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The jugular foramen (JF) is located between the temporal and occipital bones. The JF is a primary pathway for venous outflow from the skull and passage of nerves. Variations are common in this region and may have clinical and surgical implications. To analyze the sexual dimorphism and JF morphology in skulls from Northeastern Brazil. 128 human skulls from the Anatomy Laboratory of the Federal University of Paraíba, 64 male and 64 female, were selected and the JFs analyzed for bone septation and the presence of a dome. Data analysis considered P<0.05 as significant. On at least one side, complete septation was observed in 26 skulls (20.3%), incomplete septation in 93 skulls (72.6%) and 61 skulls (47.6%) did not present septation. In 114 skulls (89%), 47.6% female and 41.4% male, have a unilateral presence of the dome and 71 (55.4%) have it bilaterally. Posterolateral compartment diameters and JF area had higher values on the right side in the total sample and separated by sex (P<0.05). Most morphometric variables of the anteromedial compartment were higher in male than in female (P<0.05), fact that was not observed in the posterolateral compartment (P>0.05). This study showed a higher prevalence of complete septation in males compared to females. Morphometric analysis presented a peculiar morphology of the JF in this study. These results suggests that the surgical approach to diseases that affect the JF may be peculiar to the studied population, confirming the importance of morphological analysis of the skull base. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the prevalence and characteristics of 3 anatomical variations of the clivus: fossa navicularis magna (FNM), canalis basilaris medianus (CBM), and craniopharyngeal canal (CPC). Findings were correlated with sex, age, and facial skeletal pattern. A total of 602 cone beam computed tomography scans of Brazilian adults were retrospectively evaluated by 2 independent examiners. The presence of an FNM, CBM, or CPC was recorded, and length, depth, and width were measured. The CBM was classified according to type (3 complete and 3 incomplete varieties). All data were correlated with sex, age, and facial skeletal pattern. Results were tested using chi-square, Mann-Whitney U, and Kruskal-Wallis tests (P < 0.05). The prevalence rates for FNM, CBM, and CPC were 15.78% (n = 95), 6.64% (n = 40), and 0.17% (n = 1), respectively. No significant differences in the prevalence of the variations were found based on sex or facial skeletal patterns (P > 0.05). The median length, depth, and width of FNM were 5.55,1.83, and 4.81 mm, respectively, with no significant differences (P > 0.05) between the variables. The prevalence of FNM was significantly higher in patients aged 18 to 33 years than in those aged 34 and older (P < 0.001). An incomplete variant of the CBM, presenting as an inferior recess, was more common (32.5%). The FNM is the most prevalent anatomical variation of the clivus, especially in young adults. The sex and facial skeletal pattern of the individual do not affect the frequency of FNM, CBM, or CPC. Because of their clinical relevance, recognition of these anatomical variations is essential, as they can be misdiagnosed as pathologies. [ABSTRACT FROM AUTHOR]

Triassic cynodonts from South America are key taxa in the investigation of the emergence of mammalian characters. One of the most iconic species from the Carnian is Prozostrodon brasiliensis, found in Late Triassic strata from southern Brazil. This non-mammaliaform cynodont represents the earliest-diverging member of Prozostrodontia, a clade that encompasses Mammalia and their closest relatives. Previous descriptions of the skull of Pr. brasiliensis were based on specimens that did not preserve the posterior region, obscuring essential details of the basicranium. Here, we describe a new, complete, and exceptionally well-preserved skull of Pr. brasiliensis found in the same block as the holotype skeleton of the early predatory dinosaur Gnathovorax cabreirai and rhynchosaur specimens. Anatomical data from this specimen provide novel insights into the initial radiation of prozostrodontian cynodonts and reveal a new endemic clade of South American cynodonts – Prozostrodontidae – on the stem lineage of mammals. [ABSTRACT FROM AUTHOR]

Among terrestrial vertebrates, only crown birds (Neornithes) rival mammals in terms of relative brain size and behavioural complexity. Relatedly, the anatomy of the avian central nervous system and associated sensory structures, such as the vestibular system of the inner ear, are highly modified with respect to those of other extant reptile lineages. However, a dearth of three-dimensional Mesozoic fossils has limited our knowledge of the origins of the distinctive endocranial structures of crown birds. Traits such as an expanded, flexed brain, a ventral connection between the brain and spinal column, and a modified vestibular system have been regarded as exclusive to Neornithes. Here, we demonstrate all of these 'advanced' traits in an undistorted braincase from an Upper Cretaceous enantiornithine bonebed in southeastern Brazil. Our discovery suggests that these crown bird-like endocranial traits may have originated prior to the split between Enantiornithes and the more crownward portion of avian phylogeny over 140 Ma, while coexisting with a remarkably plesiomorphic cranial base and posterior palate region. Altogether, our results support the interpretation that the distinctive endocranial morphologies of crown birds and their Mesozoic relatives are affected by complex trade-offs between spatial constraints during development. [ABSTRACT FROM AUTHOR]

Baurusuchidae is one of the most diverse groups of South American notosuchians, unambiguously recorded in Late Cretaceous deposits of Brazil and Argentina. The group is characterized by a reduced tooth formula, a lateromedially compressed rostrum, and a verticalized quadrate, representing one of the top predators of their faunas. Historically, skull morphology is the most employed tool to investigate the relationships of baurusuchids, as most of the species have been primarily based on cranial remains. The present study describes a new baurusuchid species from the Bauru Basin of Brazil, based on the first tridimensional digital reconstruction of individualized skull bones for Notosuchia, and discusses its phylogenetic position within the group. The new species differs from all the other known baurusuchids by a depression on the posterior portion of the nasal bearing a crest, an infraorbital crest of the jugal that extends until the anterior margin of the lacrimal, the dorsal surface of the frontal lacking a longitudinal crest or depression, and the lateral convexity of the squamosal prongs participating in the occipital wall. The new taxon is consistently positioned as sister to the remaining baurusuchines, with Aplestosuchus sordidus and Stratiotosuchus maxhechti, as successive sister‐taxa to a monophyletic Baurusuchus (Ba. albertoi, Ba. Salgadoensis, and Ba. pachecoi). Our updated phylogenetic analysis helps to differentiate the two major Baurusuchidae lineages, Baurusuchinae and Pissarrachampsinae. Yet, the new species shares morphological features with both groups, suggesting the occurrence of "Zones of Variability" in the radiation of Baurusuchidae. [ABSTRACT FROM AUTHOR]

The Pterygospinous foramen and pterygoalar foramen (crotaphitico-buccinatorius) are variant and atavic formations of the skull base and arise respectively from complete or incomplete idiopathic ossifications of the pterygospinous and pterygoalar ligaments. By proximity with areas of relevance for diagnosis and surgery, such as access pathways to the parapharyngeal and retropharyngeal spaces, it is necessary to be aware of these conditions due to the difficulties generated in surgical maneuvers and the promotion of compressive syndromes of mandibular nerve branches. This study was conducted on 45 samples of dry skulls and disarticulated sphenoid bones belonging to the collection of the Federal University of Juiz de Fora, Governador Valadares campus, Minas Gerais, Brazil. Our results indicated a total incidence of complete and incomplete pterygospinous and pterygoalar foramen (crotaphiticobuccinatorius) in 15, 5% (7 skulls), with a higher incidence for the incomplete form of pterygospinous foramen (Civinini foramen) in 4 skulls (8.8%), with 3 presenting unilaterally and 3 presenting bilaterally. The pterygoalar foramen (crotaphitico-buccinatorius or Hyrtl) was noted bilaterally in 1 of the skulls (2.2%). The pterygospinous foramen and pterygoalar foramen are important findings, sometimes incidental, of an area of great anatomical expressiveness and pathological occurrences, besides the indispensable and unclear studies of phylogenetic order. [ABSTRACT FROM AUTHOR]

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INTRODUCTION: Chordoma is an uncommon, slow-growing tumor, locally invasive and destructive, arising from notochordal remnants. It originates from skull base central portion, demonstrating different patterns of invasiveness, including duramater penetration and its spread through vascular structures, compromising its completely resection. OBJECTIVE: To analyze the different options of treatment, results, and complications. METHODS: Between 2002 and 2012, 31 patients presenting skull base chordomas were treated surgically at the Evangelico University Hospital of Curitiba, Curitiba-Brazil. The follow-up period was 1-72 months. All patients were evaluated by means of head CT and MRI. Surgical approaches were chosen for each specific case, aiming to obtain a tumor radical resection. Some patients were submitted to radiotherapy after surgical resection. RESULTS: Radical resection was performed in 81% of the patients. A five-year survival rate was 75%. Radical resection had a positive impact on the survival rate. The possibility to perform a radical resection depended on the tumor volume pre-operation and number of anatomic regions invaded. The sixth cranial nerve palsy and CSF fistula were the most common surgical complications. CONCLUSION: The purpose of the surgical management treating skull base chordomas consists in performing radical resection using different types of surgical approaches, which implies an acceptable risk. [ABSTRACT FROM AUTHOR]

Objective: To quantify longitudinal cranial base growth from prepubertal through postpubertal stages of development, as defined by biological indicators of individual skeletal maturity (cervical vertebral maturation - CVM) method and to determine if there is sexual dimorphism resulting from cranial base growth. Design: A longitudinal cephalometric study. Setting: The Dental School of Paulista University, Brazil. Participants: 36 subjects (21 females, 15 males) who were part of a longitudinal growth study and exhibited normal facial and normal vertical growth patterns. Methods: Growth maturation of cervical vertebrae stages was assessed by two examiners independently. Cranial base measurements were carried out by one individual and repeated after one month. The growth increments over time were assessed with the one-way repeated-measures analysis of variance and post hoc Tukey multiple comparisions. Results: There were no significant gender differences. There was a significant increase in all cephalonietric measures between the different time points. Ba-Na showed the greatest amount of growth (mean change=2.8 mm). From T2-T3, the greatest amount of growth was found for Se-Na (mean change=3.4 mm) and the lowest for CC-Na (mean change=l.4 mm). Comparing overall changes (T1-T3) all the measurements showed statistically significantly increases (P<0.05). For all comparisons of between-stage changes the cranial base grew more than 2.0 mm during the pubertal growth. Conclusions: Linear variables of cranial base showed significant growth during pubertal stages (pre-peak, peak and post-peak). No significant differences. [ABSTRACT FROM AUTHOR]

Background: Cerebrospinal fluid (CSF) leak of the anterior skull base is an abnormal communication between the subarachnoid space and the nasal cavity or the paranasal sinus. Its presence increases the incidence of complications, as meningitis, with risk of sequelae. The early and correct diagnosis of the CSF leaks is important to perform surgical treatment as soon as possible. The CSF detection in nasal fluids could be made through the beta2-transferrin (beta2Tr) immunoelectrophoretic test, an expensive and cumbersome immunologic test, not available to the majority of the Brazilian hospitals. Recently, the detection of beta-trace protein (betaTP) for identification of CSF leaks has been described. The literature suggests there may be similar sensitivity and specificity to tests of beta2Tr, because betaTP is also a specific brain protein and it is present in CSF in high concentrations. The majority of Brazilian hospitals have the nephelometric equipment for betaTP detection. This study was designed to determine threshold values for betaTP concentrations in nasal cavity secretions as a predictor of CFS leak. Methods: Nasal secretions were collected from patients with suspicion of CSF leak and from healthy volunteers. Pure CSF samples were used. A nephelometric assay was used to determine the betaTP concentration in samples. Results: Values between 0.244 and 0.496 mg/L were determined for the cutoff. Conclusion: Beta-trace concentrations above 0.496 mg/L are highly suggestive of the presence of CSF in examined nasal secretion. Positive predictive value and negative predictive value were 100%. BetaTP nephelometric test can predict the side of the CSF leak. [ABSTRACT FROM AUTHOR]

The removal of displaced dental elements from deep anatomical spaces is a condition that requires the knowledge of the region and skills to perform the procedure. The lateral pharyngeal space contains important structures such as the internal carotid artery and close proximity with the cranium basis. The aim of this paper is to report a clinical case of a lower third molar displaced to the lateral pharyngeal space after a mandibular angle fracture and its treatment by surgical intervention. The tooth was removed under general anesthesia by direct approach and the fracture was reduced and fixed with a plate and screws. This case report illustrates the importance of an immediate procedure to avoiding severe complications and further damage to important anatomical structures.

Background: We retrospectively reviewed the medical charts of 57 patients with advanced malignant cutaneous tumors involving the anterior skull base who underwent combined craniofacial resection in our department from January 1, 1981, to December 31, 1994., Methods: The data regarding histological results, demographic aspects, clinical presentation, previous treatment, extent of the disease, extent of surgical procedure, type of reconstruction, complications, and follow-up were analyzed using the chi 2 method. Survival analysis was performed using the Kaplan-Meier method., Results: We found prevalence of the male sex (60%) and white race (86%), with a mean age of 62 years. Thirty-five patients (61%) showed extensive lesions directly invading the anterior skull base (type II); 46 patients (81%) had been treated previously; 10 patients (18%) had dural invasion; 29 patients (51%) could not have the eyeball preserved; 32 patients (56%) underwent microsurgical reconstruction; and 45 patients (79%) underwent pericranial or galeal-pericranial flap reconstruction for the anterior skull base defect. Postoperative complications occurred in 29 patients (51%). The most common complication was postoperative infection (17 patients [59%]). Thirty-two patients (56%) were free of disease, and 4 (7%) were alive with disease at the time of our study., Conclusions: The extent of facial disease (P = .005) and the type of facial reconstruction (P = .01) were the most important risk factors in the development of infectious complications. Invasion of the dura and the type of reconstruction of the anterior skull base were the most important factors related to cerebrospinal fluid leakage (P = .003) and meningoencephalitis (P = .06). Invasion of the dura mater significantly affected survival (P = .005).