Porcine Head Research Articles

SynTissue® as a surrogate material for the human scalp

Synthetic skin produced by SynDaver®, currently used primarily in medical testing and training applications, may be suitable as a surrogate for human skin in forensic investigations. To determine how accurately the company's synthetic skin, SynTissue®, could mimic the mechanical properties of human skin, tests were conducted to measure its elastic modulus and resistance to laceration. Test results were compared to published data acquired from tensile tests conducted on human scalp and impacts with blunt objects on porcine heads. The stress vs strain relation for SynTissue® 8 N corresponded closely to that of the human scalp. Deformations similar to skin lacerations were observed when SynTissue® was subjected to blunt object impacts, at forces in the range of those reported for lacerations of cadaver and porcine heads. However, the published data are insufficient to unequivocally assess the suitability of SynTissue® for forensic investigations of lacerations. Moreover, there are features of the SynTissue® impact deformations that can provide useful information even if the laceration threshold turns out to be lower than that of human skin.

Utility of Cadaveric Porcine Heads for Teaching Oral Surgical Procedures in an Australian Dental School: A Pilot Study.

Background/Objectives: Cadaveric models have traditionally been a mainstay of dental and medical education worldwide since their inception. In Australia, educators at dental schools were among the first to use cadaveric porcine heads in formal teaching in oral surgery. This practice has since fallen out of favour in most modern dental curricula. The aim of this pilot study was to determine the utility of cadaveric porcine models for oral surgery training from a student perspective (Griffith University, Gold Coast, Australia). Methods: Thirty participants who were all third-year dental students attended a two-hour session comprising a 30 min lecture followed by a 90 min practical workshop. The lecture outlined the steps and supervision of students during the practical and was provided by a consultant maxillofacial surgeon. At the conclusion of the workshop, participants were asked to anonymously complete a printed questionnaire with eight questions related to their experience. Results: Prior to the workshop, two-thirds (61%) of participants felt that they had been taught the surgical procedure for raising mucoperiosteal flaps adequately in their dental school curriculum during their third year, although only 43% of students had assisted specialty residents in raising a mucoperiosteal flap and 14% reported having performed the procedure themselves. Almost all students (96%) agreed that the porcine model was useful for their dental education and that they would practice the exercise using the model again if provided with the opportunity. The questionnaire had a 93.33% completion rate. Conclusions: This pilot study indicates that porcine heads present a useful, low-cost adjunct in the learning of basic oral surgical procedures.

Development of a radiographic technique for porcine head ballistic research

IntroductionThe porcine model shows structural features comparable to that of humans and are routinely used within research, due to the ethical, legal, and practical use of post-mortem human samples. Methods for obtaining high quality and comparable reference data using standardised acquisition protocols are essential. MethodsThe decapitated heads of three adult white sows were subjected to radiographic imaging before and after cranial trauma (9 mm, Heckler and Koch MP5). Digital radiographs were generated using a Siemens MULTIX TOP system with an Agfa digital detector, with foam blocks and sandbags as ancillary equipment. An iterative approach was adopted by the authors to generate reproducible radiographic views from two perpendicular angles. Specimens were kept at 5 °C and wrapped in polythene bags to reduce the impact of putrefaction. ResultsStandardised head radiography technique was developed for superior-inferior and lateral views demonstrating porcine anatomy. Key parameters included: automatic exposure control for tube current (∼4 mAs), tube voltage of 73 kVp, 100 cm source to image receptor distance, and an anti-scatter grid. Slight variances in specimen morphology, developmental status, and soft tissue changes did not affect imaging outcomes. ConclusionThe technique and positioning proposed in this study allows for the acquisition of high quality and reproducible radiographic images for comparable ballistic research datasets. Specimen positioning and centring of the primary beam may be applied across porcine breeds, although individual radiographic parameters may differ according to equipment specifications and specimen size. Implications for practiceDevelopment of a reproducible radiographic technique of porcine heads in forensic and veterinary research.

Everything but the squeal: a guide for head and neck surgery training on the live porcine model

PurposeThe porcine model has been demonstrated to be cost-effective for head and neck surgery training. There is no literature describing the porcine head and neck anatomy. The purpose of this study is to provide a porcine surgical guide for training head and neck residents.MethodsFive head and neck dissections were performed under general anesthesia on the Large White pig model in the animal facilities of the University Hospital Fundación Jiménez. Sessions were photographed, and reference anatomical measurements were taken.ResultsThe sternum–chin distance (x = 15.80 cm, σ = 0.44), chin–chin distance (x = 11.10 cm, σ = 2.30), prelaryngeal musculature length (x = 10.30 cm, σ = 1.92) and supraomohyoid triangle area (x = 7.07 cm2, σ = 3.91) were among the measurements obtained. The porcine head and neck anatomy was detailed.ConclusionsHead and neck porcine anatomy was thoroughly described, with emphasis on the similarities with human anatomy. The porcine model is capable of simulating human anatomy for surgery training.

A novel ex vivo perfusion-based mandibular pig model for dental product testing and training

BackgroundA translational ex vivo perfusion-based mandibular pig model was developed as an alternative to animal experiments, for initial assessment of biomaterials in dental and maxillofacial surgery and training. This study aimed to assess the face and content validity of the novel perfusion-based model.MethodsCadaveric porcine heads were connected to an organ assist perfusion device for blood circulation and tissue oxygenation. Dental professionals and dental trainees performed a surgical procedure on the mandibula resembling a submandibular extraoral incision to create bone defects. The bone defects were filled and covered with a commercial barrier membrane. All participants completed a questionnaire using a 5-point Likert scale to assess the face and content validity of the model. Validation data between the two groups of participants were compared with Mann–Whitney U test.ResultsTen dental professionals and seven trainees evaluated the model for face and content validity. Participants reported model realism, with a mean face validity score of 3.9 ± 1.0 and a content validity of 4.1 ± 0.8. No significant differences were found for overall face and content validity between experts and trainees.ConclusionWe established face and content validity in a novel perfusion-based mandibular surgery model. This model can be used as an alternative for animal studies evaluating new biomaterials and related dental and maxillofacial surgical procedural training.

Evaluation of the compatibility between corrosion casts and 3D reconstruction of pig head arterial system on cone beam computed tomography

This study aimed to compare the corrosion cast models of the porcine head arterial system with three-dimensional (3D) reconstructions using cone beam computed tomography (CBCT) of these cast models. Six heads from sows were simultaneously injected through both carotid arteries with Duracryl Plus for corrosion cast technique and an additional head, also from another one sow head, was filled with saturated lead tetroxide (Pb3O4) in a 10% hot water solution (40°C) of gelatin for CBCT study. Two-dimensional (2D) images were stored in Digital Imaging and Communications in Medicine (DICOM). Subsequently, segmentation and post-processing of these images were performed by using various software programs. The 3D models were found to be compatible with the corrosion cast models. It was observed that osseous structures and arteries were clearly identified on CBCT images. Specimen scan, segmentation, and post segmentation had a duration of 10-15 minutes, 4 hours, and 15 minutes, respectively. The internal carotid artery, external carotid artery, and its main branches were seen well on 3D models. In conclusion, it is considered that 3D models and images can be effectively used in anatomy education, radiological evaluations, pathological and variational investigations.

The sialodynamic test: A preliminary porcine head study

ObjectivesTo provide a concept of measuring pressure changes under constant fluid infusion for the diagnosis of sialolithiasis, termed the sialodynamic test, in a porcine head model.MethodsUsing a porcine head model, a constant infusion of water into the submandibular gland of the two groups over 30 s was performed and the outlet pressure was measured. Metal beads were inserted into the salivary duct for obstruction simulation after the normal submandibular gland sialodynamic measurements were completed. Statistical analyses were performed to evaluate the differences between the measured individuals and the experimental group (n = 3).ResultsThe results showed no significant difference between individuals in the control group, but intergroup variation was noted in the simulated sialolithiasis group. The volume-dependent linear increase in pressure was exacerbated in the simulated sialolithiasis group compared with the control.ConclusionThis study indicated that evaluating the relationship between pressure and volume changes can help to determine whether stones are present in the submandibular gland. The sialodynamic test might serve as a potential diagnostic method for salivary diseases.

Efficacy and hazards of 425 nm oral cavity light dosing to inactivate SARS-CoV-2

ObjectiveUsing a battery of preclinical tests to support development of a light-based treatment for COVID-19, establish a range of 425 nm light doses that are non-hazardous to the tissues of the oral cavity and assess whether a 425 nm light dose in this non-hazardous range can inactivate SARS-CoV-2 in artificial saliva. MethodsThe potential hazards to oral tissues associated with a range of acute 425 nm light doses were assessed using a battery of four preclinical tests: (1) cytotoxicity, using well-differentiated human large airway and buccal epithelial models; (2) toxicity to commensal oral bacteria, using a panel of model organisms; (3) light-induced histopathological changes, using ex vivo porcine esophageal tissue, and (4) thermal damage, by dosing the oropharynx of intact porcine head specimens. Then, 425 nm light doses established as non-hazardous using these tests were evaluated for their potential to inactivate SARS-CoV-2 in artificial saliva. ResultsA dose range was established at which 425 nm light is not cytotoxic in well-differentiated human large airway or buccal epithelial models, is not cytotoxic to a panel of commensal oral bacteria, does not induce histopathological damage in ex vivo porcine esophageal tissue, and does not induce thermal damage to the oropharynx of intact porcine head specimens. Using these tests, no hazards were observed for 425 nm light doses less than 63 J/cm2 delivered at irradiance less than 200 mW/cm2. A non-hazardous 425 nm light dose in this range (30 J/cm2 at 50 mW/cm2) was shown to inactivate SARS-CoV-2 in vitro in artificial saliva. ConclusionPreclinical hazard assessments and SARS-CoV-2 inactivation efficacy testing were combined to guide the development of a 425 nm light-based treatment for COVID-19. Clinical significanceThe process used here to evaluate the potential hazards associated with 425 nm acute light dosing of the oral cavity to treat COVID-19 can be extended to other wavelengths, anatomical targets, and therapeutic applications to accelerate the development of novel photomedicine treatments.

Ex vivo porcine model for eye, eyelid, and orbit movement analysis of 4-mm ferromagnetic foreign bodies in MRI.

Ferromagnetic foreign bodies (FFB) present during magnetic resonance imaging (MRI) explorations can lead to tissue injury due to movement, especially in and around the eyes. Ferromagnetic foreign bodies located in the intraocular area, eyelids, and orbit are thus prohibited from undergoing MRI. The aim of the study was to analyze movement of 4-mm ferromagnetic foreign bodies in MRI in the eye, eyelid, and orbit using computed tomography (CT) scan. We developed a porcine model using 12 quarters of fresh porcine heads. Each porcine head included one whole orbit with the ocular globe, orbital fat, muscles, and eyelids. Four-millimeter FFB were implanted in the eye within 2 days post-slaughter, and images were acquired within 5 days post-slaughter. Four-millimeter FFB movement was analyzed after 1.5-Tesla (T) MRI. Four locations were tested: intravitreous, suprachoroidal, intraorbital fat, and intrapalpebral. Movement analysis was assessed using computed tomography (CT) scan. The intravitreous ferromagnetic ball moved 14.0 ± 8.8 mm (p < 0.01), the suprachoroidal ball moved 16.8 ± 5.4 mm (p < 0.01), the intraorbital fat ball moved 5.8 ± 0.9 mm (p > 0.05), and the intrapalpebral ball moved 2.0 ± 0.4 mm (p > 0.05). The ex vivo porcine model was able to study FFB movement. The 4-mm ferromagnetic balls moved in intravitreous and in suprachoroidal locations after MRI.

Fibre Bragg grating sensors for sutural expansion assessment in rapid palatal expanders: an ex‐vivo validation

This study presents the development and validation of a fibre Bragg gratings (FBGs)-based sensor system for the assessment of strain in the midpalatal suture in subjects using rapid palatal expanders (RPEs). The ex-vivo experiments were made by means of positioning two RPEs in a porcine palatal region. The RPEs used were the Hyrax, a tooth-borne expander and MARPE (microimplant-assisted rapid palatal expansion), a bone-borne expander. In order to define the regions in the palatal region for the sensors positioning, a finite-element analysis was performed in a porcine head subjected to the loadings caused by an RPE. In addition, a strain transfer model was used to obtain a correction coefficient that approximates the strain estimated by the FBG to the actual strain in the structure under shear and normal stress. Results show high linearity in the sensors characterisation tests with the advantages of compactness, intrinsic safe operation and multiplexing capabilities of FBGs. In the RPE analysis, a higher strain was estimated in the anterior region, which is in accordance with the simulation and previously reported results, where MARPE showed a higher strain (with an exponential pattern) than Hyrax as the number of activations increase.

Predictions of neonatal porcine bridging vein rupture and extra-axial hemorrhage during rapid head rotations

When the head is rotated rapidly, the movement of the brain lags that of the skull. Intracranial contents between the brain and skull include meninges, cerebrospinal fluid (CSF), and cerebral vasculature. Among the cerebral vasculature in this space are the parasagittal bridging veins (BVs), which drain blood from the brain into the superior sagittal sinus (SSS), which is housed within the falx cerebri, adhered to the inner surface of the skull. Differential motion between the brain and skull that may occur during a traumatic event is thought to stretch BVs, causing damage and producing extra-axial hemorrhage (EAH). Finite element (FE) modeling is a technique often used to aid in the understanding and prediction of traumatic brain injury (TBI), and estimation of tissue deformation during traumatic events provides insight into kinematic injury thresholds. Using a FE model of the newborn porcine head with neonatal porcine brain and BV properties, single and cyclic rapid head rotations without impact were simulated. Measured BV failure properties were used to predict BV rupture. By comparing simulation outputs to observations of EAH in a development group of in vivo studies of rapid non-impact head rotations in the piglet, it was determined that failure of 16.7% of BV elements was associated with a 50% risk of EAH, and showed in a separate validation group that this threshold predicted the occurrence of EAH with 100% sensitivity and 100% specificity for single rapid non-impact rotations. This threshold for failed BV elements performed with 90% overall correct prediction in simulations of cyclic rotational head injuries. A 50% risk of EAH was associated with head angular velocities of 94.74 rad/s and angular accelerations of 29.60 krad/s2 in the newborn piglet. Future studies may build on these findings for BV failure in the piglet to develop predictive models for BV failure in human infants.

Comparison of actual porcine tooth crown development stages and computer image analysis.

Tooth developmental stage evaluation is important in dental and chronological age estimation, and it is important for accurate diagnoses and appropriate treatment in dental practice. It is routinely assessed by clinical observations and radiographic techniques. This study aimed at ascertaining tooth developmental stage judgments made by examiners and Mimics software according to the Nolla method with radiographs. Meanwhile, the true tooth developmental stages would be explored with histological analysis. Twenty freshly slaughtered porcine heads were collected and hemisected, and both the left and right mandibular samples were numbered. The developmental stages of the second and third permanent molars (M2 and M3) were evaluated by examiners and Mimics software analysis. The ratio of the radiopaque calcified area to the dental follicle (RCA/DF) at different stages was calculated. Both non-decalcified and decalcified samples were processed for histologic observation. The results showed significant differences between RCA/DF ratios from different developmental stages. There was a high positive correlation between the examiners' evaluation results and Mimics analysis results. Radiograph judgments and histology observation results were consistent from Stages 2-6. However, radiograph images of Stage 1 samples showed only crypts present, while under a surgical operating microscope, a bell-shaped tooth germ was observed. This was also confirmed by normal and hard tissue histology. In conclusion, radiograph judgments made by either examiners or Mimics software were both reliable. Mimics analysis can be a useful tool in evaluating tooth developmental stages. However, judgments need to be made cautiously in early developmental stages.

Compressive properties and constitutive modeling of different regions of 8-week-old pediatric porcine brain under large strain and wide strain rates

Porcine head is often used as a human surrogate in traumatic head injury research. Extensive research on mechanical properties of adult human/porcine brain tissues has been performed previously; however, very limited data is available for children, which is particular important for modeling the pediatric traumatic brain injury (TBI). In this study, uniaxial compression tests at strain rates of 0.01/s, 1/s and 50/s up to 50% strain were performed for the corona radiata, corpus callosum, thalamus, cortex, cerebellum and brainstem of 8-week-old piglets. No significant difference in tissue strength was found among the cerebrum regions of cortex, thalamus, corona radiata and corpus callosum. The average stress of cerebellum was approximate 21% and 15% higher than that of cerebrum at a strain of 0.25 and 0.5, respectively, but it did not reach statistical significant level than most of the cerebrum regions. Brainstem was the stiffest among these 6 regions, and it was significant stiffer than most regions of cerebrum, with average stress of about 28% and 40% higher at a strain of 0.25 and 0.5, respectively. The strengths of all these three regions showed significant strain-rate dependent characteristics, with the strain rate increasing from 0.01/s to 50/s, the average stress of cerebrum, cerebellum and brainstem increased to approximate 4.6, 6.3 and 6.3 times, respectively at a strain of 0.25; and increased to approximate 1.9, 2.6, and 2.5 times, respectively at a strain of 0.5. One-term Ogden model was used to fit the experimental data to obtain the material parameters and numerical simulation was performed on the compression of cerebrum specimen. Results show that the constitutive model and the calibrated parameters can well represent the compressive behavior of the brain tissue at different strain rates. The results of this study are useful for developing biofidelic pediatric brain FE models and further predict the brain injuries under impact conditions.

Measurement and Finite Element Model Validation of Immature Porcine Brain-Skull Displacement during Rapid Sagittal Head Rotations.

Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain–skull displacement in the neonatal piglet head (n = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain–skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain–skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain–skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain–skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations.

Classification of Porcine Cranial Fracture Patterns Using a Fracture Printing Interface,.

Distinguishing between accidental and abusive head trauma in children can be difficult, as there is a lack of baseline data for pediatric cranial fracture patterns. A porcine head model has recently been developed and utilized in a series of studies to investigate the effects of impact energy level, surface type, and constraint condition on cranial fracture patterns. In the current study, an automated pattern recognition method, or a fracture printing interface (FPI), was developed to classify cranial fracture patterns that were associated with different impact scenarios documented in previous experiments. The FPI accurately predicted the energy level when the impact surface type was rigid. Additionally, the FPI was exceedingly successful in determining fractures caused by skulls being dropped with a high-level energy (97% accuracy). The FPI, currently developed on the porcine data, may in the future be transformed to the task of cranial fracture pattern classification for human infant skulls.

Computational Study of Fracture Characteristics in Infant Skulls Using a Simplified Finite Element Model.

Skull fracture characteristics are associated with loading conditions (such as the impact point and impact velocity) and could provide indication of abuse or accident-induced head injuries. However, correlations between fracture characteristics and loading conditions in infant and toddler are ill-understood. A simplified computational model representing an infant head was built to simulate skull responses to blunt impacts. The fractures were decided through a first principal strain-based element elimination strategy. Simulation results were qualitatively compared with test data from porcine heads. This simplified model well captured the fracture pattern, initial fracture position, and direction of fracture propagation. The model also very well described fracture characteristics found in studies with human infant cadaveric specimens. A series of parametric studies was conducted, and results indicated that the parameters studied had substantial effects on fracture patterns. Additionally, the jagged shapes of sutures were associated with strain concentrations in the skull.

The Role of Interface Shape on the Impact Characteristics and Cranial Fracture Patterns Using the Immature Porcine Head Model,.

The forensic literature suggests that when adolescents fall onto edged and pointed surfaces, depressed fractures can occur at low energy levels. This study documents impact biomechanics and fracture characteristics of infant porcine skulls dropped onto flat, curved, edged, and focal surfaces. Results showed that the energy needed for fracture initiation was nearly four times higher against a flat surface than against the other surfaces. While characteristic measures of fracture such as number and length of fractures did not vary with impact surface shape, the fracture patterns did depend on impact surface shape. While experimental impacts against the flat surface produced linear fractures initiating at sutural boundaries peripheral to the point of impact (POI), more focal impacts produced depressed fractures initiating at the POI. The study supported case-based forensic literature suggesting cranial fracture patterns depend on impact surface shape and that fracture initiation energy is lower for more focal impacts.

The Role of Interface on the Impact Characteristics and Cranial Fracture Patterns Using the Immature Porcine Head Model

The role of impact interface characteristics on the biomechanics and patterns of cranial fracture has not been investigated in detail, and especially for the pediatric head. In this study, infant porcine skulls aged 2-19days were dropped with an energy to cause fracturing onto four surfaces varying in stiffness from a rigid plate to one covered with plush carpeting. Results showed that heads dropped onto the rigid surface produced more extensive cranial fracturing than onto carpeted surfaces. Contact forces generated at fracture initiation and the overall maximum contact forces were generally lower for the rigid than carpeted impacts. While the degree of cranial fracturing from impacts onto the heavy carpeted surface was comparable to that of lower-energy rigid surface impacts, there were fewer diastatic fractures. This suggests that characteristics of the cranial fracture patterns may be used to differentiate energy level from impact interface in pediatric forensic cases.

WE‐EF‐BRA‐12: Magnetic Resonance‐ Guided High‐Intensity Focused Ultrasound for Localized Ablation of Head and Neck Tissue Structures: A Feasibility Study in An Animal Model

Purpose:High‐intensity focused ultrasound (HIFU) ablation is feasible in the head and neck [1]. This study aims to expand upon these findings to assess the feasibility of treatment planning and monitoring via magnetic resonance imaging (MRI) guidance using a clinical MR‐guided HIFU platform.Methods:Two 31 kg pigs were anaesthetized, shaved, and positioned prone on the HIFU table (Sonalleve, Philips Healthcare, Vantaa, Finland). The necks were acoustically coupled to the integrated transducer using gel pads and degassed water. MR imaging verified acoustic coupling and facilitated target selection in the thyroid and thymus. Targets were thermally ablated with 130–200 W of acoustic power over a period of 16 s at a frequency of 1.2 MHz while being monitored through real‐time, multi‐planar MR‐thermometry. Contrast‐enhanced MR imaging was used to assess treatment efficacy. Post‐treatment, animals were euthanized and sonicated tissues were harvested for histology assessment.Results:MR‐thermometry, post‐contrast‐imaging, and gross pathology demonstrated that the system was capable of causing localized thermal ablation in both the thyroid and the thymus without damaging the aerodigestive tract. In one animal, superficial bruising was observed in the ultrasound beam path. Otherwise, there were no adverse events. Analysis of the tissue histology found regions of damage consistent with acute thermal injury at the targeted locations.Conclusion:It is feasible to use a clinical MR‐guided HIFU platform for extracorporeal ablation of porcine head and neck tissues. MR guidance and thermometry are sufficient to target and monitor treatment in the thyroid region, despite the presence of the inhomogeneous aerodigestive tract. Further study is necessary to assess efficacy and survival using a tumor model, and to examine what modifications should be made to the transducer positioning system and associated patient positioning aids to adapt it for clinical head and neck targets.Reference:[1] Esnault et al. (2011). Thyroid, 21(9), 965– 973.Funding support provided by Philips Healthcare. Ari Partanen is a paid employee of Philips Healthcare.

How hard is hard enough? An investigation of the force associated with lateral blunt force trauma to the porcine cranium.

Blunt force trauma forms a substantial portion of deaths worldwide. However, few studies have attempted to determine the force involved with blunt force trauma to the lateral part of the head. Nor have many studies been conducted at velocities exceeding 10 m/s. The acquisition of human tissue for experimental studies is becoming increasingly difficult. As such, the current study investigates the trauma and the force involved with cranial blunt force trauma in a porcine model. Thirty whole porcine heads were subjected to single impact tests on the fronto-parietal region at velocities ranging from 10 m/s to 25 m/s. Half the specimens were subjected to impact by a short projectile resembling a hammer head and the other half were subjected to impact with a Hopkinson pressure bar (HPB). Both implements had the same impact diameter and were machined from the same material. The HPB is an apparatus commonly used in material testing. Its use to determine fracture force in whole cranial specimens is novel. Fractures appeared similar in both the hammer tests and HPB tests. Lacerations and fractures resembled the shape of the striker surface with the most common fracture observed being a semi-circular depressed fracture. The mean peak fracture force was 7760 N (± 4150 N), with a mean displacement of 3.1mm (± 1.1mm). Peak fracture forces concur well with previous studies although no clear trend appears to exist between level of trauma and peak impact force.