Morphological and compositional variations of zircon and their metallogenetic implications: the example of the Jamon, Serra dos Carajás and Velho Guilherme suites, Amazonian Craton

Zircões de granitos das Suítes Jamon (SJ), Serra dos Carajás (SSC) e Velho Guilherme (SVG) foram estudados em MEV por meio de imagens de elétrons retroespalhados e catodoluminescência e análises pontuais por EDS. Granitos e greisens da SVG apresentam zircões dominantemente anédricos, alterados e intensamente corroídos, enriquecidos em Hf e com as mais baixas razões Zr/Hf, as quais nos granitos tendem a decrescer no sentido das fácies mais evoluídas. Zircões da SJ são euédricos a subédricos, zonados e pouco alterados, comparativamente empobrecidos em Hf e com as mais elevadas razões Zr/Hf, indicando potencial reduzido para geração de mineralização estanífera. Zircões dos granitos da SSC são subédricos a anédricos, alterados e corroídos e com conteúdos de Hf e razões Zr/Hf intermediárias a dos zircões das SJ e SVG. Granitos da SVG com mineralizações de Sn, W e Ta apresentam zircões com razões Zr/Hf entre 7 e 22. Conclui-se que razões desta ordem podem ser utilizadas como guia prospectivo de granitos especializados. Por outro lado, zircões de greisens associados ao Granito Cigano da SSC apresentaram razão Zr/Hf média em torno de 23, porém nenhuma cassiterita foi encontrada nessas rochas. Isto indica que estes zircões preservaram sua assinatura magmática original. O estudo desenvolvido permitiu distinguir as três suítes graníticas em termos de composição de zircão, e mostrou a importância da assinatura geoquímica desse mineral, sobretudo da razão Zr/Hf, na identificação de granitos especializados. Análises de zircões por MEV-EDS podem, portanto, ser utilizadas na avaliação preliminar do potencial metalogenético de granitos estaníferos.

Murcha-de-curtobacterium do feijoeiro: ocorrência em Santa Catarina, comportamento de genótipos e efeito de nitrogênio e potássio

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Caracterização do meio físico da bacia do córrego caçula e processos de degradação associados com vistas ao planejamento territorial

Pós-graduação em Engenharia Civil - FEIS

The Primary Closure Approach of Dog Bite Injuries of the Nose

The nose holds an outstanding position on the face, acquiring great importance within the context of facial aesthetics. Because of the functional, psychological, and social aspects of trauma in a society increasingly demanding about aesthetics, treatment institution must reduce, as accurate as possible, the sequelae that hinder social integration. This clinical report relates an immediate nasal reconstruction of a complex animal bite wound. A 7-year-old patient was victim of a dog bite with avulsion of the left nasal ala and part of the ipsilateral nasal tip. The treatment was immediate nasal reconstruction with auricular composite graft. After 1 year of follow-up, the shape of nasal ala was stable, and the color was consistent with the surrounding tissue. The 2 nasal sides exhibited satisfactory symmetry when evaluated. It can be concluded that the composite graft derived from the auricular helix is a safe option for reconstruction of nasal ala defects with compromised margins in pediatric patients when conditions of reimplantation do not exist.

Sagittal Mandibular Osteotomy for Removal of Intraosseous Lesion

The ramus sagittal split osteotomy or mandibular body is an established technique for correction of dentofacial deformities but can have an accurate indication in cases requiring surgical access to remove lesions or more teeth included in the region of the mandibular angle. The main advantages of this technique are the possibility of preservation of the inferior alveolar nerve bundle and significant reduction in postoperative morbidity. In this article, the authors show a case in which the sagittal osteotomy of the mandible was used to gain access for removal of a lesion (complex odontoma).

Block Bone Graft Fixation ( Onlay): A Modification of the Surgical Technique

Several reconstructive methods of the alveolar ridge have been reported to make possible future rehabilitations with implants. Many of these methods come from studies done in animals, mainly rats. With this clinical practice based on scientific evidence, any experimental procedure that can be undertaken in real life is fundamental. Thus, any research that emulates as closely as possible those techniques used in humans are important. This study describes the modification of the technique for block bone graft fixation (onlay) in rats using the lag screw-type technique, normally used in clinical procedures for grafts in humans. The conclusion was that the execution of the described procedures minimizes interference of blood flow in the area because of the maintenance of the muscle insertion in the buckle aspect of the most anterior region of the mandible, providing better stability to the graft and better contact interface of the graft and receptor bed.

Conservative Approach: Using Decompression Procedure for Management of a Large Unicystic Ameloblastoma of the Mandible

Ameloblastoma is a relatively uncommon benign odontogenic tumor, which is locally aggressive and has a high tendency to recur, despite its benign histopathologic features. This pathology can be classified into 4 groups: unicystic, solid or multicystic, peripheral, and malignant. There are 3 variants of unicystic ameloblastoma, as luminal, intraluminal, and mural. Therefore, in mural ameloblastoma, the fibrous wall of the cyst is infiltrated with tumor nodules, and for this reason it is considered the most aggressive variant of unicystic ameloblastomas. Various treatment techniques for ameloblastomas have been proposed, which include decompression, enucleation/curettage, sclerotizing solution, cryosurgery, marginal resection, and aggressive resection. Literature shows treatment of this lesion continues to be a subject of intense interest and some controversy. Thus, the authors aimed to describe a case of a mural unicystic ameloblastoma of follicular subtype in a 19-year-old subject who was successfully treated using conservative approaches, as decompression. The patient has been followed up for 3 years, and has remained clinically and radiographically disease-free.

Extensive Cervical Necrotizing Fasciitis of Odontogenic Origin

Necrotizing fasciitis (NF) is an uncommon infection, but potentially lethal, especially when associated with systemic disorders such as diabetes. The authors report a case of necrotizing fasciitis from odontogenic origin in a patient with uncontrolled diabetes mellitus. The initial diagnosis was based on clinical information, in which multiple necrosis areas in cervical and thoracic regions were observed. Wide antibiotic therapy was applied, followed by surgical drain age and debridement. Culture was positive for methicillin-resistant Staphylococcus aureus. Although the treatment is established, the patient dies after sepsis and failure of vital organs. Clearly, the morbidity associated to this infection, even in diabetic patients, can be minimized if an early diagnosis and effective debridement are done.

Rehabilitation of the Maxillary Arch After Bone Graft Using Immediate Loading With Implant-Supported Fixed Restoration

Moderate and controlled loading environments support or enhance osteogenesis, and, consequently, a high degree of bone-to-implant contact can be acquired. This is because when osteoprogenitor cells are exposed to limited physical deformation, their differentiation into osteoblasts is enhanced. Then, some range of microstrain is considered advantageous for bone ingrowth and osseointegration. The primary stability has been considered one of the main clinical means of controlling micromotion between the implant and the forming interfacial tissue, which helps to establish the proper mechanical environment for osteogenesis. Based on the biological aspects of immediate loading (IL), the objective of this study is to present a clinical case of maxillary arch rehabilitation using immediate loading with implant-supported fixed restoration after bone graft. Ten dental implants were placed in the maxilla 6 months after the autogenous bone graft, removed from the mandible (bilateral oblique line and chin), followed by the installation of an immediate-load fixed cross-arch implant-supported restoration because primary stability was reached for 8 implants. In addition, instructions about masticatory function and how it is related to interfacial micromotion were addressed and emphasized to the patient. The reasons for the IL were further avoidance of an interim healing phase, a potential reduction in the number of clinical interventions for the patient, and aesthetic reasons. After monitoring the rehabilitation for 8 years, the authors can conclude that maxillary IL can be performed followed by a well-established treatment planning based on computed tomography, providing immediate esthetics and function to the patient even when autogenous bone graft was previously performed in the maxilla.

Unerupted Lower Third Molar Extractions and Their Risks for Mandibular Fracture

As every surgical procedure extraction of third molars can result in several complications, among them the mandibular angle fracture. Predisposing factors for fracture should be analyzed during and after the surgery. This paper aims to discuss the predisposing factors to the occurrence of mandibular angle fractures during and after the procedure for third molars extraction, as well as surgical principles to avoid this complication.

Unilateral Condylar Hyperplasia: A Treatment Strategy

Condylar hyperplasia (CH) is a pathologic condition that causes overdevelopment of the condylar head and neck as well as the mandible. Slowly progressive unilateral enlargement of the head and the neck of the condyle causes crossbite malocclusion, facial asymmetry, and shifting of the midpoint of the chin to the unaffected side. The etiology and the pathogenesis of CH remain uncertain. The diagnosis is made by clinical and radiologic examinations and bone scintigraph. A difference in uptake of 10% or more between condyles is regarded as indicative of CH, and the affected condyles had a relative uptake of 55% or more. When the diagnosis of active CH is established, the treatment consists of removal of the growth center by a partial condylectomy. The authors present the case of a 46-year-old male patient with right active type II CH or hemimandibular hyperplasia who underwent a high condylectomy.

Using Conservative Condylectomy for Management of a Large Osteochondroma of the Mandibular Condyle With 6-Year Follow- up

Osteochondroma is a hamartomatous proliferation of cartilaginous tissue, which is the most common benign tumor of the long bones, but is relatively rare in the maxillofacial region. Most cases of mandibular condylar osteochondroma manifest with facial asymmetry or malocclusion with limited temporomandibular joint movements. Several approaches for management of this lesion have been proposed, as conservative condylectomy technique. This procedure has been suggested a valid approach to minimize facial asymmetry, contributing to the recovery of occlusion associated with no local tumor recurrence, and without condylar reconstruction procedure. Therefore, this article aims to describe a clinical report of a true osteochondroma of the mandibular condyle in a 35-year-old patient who was successfully treated using conservative condylectomy procedure.