species are more closely related to one another than they are to M. semitorquatus. Phylogenetic analysis performed a posteriori may confirm the relationship between these three species.

Osteologia craniana comparada de Caracara cheriway (Jacquin, 1784) e Caracara plancus (Miller, 1777) (AVES: FALCONIDAE)

The Caracara genus (Aves: Falconidae) is composed by species C. cheriway, ("Crested Caracara"), and C. plancus (Southern Caracara). This study aimed to describe in detail and compared the cranial osteology of C. cheriway and C. plancus, identifying osteological cranial characters for a future systematic work. The two common characters of Caracara species are: the projection of rostro parasphenoid reaches 50% of the distance from the occipital condyle to the pterygoid; the upper maxilla has about 4/9 of the total length of theskull, the symphysial portion of mandible occupies about 1/7 of its total length, the proximal portion of lacrimal bone ends in a rounded shape and has about 1/4 of the width of the distal portion. The unique characters of C. cheriway are: the interorbital width is about 1/2 of the parietal region, shows a frontal bone prominence; presence of lacrimal process of frontal bone; the proximal portion of the lacrimal bone reaches 1/5 of the distance from the orbital arc to the jugal bone; the distance between the distal portions of two lacrimal bones reach 5/6 of the parietal width, the ratio between the interorbital diameter and parietal region ranges from 2 times; the zygomatic process occupies about 40% of the distance between its origin in the skull and jugal bone. The unique characters of C. plancus are: the interorbital width is approximately 4/7 of the parietal width; show a rostral medial concavity; the proximal portion of the lacrimal bone is about 1/4 of the width of the distal; the proximal portion of the lacrimal bone reaches 1/7 of the distance from the orbital arc to the jugal bone; the distance between the distal portions of two lacrimal bones reaches 6/7 of the width parietal one; the ratio between the interorbital diameter and parietal region varies 1, 75 times, the zygomatic process occupies about 35% of the distance between its origin in the skull and jugal bone.

Avaliação da distribuição das forças produzidas com arco lingual removível pelo método de elementos finitos

Pós-graduação em Ciências Odontológicas - FOAR

Efeito in vivo da deposição de filmes de DLC com e sem nanopartículas de prata sobre liga de titânio para utilização em próteses articulares

Pós-graduação em Biopatologia Bucal - ICT

Ex vivo torsional properties of the Targon Vet Nail System in canine femurs: comparison with the 2.4 mm LC-DCP Plate

Pós-graduação em Cirurgia Veterinária - FCAV

Surgical interventions for treating pectus excavatum

Pectus excavatum is characterized by a depression of the anterior chest wall (sternum and lower costal cartilages) and is the most frequently occurring chest wall deformity. The prevalence ranges from 6.28 to 12 cases per 1000 around the world. Generally pectus excavatum is present at birth or is identified after a few weeks or months; however, sometimes it becomes evident only at puberty. The consequence of the condition on a individual’s life is variable, some live a normal life and others have physical and psychological symptoms such as: precordial pain after exercises; impairments of pulmonary and cardiac function; shyness and social isolation. For many years, sub-perichondrial resection of the costal cartilages, with or without transverse cuneiform osteotomy of the sternum and placement of a substernal support, called conventional surgery, was the most accepted option for surgical repair of these patients. From 1997 a new surgical repair called, minimally invasive surgery, became available. This less invasive surgical option consists of the retrosternal placement of a curved metal bar, without resections of the costal cartilages or sternum osteotomy, and is performed by videothoracoscopy. However, many aspects that relate to the benefits and harms of both techniques have not been defined. Objectives To evaluate the effectiveness and safety of the conventional surgery compared with minimally invasive surgery for treating people with pectus excavatum. Search methods With the aim of increasing the sensitivity of the search strategy we used only terms related to the individual’s condition (pectus excavatum); terms related to the interventions, outcomes and types of studies were not included. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, LILACS, and ICTPR. Additionally we searched yet reference lists of articles and conference proceedings. All searches were done without language restriction.

Intervenções cirúrgicas para o tratamento do pectus excavatum: revisão sistemática

Pós-graduação em Bases Gerais da Cirurgia - FMB