Paleoambiente da formação mosquito e a implantação do sistema desértico úmido da formação corda, jurássico superior, Centro-Oeste da Bacia do Parnaíba

O Mesozóico foi marcado por mudanças geológicas significativas, decorrentes de soerguimentos resultante da orogenia Gonduanide, que possibilitou a implantação de sistemas desérticos concomitantemente com expressivos eventos magmáticos. Na Bacia do Parnaíba, Nordeste do Brasil, estes eventos estão registrados nas unidades siliciclásticas do Triássico, os arenitos da Formação Sambaíba, representadas pelos derrames basálticos e arenitos fluviais e eólicos subordinados da Formação Mosquito e pelos arenitos flúvio-eólicos da Formação Corda. O estudo de fácies e estratigráfico realizado em afloramentos e testemunhos de sondagem na região entre Formosa da Serra Negra e Montes Altos, Estado do Maranhão, possibilitou reconstituir o paleoambiente do topo da Formação Mosquito e da Formação Corda, e inferir condições paleoclimáticas para a porção centro-oeste da Bacia do Parnaíba durante o Jurássico. Foram identificadas vinte fácies sedimentares agrupadas em cinco associações de fácies (AF) representativas de uma planície vulcânica com depósitos fluviais esporádicos e arenitos eólicos subordinados (AF1-Formação Mosquito), sucedida pela instalação de um sistema desértico úmido (AF2-AF5; Formação Corda). A planície vulcânica (AF1) constitui derrames basálticos intercalados com arenitos finos a grossos (arenitos intertrap) compostos por grãos arredondados a subangulosos de quartzo, feldspatos e fragmentos de vidro vulcânico. Os arenitos apresentam estratificações plano-paralela e cruzada de baixo ângulo, preenchendo geometria de canal ou em corpos tabulares. Depósitos de canal fluvial entrelaçado (AF2) consistem em conglomerados polimíticos, com grânulos e seixos subarredondados a angulosos de basalto, e arenitos grossos com estratificação cruzada acanalada e acamamento maciço. Os lençóis arenosos (AF3) foram divididos em dois elementos arquiteturais (EA), o primeiro (EA1) consistem em arenitos finos a muitos com geometria tabular e estruturas de deformação, o segundo (EA2) é composto por arenito fino a grosso com estratificação cruzada acanalada e laminação cruzada cavalgante, gutter cast de pequeno porte. O campo de dunas (AF4) foi subdividido em dois conjuntos de fácies (C), o primeiro (CI) é caracterizado por arenitos com estratificações cruzadas tabular e tangencial de pequeno a médio porte, estratificação planoparalela e laminação cruzada cavalgante transladante subcrítica. O segundo (CII) consiste de arenitos finos a médios, moderadamente selecionados, laminação ondulada e estruturas de adesão e gretas de contração com rip-up clast, curled mud flakes, forma ciclos de raseamento centimétricos, com topo marcado por horizontes mosqueados, ricos em óxido/hidróxido de ferro, bioturbações e gretas de contração, interpretados como depósitos de interdunas úmidas. Os lobos de suspensão (AF5) consistem em arenitos finos intercalados com pelitos e arenito/pelito com estratificação cruzada complexa. A abundância de esmectita na AF4 aponta para condições de clima semiárido. No Jurássico, a região centro-oeste da Bacia do Parnaíba, foi submetida a movimentos distensivos com recorrência de derrames básicos advindos de fissuras na crosta. Durante os intervalos de aquiescência sedimentos de rios efêmeros preenchiam depressões ou espraiavam-se na planície vulcânica. O final da atividade magmática foi sucedido pela implantação do desérto Corda com campo de dunas e canais fluviais efêmeros (wadi) que retrabalharam parte da planície vulcânica e esporadicamente invadiam os lençóis arenosos. Comparado aos ergs do Permo-Triássico (Formação Sambaíba), o deserto Jurássico da Formação Corda foi mais úmido e menos extenso precedendo os sistemas fluviais e costeiros de clima mais ameno do Cretáceo da Bacia do Parnaíba.

Efeitos biológicos da radioterapia na expressão do fator de crescimento epidérmico (EGF) durante a odontotogênese em camundongos (Mus musculus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prevalence of mesiodens in orthodontic patients with deciduous and mixed dentition and its association with other dental anomalies

OBJECTIVE: To determine the prevalence of mesiodens in deciduous and mixed dentitions and its association with other dental anomalies. MATERIAL AND METHODS: Panoramic radiographs of 1,995 orthodontic patients were analyzed retrospectively, obtaining a final sample of 30 patients with mesiodens. The following aspects were analyzed: gender ; number of mesiodens; proportion between erupted and non-erupted mesiodens; initial position of the supernumerary tooth; related complications; treatment plan accomplished; and associated dental anomalies. The frequency of dental anomalies in the sample was compared to reference values for the general population using the chi-square test (c²), with a significance level set at 5%. RESULTS: The prevalence of mesiodens was 1.5% more common among males (1.5:1). Most of the mesiodens were non-erupted (75%) and in a vertical position, facing the oral cavity. Extraction of the mesiodens was the most common treatment. The main complications associated with mesiodens were: delayed eruption of permanent incisors (34.28%) and midline diastema (28.57%). From all the dental anomalies analyzed, only the prevalence of maxillary lateral incisor agenesis was higher in comparison to the general population. CONCLUSION: There was a low prevalence of mesiodens (1.5%) in deciduous and mixed dentition and the condition was not associated with other dental anomalies, except for the maxillary lateral incisor agenesis.

Estudo de rochas alcalinas intrusivas na região de Três Fontes - MG

Geological researches conducted in the past few years detected, through deep drill hole data, the presence of alkaline rocks in the region of Três Fontes-MG, where the Barbacena Group rocks, the Morro do Ferro Greenstone Belt rocks and Araxá/Canastra groups‟ rocks are exposed. This paper aimed the petrographic and chemical characterization of these alkaline rock types, which have not yet been described in the literature. Based on petrographic descriptions and geochemical and Scanning Electron Microscopy analysis, it was possible to characterize the rock in question as lamprophyre, rich in carbonates, phlogopite, pyroxene, olivine, titaniferous opaque minerals and apatite concentrations that reach 7%. This occurrence corresponds to an alkaline intrusion, which caused brecciation of host rocks, possibly indicating that the material is explosive, however, in the study area there was no evidence of volcanic activity on the surface

Mapeamento da ilha da Trindade, Atlântico Sul

The area chosen for this study is the island of Trinidade, which is located 1167 km off the Brazilian coast, in parallel Victory at 20 ° 30'S and 29 º 19'W, being the most easterly point of our continent. The isolation of oceanic island of Trinidade leaves no noticeable that she is part of a large submarine volcanic chain oriented east-west lineament known as Vitória- Trindade. Along with the island of Martin Vaz, who is Federal Territory is administered by the Navy of Brazil. Both correspond to Source alkaline volcanic islands. The area of the island of Trinidad has approximately 10 km2. Geologically consisting ankaratritic spills, spills tannbuschiticos, volcanic tuff spills analcite-ankaratrite, phonolite spills, spills nefelinite, pyroclastics, spills grazinite, tinguaitos, olivine-analcitito, calcarenite dunes and wind according to Almeida (1961). The island has its base on the ocean floor, at 5,800 m depth. It is the only place still recognizes preserved volcanic necks and plugs, as well as remnants of a volcano in Brazil. Magmatism occurred here a sodium alkali-silica subsaturated where his wrist was last 50,000 years according to Almeida (1961). It is a place with restricted access due to their distance from the coast, his contribution and hard to be an exclusive area of the Navy. On the island with peaks occur up to 620 meters high, and its rugged mountainous terrain and difficult access to very specific points, as the peak of Desire, peak Fazendinha, Monument and other points on the island. Because of its location far from the coast, its small infrastructure, difficulty of landing and restricted access by sea, the island of Trinidad offers no possibility of tourism, being a military outpost, and scientific basis of great importance, which conduct research in area of marine biology, oceanography, geology and others

Seqüelas em dentes permanentes após trauma nos predecessores decíduos e sua implicação clínica

In regarding to the high prevalence of traumatic dental injuries in primary teeth and the possible disturbances on developing permanent successor germs, an early diagnosis and an adequate establishment of treatment planning are very important to minimize the damage caused by the trauma. Sequelaes can affect the coronal portion (white or yellow-brown discoloration associated or not with enamel hipoplasia, dilacerations of the crown), the root portion (dilaceration, duplication or cessation of root formation) or the whole successor permanent tooth (odontoma sequestration or disturbances of permanent successor eruption). The aim of this study is to make a literature review of the developmental disturbances of permanent teeth followed by traumatic injuries to theirs primary predecessors and to present cases reports to advise the dentists, their patients and parents about the damage that developing permanents teeth can undergo.

Manifestation of molar-incisor hypomineralisation in twins: clinical case reports

Molar-incisor hypomineralisation is a qualitative defect of dental tissue of systemic origin affecting one or more permanent first molars and sometimes the permanent incisors as well. There are still no conclusive data on the aetiology of this hypomineralisation, however, systemic factors such as respiratory diseases and prenatal and perinatal complications are regarded as possible causes. The objective is to present three clinical cases of twins, one Monozygotic and two Dizygotic Twins with molar-incisor hypomineralisation, showing evidence of its manifestation as well as clinical the characteristics and aetiological factors involved. The clinical findings involving twins suggest that ameloblasts are specifically affected in their developmental phase, which includes a number of factors. Although prenatal and perinatal complications are not decisive in the development of molar-incisor hypomineralization, it is suggested a possible genetic susceptibility to the disease. Prospective observational studies using a population sample containing data on the last three months of gestation to the eruption of permanent teeth are needed to confirm the causeeffect relationships.

Alterações dentoesqueléticas verticais e horizontais induzidas pelo ativador elástico Aberto de Klammt

The aim of this study was to evaluate the vertical and horizontal dentoskeletal changes induced by the Klammt Open Elastic Activator in the treatment of the Class II Division 1 malocclusion. The sample of 34 children was divided into two groups of 17 subjects each (ten girls, seven boys), matched by age and gender and with an initial mean age of 8.5 years. The data was analyzed using a Student's t-test for intragroup and intergroup comparison. The results showed that the appliance promoted dentoalveolar restriction of the maxilar growth within normal anteroposterior and vertical growth of the maxillary apical base; increment in the vertical displacement the mandibular symphysis associated with normal horizontal growth of the mandible; palatal tipping of the upper incisors; restriction of the anterior migration of the upper molars; greater eruption pattern and normal anterior displacement of the lower incisors and molars. It was concluded that Klammt appliance induce changes that are predominantly horizontal dentoalveolar in upper arch and vertical dentoalveolar in lower arch and vertical skeletal changes in the mandible.

Utilização do bite block para correção da mordida aberta anterior

Bite block is a functional orthodontic appliance that promotes relative intrusion or dental eruption inhibition. The purpose of this study is to present the effects of bite block on the treatment of an open bite case report.

Intrusão de incisivos superiores com periodonto comprometido

O tratamento ortodôntico de pacientes periodontalmente comprometidos requer abordagem interdisciplinar que envolva diferentes especialidades odontológicas para que sejam obtidos resultados estéticos e funcionais satisfatórios. Normalmente, pacientes adultos com problemas periodontais apresentam migração dentária, erupção patológica e diastemas. Essas alterações de posição, geralmente, são o resultado da falta de equilíbrio entre o suporte periodontal e as forças oclusais que estão atuando nos dentes durante a mastigação e movimentos funcionais.

Innovation in pediatric surgery: the use of ultrasonic CVD tips: case report

The non-eruption of teeth due to highly keratinized gingival mucosa is a frequent event in the pediatric dentistry, which harms the oral aesthetics and function. A surgical excision of the involved area is indicated, exposing the non-erupted tooth. This procedure involves anesthesia and cutting instruments that may increase the fear and anxiety in young patients. The use of new technologies has avoided these instruments and has promoted more comfort to the patients. This study presents clinical cases in which gingivectomy was performed using the innovative method with an ultrasound-activated CVD tip. It was concluded that this method presented effectiveness, promoted more comfort, and less fear to the patients, making its use a viable alternative to pediatric surgery.

Tratamento cirúrgico de canino incluso em mento: relato de caso

The mandibular and maxillary canines when well positioned in the arch, are important functionally and aesthetically. Although these teeth are frequently malpositioned in the dental arch, their absence of eruption are not common, occuring more frequently with the maxillary canine than the mandibular canine. The canine transmigration is a well-known pre eruptive phenomenon in which the tooth goes thru the facial midline, occurring more frequently in the mandible than in maxila. Females are more susceptible than males and the right side more than the left one. Normally the patients do not show any symptoms, and this condition is observed during radiographic exams to diagnose the late exfoliation of the deciduous canine or for any other purpose. Due to the relationship between impacted canines and pathologic lesions, infection, trauma to the adjacent teeth, pain, ectopic eruption and interference with prosthesis, it´s indicated the surgical extraction of these teeth. The goal of this article is to describe and discuss the surgical treatment of an impacted canine (43) in the chin.

Tratamento do sorriso gengival: como estabelecer proporção e harmonia

The etiology of gingival smile is multifactorial and the correct diagnosis eill determine a successful treatment planning. Altered passive eruption occurs during the final stages of tooth eruption, when apical migration of the periodontal tissues does not occur, resulting in a distance > 2mm between the alveolar crest and the cement-enamel juncrion. This change leads to the shortening of the clinical crown and even further may lead to excessive gingival exposure. For treatment, there is a necessity for the combined removal of gingiva and bone tissue. This article discusses the literature on the issue and reports a case where periodontal plastic surgery was performed for the correcrion of a gingival smile.

Tratamento estético periodontal: revisão de literatura sobre alguns tipos de cirurgias

Currently, periodontal aesthetics has been prized for harmony of the smile. The clinical crown lengthening, gingival excess or altered passive eruption, is effectively corrected by periodontal surgery. The purpose of this paper is to show, through a literature review, some types of surgery on clinical crown lengthening and root coverage. Clinical crown lengthening is done to Change the size of the anterior teeth and to optimize the cosmetic result of treatment with new coronal restoration and other cosmetic dental care. In general, the treatment plan and the choice of operative technique begin with careful clinical examination. Recessions tissue can be defined as a displacement of the gingival margin toward the junction mucogingival exposing the root surface. These, when present, impacting on patient comfort by providing the occurrence of cervical dentin hypersensitivity, and the esthetic, the amendment of the gum line. Successful treatment of recessions is based on knowledge of its etiology and assessment of predictability of surgical techniques that aim to root coverage. Through literature review, we can conclude that the types of surgery most often used are: 1) to increase the clinical crown, gingivectomy, flap surgery and gingivoplasty osteotomy, and 2) for root coverage, the use will depend on the amount of gum keratinized and especially the classification of Miller.

Dentinogenesis imperfecta type II: approach for dental treatment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)