Skull Model Research Articles

3D wildlife skull models for wildlife veterinary training.

Wildlife veterinarians are necessary for zoonotic diseases and species loss management, and there is a rising interest to enroll at veterinary schools with the wish to work in zoo and wildlife medicine. However, teaching wildlife is challenging due to the difficulty faced by universities to work with wild animal specimens. The aim of the present was to evaluate the understanding efficiency of some anatomical and behavioral aspects using 3D printed models of four wildlife species skulls, the kinkaju (Potos flavus), the white-nosed coati (Nasua narica), the northern anteater (Tamandua mexicana), and the nine-banded armadillo (Dasypus novemcinctus). This study was performed on 85 third-year veterinary students, divided into an experimental and a control group, who used and not used 3D printed skulls, respectively. Results show that the experimental group shows higher scores, in three of the four variables evaluated, than the control group. Then, 3D wildlife printed skulls constitute a promising teaching tool for veterinary students. In fact, it may be as good as real skulls, since new 3D printers can print on high endurance and firmness stock with high accuracy at reduced costs. In this context, it is important to encourage its use for the training of new generations and keep professionals up to date.

Trueness of cone-beam computed tomography-derived skull models fabricated by different technology-based three-dimensional printers

BackgroundThree-dimensional (3D) printing is a novel innovation in the field of craniomaxillofacial surgery, however, a lack of evidence exists related to the comparison of the trueness of skull models fabricated using different technology-based printers belonging to different cost segments.MethodsA study was performed to investigate the trueness of cone-beam computed tomography-derived skull models fabricated using different technology based on low-, medium-, and high-cost 3D printers. Following the segmentation of a patient’s skull, the model was printed by: (i) a low-cost fused filament fabrication printer; (ii) a medium-cost stereolithography printer; and (iii) a high-cost material jetting printer. The fabricated models were later scanned by industrial computed tomography and superimposed onto the original reference virtual model by applying surface-based registration. A part comparison color-coded analysis was conducted for assessing the difference between the reference and scanned models. A one-way analysis of variance (ANOVA) with Bonferroni correction was applied for statistical analysis.ResultsThe model printed with the low-cost fused filament fabrication printer showed the highest mean absolute error (1.33pm 0.24 text{mm}), whereas both medium-cost stereolithography-based and the high-cost material jetting models had an overall similar dimensional error of 0.07pm 0.03 text{mm} and 0.07pm 0.01 text{mm}, respectively. Overall, the models printed with medium- and high-cost printers showed a significantly (p<0.01) lower error compared to the low-cost printer.ConclusionsBoth stereolithography and material jetting based printers, belonging to the medium- and high-cost market segment, were able to replicate the skeletal anatomy with optimal trueness, which might be suitable for patient-specific treatment planning tasks in craniomaxillofacial surgery. In contrast, the low-cost fused filament fabrication printer could serve as a cost-effective alternative for anatomical education, and/or patient communication.

Late Frontal Bone Reconstruction Using Three-Dimensional Printed Models for Titanium Mesh Customization: A Case Series

The convex frontal bone is covered by thin skin rendering its reconstruction cosmetically challenging. Customized alloplastic implants provide better contouring than autologous bone, yet their high cost and availability limit their application. We assess customized titanium mesh implants pre-contoured using patient specific 3-D printed models for late frontal cranioplasty. We retrospectively analyzed the prospectively collected cases of unilateral frontal titanium mesh cranioplasty with 3-D printing assisted preplanning from 2017 to 2019. We used two 3-D printed patient specific skull models for preoperative planning: the mirrored normal model for implant contouring, and the defect model for edge trimming and fixation planning. The endoscope was used in four cases for percutaneous mesh fixation. We documented postoperative complications. We assessed the reconstruction symmetry clinically, and radiologically on postoperative computed tomography. 15 patients were included. The duration after previous surgery ranged from 8-24 months. Four patients developed complications that were managed conservatively. Favorable cosmetic outcomes were achieved in all patients. Pre-contouring of titanium mesh implants using in-house 3-D printed models could optimize cosmetic and surgical outcomes in late frontal cranioplasty. Preoperative planning could permit minimal access surgery that could be aided by the endoscope in select cases.

Customized Cost-Effective Cranioplasty for Large Asymmetrical Defects

Cranioplasty or cranial reconstruction is always a challenging procedure even for experienced surgeons. In this study, two different design techniques for customized cranial prostheses are assessed for cranial reconstruction. Mirror reconstruction is one of the commonly used reconstruction techniques that fails when cranial defects cross the midline of symmetry. Hence, there is a need for a design technique for the reconstruction of cranial defects irrespective of their location on the symmetrical plane. The anatomical reconstruction technique demonstrates its applicability for a wide spectrum of complex skull defects irrespective of the defective position in the anatomical structure. The paper outlines a methodological procedure involving a multi-disciplinary approach involving physicians and engineers in the design and reconstruction of customized cranial implants for asymmetrical skull defects. The proposed methodology is based on five foundation pillars including the multi-disciplinary approach, implant design process, additive-manufactured implant, implant fitting analysis, and cost and time analysis for the customized implant. The patient’s computed tomography scan data are utilized to model a customized cranial implant, which is then fabricated using electron beam melting technology. The dimensional validation of the designed and fabricated titanium implant based on the anatomical approach results in a precision of 0.6345 mm, thus indicating a better fit than the standard mirroring method. The results of fitting accuracy also reveal that the manufactured implant’s average deviation is very close to the planned reconstruction area with an error less than 1 mm, suggesting that the customized titanium implant fits the skull model quite precisely. The cost and time analysis reports that the cost for producing a customized cranial implant using electron beam melting technology is around USD 217.5 and the time taken to build is approximately 14 h and 27 min, which is low when compared to other studies. The cost and time analysis also demonstrates that the proposed design would be less burdensome to patients when compared to standard practice. Therefore, the new anatomical design process can be used effectively and efficiently to treat a number of diverse cranial abnormalities with the enhanced cranial implant design.

The effect of morphometric and geometric indices of the human calvarium on mechanical response

BackgroundWhen developing a surrogate model of the human skull, there is a multitude of morphometric and geometric properties to consider when constructing the model. To simplify this approach, it is important to identify only the properties that have a significant influence on the mechanical response of the skull. The objective of this study was to identify which morphometric and geometric properties of the calvarium were significant predictors of mechanical response. MethodsCalvarium specimens (N = 24) were micro-computed tomography scanned to determine morphometric and geometric properties. The specimens were assumed to be Euler-Bernoulli beams and were subject to 4-point quasi-static bending to determine mechanical response. Univariate linear regressions were performed whereby the morphometric and geometric properties were independent or predictor variables and the mechanical responses were dependent or outcome variables. FindingsNine significant linear regression models were established (p < 0.05). In the diploë, trabecular bone pattern factor was a significant predictor of force and bending moment at fracture. The inner cortical table had more significant predictors (thickness, tissue mineral density, and porosity) of mechanical response compared to the outer cortical table and diploë. InterpretationMorphometric and geometric properties had a key influence on the calvarium's biomechanics. Trabecular bone pattern factor and the morphometry and geometry of the cortical tables must be considered when evaluating the mechanical response of the calvarium. These properties can aid the design of surrogate models of the skull that seek to mimic its mechanical response for head impact simulation.

Impacts of residual 3D printing metal powders on immunological response and bone regeneration: an in vivo study

Residual powder is a defect in powder bed fusion-based additive manufacturing (3D printing), and it is difficult to completely remove it from as-printed materials. In addition, it is not necessary to apply 3D printed implants with residual powder in the clinic. The immunological response triggered by the residual powder is an important area of study in medical research. To further understand the possible immunological reactions and hidden dangers caused by residual powders in vivo, this study compared the immunological reactions and osteolysis caused by typical powders for four implant materials: 316 L stainless steel, CoCrMo, CP-Ti, and Ti-6Al-4V (particle size range of 15–45 μm), in a mouse skull model. Furthermore, the possible immunological responses and bone regeneration induced by the four 3D printed implants with residual powder in a rat femur model were compared. In the mouse skull model, it was found that the 316L-S, CoCrMo-S, and especially the 316L-M powders, upregulated the expression of pro-inflammatory factors, increased the ratio of RANKL/OPG, and activated more functional osteoclasts, resulting in more severe bone resorption compared with those in other groups. In the rat femur model, which is more suitable for clinical practice, there is no bone resorption in implants with residual powders, but they show good bone regeneration and integration ability because of their original roughness. The results indicate that the expressions of inflammatory cytokines in all experimental groups were the same as those in the control group, showing good biological safety. The results answered some critical questions related to additively manufactured medical materials in vivo and indicated that as-printed implants may have great potential in future clinical applications.Graphical

A Case Report of Zygomatic Fracture Reconstruction: Evaluation with Orbital Measurements and Models Registration

The repair and reconstruction of defects in the craniomaxillofacial region can be particularly challenging due to the complex anatomy, individuality of each defect, and sensitivity of the involved systems. This study aims to enhance the facial appearance and contribute to the reconstruction of the zygomatic arch. This was achieved through virtual planning of the surgery and assessment of clinical matching, including orbital measurements and registration of numerical models. A three-dimensional design of a young female case was generated on a skull model using Mimics® software, and the orbit was isolated using 3-Matic® to assess the reconstructive effect. 3D-printed implants were then surgically placed on the injured region, and Netfabb® software was used to make a virtual registration between the numerical models before and after the intervention. This allowed for the calculation of a deviation of 7 mm, equivalent to 86.23% of the shape restoration rate, to assess the success of the surgery. The computerized method enabled a precise design of the needed plates and analysis of the fixation places, resulting in a satisfactory cosmetic and functional outcome for the patient with minimal complications and good implant stability. Notably, a significant difference was observed in the orbital frontal area after 3 months of surgery (p &lt; 0.001). Within the limitations of the study, these results suggest that virtual planning and customized titanium implants can serve as useful tools in the management of complex zygomatic-orbital injuries.

Evaluation of dental and skeletal effects of the asymmetric rapid maxillary expansion appliance: A three-dimensional finite element study.

Transverse maxillary deficiency is one of the most common skeletal anomalies. The incidence of posterior crossbite caused by maxillary deficiency is between 2.7% and 23.3%. Unilateral posterior crossbite is more common than bilateral crossbite. The most common treatment for skeletal posterior crossbite is rapid maxillary expansion (RME), in which the base of the maxillary bone is expanded by separating the midpalatal suture. This study compares the biomechanical effects of three different RME appliances, especially the effects on the midline, and evaluates the usability of the modified asymmetric RME (ARME) appliance for treating unilateral crossbites. Three scenarios were created with skull models using three different appliances: (1) conventional-bonded RME appliance; (2) full-cap splint RME appliance, with all teeth covered with acrylic; and (3) ARME, with all teeth on the right side and premolars and molars on the left side covered with acrylic. The finite element method was used to assess stress levels and displacements in all models after applying a 5-mm horizontal displacement to the RME screw. The lateral transverse movement of the first molars was greater with the conventional RME appliance than with the full-cap splint RME appliance. The lateral transverse movement of the first molar was greater on the left than on the right side with the ARME. The lateral transverse movement of the central incisors was greater with the full-cap splint RME appliance than with the conventional RME appliance. The lateral transverse movement of the central incisor was greater on the right than on the left side with the ARME. Asymmetrical RME appliance increases unilateral expansion compared to other appliances. Therefore, it should be used in cases of unilateral posterior crossbite. This appliance can also successfully treat posterior crossbite with upper midline deviation, since it corrects the shifted midline.

Accuracy of Soft Tissue Prediction in Skeletal Type III Relationship Using a Computer-Aided Three-Dimensional Surgical Simulation Planning Program

Using a computer-aided, three-dimensional surgical simulation planning program, soft-tissue planning can help achieve adequate facial esthetics and patient satisfaction after orthognathic surgery. This study aimed to assess the Simplant O&amp;O software’s soft tissue prediction accuracy. Fourteen skeletal type III patients who underwent orthognathic surgery by the same surgeons were included in this prospective study, and they were separated into two groups: the one-jaw (n = 5) and two-jaw (n = 9) groups. The software was used to analyze the preoperative (T0) and 4-month postoperative computed tomography data (T1), as well as intraoral scans. Data from cone-beam computed tomography and stereolithography from a scanned dental cast were used to reconstruct a composite skull model. Based on the presurgical CT data, the program generated a predicted soft tissue image (TP), which was then superimposed on the T1. The distances between seven T1 and TP landmarks were measured and evaluated using a one-sample t-test. In the one-jaw group, the mean error for all linear measurements was 1.73 ± 1.14 mm, whereas the mean error of the two-jaw group was 1.03 ± 0.83 mm, and both measurements were within clinically acceptable limits. Pronasele had the best correlation (mean error of 0.63 ± 0.45 mm) while soft tissue pogonion and soft tissue point B had the worst correlations (mean error of 2.87 ± 2.22 mm and 1.31 ± 0.98 mm, respectively). Even though there were some limitations, it was possible to conclude that the ability to accurately predict soft tissue changes using Simplant O&amp;O for skeletal type III patients makes it adequate for use in clinical practice.

BushenHuoxue decoction suppresses M1 macrophage polarization and prevents LPS induced inflammatory bone loss by activating AMPK pathway

Abnormal bone metabolism and subsequence osteoporotic fractures are common complications of chronic inflammatory diseases. No effective treatment for these bone-related complications is available at present. The chronic inflammatory state in these diseases has been considered as a key factor of bone loss. Therefore, the combination of inflammation inhibition and bone loss suppression may be an important strategy for reducing bone damage associated with inflammatory diseases. Bushen Huoxue Decoction (BSHXD) is a traditional Chinese herbal compound that has demonstrated the ability to improve bone quality and increase bone density. However, the efficacy of BSHXD on inflammatory bone loss and its underlying mechanisms remain unclear. This study aimed to investigate whether BSHXD inhibits inflammatory bone loss in mice and its potential molecular mechanisms. In the present study, the effect of BSHXD on lipopolysaccharide (LPS)-induced M1 polarization of RAW264.7 macrophage and on local inflammatory bone loss model of mouse skull was determined. The results showed that after treating RAW264.7 cells with LPS for 24 h, the expression levels of IL-1β (39.42 ± 3.076 ng/L, p < 0.05), IL-6 (49.24 ± 1.766 mg/L, p < 0.05) and TNF-α (286.3 ± 27.12 ng/L, p < 0.05) were significantly increased. The addition of BSHXD decreased the expression levels of IL-1β, IL-6, and TNF-α to 31.55 ± 1.296 ng/L, 37.94 ± 0.8869 mg/L, and 196.4 ± 25.25 ng/L, respectively (p < 0.05). The results of immunofluorescence staining, Western blotting (WB) and flow cytometry indicated that the proportion of M1 macrophages in RAW264.7 cells treated with BSHXD for 24 h was significantly lower than that in the LPS group (13.36% ± 0.9829% VS 24.80% ± 4.619%, p < 0.05). The evidence from in-vitro experiments showed that the immunomodulatory ability of BSHXD may be associated with the activation of AMP-dependent protein kinase (AMPK) pathway in LPS-treated macrophages. In addition, the results of micro-CT, H&E staining, immunohistochemical staining and immunofluorescence staining of mouse skull further demonstrated that BSHXD treatment significantly alleviated LPS-induced local bone loss and inflammatory damage in mouse skull model. All results indicated that BSHXD significantly inhibited inflammatory factors release and M1 polarization of macrophage through AMPK signaling pathway. Therefore, BSHXD may be a promising drug for the treatment of inflammatory bone loss.

Regulated contribution of local and systemic immunity to new bone regeneration by modulating B/Sr concentration of bioactive borosilicate glass.

The local immune response induced by bioactive borosilicate glass (BG) plays a vital role in bone regeneration, but its effect in the systemic immune response of distal tissues, such as spleen, remains unknown. In this study, the network structures and the relative theoretical structural descriptors (Fnet) of the novel BG composition containing boron (B) and strontium (Sr) were calculated and stimulated by molecular dynamics (MD) simulation, and the linear relationships of Fnet and B and Sr releasing rate in pure water and simulate body fluid were built. Next, the synergistic effects of the released B and Sr on promoting osteogenic differentiation, angiogenesis, and macrophage polarization were analyzed in vitro and convinced in rats skull models in vivo. Results show that the optimal synergistic effects of B and Sr both in vitro and in vivo released from 1393B2Sr8 BG increased vessel regeneration, modulated M2 macrophages polarization and promoted new-bone formation. Interestingly, the 1393B2Sr8 BG was found to mobilize monocytes from the spleen to the defects and subsequently modulate them into M2 macrophages. Then, these modulated cells cycled from the bone defects back to the spleen. To analyze the necessity of spleen-derived immune cells in bone regeneration, two contrasting rat models (with/without spleen) of skull defects were furtherly established. As results, rats without spleen had fewer M2 macrophages surrounding skull defects and the bone tissues recovered more slowly, indicating the beneficial effects on bone regeneration of circulating monocytes and polarized macrophages provided by spleen. The present study provides a new approach and strategy in optimizing complex composition of novel BG and sheds light on the importance of spleen through modulating systemic immune response to contribute to local bone regeneration.

Application of a neural network to restore the lost surface of skull bones

Objective: to evaluate the sensitivity, specificity and accuracy of a digital algorithm based on convo-lutional neural networks to restore of bones of cranium defects. Material and methods. Neural network training was carried out as a result of 6,000 epochs on 78,000 variants of skull models with artificially generated skull injuries. The evaluation was performed on 222 DICOM series of patients computerized tomography with bones of cranium defects. Results. The indicators of sensitivity, specificity and accuracy were 95.3%, 85.5% and 79.4% respectively. A number of experiments were carried out with step-by-step sorting of three-dimensional models in order to find the reasons for the unsatisfactory skull reconstructing results. Incorrect detection of the skull defect most often occurred in the area of the facial skeleton. After excluding the series with artifacts, the average increase in metrics was 2.6%. Conclusion. Correct determination of the bone defect at the scull model (specificity) by the algorithm had the greatest impact on the surface accuracy. The maximum accuracy of the algorithm, which allows using the obtained surfaces without additional processing in a three-dimensional modeling environment, was achieved on series without the presence of artifacts during computed tomography (83.5%), as well as with defects that do not extend to the skull base (79.5%).

Resection and Reconstruction of a Giant Paranasal Osteoma in a Pediatric Patient

Study Design Case Report. Objective Paranasal osteomas are rare, benign bony tumors of the craniofacial skeleton and most are treated endoscopically without the need for reconstruction. In rare cases, open traditional craniofacial approaches are required with a paucity of literature describing extirpative maneuvers in this setting. We present a unique case of a rapidly growing, paranasal bony tumor in a pediatric patient and describe our surgical technique for resection and reconstruction. Methods A 13-year old male presented with eight months of progressive, painless right periorbital swelling and proptosis. Trans-nasal biopsy confirmed an osteoma of the right ethmoid sinus and endoscopic resection was recommended. Due to interval tumor growth, there was worsening visual acuity that precluded a minimally invasive approach. Pre-operative and post-operative 3D computed tomography (CT) scans were completed, and a 3D printed skull model was produced to aid in surgical planning. A multi-disciplinary team of Otolaryngology, Neurosurgery, and Plastic Surgery was employed. The majority of the extirpation was performed with a highspeed carbide burr. Results Post-operative course was unremarkable and CT scan demonstrated a complete resection. Pathology confirmed the diagnosis of an osteoma. Six-month follow-up demonstrated normal ophthalmologic function and visual acuity with excellent aesthetic results. Conclusions This is a rare, complex presentation of a paranasal osteoma that was successfully managed with an open, multi-disciplinary approach. We highlight pearls gleaned from this extirpative and reconstructive technique. Due to the tumor density and location, a multidisciplinary team, Stealth navigation, an open, intra- and extra-cranial approach and use of a highspeed carbide burr were essential.

Simulation and experimental studies of debris penetrating skull

Studying the critical kinetic energy (CKE) and critical specific kinetic energy (CSKE) of the debris penetrating the human skull is of great importance for the development of head protection devices. In general, obtaining human skull specimens and conducting direct penetration experiments is difficult. Finite element simulation, on the other hand, is an effective method for determining critical values. However, it is necessary to validate the modeling and simulation method before conducting simulations on the human skull. To validate the method, this study first established a finite element model of a pig skull and performed simulations of debris penetrating the skull. The modeling and simulation methods were verified by comparing the corresponding penetration experimental results on pig skulls with those of the simulations. As the modeling and simulation methods were indirectly validated, an anatomical human skull finite element model was developed to conduct simulations of spherical and cubic debris penetrating the skull to iteratively obtain the CKE and CSKE of the two pieces of debris. Finally, the influence of different attitudes of cubic debris on the penetration energy of the human skull was investigated.

Using neural network for restoring the lost surface of skull bones

Objective: To assess the sensitivity, specificity and accuracy of a digital algorithm based on convolutional neural networks used for restoring the lost surface of the skull bones. Materials and methods. The neural network was trained over 6,000 epochs on 78,000 variants of skull models with artificially generated skull injuries. The key parameters of the algorithm were assessed on 222 series of multislice computed tomography (MSCT) of patients with defects of the skull bones, presented in DICOM format. Results. For the group as a whole, the sensitivity, specificity, and accuracy rates were 95.3%, 85.5%, and 79.4%, respectively. Multiple experiments were conducted with a step-by-step elimination of 3D models in order to find the underlying cause of unsatisfactory outcomes of the skull lost surface restoration. Incorrect identification of the defect zone most often occurred in the area of the facial skeleton. After excluding series with the presence of artifacts, the mean increase in metrics was 2.6%. Conclusion. The accuracy of identifying the reference points (specificity) on a 3D model of the skull by the algorithm had the greatest impact on the ultimate accuracy of repairing the lost surface. The maximum accuracy of the algorithm allowing the use of the resulting surfaces without additional processing in a 3D modeling environment was achieved in series without the presence of artifacts in computed tomography (83.5%), as well as with defects that did not extend to the base of the skull (79.5%).

Experimental detection of skull-based ultrasonic Lamb waves as an intracranial pressure monitoring method

Pressure within the cranial vault, which consists of cerebrospinal fluid, the central nervous system (CNS), and blood, is referred to as intracranial pressure (ICP). Severely high ICP can damage the CNS so its monitoring is crucial for patients deemed to be at high risk of elevated ICP, such as those with traumatic brain injuries or undergoing neurosurgery. The standard approach requires the insertion of a pressure probe into the ventricles through a burr hole on the skull. A noninvasive alternative to ICP monitoring using guided acoustic waves on the skull was investigated. Different modes of Lamb waves were generated in submerged acrylic skull models and their corresponding leaky components were detected. The behavior of Lamb waves upon asymmetrical pressure loading of the plate was examined to reveal metrics that were sensitive to pressure changes underneath the skull. Dispersion curves, including the anti-symmetrical and symmetrical modes of Lamb waves propagation in thin, isotropic acrylic plate comparable to thickness of cortical skull bone were computed using the Rayleigh–Lamb equation and the bisection method. Physical parameters, such as critical angle, frequency-dependence phase velocity, and time-of-arrival were analyzed.

Replacing cutting guides with an augmented reality-based navigation system: A feasibility study in the maxillofacial region.

The work presents outcomes of simulated maxillofacial skeleton osteotomies supported with cutting guides or one of two AR-based intraoperative navigation systems. The series of osteotomies supported with a cutting guide, simple AR (sAR) or navigated AR (nAR) module were carried out on 15 (five per each method) skull models according to the virtual surgical plan (VSP). Each method was used to support 40 osteotomies involving the upper jaw and 40 involving the orbital region (16 osteotomies on each model). Postoperative computed tomography scans were fused with the VSP to analyse angular deviations from the planned cutting trajectory (°) and the deviations of labelled control points (mm). Guides provided the highest accuracy, with a mean osteotomy angular deviation of 3.73±2.94° and a mean control point deviation of 1.30±0.73 mm. Mean angular deviations for the sAR- and nAR-assisted osteotomies were 5.93±5.12° and 6.75±5.33°, and mean control point deviations amounted to 1.86±0.88 mm and 1.97±0.70 mm.

Bistable magnetic microwire for contactless sensor of intracranial pressure

The given paper presents one new opportunity of glass-coated microwires for biomedical applications, especially the possibility of pressure measuring inside a human cranium. The application allows noninvasive and contactless sensing of the intracranial pressure (ICP) using FeSiBP glass-coated microwire for a sensor in a model of skull. First, the measurement of the mechanical dependence of the switching time dt on the microwire shows almost linear progression. In this case the middle tensile sensibility ST (slope value) of microwire is 1.84 μs/MPa. The studied microwire, implanted in the skull as a sensor, could measure intracranial parameters simultaneously at any time, only by attaching the probe from the outside of the head. The experimental measurements have been carried out on the skull model with the water balloon, which has similar properties and Young's modulus of cerebral membrane - dura. The measurements, in the range of values corresponding to normal intracranial pressure show, that the switching time dt monotonously increases with increasing hydrostatic pressure in the water balloon, where the average tensile sensibility ST is about 38 ns/Pa. The high theoretical sensibility about 0.3 Pa can be achieved. This approach makes this technology very interesting for the practical application.

Patient-specific Composite Anatomic Models: Improving the Foundation for Craniosynostosis Repair.

Preoperative surgical planning incorporating computer-aided design and manufacturing is increasingly being utilized today within the fields of craniomaxillofacial, orthopedic, and neurosurgery. Application of these techniques for craniosynostosis reconstruction can include patient-specific anatomic reference models, "normal" reference models or patient-specific cutting/marking guides based on the presurgical plan. The major challenge remains the lack of tangible means to transfer the preoperative plan to the operating table. We propose a simple solution to utilize a digitally designed, 3D-printed "composite model" as a structural template for cranial vault reconstruction. The composite model is generated by merging the abnormal patient cranial anatomy with the "dural surface topography" of an age-matched, sex-matched, and ethnicity-matched normative skull model. We illustrate the applicability of this approach in 2 divergent cases: 22-month-old African American male with sagittal synostosis and 5-month-old White male with metopic synostosis. The aim of this technical report is to describe our application of this computer-aided design and modeling workflow for the creation of practical 3D-printed skulls that can serve as intraoperative frameworks for the correction of craniosynostosis. With success in our first 2 cases, we believe this approach of a composite model is another step in reducing our reliance on subjective guesswork, and the fundamental aspect of the workflow has a wider application within the field of craniofacial surgery for both clinical patient care and education.

Application of 3D Modeling and 3D Printing Methods in Preoperative Planning of Cranioplasty and Preoperative Personalized Training in Treatment Cranio-synostoses

On the example of a clinical case, we used software 3D modeling of the reconstruction of the shape of the skull of a child aged 2 years and 5 months with metopic craniosynostosis, as well as manual training using a craniotomy on an individual 3D model of the patient's skull before surgery. The use of a plastic 3D model of a particular patient made it possible to conduct a “trial, training operation” to work out the optimal osteotomy geometry. An intraoperative evaluation of the result obtained on a visual scanner was also carried out.Purpose of the study. Improving the result of surgical treatment of a child with metopic craniosynostosis using preoperative 3D planning and personalized simulation of a planned operation. For the purpose of preoperative planning we used an algorithm with the inclusion of 3D technologies: preoperative modeling on software, simulation of surgery on plastic models of the skull, surgical intervention along craniotomy lines, intraoperative visual scanning and assessment of the results of skull reconstruction.Conclusion. The preoperative 3D modeling of the skull formed a complete plan for individual reconstructive changes in the skull in our patient with metopic craniosynostosis over the age of two years, and allowed us to perform a “trial, training operation” on a plastic model to work out the optimal osteotomy geometry. This made it possible to provide the optimal technique for a real operation, speed up its implementation, reduce trauma and blood loss, the duration of anesthesia, and, in combination, improve the results of surgical treatment.