ANATOMICAL STUDY OF THE OPOSSUM (DIDELPHIS-ALBIVENTRIS) EXTRAOCULAR-MUSCLES

The anatomy of the extraocular muscles was studied in 10 adult opossums (Didelphis albiventris) of both sexes. Eight extraocular muscles were identified: 4 rectus muscles, 2 oblique muscles, the levator palpebrae superioris and the retractor ocular bulbi. The rectus muscles originate very close one to another between the orbital surfaces of the presphenoid and palatine bones. These muscles diverge on the way to their insertion which occurs at about 2 mm from the limbus. The levator palpebrae superioris originates with the dorsal rectus and is positioned dorsally in relation to it. The retractor ocular bulbi forms a cone which embraces the optic nerve and is located internally in relation to the rectus muscles. The dorsal oblique originates on the presphenoid bone and after a tendinous trajectory through a trochlea on the medial wall of the orbit, inserts into the ocular bulb. The only muscle arising from the anterior orbital floor is the ventral oblique. The main nerve supply for these muscles is the oculomotor, except for the dorsal oblique which is innervated by the trochlear nerve, and the lateral rectus which is innervated by the abducens nerve. The retractor ocular bulbi receives branches from the inferior division of the oculomotor nerve and some branches from the abducens nerve.

Stress analysis of an upper central incisor restored with different posts

The effect of different anatomic shapes and materials of posts in the stress distribution on an endodontically treated incisor was evaluated in this work. This study compared three post shapes (tapered, cylindrical and two-stage cylindrical) made of three different materials (stainless steel, titanium and carbon fibre on Bisphenol A-Glycidyl Methacrylate (Bis-GMA) matrix). Two-dimensional stress analysis was performed using the Finite Element Method. A static load of 100N was applied at 45degrees inclination with respect to the incisor's edge. The stress concentrations did not significantly affect the region adjacent to the alveolar bone crest at the palatine portion of the tooth, regardless of the post shape or material. However, stress concentrations on the post/dentin interface on the palatine side of the tooth root presented significant variations for different post shapes and materials. Post shapes had relatively small impact on the stress concentrations while post materials introduced higher variations on them. Stainless steel posts presented the highest level of stress concentration, followed by titanium and carbon/Bis-GMA posts.

Cranial osteology in mornoticlae (Aves : Coradiformes)

Momotidae (motmots) is found throughout Latin America between Mexico and northern Argentina. Given the absence of detailed studies of cranial osteology of Momotidae in the literature, this article presents a comprehensive description of the variation of the cranial osteology in all nine species of Momotidae and compares the results with published studies of other families of Coraciiformes and families in other orders. In addition, the cranial structures described are related to ecological and behavioral aspects of Momotidae. The cranial osteology of Baryphthengus ruficapillus is described in detail and compared with other species of Momotidae. The results indicate the presence in Momotidae of modified cranial structures, among which the most conspicuous are the frontal, lacrimal, squamosal, orbital, and laterosphenoid regions, as well as the palatine, upper jaw, pterygoid, and mandible. (C) 2003 Wiley-Liss, Inc.

Morphology and incidence of torus palatinus and mandibularis in Brazilian Indians

The incidence and morphology of torus platinus and mandibularis was verified in 200 Indians, residents of two Brazilian Indian Reserves in Sao Paulo State, Brazil. A low incidence of both types of exostoses was observed, with torus palatinus occurring more frequently than mandibularis. These structures did not occur in individuals less than 10 years of age. Flattened torus palatinus predominated in relation to the other forms.

Role of annexin 1 gene expression in mouse craniofacial bone development

BACKGROUND: Annexin 1 is a 37-kDa protein that has complex intra- and extracellular effects. To discover whether the absence of this protein alters bone development, we monitored this event in the annexin-A1 null mice in comparison with littermate wild-type controls. METHODS: Radiographic and densitometry methods were used for the assessment of bone in annexin-A1 null mice at a gross level. We used whole-skeleton staining, histological analysis, and Western blotting techniques to monitor changes at the tissue and cellular levels. RESULTS: There were no gross differences in the appendicular skeleton between the genotypes, but an anomalous development of the skull was observed in the annexin-A1 null mice. This was characterized in the newborn annexin-A1 null animals by a delayed intramembranous ossification of the skull, incomplete fusion of the interfrontal suture and palatine bone, and the presence of an abnormal suture structure. The annexin-A1 gene was shown to be active in osteocytes during this phase and COX-2 was abundantly expressed in cartilage and bone taken from annexin-A1 null mice. CONCLUSIONS: Expression of the annexin-A1 gene is important for the normal development of the skull in mice, possibly through the regulation of osteoblast differentiation and a secondary effect on the expression of components of the cPLA2-COX-2 system. © 2007 Wiley-Liss, Inc.

Immunohistochemical expression of PCNA, p53, bax and bcl-2 in oral lichen planus and epithelial dysplasia.

The potential for malignant transformation of oral lichen planus is still controversial. The expression of proteins related to cell proliferation and apoptosis in oral lichen planus and epithelial dysplasia was analyzed to evaluate the true potential for malignant transformation of this disease. Twenty-four cases of each lesion were subjected to the streptoavidin-biotin technique for identifying the immunohistochemical expression of PCNA, p53, bax, and bcl-2 proteins. Of the 24 cases of oral lichen planus, 14 (58.33%) were positive for PCNA, 10 (41.67%) for p53, 4 (16.67%) for bcl-2 and 12 (50%) for bax, whereas of the 24 cases of epithelial dysplasia, 20 (83.33%) were positive for PCNA, 10 (41.67%) for p53, 6 (25%) for bcl-2, and 20 (83.33%) for bax. Chi-squared test showed no statistically significant differences between the expression of p53 and bcl-2 in oral lichen planus and epithelial dysplasia, regardless of the grade (P > 0.05). However, the expression of PCNA and bax was significantly increased in epithelial dysplasia (P < 0.05). The results of this study showed that alterations in expression of these proteins are observed in oral lichen planus and epithelial dysplasia, suggesting the potential for malignant transformation in both lesions.

Osteologia craniana de Nyctibiidae (Aves, Caprimulgiformes)

The Potoos form an exclusively neotropical family of nocturnal birds distributed throughout Central and South America, except Chile, and reaching their highest diversity in the Amazon region. The seven currently recognized species are certainly among the most poorly known birds of this region. They are characterized by a distinctive mimicry of vegetal trunks, where they remain almost motionless during daytime. For this reason, their nocturnal and cryptic habits make them exceedingly difficult to study. Published accounts on behavior and natural history of the family are scarce and contributions regarding its anatomy are rare. Here we sample six of the seven currently recognized species of Nyctibiidae, including Nyctibius grandis, N. aethereus, N. griseus, N. jamaicensis, N. leucopterus and N. bracteatus, in order to conduct a detailed and illustrated description of the skull and jaw osteology. High interspecific variation in skull osteology was observed in the family. Species of this family possess a highly modified skull, adapted to their life habits, which shelters their well developed eyes and permits a large mouth opening. The bones that form the palate structure exhibit a dorsoventral flattening, particularly in the pterigoid and parasphenoid bones, with the palatine bone being a broadly developed, wing-shaped structure. In the maxilar region, near the jugal arch, there is a tooth-like projection, unique among birds, which may assist in the retention of prey upon capture. The vomer bone is highly variable within the family, showing varying numbers of rostral projections amongst species. The broad occipital region exhibits large spacing between the quadrate bones, which are vertically disposed and possess a reduced processus orbitalis. The mandible, which is flexible and elastic, has an extremely short symphyseal region and sindesmotic joints in both mandibular rami. As a family, potoos possess a highly specialized skull which provides insight into the relationship between the form of the structures and the feeding habits of the species. Furthermore, the large interspecific variation in skull morphology emphasizes the needs for taxonomic revision within the family, which at present is lumped into a single genus.

Influence of the construction bite vertical and horizontal dimensions on dentoskeletal structures induced by the Klammt appliance in Class II treatment

Aim: To evaluate the influence of construction bite in the dentoskeletal changes induced by Klammt Appliance. Methods: The sample consisted of 17 children, with Class II malocclusion and initial mean age of 8.5 years. The construction bite was obtained using an Exactobite on edge-toedge anteroposterior relationship with 3 mm interincisal clearance. The height of the acrylic was determined by initial overbite associated to interincisal clearance and measured with digital caliper. The amount of advancement was obtained and measured by initial overjet in the lateral radiography. Pearson's correlation, linear regression and ANOVA were used to determine the relationship between dentoskeletal and construction bite variables. Results: The increase in the height of the acrylic promotes a greater inhibition of the forward displacement of the nasal spine and reduction in the facial growth index. The increase in the mandibular advancement induces more downward displacement of nasal spine and pogonion; a counter-clockwise rotation of palatine plane; an increase in mandibular length, maxillary alveolar height and interincisal angle; a decrease in mandibular alveolar height, the intermaxillary discrepancy and overjet; and palatal tipping of upper incisors. Conclusions: The different dimensions of the construction bite influence the dentoskeletal changes induced by the appliance in Class II treatment.

Low latitude scintillations: A comparison of modeling and observations within the CIGALA project

Ionospheric scintillations can seriously jeopardize the reliability of the GNSS signals and consequently can cause significant error or outage on precise positioning applications. The threat is most acute at low latitudes where ionospheric irregularities are more likely to occur resulting in L-band signal scintillations. This paper describes the effort made to model the ionospheric scintillations over the Latin American region in the frame of the CIGALA project funded by the European GNSS Supervisory Authority within the 7th Framework Programme of the European Commission. Comparisons between the low-latitude model of scintillations and observations are here presented and discussed within the project perspectives. © 2011 IEEE.

A single multiplex SNaPshot reaction of 42 SNPs to classify admixture populations into mitochondrial DNA haplogroups

SNaPshot minisequencing reaction is in increasing use because of its fast detection of many polymorphisms in a single assay. In this work we described a highly sensitive single nucleotide polymorphisms (SNPs) typing method with detection of 42 mitochondrial DNA (mtDNA) SNPs in a single PCR and SNaPshot multiplex reaction in order to allow haplogroup classification in Latin American admixture population. We validated the panel typing 160 Brazilian individuals. DNA was extracted from blood spotted on filter paper using Chelex protocol. Forty SNPs were selected targeting haplogroup-specific mutations in Europeans, Africans and Asians (only precursors of Native Americans haplogroups A2, B2, C1, and D1) and two non-coding SNPs were chosen to increase the power of discrimination between individuals (SNPs positions 16,519 and 16,362). It was done using a modified version of a previously published multiplex SNaPshot minisequencing reaction established to resolve European haplogroups, adding SNPs targeting Africans (L0, L1, L2, L3, and L*) and Asians (A, B, C, and D) haplogroups based on SNPs described at PhyloTree.org build 2. PCR primers were designed using PerlPrimer software and checked with the Autodimer program. Thirty-three primer-pairs were used to amplify 42 SNPs. Using this panel, we were able to successfully classify 160 individuals into their correct haplogroups. Complete SNP profiles were obtained from 10. pg of total DNA. We conclude that it is possible to build and genotype more than 40 mtDNA SNPs in a single multiplex PCR and SNaPshot reaction, with sensitivity and reliability, resolving haplogroup classification in admixture populations. © 2011.

Osteologia craniana de Micrastur semitorquatus Vieillot, 1817 (Falconiformes: Falconidae)

Micrastur semitorquatus, popularly known as Collared Forest-Falcon is an inhabitant of the rainforests of the Neotropical Region. Studies on the cranial osteology are scarce in the literature. To increase the knowledge about the anatomy of this species its cranial osteology was described and compared with other species of birds of prey. Three specimens of M. semitorquatus were examined at the Bird Division of the osteological collection at the Smithsonian National Museum of Natural History (USNM), Washington, DC (USNM: 245788, USNM 013493 and USNM 289773). Although the relationship between the form of a structure and its function is not fully established, many of the adaptations of the skull of M. semitorquatus may be related to this lifestyle and behavior, such as narrowing of the interorbital width, the robustness of pila supranasalis coupled with the prokinesis of the skull, a process developed post-orbital, and palatine expansion. In addition, the cranial osteology of M. semitorquatus can provide useful characters for cladistic analysis, sustaining the hypothesis of phylogenetic relationships with other species of the same genus or the same family.

Influence of microthreads and platform switching on stress distribution in bone using angled abutments

Purpose: To evaluate the stress distribution in peri-implant bone by simulating the effect of an implant with microthreads and platform switching on angled abutments through tridimensional finite element analysis. The postulated hypothesis was that the presence of microthreads and platform switching would reduce the stress concentration in the cortical bone. Methods: Four mathematical models of a central incisor supported by an implant (5.0mm×13mm) were created in which the type of thread surface in the neck portion (microthreaded or smooth) and the diameter of the angled abutment connection (5.0 and 4.1mm) were varied. These models included the RM (regular platform and microthreads), the RS (regular platform and smooth neck surface), the SM (platform switching and microthreads), and the SS (platform switching and smooth neck). The analysis was performed using ANSYS Workbench 10.0 (Swanson Analysis System). An oblique load (100N) was applied to the palatine surface of the central incisor. The bone/implant interface was considered to be perfectly integrated. Values for the maximum (σmax) and minimum (σmin) principal stress, the equivalent von Mises stress (σvM), and the maximum principal elastic strain (e{open}max) for cortical and trabecular bone were obtained. Results: For the cortical bone, the highest σmax (MPa) were observed for the RM (55.1), the RS (51.0), the SM (49.5), and the SS (44.8) models. The highest σvM (MPa) were found for the RM (45.4), the SM (42.1), the RS (38.7), and the SS models (37). The highest values for σmin were found for the RM, SM, RS and SS models. For the trabecular bone, the highest σmax values (MPa) were observed in the RS model (6.55), followed by the RM (6.37), SS (5.6), and SM (5.2) models. Conclusion: The hypothesis that the presence of microthreads and a switching platform would reduce the stress concentration in the cortical bone was partially rejected, mainly because the microthreads increased the stress concentration in cortical bone. Only platform switching reduced the stress in cortical bone. © 2012 Japan Prosthodontic Society.

Cranial osteology of Picini (Aves: Piciformes: Picidae)

The Picini is composed of 26 species of woodpeckers from the old world that are grouped into seven genera. Given the absence of detailed studies on the cranial osteology of the Picini, the purpose of this study is to describe the cranial osteology of 14 species of Picini from six genera and to compare these species with each other, with other species of woodpeckers and with other bird groups. The results of the analysis of the bone structures of the skull of the Picini indicate that there are seven outstanding characteristic of bones involved in the functional mechanistics of the jaw apparatus. In the ossa cranii, these include the frontal overhang, the postorbital process, the extension of the parietal versus the frontal region and the temporal fossa. In the ossa faciei, these include the rostral expansion of the pterygoid, the ventral palatine fossa and the orbital process of the quadrate bone. For all of the structures associated with the cranial osteology of the investigated species, there is a clear distinction between the species of the genus Picus and the other species studied. Blythipicus rubiginosus, Chrysocolaptes lucidus, Reinwardtipicus validus, Gecinulus viridis and the species of the genus Dinopium exhibit additional particularities. © 2012 The Royal Swedish Academy of Sciences.

The Evidence of the Rugoscopy Effectiveness as a Human Identification Method in Patients Submitted to Rapid Palatal Expansion

The objective of this study was to demonstrate the effectiveness of rugoscopy as a human identification method, even when the patient is submitted to rapid palatal expansion, which in theory would introduce doubt. With this intent, the Rugoscopic Identity was obtained for each subject using the classification formula proposed by Santos based on the intra-oral casts made before and after treatment from patients who were subjected to palatal expansion. The casts were labeled with the patients' initials and randomly arranged for studying. The palatine rugae kept the same patterns in every case studied. The technical error of the intra-evaluator measurement provided a confidence interval of 95%, making rugoscopy a reliable identification method for patients who were submitted to rapid palatal expansion, because even in the presence of intra-oral changes owing to the use of palatal expanders, the palatine rugae retained the biological and technical requirements for the human identification process. © 2012 American Academy of Forensic Sciences.

Tonsilar metastases of melanoma in an older person

We presented a rare case of metastasis of melanoma in palatine tonsils alerting healthcare professionals to this diagnose in black oral lesions. © The Author 2013. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved.