Alexandre Rodrigues Freire

Incidence of Retromolar Foramen in Human Mandibles: Ethnic and Clinical Aspects

SUMMARY: The retromolar foramen allows the passage of the neurovascular bundles that contribute to nutrition and innervation of the pulp and periodontium of the lower teeth. Knowledge of this anatomical variation may prevent complications in the anesthesia and surgical procedures in this area and serve as an anatomical landmark for ethnic identification. The aim of this study was to evaluate the impact of the retromolar foramen in human mandibles of adult Brazilians and discuss the clinical and ethnic related to the presence of this foramen. Were evaluated 222 human mandibles, dry, adults, Brazilians, independent of gender. The evaluation was performed by two examiners who standardized search from a previous anatomical study. The mandibles were analyzed: the presence of the retromolar foramen (bilateral or unilateral), the presence of the foramen on right and left sides, and the number of foramens present on each side. It was found that 59 had at least one mandible retromolar foramens resulting in an incidence of 26.58%. The retromolar foramen was present unilaterally in 41 mandibles and 18 bilaterally, with incidences of 18.47% and 12.16% respectively. On the right side, the retromolar foramen was present in incidences of 16.22% and 18.92% respectively. The analysis of the right side of the mandibles revealed that 47.46%, 21.21% and 3.03% had one, two and three foramens, respectively. The left side showed 55.93%, 16.22% and 8.11% of the 222 mandibles with one, two and three retromolar foramens, respectively. The incidence of retromolar foramen in the Brazilian population is significant and should be considered in the planning and execution of procedures in several areas of clinical practice dentistry in order to avoid complications. Moreover, it was found that the incidence of retromolar foramen contributes to differentiation of ethnic groups in the area of forensic anthropology. ˚

Caroticoclinoid foramen in human skulls: incidence, morphometry and its clinical implications

The caroticoclinoid foramen is an inconstant structure, formed by the union of the anterior and middle clinoid processes. The aim of this study was to perform an incidence and morphometry of the caroticoclinoid foramen in Brazilian human skulls and discuss its clinical implications. Eighty dry human skulls with sex distinction were used, and 3 groups of incidence were determined: General, sex, and sides. The morphometry was performed using a manual caliper and the major diameter of the foramina was measured; the values were also divided in general, according to sex and sides. The incidence of skulls with at least one foramen was 8.5%. According to the sides, 8.5% of the skulls showed foramen on the right side and 2.5% on the left. We found 2.5% of the skulls with bilateral foramen and 6.25% with unilateral foramen. In relation to sex, the foramens were found in 5% of male skulls and 12.5% of female skulls. The major diameter of this structure presented on mean, values of 5.23 mm on general, 5.18 mm on the right side and 5.35 mm on the left, 5.30 mm in male skulls and 5.18 mm in female skulls. The anatomical characteristics of this foramen should be considered in view of its clinical implications associated with neurosurgery as clinoid process removal, and symptoms as headache due to internal carotid artery alterations in this region. In conclusion knowledge of this structure supports the diagnosis and treatment of clinical complications related to this variation.

Identification and quantitative analysis of human transthyretin variants in human serum by Fourier transform ion-cyclotron resonance mass spectrometry

Transthyretin (TTR) is a homotetrameric protein involved in thyroid hormone transport in blood and in retinol binding in the central nervous system. More than 80 point mutations in this protein are known to be associated with the formation of amyloid deposits and systemic amyloidotic pathologies. Age at onset varies according to the mutation but considerable variations also occur for subjects carrying the same mutation. Moreover, wild-type TTR forms amyloid deposits in systemic senile amyloidosis, a geriatric disorder. An accurate diagnostic and the choice of therapeutic options depend on the identification of the specific mutation. Previous characterization of TTR variants by mass spectrometry required the use of antibodies for sample enrichment. We developed a novel assay based on ultra high-resolution mass spectrometry to identify human TTR variants. The method, requiring a very low sample amount, is based on SDS-PAGE fractionation of human serum, followed by peptide mass fingerprinting by MALDI-FTICR-MS (matrix assisted laser desorption ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry). Moreover, it is possible to perform a relative quantification of wild type and mutant TTR forms by mass spectrometry. The method was tested and validated with the V30M mutant, involved in familial amyloidotic neuropathy of Portuguese type.

Comparison of gunshot entrance morphologies caused by .40-caliber Smith & Wesson, .380-caliber, and 9-mm Luger bullets: a finite element analysis study.

Firearms can cause fatal wounds, which can be identified by traces on or around the body. However, there are cases where neither the bullet nor gun is found at the crime scene. Ballistic research involving finite element models can reproduce computational biomechanical conditions, without compromising bioethics, as they involve no direct tests on animals or humans. This study aims to compare the morphologies of gunshot entrance holes caused by.40-caliber Smith & Wesson (S&W), .380-caliber, and 9×19-mm Luger bullets. A fully metal-jacketed.40 S&W projectile, a fully metal-jacketed.380 projectile, and a fully metal-jacketed 9×19-mm Luger projectile were computationally fired at the glabellar region of the finite element model from a distance of 10 cm, at perpendicular incidence. The results show different morphologies in the entrance holes produced by the three bullets, using the same skull at the same shot distance. The results and traits of the entrance holes are discussed. Finite element models allow feasible computational ballistic research, which may be useful to forensic experts when comparing and analyzing data related to gunshot wounds in the forehead.

Stress Distribution in Human Zygomatic Pillar Using Three-Dimensional Finite Element Analysis

El objetivo de este articulo fue analizar la distribucion de la tension en el pilar cigomatico humano durante la contraccion del musculo masetero utilizando analisis de elementos finitos tridimensionales. Un modelo de tres dimensiones de dientes del hemicraneo facial fueron producidos sobre la base de datos de CT-scan. Se utilizo como modelo un craneo adulto de sexo masculino con la integridad de la anatomia estructural. Fuerzas musculares se aplicaron en el origen de los ascensores de los musculos de la mandibula y soportes se aplicaron a la superficie oclusal del primer y segundo molar para simular una carga masticatoria y estimular el pilar cigomatico. Condiciones de simetria se colocaron en el plano mediano. Se utilizaron restricciones en los planos superior y posterior. El analisis de las tensiones equivalentes von-Mises y maximo director se realizo a traves del campo de esfuerzos a lo largo del pilar cigomatico. Fue representada la concentracion de esfuerzos en el proceso alveolar, hueso cigomatico, proceso frontal y temporal del hueso cigomatico y el arco superciliar. La linea de tension indica la distribucion de la tension del maxilar hacia el hueso frontal y temporal. Las tensiones se produjeron debido a las fuerzas oclusales resultantes, que se apoyan principalmente por el hueso cigomatico, distribuidas de manera no uniforme y sobre todo a traves del pilar cigomatico. Este estudio ha contribuido a una mejor comprension de la distribucion de la tension en el pilar cigomatico para entender la influencia de la masticacion sobre la morfologia de este pilar y ser de utilidad en la practica clinica.

Forámenes Emisarios del Cráneo Humano: Características Anatómicas y sus Relaciones con la Neurocirugía Clínica

Department of Morphology State University of Campinas - UNICAMP, Anatomy Area, Piracicaba, SP

Review of In Vivo Bone Strain Studies and Finite Element Models of the Zygomatic Complex in Humans and Nonhuman Primates: Implications for Clinical Research and Practice.

The craniofacial skeleton is often described in the clinical literature as being comprised of vertical bony pillars, which transmit forces from the toothrow to the neurocranium as axial compressive stresses, reinforced transversely by buttresses. Here, we review the literature on bony microarchitecture, in vivo bone strain, and finite‐element modeling of the facial skeleton of humans and nonhuman primates to address questions regarding the structural and functional existence of facial pillars and buttresses. Available bone material properties data do not support the existence of pillars and buttresses in humans or Sapajus apella. Deformation regimes in the zygomatic complex emphasize bending and shear, therefore conceptualizing the zygomatic complex of humans or nonhuman primates as a pillar obscures its patterns of stress, strain, and deformation. Human fossil relatives and chimpanzees exhibit strain regimes corroborating the existence of a canine‐frontal pillar, but the notion of a zygomatic pillar has no support. The emerging consensus on patterns of strain and deformation in finite element models (FEMs) of the human facial skeleton corroborates hypotheses in the clinical literature regarding zygomatic complex function, and provide new insights into patterns of failure of titanium and resorbable plates in experimental studies. It is suggested that the “pillar and buttress” model of human craniofacial skeleton function be replaced with FEMs that more accurately and precisely represent in vivo function, and which can serve as the basis for future research into implants used in restoration of occlusal function and fracture repair. Anat Rec, 299:1753–1778, 2016.

Computer Graphics Applied to Anatomy: A Study of two Bio-CAD Modeling Methods on Finite Element Analysis of Human Edentulous Hemi-Mandible

Univ Estadual Campinas, Piracicaba Dent Sch, Anat Area, Dept Morphol, Piracicaba, SP, Brazil

Orbital aperture morphometry in Brazilian population by postero-anterior Caldwell radiographs

Morphological variations of the orbital aperture measurements act as parameter for sexual and ethnic determination. The aim of this study evaluated the dimensions of the orbital aperture in Brazilian subjects to verify its relationship to gender. The orbital apertures of 97 individuals were examined through Caldwell radiographic technique. The maximum width and height of the orbits were measured. The inter-orbital distance, which is the minimum distance between the medial walls of the orbits, was also measured. Statistical analysis was performed through the Pearson test for correlation between measurements and Student t test with 5% significance level to verify the relation between the gender. Determination of significance attributed to non-parametric Kruskal-Wallis and Mann-Whitney tests (p<0.05). The test of intra-class correlation (ICC) showed satisfactory repeatability (ICC=0.9932, p<0.0001) between measurements performed, taken at different time periods. The ICC showed satisfactory repeatability (ICC=0.9932, p<0.0001) between measurements performed at different periods. In the t test, significant differences between the genders, the width, and area of the orbital aperture were obtained. In conclusion, if the area of orbital aperture is <8.5 cm2, the skull is likely to be a female; if it is >9.0 cm2, it is likely to be a male. If the width of orbital aperture is <3.5 cm the skull is likely to be a female; if it is >3.5 cm, it is likely to be a male. If the inter-orbital distance is <2.4 cm the skull is likely to be a female; if it is >2.5 cm, it is likely to be a male.

The effect of a hydroxyapatite impregnated PCL membrane in rat subcritical calvarial bone defects

OBJECTIVE The present study evaluated the effect of polymeric-nanofibers membranes impregnated with microparticulate hydroxyapatite (HA) in the subcritical calvarial bone defects (SCBD) healing. DESIGN PCL membranes with and without HA were obtained by electrospinning. SCBD were perforated (3.3mm) in left and right sides of 36 rat calvarias. The right-side SBCD of 18 animals was filled with HA mixed with blood clot and blood clot at the contralateral side. The remaining animals received PCL+HA membrane at the right-side SCBD and PCL membrane at the contralateral side. Animals were killed after 30, 60 and 90days after surgery. Bone defect volume (in mm3) was measured by tomography (CBCT). Qualitative histological analysis and SBCD area (in mm2) were measured. Quantitative data were submitted to Kruskal-Wallis/Dunn tests. RESULTS Reduction of SBCD volume was observed in all treatments but PCL. Association with HA significantly improved bone healing induced by PCL and blood clot. PCL+HA induced the lowest SBCD volume at 60 and 90days. Complete bone healing was not observed even at 90days in SCBD treated with blood clot. In every period, more bone formation was observed for SCBD treated with membranes. CONCLUSIONS We concluded that both PCL membrane and HA were able to improve bone healing.