Search

The frequency of midface and frontobasal fractures has increased over the past 40 years despite the improvement and stringent regulation implemented on modern safety equipment (belts, helmets…). This observation might be correlated with the progress of radiodiagnosis tools. Literature was reviewed according to Prisma guidelines. We searched for reviewed articles, published between January 2000 and December 2017, through Medline (Pubmed) online databases and ScienceDirect, using the following MeSH Keywords: "Le Fort classification", "Le Fort fracture", "Frontobasal fracture", "skull base fracture", "Midface Fractures". Among 652 patients with frontobasal fractures, 125 (19.1%) were associated with a Le Fort fracture. 59 (9%) were associated with Le Fort III fracture, 51 (7.8%) with Le Fort II fracture and 15 (2.3%) with Le Fort I fracture. When frontobasal fractures were associated with midfacial fractures, we found 18 cerebrospinal fluid leaks (11.8 %) and 19 cases of meningitis (12.5 %). When only the frontobasal area was involved, there were 6 cerebrospinal fluid leaks (4.3 %) and 6 meningitis (4.3 %). Our results highlight a regular association between Le Fort fractures and frontobasal fractures for stages II and stage III of Le Fort fractures and also found a higher rate of neuro-septic complication. Further research shall investigate treatment and monitoring recommendations fitting modern epidemiology of craniofacial traumatology.

Objective: This study aimed to analyze the morphology of the hypoplasic mandible and its evolution during the growth period to better understand how it differs from the pediatric healthy mandible. Method: Three-dimensional mandibular models of hypoplasic and healthy children aged from 39 gestational weeks to 7 years old were analyzed with a morphometric method including data clustering. Morphological distinctions between pathological and healthy mandibles were highlighted. Bilateral and unilateral mandibular hypoplasia were distinguished. Results: The study sample was composed of 31 hypoplasic children and as many sex- and age-matched healthy children. Morphological distinctions between pathological and healthy mandibles were highlighted only from the first year of life. In bilateral hypoplasia, the overall mandibular dimensions were reduced while there was only a ramus asymmetry in unilateral mandibular hypoplasia (mean ± SD of the difference between the Grp03c and Grp03b subgroups: 6.80 ± 6.37 – P value = 1.64e–3 for the height of the left ramus versus 0.18 ± 4.18 – P value = .82 for the height of the right ramus). Supervised classification trees were built to identify the pathology and discriminate unilateral from bilateral mandibular hypoplasia (prediction rates = 81% and 84%, respectively). Conclusions: Based on a morphometric analysis, we demonstrated that mandibular hypoplasia significantly impacts the mandibular morphology only from the first year of life, with a distinction between bilateral and unilateral hypoplasia.

International audience; OBJECTIVE/BACKGROUND: This retrospective non-randomized controlled cohort study aimed to evaluate the efficiency of simultaneous maxillary expansion and mandibular advancement for the management of pediatric OSAS. PATIENTS/METHODS: The sample was composed of 94 children treated with an innovative orthopedic device to correct a Class II malocclusion associated with an OSAS. Polysomnographic recordings were performed before and after the treatment. We also included a group of 113 age-matched control patients who had the same pathologies, but who did not receive the orthopedic treatment at the time they undergone polysomnographic exams. Statistical tests evaluated the significance of the evolution of these data, both in treated and untreated control patients. RESULTS: After nine months (±3 months) of treatment, respiratory OSAS symptoms significantly improved: the AHI significantly decreased as it became inferior to the pathological threshold (

Calcified aortic stenoses are among the most prevalent form of cardiovascular diseases in the industrialized countries. This progressive disease, with no effective medical therapy, ultimately requi...

Introduction This study aims at identifying mechanical characteristics under bi-axial loading conditions of extracted swine pia mater (PM) and dura and arachnoid complex (DAC). Methods 59 porcine spinal samples have been tested on a bi-axial experimental device with a pre-load of 0.01 N and a displacement rate of 0.05 mm.s−1. Post-processing analysis included an elastic modulus, as well as constitutive model identification for Ogden model, reduced Gasser Ogden Holzapfel (GOH) model, anisotropic GOH model, transverse isotropic and anisotropic Gasser models as well as a Mooney-Rivlin model including fiber strengthening for PM. Additionally, micro-structure of the tissue was investigated using a bi-photon microscopy. Results Linear elastic moduli of 108±40 MPa were found for DAC longitudinal direction, 53±32 MPa for DAC circumferential direction, with a significant difference between directions (p Statement of Significance This study is the first to present biaxial tensile test of pia mater as well as constitutive model comparisons for dura and arachnoid complex tissue based on such tests. Collagen structures observed by semi-quantitative analysis of two photon microscopy confirmed the use of anisotropic Gasser model for pia mater and existence of fenestration. While clear identification of fibre population was not possible in DAC, results from anisotropic Gasser model depicted better fitting on experimental data as per this protocol. Bi-axial mechanical testing allows quasi-static characterization under conditions closr to the physiological context and the results presented could be used for further simulations of physiology. Indeed, the inclusion of meningeal tissue in finite element models will allow more accurate and reliable numerical simulations.

Summary Three deaths following facial impacts in the presence of witnesses and resulting in brain lesions that were visualized only on pathological examination were studied at the forensic medicine institute of Marseille. Craniofacial impacts, even of low intensity, received during brawls may be associated with brain lesions ranging from a simple knock-out to fatal injuries. In criminal cases that are brought to court, even by autopsy it is still difficult to establish a direct link between the violence of the impact and the injuries that resulted in death. During a facial impact, the head undergoes a movement of violent forced hyperextension. Death may thus be secondary to the transmission of forces to the brain, either by a mechanism involving nerve conduction that may be termed a reflex mechanism (for example by vagal hyperstimulation) or by injury to the central nervous system (axonal damage). In such situations, autopsy does not make it possible to determine the cause of death, but only to suspect it in a context of voluntary violence in the presence of witnesses, with or without violent injury observed on external examination or on superficial incisions to determine the extent of bruises or hematoma. Systemic and comprehensive investigation involving pathology and toxicology is essential in any medicolegal case for positive interpretation and discrimination of other causes of death.

Calcified aortic stenoses are among the most prevalent form of cardiovascular diseases in the industrialized countries. This progressive disease, with no effective medical therapy, ultimately requires aortic valve replacement - either a surgical or very recently transcatheter aortic valve implantation. Increase leaflet mechanical stress is one of the main determinants of the structural deterioration of bioprosthetic aortic valves. We applied a coupled

Purpose The aim of this study was to show the displacements and strain induced by the supraorbital band advancement during a craniofacial surgery for an anterior plagiocephaly on the orbital bones and the orbital content thanks to a numerical surgical simulation using the finite element method. Methods A three-dimensional (3D) finite element model of a child with an anterior plagiocephaly was entirely created from a tomodensitometry of a patient followed by our Craniofacial Pediatric team. Data of the tomodensitometry were computed with Slicer 3D to re-create the orbit geometry. Mesh production, properties of the model, and simulations of the fronto-orbital advancement were conducted on Hyperworks software (Altair Engineering, Inc., Detroit, MI, USA). Results The resulting 3D Finite Element Model was used to perform the supraorbital advancement simulation. Displacement and strain patterns were studied for orbital bones, oculomotor muscles, and eyeballs. Relative high strain in the both trochlear area and excycloration of the right orbit are among the most interesting results as torsional strabismus as V-pattern strabismus are often described in children with an anterior plagiocephaly. Conclusions This pediatric Finite-Element Model of both orbits of a child with an anterior plagiocephaly showed the impact of the fronto-orbital advancement on the oculomotor system. This model described the relationship between the craniofacial surgery and the strabismus in the unilateral coronal synostosis. The advantages of this model are the many opportunities for improvement, including postoperative period and additional surgical procedures.

International audience; Objective: This study aimed to analyze the morphology of the hypoplasic mandible and its evolution during the growth period to better understand how it differs from the pediatric healthy mandible. Method: Three-dimensional mandibular models of hypoplasic and healthy children aged from 39 gestational weeks to 7 years old were analyzed with a morphometric method including data clustering. Morphological distinctions between pathological and healthy mandibles were highlighted. Bilateral and unilateral mandibular hypoplasia were distinguished. Results: The study sample was composed of 31 hypoplasic children and as many sex- and age-matched healthy children. Morphological distinctions between pathological and healthy mandibles were highlighted only from the first year of life. In bilateral hypoplasia, the overall mandibular dimensions were reduced while there was only a ramus asymmetry in unilateral mandibular hypoplasia (mean ± SD of the difference between the Grp03c and Grp03b subgroups: 6.80 ± 6.37 – P value = 1.64e –3 for the height of the left ramus versus 0.18 ± 4.18 – P value = .82 for the height of the right ramus). Supervised classification trees were built to identify the pathology and discriminate unilateral from bilateral mandibular hypoplasia (prediction rates = 81% and 84%, respectively). Conclusions: Based on a morphometric analysis, we demonstrated that mandibular hypoplasia significantly impacts the mandibular morphology only from the first year of life, with a distinction between bilateral and unilateral hypoplasia.

Introduction The authors’ main purpose was to simulate the behavior of a titanium mesh implant (TMI) used to reconstruct the orbital floor under the stress of a blunt trauma. Materials and methods The orbital floor of a previously validated finite element model (FEM) of the human orbit was numerically fractured and reconstructed by a simplified TMI. Data from a CT scan of the head were computed with MICMICS (Materialise, Louvain, Belgium) software to re-create the skull's geometry. The meshing production, the model's properties management and the simulations of blunt traumas of the orbit were conducted on HYPERWORKS® software (Altair Engineering, Detroit, MI, USA). Some of the elements of the orbital floor were selected and removed to model the fracture; these elements were duplicated, their characteristics being changed by those of titanium to create a TMI covering this fracture. A 3D FEM composed of 640,000 elements was used to perform 21 blunt trauma simulations on the reconstructed orbit. Results In 90.4% (19/21) of the tests conducted, the TMI, whether free from any bony attachment or screwed to the orbital rim, has tended to move in the orbit and/or to deform. Discussion In the event of traumatic recurrence, which is not rare, TMIs may deform in a “blow-in” motion and threaten intra-orbital structures.

Strangulation is a violent act which can be lethal and is often studied in forensic context. The neck includes several anatomical elements that can evolve with aging. We therefore created a numerical human neck model including the main anatomical elements and simulated one-handed grip strangulation cases. In addition, we created 3 models each representing age groups: 20–30 years old, 30–50 years old and over 50 years old. The main changes between the different age groups are the ossification of the cartilages and the muscles mechanical properties. Several initial and boundary conditions have been tested to perform a realistic simulation of one-handed grip strangulation. Stress analysis and fracture observation were compared with the grip strength of an average man, 552 N, to look at the intentionality of the gesture. In each age group, the results show no model fracture for a force of 552 N. It is necessary to reach a minimum of 1406 N before observing a first fracture on the hyoid bone. However, it is possible to get stresses on the hyoid bone and on the thyroid cartilage way before 552 N. It thus appears that the force created by one-handed grip strangulation is not sufficient to cause fractures of the bony elements of the neck, but it remains sufficient to compress the larynx and at least reduce airflow.

ICTAEM 2020, Proceedings of the Third International Conference on Theoretical, Applied and Experimental Mechanics , Athenes, GRECE, 14-/06/2020 - 17/06/2020; The paper presents an experimental test of macrocrack propagation in bones associated with a numerical strategy to determine from this test some mechanical properties by inverse identification. A 3 point bending test is performed on a notched segment of long human bone, and the load vs notch opening displacement is measured. The compliance method is applied in the context of a realistic FE simulation of the test. A first application of this methodology is described and shows its feasibility and capabilities. The ultimate objective of this research project is to develop a probabilistic modelling of the macrocracking processes in human long bone tissues based on an experimental database of mechanical parameters fed up by this methodology.

Background The sacroiliac joint is an important source of low back pain. In severe cases, sacroiliac joint fusion is used to reduce pain, but revision rates can reach 30%. The lack of initial mechanical stability may lead to pseudarthrosis, thus not alleviating the patient's symptoms. This could be due to the damage induced to the interosseous ligament during implant insertion. Decoupling instrumentation steps (drilling-tapping and implant insertion) would allow verifying this hypothesis. Moreover, no biomechanical studies have been published on sacroiliac joint fixation with an oblique lateral approach, while it has important clinical advantages over the direct lateral approach. Methods Eight cadaveric human pelves with both ischia embedded were tested in three sequential states: intact, drilled-tapped and instrumented with one cylindrical threaded implant with an oblique lateral trajectory. Specimens were assigned one of two insertion sites (distal point; near the posterior superior iliac spine, and proximal point; anterosuperior to the distal point) and tested in compression and flexion-extension. Vertical and angular displacements of the sacroiliac joint were measured locally using digital image correlation methods. Findings In compression, instrumentation significantly reduced vertical displacements (17% (SD 22%), P = 0.04) but no difference was found for angular displacements or flexion-extension loads (P > 0.05). Drilling-tapping did not change the stability of the sacroiliac joint (P > 0.05); there was no statistical difference between the insertion sites (P > 0.05). Interpretations Insertion of one implant through either the distal or proximal insertion site with an oblique lateral approach significantly reduced vertical displacements of the sacroiliac joint in compression, a predominant load of this joint. Research ethics committee Polytechnique Montreal: CER-1617-30.

Objectif : Caractériser l’os maxillaire postérieur chez l’adulte d’un point de vue géométrique pour obtenir des modèles numériques standards par éléments finis. Matériel et méthodes : Les images CBCT maxillaires des patients qui ont visité le service de Chirurgie Orale du CHU de La Timone à Marseille, France ont été recueillies au cours de l’année 2016. Les sujets inclus devaient être âgés de plus de 21 ans et être édentés au moins à partir de la première prémolaire maxillaire. Les patients atteints d’une pathologie osseuse ou d’un traitement influençant le remodelage osseux n’ont pas été inclus. La zone maxillaire postérieure a été définie pour chaque CBCT et 6 mesures de hauteur et de largeur de la crête alvéolaire ont été réalisées à l’aide d’une méthode anthropométrique. Une étude Gauge Anova R&R avec analyse de la répétabilité et de la reproductibilité de la variance des mesures, ainsi qu’une analyse en composantes principales (ACP) pour isoler des modèles standards, ont été menées. Les modèles 3D ont été réalisés à partir d’images au format DICOM. Résultats : Le CBCT de 100 hommes et 100 femmes ont été retenus dans notre étude. 1200 mesures de crête alvéolaire ont été réalisée et les valeurs moyennes de hauteur et de largeur des différentes parties de la zone maxillaire postérieure étaient très disparates. L’analyse statistique de variance a validé la répétabilité et la reproductibilité de notre protocole de mesures. L’ACP n’a pas permis d’identifier les modèles standards et ceux- ci ont été modélisés à partir de notre base de données. Conclusion : Notre travail est le premier à considérer des paramètres anthropométriques sur un large échantillon de sujets dans la méthode des éléments finis. Nous mettons ainsi en évidence la perspective de réaliser des modèles anatomiques complexes et réalistes à partir de l’anatomie humaine pour réaliser des tests biomécaniques en implantologie orale.

An original in vitro/in silico method was developed to estimate the local and global mechanical stress applied on the bioprosthetic valve leaflet, which can be important for better understanding of the valve durability. A non-contact system based on stereophotogammetry and digital image correlation enabled filming and studying the valve leaflet movement frame by frame and performing three-dimensional analysis. The deformation was applied in a finite element model in order to calculate the local mechanical stress applied. High stress regions were primarily observed in the upper leaflet edge and belly and to a lesser extent at the free leaflet edge.

The presence of fracture on neck elements is an indication of violence. Both the hyoid bone and the larynx can be damaged by a strangulation mechanism. Thyroid cartilage, more specifically, may present lesions in response to this mechanical stress. These lesions result in fractures at the bases of the horns of the thyroid cartilage. This study focuses on the thyroid cartilage behavior in cases of bi-digital strangulation, using an anthropometric and biomechanical approach. To develop a biomechanical model, we performed an anthropometric study taking into account 14 distances measurements as well as 3 measurements of angles. These measures allowed us to determine a significant sexual dimorphism between individuals. Then, we define 6 morphologies models, composed of 3 females and 3 males individuals. In order to visualize the ossification of the cartilage, each model has been tested with bone properties. Strangulation cases were simulated by applying an imposed velocity of 0.4m/s then 1m/s. We observed different behaviors of the thyroid cartilage according to the sex and the morphology.

Brain and cervical injuries are often described after major facial impacts but rarely after low-intensity mandibular impacts. Force transmission to the brain and spinal cord from a mandibular impact such as a punch was evaluated by the creation and validation of a complete finite element model of the head and neck. Anteroposterior uppercut impacts on the jaw were associated with considerable extension and strong stresses at the junction of the brainstem and spinal cord. Hook punch impacts transmitted forces directly to the brainstem and the spinal cord without extension of the spinal cord. Deaths after this type of blow with no observed histological lesions may be related to excessive stressing of the brainstem, through which pass the sensory-motor pathways and the vagus nerve and which is the regulatory center of the major vegetative functions. Biological parameters are different in each individual, and by using digital modeling they can be modulated at will (jaw shape, dentition…) for a realistic approach to forensic applications.

We present an original method using a low cost accelerometer and a Kalman-filter based algorithm to monitor cardiopulmonary resuscitation chest compressions (CC) depth. A three-axis accelerometer connected to a computer was used during CC. A Kalman filter was used to retrieve speed and position from acceleration data. We first tested the algorithm for its accuracy and stability on surrogate data. The device was implemented for CC performed on a manikin. Different accelerometer locations were tested. We used a classical inertial navigation algorithm to reconstruct CPR depth and frequency. The device was found accurate enough to monitor CPR depth and its stability was checked for half an hour without any drift. Average error on displacement was ±0.5mm. We showed that depth measurement was dependent on the device location on the patient or the rescuer. The accuracy and stability of this small low-cost accelerometer coupled to a Kalman-filter based algorithm to reconstruct CC depth and frequency, was found well adapted and could be easily implemented.

The fetal development of the mandible is nowadays quite understood, and it is already known that craniofacial growth reaches its highest rate during the first 5 years of postnatal life. However, there are very few data focusing on the perinatal period. Thus, the present article is addressing this concern by studying the mandible morphology and its evolution around the birth with a morphometric method. Thirty-one mandibles modelled in three dimensions from post-mortem CT-scans were analyzed. This sample was divided into two subgroups composed of, respectively, 15 fetuses (aged from 36 gestational weeks), and 16 infants (aged to 12 postnatal weeks). 17 distances, 3 angles, and 8 thicknesses were measured via the prior set of 14 landmarks, illustrating the whole mandible morphology. Although this methodology may depend on the image reconstruction quality, its reliability was demonstrated with low variability in the results. It highlighted two distinct growth patterns around birth: fetuses mandibles do not significantly evolve during the perinatal period, whereas, from the second postnatal weeks, most of the measurements increased in a homogeneous tendency and in correlation with age. The protocol developed in this study highlighted the morphologic evolution of the mandible around birth, identifying a different growth pattern from 2 postnatal weeks, probably because of the progressive activation of masticatory muscles and tongue. However, considering the small sample size, these results should be thorough, so identification and management of anatomic abnormalities could eventually be achieved.

Background Sacroiliac joint (SIJ) is a known chronic pain-generator. The last resort of treatment is the arthrodesis. Different implants allow fixation of the joint, but to date there is no tool to analyze their influence on the SIJ biomechanics under physiological loads. The objective was to develop a computational model to biomechanically analyze different parameters of the stable SIJ fixation instrumentation. Methods A comprehensive finite element model (FEM) of the pelvis was built with detailed SIJ representation. Bone and sacroiliac joint ligament material properties were calibrated against experimentally acquired load-displacement data of the SIJ. Model evaluation was performed with experimental load-displacement measurements of instrumented cadaveric SIJ. Then six fixation scenarios with one or two implants on one side with two different trajectories (proximal, distal) were simulated and assessed with the FEM under vertical compression loads. Results The simulated S1 endplate displacement reduction achieved with the fixation devices was within 3% of the experimentally measured data. Under compression loads, the uninstrumented sacrum exhibited mainly a rotation motion (nutation) of 1.38° and 2.80° respectively at 600 N and 1000 N, with a combined relative translation (0.3 mm). The instrumentation with one screw reduced the local displacement within the SIJ by up to 62.5% for the proximal trajectory vs. 15.6% for the distal trajectory. Adding a second implant had no significant additional effect. Conclusion A comprehensive finite element model was developed to assess the biomechanics of SIJ fixation. SIJ devices enable to reduce the motion, mainly rotational, between the sacrum and ilium. Positioning the implant farther from the SIJ instantaneous rotation center was an important factor to reduce the intra-articular displacement. Clinical relevance Knowledge provided by this biomechanical study enables improvement of SIJ fixation through optimal implant trajectory.

Introduction Strangulation is a medicolegal form of mechanical asphyxia, and can be difficult to identify if cutaneous damage to the neck is limited. We began by creating a numerical model of a hyoid bone with adjustable anthropometric parameters and then subjected our model to compression simulating a precision grip on the neck from the front. Materials and methods We selected six bones from the 77 hyoid bones contained in the database we created during a previous study led by our laboratory, in which we demonstrated the sexual dimorphism of this bone and identified the minimal force required for fracture. The anthropometric characteristics of these six bones (angle, length and width) corresponded to those of the 10th, 50th and 90th percentiles from cluster 1 (male individuals) and cluster 2 (female individuals), respectively. After enhancing, developing and meshing the selected 3D models, we analysed and reproduced simulation conditions that were as close as possible to the in vivo conditions of neck strangulation from the front (area of pressure on the bone, tissue environment, and biological variability of this bone). Results We modelled the six numerical hyoid bone models using the finite element method. For all models, the simulation of mechanical pressure applied to simulate anterior strangulation resulted in fractures. The forces required to produce these fractures matched the results obtained in the experimental testing of dissected hyoid bones. Conclusion Six finite element numerical models were created, covering the anthropometric morphological variability of the hyoid bone. These six models enabled numerical simulation of the in vivo behaviour of a hyoid bone subjected to one-handed strangulation.

Objective Some cardiopulmonary resuscitation (CPR) monitoring devices were released in recent years. Some of them are motion sensors. There are no guidelines were to position future or present sensors during CPR. We evaluate the possible influence of the location of motion sensors by a high-speed camera during a CPR on a manikin. Material and methods We performed a motion analysis by a high-speed camera during chest compression (CC) on a manikin to quantify chest inhomogeneous displacements and rescuer motion. Results Midline chest was found to have an inhomogeneous depth during CC (19 mm for the upper sternum, 27 mm for the middle of the sternum, and 47 mm for the xiphoid). Rescuer anatomy has a complex motion. Conclusion The direct application of the sensor under the hand performing CC seems to be the more accurate solution if the device allows it.

International audience; Discovery of a fracture of the hyoid bone during forensic autopsy is a feature that raises suspicions of constriction of the neck. Studies have shown the influence of gender and build of the individual on the morphology of this bone. Our aims were to confirm these findings and to develop an experimental protocol for simulating manual strangulation in order to determine the force required to fracture the hyoid bone and the influence of anthropometric parameters on this force. A total of 77 intact hyoid bones were obtained, scanned, modeled, measured and embedded in resin. Using a hydraulic press, we applied force to the distal extremity of the greater horn. The relationships between the parameters of sex, weight and height of the subject, anteroposterior length of the hyoid, width between the greater horns, angle, fusion of the greater horns and force applied were analyzed. Our study confirmed sexual dimorphism, shown by greater length in males ( > 37.8 mm) than in females, and a larger angle in females (a shorter bone with a width > 43.7 mm and an angle > 31 8 01). The study confirmed the positive correlation between the length of the hyoid and the weight and height of the subject ( p < 0.05). Sixty-seven of the 77 hyoid bones fractured during the experiment (87% fracture rate). Of the fractures, 48% occurred at the junction between the body and the greater horns, 49% in the greater horns (mean distance from the distal extremity of the horn 17.33 4.37 mm), and 3% in the median part of the body. No significant association was found between gender and type of fracture, or between fusion or non-fusion of the horn ( p > 0.05). Fused bones were not more susceptible to fracture than non-fused bones. Fracture occurred at a mean force of 30.55 N ( 18.189). Multiple linear regression showed a significant negative correlation between force required for fracture and age, weight and height of the subject, anteroposterior length and angle. The younger the individual, the slighter their build, the longer the bone and the smaller the angle, the greater the force required to fracture the hyoid bone

Introduction The authors’ main purpose was to develop a detailed finite element model (FEM) of the human orbit and to validate it by analyzing its behavior under the stress of blunt traumas. Materials and methods A pre-existing 3D FEM of a human head was modified and used in this study. Modifications took into account preliminary research carried out on PubMed database. Data from a CT scan of the head were computed with Mimics® software to re-create the skull geometry. The mesh production, the model's properties and the simulations of blunt orbital traumas were conducted on Hyperworks® software. Results The resulting 3D FEM was composed of 640 000 elements and was used to perform blunt trauma simulations on an intact orbit. A total of 27 tests were simulated. Fifteen tests were realized with a metallic cylinder impactor; 12 tests simulated a hit by a closed fist. In all the tests conducted (27/27), the orbital floor was fractured. Fracture patterns were similar to those found in real clinical situations according to the buckling and hydraulic theories of orbital floor fractures. Discussion The similitude between the fracture patterns produced on the model and those observed in vivo allows for a validation of the model. This model constitutes, at the authors knowledge, the most sophisticated one ever developed.

International audience