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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. The aim of the study was to use the finite element method (FEM) to test hypotheses of predictive factors for fenestrations and dehiscence in human alveolar bone., Methods: A FEM simulation of the action of functional, parafunctional, and orthodontic occlusal loads on the upper central incisor and upper canine was performed. For the simulation, a three-dimensional model of an adult human skull, fully dented and with intact bone structure, was constructed from computed tomography images. The buccal alveolar bone lamina was evaluated considering the calculation of equivalent stresses, as well as maximum principal stresses., Results: The action of functional and parafunctional forces on the incisal edges and the orthodontic force on the buccal face of the upper central incisor and upper canine teeth generated tensions at different levels of magnitude in the buccal bone lamina, varying in regions, at all levels of strength. Changing levels of force magnitude resulted in variations in relation to the level of deformation., Conclusion: The computational simulation using the FEM was able to identify a difference in stress in the alveolar bone tissue in each of the applied forces. The difference in stresses obtained may suggest the formation of dehiscence or fenestration in the region studied., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Furlan et al.)

Background: Cases of variations in anterior belly of the digastric muscle must be carefully identified to avoid misinterpretations and assist in the correct surgical or aesthetic procedure and help in the teaching of anatomy. The aim of this study was to describe the anatomical variations of anterior belly of digastric muscle in Brazilian cadavers., Materials and Methods: Thirty-one human heads were selected, from adult cadavers (18-80 years, 29 males and 2 females). The morphology of the anterior belly of the digastric muscle was observed, identifying the possible anatomical variations that were characterised and classified according to the amount of muscle bellies, fibre direction and place of origin and insertion. The morphometric measurements were performed using a digital calliper. To analyse the data obtained, photographic documentation, anatomical description and individual morphometric description of each muscle belly were performed. The incidence of anatomical variation was obtained in percentage (%)., Results: The anatomical variation of the anterior belly of the digastric muscle was present in 6 cadavers (19.31%; 1 female and 5 male). All anatomical variations presented an accessory belly to the anterior belly. However, these accessory bellies were configured differently in the location, direction of muscle fibres and in their dimensions (length and width)., Conclusions: The gross anatomy of the anterior belly of the digastric muscle and their variations is important to assist in surgical procedures, pathological or diagnostic function. In addition, asymmetrical variations in the submental region must be carefully identified to avoid misinterpretations.

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. These animals were euthanized and had their mandible removed. Each mandible was divided into hemimandibles, and the alveolar bone was used for bone lead quantification, crystallinity analysis, microstructure evaluation by the percentage of bone volume (BV/TV), number of trabeculae (Tb.N), thickness of the trabecular (Tb.Th), and trabecular space (Tb.Sp). Morphometric analysis of the exposed root area was also performed. Long-term exposure to Pb resulted in high levels of Pb in the alveolar bone but showed no changes in the organization of crystallinity. The microstructural analyses showed a reduction of BV/TV, Tb.Th, and Tb.N and increase of Tb.Sp parameters, resulting in an increase in the exposed root area and an alveolar bone loss in height. The findings of this study reveal the ability of Pb to alter the alveolar bone microstructure after long-term exposure to the metal, possibly due to changes in tissue homeostasis, contributing to the reduction of bone quality., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The foramen tympanicum is located on the anteroinferior region of the external acoustic meatus and posteromedial to the temporomandibular joint in children between the 1st and the 5th year of life. It is considered an anatomical variation when it persists in adults. The aim of this study was to verify the prevalence as well as to characterise the foramen tympanicum in computed tomography (CT) scans of the population from southeastern part of Brazil., Materials and Methods: A total of 78 CT scans of dry human skulls (20 female and 58 male) were used, which were selected randomly regarding the ages, ranged from 15 to 100 years. The foramen tympanicum was identified in the images of the axial plane and confirmed in the images of the coronal and sagittal planes. The largest diameter (in mm) was obtained. The descriptive statistics (in %), Fisher's test and χ2 test were performed to compare the prevalence of foramen tympanicum between sexes and sides. The probability value ≤ 0.05 was defined as a level of significance. Descriptive statistics were performed to verify the mean diameter of the foramen on the right and left sides of the skulls., Results: The prevalence of foramen tympanicum was higher in females (p = 0.0070), bilaterally, as the absolute values of females were lower in relation to males. Fisher's exact test showed that the prevalence of foramen tympanicum was significantly higher in females (45%) than in males (15.52%). On the right side, the mean axial diameter was 2.23 mm (range 0.93-3.75 mm). On the left side, the mean axial diameter was 2.22 mm (range 0.9-3.61 mm)., Conclusions: The knowledge of anatomical variations is extremely valuable for an accurate diagnosis, treatment plan and prognosis and a thorough preoperative assessment.

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. The animals were distributed in 4 subgroups according to the periods of euthanasia: 7, 14, 21, and 28 days after cementation (N=10, for each period). For the control group (N=10), the teeth were kept without resin, featuring a normal occlusion. The pieces including the upper first molars, alveolar bone, and periodontal tissue were processed to histological and immunohistochemical evaluation of RANK-L and TRAP protein expression. A three-dimensional bone microarchitecture analysis was performed, where the heads of animals were scanned using microtomography and analyzed using CT-Analyser software (Bruker, Kontich, Belgium). In the computer simulation by finite element analysis, two micro-scaled three-dimensional finite element models of first molar and dentoalveolar tissues were constructed, in representation of control and premature contact groups, using Materialise MIMICS Academic Research v18 (Materialise, Leuven, Belgium). The analysis was set to simulate a maxillary molar biting during the power stroke phase. The total deformation, equivalent strain, and minimum principal strain distribution were calculated., Results: The expression of RANK-L and TRAP presented higher positive ratio in the 7-day period compared to the control group. The three-dimensional morphometry showed decrease of bone volume in the premature contact, with significant values between the control and the 7-day and 14-day groups (P = 0.007). In FEA, the premature contact model presented a uniform compressive strain distribution in the alveolar bone crest compared to a non-uniform compressive strain distribution in the control model., Conclusions: The results from FEA, 3D bone microarchitecture, and histological and immunohistochemical analyses showed that a model with dental traumatic occlusion resulted in changes of alveolar bone mechanobiology and, consequently, its morphology., Clinical Relevance: These results could be applied in dental treatment planning bringing biological and mechanical feedback to provide an effective mechanism to obtain physiological bone loss responses. Furthermore, this association between experimental and computational analyses will be important to figure out the alveolar bone response to mechanical stimulation in different clinical conditions., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Purpose: As the hard palate is a central structure of the skull and is involved in orthodontic and surgical procedures, it would be of interest to study the morphological aspects of this bone and its possible variations as per different patterns of skeletal development. Thus, this study aimed to develop a classification for the different morphological characteristics of the hard palate and to evaluate the relationship between these characteristics and the different skeletal patterns, using cone-beam computed tomography (CBCT)., Materials and Methods: This retrospective and cross-sectional study used CBCT scans of patients seen from January 2014 to December 2016. Carestream Dental 3D Imaging software was applied to classify each patient according to vertical and sagittal skeletal patterns, and to evaluate the 3 morphological characteristics of the hard palate: depth (flat, regular, or deep), inclination (superior, parallel, or inferior), and presence of a bony projection (S-shaped). χ 2 and Fisher's exact tests evaluated the relationship between the hard palate characteristics and the different skeletal patterns., Results: A total of 298 CBCT scans (144 males and 154 females) were evaluated. The depth of the hard palate was significantly related to both skeletal patterns in males (P < .05), with Class II and dolichocephalics presenting a greater amount of deep palates, while classes I and III and brachycephalics had a greater amount of regular palates. The inclination of the hard palate was significantly associated with the facial type in females (P < .05), with brachycephalics and mesocephalics presenting a greater amount of parallel palates, whereas dolichocephalics had a greater number of inferiorly inclined palates. Regarding the presence of the S-shape in the hard palate, there was a greater number of this projection in Class II males and brachycephalic females., Conclusions: A morphological classification for the hard palate was developed. The morphology of the hard palate varied among the different skeletal patterns., (Copyright © 2020 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

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 ( Rattus norvegicus albinus ), Wistar linage, at 2 months of age, were used. The right upper incisor tooth was extracted, and euthanasia occurred in periods 5 ( n = 6), 7 ( n = 6), and 14 ( n = 6) days after Day 0. In the control group ( n = 6), the dentition was maintained. The euthanasia occurred within 14 days after day 0. After euthanasia, the rats of all groups had their left jaw with tooth removed and separated in the middle. The pieces were undergone routine histological processing and then the immunohistochemical marking were performed to label expression of the primary β-catenin antibody, which was evaluated by qualitative and quantitative analysis. One head by each group (control and experimental) was submitted to computerized microtomography. After the three-dimensional reconstruction of the skull of the rat in each group, the computational simulation for finite elements analysis were performed to simulate a bite in the incisors. In finite element analysis, the strain patterns were evaluated after the application of bite force. The results were analyzed considering the areas in which changes in the amount of deformations were detected. The action of the bite force in the experimental condition, resulted in a uniform distribution of the amount of deformations, in addition to lower amount of deformation areas, differentiating from the control group. Comparing with the control group, the levels of β-catenin signaled in the lingual bone of the middle third of the alveolar bone were raised in the periods of 5 and 14 days. The increased β-catenin positive staining intensity was concentrated on osteocytes and gaps of osteocytes. The findings of the present study were in accordance with our hypothesis that the condition of dental extraction can cause the expression of β-catenin and alter the regimes of bone deformation., (Copyright © 2020 Ferreira, Freire, Araujo, Amaral-Silva, Okamoto, Prado and Rossi.)

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. Data extracted included sex, skin color and age of the victim, craniofacial region reached, shooting distance, shape and size of the injuries and manner of death (homicide, suicide or accident). Based on the 868 reports analyzed, it was possible to observe 1700 entrance lesions of firearm projectiles in craniofacial regions. Among cases of known manner of death, homicides were the most frequent (97.0%). It was observed a higher frequency of male victims (93.3%), mixed race (62.0%), between the ages of 12 and 29 years (59.4%). In all cases considered as suicide or accident there was only one entrance wound, but in 82.8% of the homicides there were multiple gunshot wounds. The craniofacial most affected regions were temporal (25.2%) and occipital (19.8%). The most common sites of projectiles exit were the temporal (25.3%) and parietal (16.1%). All cases of suicide were related to contact shot (69.2%) or close-range shot (30.8%), and among the homicides the distant range shots were more frequent (54.0%). The shape of entrance wounds was mostly circular (56.8%) and oval (31.3%), and among the exit injuries, the lesions were irregular (43.3%) and starry (24.1%). The entrance wounds showed smaller sizes than the exit lesions (p < 0.0001). The data obtained are useful for guiding research that takes into account craniofacial trauma caused by firearm projectiles, makes it possible to compare this data with those of other countries and can base investigative conclusions based on the analyzes discussed in the present work., (Copyright © 2019. Published by Elsevier Ltd.)

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). The modeling process was performed using the reverse engineering technique provided by the Rhinoceros 3D 5.0 software. The third molar position was changed in order to produce different inclinations of the impacted tooth. Bite forces were simulated to evaluate total deformation, the equivalent von Mises stress, minimum principal stress on hard tissue, and equivalent elastic strain on soft tissue., Results: Areas of high energy dissipation and compression stress were detected in the second molar root, independently of the inclination of the impacted third molar. In general, the horizontal position was the situation in which major stress and the amount of deformation occurred in the second and third molar regions., Conclusion: Impacted third molars in close proximity with the adjacent tooth can generate areas of compression concentrated at the site of contact, which suggests an involvement of mechanical factors in the triggering of resorption lesions., Clinical Relevance: The results of these computational experiments contribute to the understanding of the triggering and progression of resorptive lesions in the adjacent second molar.

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. The goal of this study is to apply and validate DSP2 in the identification of 103 os coxae (53 male and 50 female) belonging to a Brazilian-identified skeletal collection. Differences between sexes were statistically significant for all measurements, except for the acetabulo-symphyseal and spino-auricular lengths. From the 103 os coxae analyzed, there was a 9.43% error in male individuals and a 14% error in females. The results revealed that DSP2 can be applied to Brazilian-mixed populations with a good index of accuracy, although at a lower accuracy than other population samples. This study also clearly demonstrates that metric variation of the os coxae is extremely useful in sex estimation and reinforces the notion that pelvic sexual dimorphism is not population-specific., (Copyright © 2018 Elsevier B.V. All rights reserved.)

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. This study aimed to evaluate the bone dynamics and molecular and microstructural features at the peri-implant bone interface in osteoporotic rats., Materials and Methods: Thirty female rats underwent ovariectomy and were fed a diet low in calcium and phosphate and treated with alendronate or raloxifene for 30 days or underwent fictional ovariectomy surgery (SHAM) prior to implant insertion in the tibia; osteoporosis therapies continued thereafter. After 42 days, peri-implant bone was evaluated by histometric and micro-CT analysis. Fluorochrome incorporation and gene expression was determined to evaluate bone turnover., Results: We report here that alendronate had no impact on bone-to-implant contacts and the mineral apposition rate. The RANKL/OPG ratio and local bone volume, however, were increased compared to the untreated osteoporotic rats. Even though signaling to bone resorption activity through RANKL production was observed in the alendronate group, the blockade of bone resorption activity that occurs in decorrence to alendronate activity took place and resulted in an increase in bone volume. Raloxifene significantly increased osseointegration in osteoporotic rats, as indicated by bone-to-implant contacts, mineral apposition, and local bone volume. Raloxifene, however, had no considerable impact on the RANKL/OPG ratio compared to untreated osteoporotic rats. As expected, the SH group showed higher bone-to-implant contacts and mineral apposition rates than the untreated osteoporotic rats., Conclusions: These findings suggest that raloxifene but not alendronate can compensate for the impaired osseointegration in osteoporotic rats., Clinical Relevance: Regarding the superiority of raloxifene observed in the improvement of bone dynamics response, this statement suggests that raloxifene could be a good option for osteoporosis patients in oral rehabilitation procedures.

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). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healing.

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 mm 3 ) was measured by tomography (CBCT). Qualitative histological analysis and SBCD area (in mm 2 ) 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., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

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, .40-caliber S&W, .380-caliber, and 9 × 19-mm Luger, were constructed with free-form NURBS surfaces. In a dynamic simulation, projectiles were fired against mandibular body 3D model at 5 and 15 cm. All entrance wounds presented oval aspect. Maximum diameter and von Mises stress values were 16.5 mm and 50.8 MPa, both for .40-caliber S&W fired at 5 cm. The maximum energy loss was 138.4 J for .40 S&W fired at 15 cm. In conclusion, the mandible was most affected by .40-caliber S&W and morphological differences were observable in holes caused by different incoming projectile calibers fired at different distances., (© 2017 American Academy of Forensic Sciences.)

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. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

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. The sample distribution was determined by facial type and sex. The course of the mandibular canal, as seen in the panoramic radiographs, was classified into 3 types, bilaterally. The classification used was: type 1 if the mandibular canal is in contact or is positioned at most 2 mm from the root apex of the three permanent molars; type 2 if the mandibular canal is located halfway between the root apex of the three permanent molars and a half away from the mandibular basis; and type 3 if the mandibular canal is in contact with or approaches, a maximum of 2 mm from the cortical bone of the mandibular basis. For results, the data were analyzed by Chi-square test (p<0.05). Data analysis (Chi-square) showed there were more canals type 2 (p=0.0012) and fewer canals type 1 (p=0.0336) in females than in males, without association with the facial types. In conclusion, the facial type does not associated with the mandibular canal course analyzed.

The aim of this study was to evaluate bone healing at the bone-implant interface in rats with induced osteoporosis. The rats underwent a bilateral ovariectomy (OVX) and were fed a low calcium and phosphate diet. The OVX rats were divided into three groups: one was treated with raloxifene (OVX-RAL), one with alendronate (OVX-ALE), and one received no medication (OVX-NT). The control group rats (SHAM-DN) underwent sham surgery and were fed a normal diet. Each animal received one implant in each tibia: a machined surface implant in the right tibia and an implant with surface etching in the left tibia. All animals were euthanized after 42 days. Analysis of variance (ANOVA) and Tukey post hoc tests were applied to the biomechanics (reverse torque) and bone-implant contact (BIC) data (P<0.05). The RAL and ALE groups showed improved peri-implant bone healing. However, the ALE group showed no significant difference from the OVX-NT group. Surface treatment promoted higher corticalization at the bone-implant interface, but showed the same characteristics of mature bone and bone neoformation in concentric laminations as the machined implant. There were no statistically significant differences in reverse torque (P=0.861) or BIC (P=0.745) between the OVX-RAL and SHAM-DN groups. Therefore, the use of raloxifene resulted in good biomechanical, BIC, and histological findings in the treatment of induced osteoporosis in rats., (Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

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)., Materials and Methods: Computerized tomographic analysis of an edentulous macerated human mandible of a patient approximately 65 years old was performed. The bone structure was converted into a 3-dimensional stereolithographic model, which was used to construct the computer-aided design (CAD) geometry for FEA. The mechanical properties of cortical and cancellous bone were characterized as isotropic and elastic structures, respectively, in the CAD model. The condyles were constrained to prevent free movement in the x-, y-, and z-axes during simulation. This enabled the simulation to include the presence of masticatory muscles during trauma. Three different simulations were performed. Loads of 700 N were applied perpendicular to the surface of the cortical bone in the symphyseal, parasymphyseal, and mandibular body regions. The simulation results were evaluated according to equivalent von Mises stress distributions., Results: Traumatic load at the symphyseal region generated low stress levels in the mental region and high stress levels in the mandibular neck. Traumatic load at the parasymphyseal region concentrated the resulting stress close to the mental foramen. Traumatic load in the mandibular body generated extensive stress in the mandibular body, angle, and ramus., Conclusions: FEA enabled precise mapping of the stress distribution in a human elderly edentulous mandible (neck and mandibular angle) in response to 3 different traumatic load conditions. This knowledge can help guide emergency responders as they evaluate patients after a traumatic event., (Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The use of screening techniques, such as an alternative light source (ALS), is important for finding biological evidence at a crime scene. The objective of this study was to evaluate whether biological fluid (blood, semen, saliva, and urine) deposited on different surfaces changes as a function of the age of the sample. Stains were illuminated with a Megamaxx™ ALS System and photographed with a Canon EOS Utility™ camera. Adobe Photoshop™ was utilized to prepare photographs for analysis, and then ImageJ™ was used to record the brightness values of pixels in the images. Data were submitted to analysis of variance using a generalized linear mixed model with two fixed effects (surface and fluid). Time was treated as a random effect (through repeated measures) with a first-order autoregressive covariance structure. Means of significant effects were compared by the Tukey test. The fluorescence of the analyzed biological material varied depending on the age of the sample. Fluorescence was lower when the samples were moist. Fluorescence remained constant when the sample was dry, up to the maximum period analyzed (60 days), independent of the substrate on which the fluid was deposited, showing the novelty of this study. Therefore, the forensic expert can detect biological fluids at the crime scene using an ALS even several days after a crime has occurred., (Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.)

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.

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. The aim of this study was to review the literature on the advantages and limitations of FEA in the skull biomechanics and Dentistry study. The keywords of the selected original research articles were: Finite element analysis, biomechanics, skull, Dentistry, teeth, and implant. The literature review was performed in the databases, PUBMED, MEDLINE and SCOPUS. The selected books and articles were between the years 1928 and 2010. The FEA is an assessment tool whose application in different areas of the Dentistry has gradually increased over the past 10 years, but its application in the analysis of the skull biomechanics is scarce. The main advantages of the FEA are the realistic mode of approach and the possibility of results being based on analysis of only one model. On the other hand, the main limitation of the FEA studies is the lack of anatomical details in the modeling phase of the craniofacial structures and the lack of information about the material properties.

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. The photoelastic analysis was configured through a vertical load on the first upper molar and fixed support at the ramus of mandible. The same configuration was used in the computer simulation. Force magnitudes of 50, 100, 150, and 200 N were applied to evaluate the bone stress. The stress results presented similar distribution in both analyses, with the more intense stress being at retromolar area and oblique line and alveolar process at molar level. This study presented the similarity of results in the experimental and computational analyses and, thus, showed the high importance of morphology biomechanical characterization at posterior dentition.

Human identification is usually obtained by comparing fingerprints, antemortem and postmortem radiographs, dental records and also by DNA profiling. Sometimes forensic investigators come across some medical appliances such as orthopedic devices. These medical devices may be useful to achieve positive human identification. This paper aims to present a positive identification of a burned human body by tracking batch numbers engraved in an implanted orthopedic device found in the decedent's left ulna bone. The examiners also collected and analyzed other valuable hints related to the case. Forensic examination can provide reliable positive human identification, even if few, but precise information can be obtained from antemortem and postmortem records. The present report illustrates a set of valuable techniques and how identifying numbers in orthopedic devices are helpful to determine positive human identification in cases of carbonization. As seen in this case, the forensic experts used low-cost identification procedures with accurate results, avoiding DNA profiling method that would be of higher cost and time consuming. Considering social and legal aspects, it is quite important that physicians and dentists understand that correct and accurate records of surgeries they perform, such as fixation of orthopedic devices and dental implants, are utterly relevant and helpful in cases of human identification., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

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., (Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Objectives: The purpose of this study was to cephalometrically evaluate the pharyngeal airway space and frontal and sphenoid sinus changes after maxillomandibular advancement counterclockwise rotation for class II anterior open bite malocclusion., Methods: The study included 49 patients (98 lateral teleradiographs; 36 females and 13 males) who were analysed in the pre-operative (1 week before surgery) and post-operative (6 months after surgery) periods. In each lateral teleradiography, the dimensions of the inferior and superior pharyngeal airway space, TB-PhW1 [the point between the posterior aspect of the tongue to the dorsal pharyngeal wall (oropharynx) (TB) and the point on the dorsal pharyngeal wall closest to TB (PhW1)] and UP-PhW2 [and the point between the posterior aspect of the soft palate to the dorsal pharyngeal wall (nasopharynx) (UP) (PhW2)] measurements were evaluated, as well as the dimensions of the frontal and sphenoid sinuses. The differences between the two operative times were evaluated by Student's t-test., Results: All measurements showed excellent reproducibility for the intraclass correlation coefficient (ICC > 0.9; p < 0.0001). There was an increase in the measurements TB-PhW1 and UP-PhW2 and a decrease in the dimensions of the frontal and sphenoid sinuses after orthognathic surgery., Conclusions: The morphology of the superior and inferior pharyngeal airway space and frontal and sphenoid sinuses changes after 6 months of maxillomandibular advancement counterclockwise rotation for class II anterior open bite malocclusion.

The use of a rubber dam is an essential procedure when treating root canals, and not using it may compromise the success of the treatment, as well as the patient's health. This report presents a case in which a K-file was accidentally swallowed during an endodontic procedure, performed without the use of a rubber dam. Given the absence of immediate clinical complications, the subject underwent a chest radiograph. The file was located at the oesophagogastric junction and was later removed by endoscopy. In addition to the clinical repercussions, this example also illustrates the ethical-legal aspects of this type of accident., (© 2009 The Authors. Australian Endodontic Journal © 2009 Australian Society of Endodontology.)

Today, there is increasing use of CT scanning on a clinical basis, aiding in the diagnosis of diseases or injuries. This exam also provides important information that allows identification of individuals. This paper reports the use of a CT scan on the skull, taken when the victim was alive, for the positive identification of a victim of a traffic accident in which the fingerprint analysis was impossible. The authors emphasize that the CT scan is a tool primarily used in clinical diagnosis and may contribute significantly to forensic purpose, allowing the exploration of virtual corpses before the classic autopsy. The use of CT scans might increase the quantity and quality of information involved in the death of the person examined.

Forensic odontology and anthropology provide valuable support with regard to human identification. In some cases, when soft tissue is destroyed, carbonized or absent for whatever reason, bones and teeth become the only source of information about the identity of the deceased. In human identification, anything different, such as variation from normality, becomes an important tool when trying to establish the identity of the deceased. This paper illustrates a positive identification case achieved by the diagnosis of an anomaly of tooth position, with confirmation using skull-photo superimposition. Even though forensic science presents modern techniques, in this particular case, the anomalous position of the canine played a key role on the identification, showing that the presence of a forensic dentist on the forensic team can be of great value.

This study assessed the mandibular foramen (MF) position variability in dentate and edentate Brazilian mandibles. Eighty dentate and 79 edentate mandibles of unknown sex were measured bilaterally using a digital caliper (0.1-mm precision). Horizontal linear measurements (HM) were done from the MF to the anterior border of the mandibular ramus (MF-A) and from the MF to the posterior border of the mandibular ramus (MF-B). Vertical linear measurements (VM) were done from the MF to the most inferior point of the mandibular notch (MF-C) and from the MF to the inferior border of the mandibular ramus (MF-D). Data were analyzed by two-way ANOVA (alpha = 5%). The HM means and standard deviations (+/-SD) for MF-A were, edentate right (ER): 17.5 (+/-3.2) mm, edentate left (EL): 17.4 (+/-3.4) mm, dentate right (DR): 19.2 (+/-3.6) mm, and dentate left (DL): 18.8 (+/-3.8) mm. The means (+/-SD) for the MF-B measurements were, respectively, ER: 12.8 (+/-2.4) mm, EL: 12.9 (+/-2.3) mm, DR: 14.2 (+/-2.4) mm, and DL: 13.9 (+/-2.6) mm. The VM values for the MF-C measurements were, ER: 23.4 (+/-3.8) mm, EL: 22.9 (+/-3.7) mm, DR: 23.6 (+/-3.1) mm, and DL: 23.1 (+/-3) mm, and for the MF-D measurements, ER: 26.4 (+/-4.2) mm, EL: 26.4 (+/-4) mm, DR 28.3 (+/-3.9) mm, and DL 28 (+/-3.8) mm. Side had no influence (p>0.05) on any edentate or dentate mandible measurement. Dentate mandible measurements showed statistically significant differences compared to the edentate mandibles, except for MF-C. The mandibular foramen position changes with loss of teeth and this variability may be responsible for occasional failure of inferior alveolar nerve block., (2010 Wiley-Liss, Inc.)

In the last years, anthropology has been widely explored mainly when related to bones due to its morphologic characteristics, such as the rhomboid fossa of the clavicle. This study examined the incidence of the rhomboid fossa in paired clavicles of Brazilian subjects obtained from 209 adult bodies of known age and sex (107 males and 102 females) on which postmortem examinations had been performed by the senior author. The data were submitted to qualitative statistical analysis according to Fisher. There was a statistical difference (p= 5.98 x 10-23) between sexes related to the frequency of the rhomboid fossa. The fossa was absent in 97,1% of the female clavicles and the incidence of bilateral fossa was present in 2,9% of females. The incidence of bilateral fossa was 29% for male clavicles. The sexual or side differences in the incidence of the fossa could be found in this study, and qualitative analysis can corroborate sex determination of unidentified bodies in forensic medicine.

The identification of unidentified human remains through the comparison of antemortem and postmortem radiographs has found wide acceptance in recent years. Reported here is the forensic case of an unidentified adult male who had died as the result of a traffic accident, after which the body was identified by matching images of ante- and postmortem radiographs of the frontal sinus. A general discussion on identification using frontal sinus radiographs is presented, highlighting the reliability of this method, in reference to the uniqueness of the frontal sinus in humans. However, it also notes a few difficulties, especially in reference to the X-ray technique in cases where antemortem radiographs are available and a potentially larger number of anatomical, pathological or traumatic features are present. The comparison of frontal sinus outlines is recommended when it may become necessary to provide quantitative substantiation for forensic identification based on these structures.

The identification of unknown human by smile photographs that show specific characteristics of each individual has found wide acceptance all over the world. Therefore this paper shows this situation reporting different cases which smile photograph analysis were crucial to determine the positive identification of unidentified human bodies. All the cases were subjected to personal identification by photographs of smile including one adult male found in an advanced stage of decomposition, one adult female disappeared during an ecotourism trip, and one carbonized body of a male individual found in a forest region. During the autopsy the photographs of the smile were used by comparison of the ante and postmortem images gave accurate and useful information not only about dental state but also the anatomical features surrounding the upper and lower anterior dental arches. This method is not time-consuming and also has the advantage of allowing extraoral dental examination. It is also recommended when there is a need to provide quantitative data for a forensic identification based on these structures.