133 resultados para Mesaticephalic skull


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Skull represents the segment with conspicuous adaptations that, in lizards, may be conservative or promoted by selective pressures. The aim of assisting the morphological knowledge of reptiles, we provide a detailed description of the neurocranium of Iguana iguana iguana based on analysis of three dried adult skeletons. The skull of this species has basal characteristics in lizards without closure of cranial openings and general triangular shape. Bony structures that form the caudal base have many fusions, especially on the floor. In the caudal face the exoccipital and the opisthotic are fused and form the otooccipital, which contributes to the formation of the lateral part of the condyle. The central part is formed by the condyle supraocciopital. Fusions and skeletal structures in Iguana are similar to other lizards. There are no autopomorphies in the neurocranium for this species.

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Periodontitis has been associated with rheumatoid arthritis. In experimental arthritis, concomitant periodontitis caused by oral infection with Porphyromonas gingivalis enhances articular bone loss. The aim of this study was to investigate how lipopolysaccharide (LPS) from P. gingivalis stimulates bone resorption. The effects by LPS P. gingivalis and four other TLR2 ligands on bone resorption, osteoclast formation, and gene expression in wild type and Tlr2-deficient mice were assessed in ex vivo cultures of mouse parietal bones and in an in vivo model in which TLR2 agonists were injected subcutaneously over the skull bones. LPS P. gingivalis stimulated mineral release and matrix degradation in the parietal bone organ cultures by increasing differentiation and formation of mature osteoclasts, a response dependent on increased RANKL (receptor activator of NF-κB ligand). LPS P. gingivalis stimulated RANKL in parietal osteoblasts dependent on the presence of TLR2 and through a MyD88 and NF-κB-mediated mechanism. Similarly, the TLR2 agonists HKLM, FSL1, Pam2, and Pam3 stimulated RANKL in osteoblasts and parietal bone resorption. LPS P. gingivalis and Pam2 robustly enhanced osteoclast formation in periosteal/endosteal cell cultures by increasing RANKL. LPS P. gingivalis and Pam2 also up-regulated RANKL and osteoclastic genes in vivo, resulting in an increased number of periosteal osteoclasts and immense bone loss in wild type mice but not in Tlr2-deficient mice. These data demonstrate that LPS P. gingivalis stimulates periosteal osteoclast formation and bone resorption by stimulating RANKL in osteoblasts via TLR2. This effect might be important for periodontal bone loss and for the enhanced bone loss seen in rheumatoid arthritis patients with concomitant periodontal disease.

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ln order to predict the facial growth using Jarahak's analysis, cephalometric radiographies of 120 subjects during the mixed dentition and between 6 and 10 years of age were studied. From the total, 60 subjects (30 males and 30 females) were classified as Angle's Class I and 60 subjects (30 males and 30 females) were classified as Angle's Class II, Division 1. AIl subjects did not receive any orthodontic treatment. The proportion between anterior and posterior facial heigth (SGo-NMe) was studied, which is determined by the formula PFH x 100/ AFH = %, neither being straight (> 62% < 65), clockwise ( > 58% < 62%) and anti-clockwise ( > 65% - 80%). Mean average, standard deviation and facial height proportion (SGo - NMe) were determined for males and females according to Angle's classification of malocc!usion. Sexual dimorphism was examined with regard to different types of Angle's malocclusion and the direction of the facial growth, and the correlation of four cephalometrics measurements were analvsed

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Introduction: The mandibular injuries account for about 20% to 50% of cases of facial fractures. Some consider the jaw the second most commonly fractured bone of the skull, and is the only mobile bone of the facial framework, which results in decreased stability compared to the trauma. When one takes into account the degree of airway obstruction in patients with facial fractures, the problem becomes much more serious since it is one of the most troubling complications of trauma. Objective: the relevance of the topic is aimed to report a case of a patient victim of mandibular fracture associated with trauma to the trachea. Case report: Case report: Patient 24 years old patient with tracheal trauma concomitant mandibular fracture surgically treated in conjunction with the thoracic surgeon. After 5 months postoperatively, the patient is in good condition general, no complaints. Final comments: This form is observed that the key to proper treatment of tracheal trauma associated with facial fractures is the knowledge of the type of injury, and an accurate diagnosis multidisciplinary.

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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.

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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.

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Introduction: In dentistry, alveolar bone resorption is a limiting factor in the well being of individuals directly interfering in the stomatognathic system, causing problems in the context of overall health. Aiming to promote biological methods that can stimulate bone regeneration, several biomimetic strategies have been developed by the use of diverse materials possible to the bone matrix, culminating in the development of techniques that promote such repair. Objective: This work is a comparative study of the performance of films made with latex as occlusive membrane for Guided Bone Regeneration (GBR) procedure in three preparations: Latex preserved in ammonia, produced by Latex rubber clones IAN873 and PR255 polymerized immediately after collection and without use ammonia as a preservative. Methods: Sixty Wistar rats were randomly divided into 4 groups of 15 animals in which bone defects of critical size (8mm diameter) were made surgically in the skull. Group A was treated by GBR through the membrane latex preserved with ammonia, Group B received the membrane made of latex from IAN873, Group C, the membrane clone PR255 and group D was not treated by GBR. After a period of 7, 15 and 50 days, 5 animals from each group were euthanized, and specimens containing bone defect collected for microscopic examination (descriptive histology and histomorphometry). Results: The results showed that after 50 days there was bone formation in higher proportions in group D (p <0.05, ANOVA followed by Tukey), suggesting that further experiments should be conducted to conclude about the presence of ammonia and the influence of kind of rubber. Conclusion: GOR is a procedure proven effective in the treatment of bone defects. Therefore, further experiments should be conducted to reach a conclusion regarding the presence of ammonia in the latex composition for the manufacture of membranes, as well as the difference induced by the species of rubber.

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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.

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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.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)