Does Ovariectomy Affect the Mechanics of the Mandibular Alveolar Bone Structure of Wistar Rats Subjected to Tooth Loss and Modified Diet?-A FEA Study.

The aim of this study was to evaluate the mechanical effect of ovariectomy, diet, and tooth extraction on the bone structure of the mandible of Wistar rats. Mandibles from 40 female Wistar rats were used, divided into rats with ovariectomy surgery or surgical simulation. Half of the rats had the right upper incisor extracted and a soft diet was introduced for half of the animals for 30 days.

Fenestration and Dehiscence in Human Maxillary Alveolar Bone: An In Silico Study Using the Finite Element Method.

Introduction: Fenestration and dehiscence are alveolar bone defects. Although not considered a pathology, these alveolar bone defects end up influencing dental treatment, such as surgeries, mainly periodontal, and therefore must be considered during treatment planning. However, currently, little is known about the biomechanical origin of these bone formations.

A Different Pattern of Arrangement of the Risorius Muscle Fibers: A Case Report.

The risorius is a very thin muscle and is one of the superficial muscles of facial expression, which is reported as being inconstant, as it is absent in most people, and is a unique muscle; once it has no bony origin. The study aimed to report a different pattern of arrangement of the risorius muscle fibers. During a routine Anatomy class, a different pattern of arrangement of the risorius muscles fibers was found from the observation of an adult (around 40 years old) male cadaver hemiface (right side).

Chronic exposure to lead acetate promotes changes in the alveolar bone of rats: microstructural and physical-chemical characterization.

There are a few data relating to the effects of lead (Pb) exposure on the alveolar bone, which has very distinct morphophysiological characteristics and is of great importance in the oral cavity. In this context, the aim of this study was to investigate the changes promoted after long-term exposure to Pb in the microstructure of the alveolar bone of rats. Twenty adult Wistar rats were exposed to 50 mg/kg/day of lead acetate for 55 days.

Effects of premature contact in maxillary alveolar bone in rats: relationship between experimental analyses and a micro scale FEA computational simulation study.

Objective: The aim of the investigation was to evaluate the maxillary alveolar bone morphology, bone architecture, and bone turnover in relation to the mechanical strain distribution in rats with dental premature contact.

Materials And Methods: Fifty 2-month-old male Wistar rats were used. The premature contact group (N=40) received a unilateral (right side) resin cementation on the occlusal surface of the upper first molar.

β-catenin and Its Relation to Alveolar Bone Mechanical Deformation - A Study Conducted in Rats With Tooth Extraction.

The aim of this study was to analyze the relationship between alveolar bone deformation and β-catenin expression levels in response to the mechanical load changed by dental extraction in adult rats. Twenty-four male rats (), Wistar linage, at 2 months of age, were used. The right upper incisor tooth was extracted, and euthanasia occurred in periods 5 ( = 6), 7 ( = 6), and 14 ( = 6) days after Day 0.

Craniofacial injuries by firearms projectiles: An analysis of 868 deaths in the five regions of Brazil.

Firearms injuries have a legal and medico-legal importance, and are especially lethal when they reach the craniofacial regions of the victim. The present study aims to identify the characteristics of craniofacial lesions resulting from firearm projectiles, to register the most affected craniofacial regions by this type of injury and to verify the demographic profile of the victims. A retrospective study was carried out on the autopsy records produced in the first semester of 2015, in five Institutes of Legal Medicine in Porto Velho, situated in the cities of João Pessoa, Vitória, Porto Alegre and Brasília.

Application and validation of Diagnose Sexuelle Probabiliste V2 tool in a miscegenated population.

The hip bone (os coxae) is the skeletal element that presents the greatest level of sexual dimorphism. Therefore, methods involving the analysis of the os coxae provide the most accurate sex estimation, and DSP2 (Diagnose Sexuelle Probabiliste v.2) is one of the most accurate tools used in this identification.

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis.

Introduction: Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study.

Objectives: The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis.

A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis.

Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene).

Resorptive potential of impacted mandibular third molars: 3D simulation by finite element analysis.

Objectives: Previous studies have suggested a relationship between resorption in second molars and pressure from the eruptive force of the third molar. The aim of this study was to simulate functional forces in a mandible model by means of finite element analysis and then assess the biomechanical response produced by impacted third molars on the roots of the second molar.

Materials And Methods: A cone beam computed tomography scan presenting an impacted mandibular third molar was segmented (Mimics V17 software).

Morphometric and histologic characterization of alveolar bone from hypertensive patients.

Background: Hypertension is considered a risk factor in implant dentistry but the underlying reasons remain unclear. It may be that hypertension has a negative impact on the local bone quality.

Purpose: Here we evaluated the structural and histological parameters of bone collected from hypertensive patients treated by antagonists of the renin-angiotensin system, and of bone collected from normotensive patients.

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.

Raloxifene but not alendronate can compensate the impaired osseointegration in osteoporotic rats.

Objectives: Alendronate and raloxifene, a bisphosphonate and a selective estrogen modulator, respectively, are established osteoporosis therapies. Current evidence suggests that simultaneous application of osteoporosis therapies modulates osseointegration. However, alendronate shows inconsistent findings and raloxifene has not been studied comprehensively.

Computational Approach to Identify Different Injuries by Firearms.

Complications arise in the analysis of gunshot wounds to the maxillofacial region, when neither the projectile nor the gun is found at the crime scene. We simulated 5- and 15-cm firing distances at a human mandible to investigate the external morphology of entrance wounds based on fire range. The ammunition models, .

Association between Facial Type and Mandibular Canal Morphology - Analysis in Digital Panoramic Radiographs.

In this study we investigate the association between facial type and mandibular canal course morphology analysing this in digital panoramic radiographs images. We used 603 digital images from panoramic radiographs. We selected only panoramic radiographs of fully dentate individuals, who had all lower molars bilaterally and with complete root formation.

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.

Finite-element analysis of 3 situations of trauma in the human edentulous mandible.

Purpose: Maxillofacial trauma resulting from falls in elderly patients is a major social and health care concern. Most of these traumatic events involve mandibular fractures. The aim of this study was to analyze stress distributions from traumatic loads applied on the symphyseal, parasymphyseal, and mandibular body regions in the elderly edentulous mandible using finite-element analysis (FEA).

Photoelastic and finite element analyses of occlusal loads in mandibular body.

This study proposed to evaluate the mandibular biomechanics in the posterior dentition based on experimental and computational analyses. The analyses were performed on a model of human mandible, which was modeled by epoxy resin for photoelastic analysis and by computer-aided design for finite element analysis. To standardize the evaluation, specific areas were determined at the lateral surface of mandibular body.

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.

The application of finite element analysis in the skull biomechanics and dentistry.

Empirical concepts describe the direction of the masticatory stress dissipation in the skull. The scientific evidence of the trajectories and the magnitude of stress dissipation can help in the diagnosis of the masticatory alterations and the planning of oral rehabilitation in the different areas of Dentistry. The Finite Element Analysis (FEA) is a tool that may reproduce complex structures with irregular geometries of natural and artificial tissues of the human body because it uses mathematical functions that enable the understanding of the craniofacial biomechanics.

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.

Histometric analysis of bone repair in bone-implant interface using a polylactic/polyglycolic acid copolymer associated with implants in rabbit tibia.

The purpose of this study was to evaluate the association of the combination of polylactic/polyglycolic acid around implants installed with and without primary stability through the histometric analysis of bone-implant interface. We used male rabbits, each of which received 2 titanium implants in each tibial metaphysis. The animals were divided into 4 groups: control with primary stability (CPS), control without primary stability (C), polymer with primary stability (PPS), and polymer without primary stability (P).