Three-dimensional Skull Models Research Articles

Association between maxillary incisor width and craniofacial measurements: A cone beam computed tomography study

Accurate prediction of maxillary central incisor width (CIW) is essential in prosthodontics for selecting appropriately sized denture teeth. While traditional methods exist, the digital era may offer more reliable techniques for anterior tooth selection. The purpose of this study was to investigate the correlation between CIW and craniofacial measurements derived from cone beam computed tomography (CBCT) scans to identify predictors for CIW and examine possible sexual dimorphism. A retrospective analysis was conducted on 80 three-dimensional skull models (40 men, 40 women; age range: 20 to 48 years) generated from segmented CBCT scans. Measurements included CIW, interpterygoid hamulus distance, bi-orbital width, interorbital distance, and piriform aperture width. Statistical analyses comprised independent t tests, bivariate correlations, and multiple linear regression (α=.05). Significant sexual dimorphism was observed in CIW, interpterygoid hamulus distance, and bi-orbital width (P<.05). CIW positively correlated with bi-orbital width (r=.75, P<.001) and piriform aperture width (r=.49, P<.001). Multiple regression analysis revealed bi-orbital width, and interorbital distance, along with sex, as significant predictors of CIW (R²=.59, P<.001). Bony bi-orbital width, interorbital distance, and sex can be used to estimate the maxillary CIW.

A Single Standard Polyvinyl Chloride 3D Skull Model to Create the Polymethyl Methacrylate Cranioplasty Flap: A Novel and Low-Cost Technique.

Although, cranioplasty is a commonly performed neurosurgical procedure worldwide, the cost of available cranioplasty implants is a major issue in a low-income country like India. The aims of this study were to introduce a novel and low-cost technique using a single standard three-dimensional (3D) skull model to guide the polymethyl methacrylate (PMMA) cranioplasty flap production and to evaluate the functional and cosmetic outcomes. We retrospectively evaluated 47 cases of PMMA cranioplasty in the period from February 2019 to June 2022. A single standard 3D skull model was used to make the PMMA cranioplasty flaps. The overall cost of this PMMA implant was compared with that of other available cranioplasty implants. The functional and cosmetic outcomes were evaluated postoperatively. The mean age of our patients was 37.17 ± 13.83 years and the age range was 17 to 63 years. The primary cause of surgery was trauma in the majority of cases (n = 31, 65.96%). The mean operative time was 78.55 ± 19.82 minutes. The cosmetic results were very satisfying in 46 of 47 (97.87%) patients and moderately satisfying in 1 (2.12%) patient. Overall, there were three (6.38%) complications. Our technique provides excellent functional and cosmetic outcomes. The overall surgical cost of these PMMA implants was lower than that of the other available cranioplasty implants. This technique is currently the most cost-effective option for cranioplasty.

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

Fenestration and dehiscence are alveolar bone defects. Although not considered a pathology, these alveolar bone defects end up influencing dental treatment, such as surgeries, mainly periodontal, and therefore must be considered during treatment planning. However, currently, little is known about the biomechanical origin of these bone formations. The aim of the study was to use the finite element method (FEM) to test hypotheses of predictive factors for fenestrations and dehiscence in human alveolar bone. A FEM simulation of the action of functional, parafunctional, and orthodontic occlusal loads on the upper central incisor and upper canine was performed. For the simulation, a three-dimensional model of an adult human skull, fully dented and with intact bone structure, was constructed from computed tomography images. The buccal alveolar bone lamina was evaluated considering the calculation of equivalent stresses, as well as maximum principal stresses. The action of functional and parafunctional forces on the incisal edges and the orthodontic force on the buccal face of the upper central incisor and upper canine teeth generated tensions at different levels of magnitude in the buccal bone lamina, varying in regions, at all levels of strength. Changing levels of force magnitude resulted in variations in relation to the level of deformation. The computational simulation using the FEM was able to identify a difference in stress in the alveolar bone tissue in each of the applied forces. The difference in stresses obtained may suggest the formation of dehiscence or fenestration in the region studied.

Finite Element Analysis Model for Assessing Expansion Patterns from Surgically Assisted Rapid Palatal Expansion.

Surgically assisted rapid palatal expansion (SARPE) was introduced to release bony resistance to facilitate skeletal expansion in skeletally mature patients. However, asymmetric expansion between the left and right sides has been reported in 7.52% of all SARPE patients, of which 12.90% had to undergo a second surgery for correction. The etiologies leading to asymmetric expansion remain unclear. Finite element analysis has been used to evaluate the stress associated with SARPE in the maxillofacial structures. However, as a collision of the bone at the LeFort I osteotomy sites occurs only after a certain amount of expansion, most of the existing models do not truly represent the force distribution, given that the expansion amount of these existing models rarely exceeds 1 mm. Therefore, there is a need to create a novel finite element model of SARPE that could perform a clinically required amount of expander activation for further analysis of the expansion patterns of the hemimaxillae in all three dimensions. A three-dimensional (3D) skull model from cone beam computed tomography (CBCT) was imported into Mimics and converted into mathematical entities to segment the maxillary complex, maxillary first premolars, and maxillary first molars. These structures were transferred into Geomagic for surface smoothing and cancellous bone and periodontal ligament creation. The right half of the maxillary complex was then retained and mirrored to create a perfectly symmetrical model in SolidWorks. A Haas expander was constructed and banded to the maxillary first premolars and first molars. Finite element analysis of various combinations of buccal osteotomies at different angles with 1 mm clearance was performed in Ansys. A convergence test was conducted until the desired amount of expansion on both sides (at least 6 mm in total) was achieved. This study lays the foundation for evaluating how buccal osteotomy angulation influences the expansion patterns of SARPE.

Three-Dimensional Cephalometric Analysis of Skeletal and Dental Effects in Patients Undergoing Transpalatal Distraction

The present study aimed to assess dental and skeletal effects after transpalatal distraction using 3D cephalometry methodology. The study group comprised 34 patients (mean age 27.7 years) who were diagnosed with transverse skeletal maxillary deficiency of at least 7 mm. Computed tomography scans were obtained before surgical procedure (T1), after completion of expansion (T2) and at 6-month follow-up (T3). Computed tomography scans were imported into Dolphin Imaging software version 11.7 (Chatsworth, CA, USA). Three-dimensional skull models were oriented according to the Frankfurt horizontal plane, midsagittal plane (passing through the skeletal nasion) and frontal plane (passing through the right and left porion). Cephalometric landmarks related to skeletal, and dental structures were traced and linear and angular measurements were calculated. Following transpalatal distraction N-ANS and S-PNS distances increased by 1.27 mm and 0.54 mm, respectively. Skeletal expansion at the canine region (ARCR-ARCL) was 8.43 mm at T2 and 6.39 mm at T3. Expansion at the distal part of the maxilla (ARMR-ARML) was 5.95 mm at T2 and 4.81 mm after retention. The highest increase in maxillary arch width at T2 was observed at canines (8.74 mm), lower at premolars (8.33 mm) and the lowest at molars (6.76 mm). There is no anteroposterior movement of maxilla following transpalatal distraction; however, the maxilla shifts downward which is particularly marked anteriorly. Skeletal and dental expansion in the transversal plane occurs in a V-shaped manner, with more expansion at the anterior part of the maxilla.

Effect of 125–150 Hz Vibrational Frequency Electric Toothbrush on Teeth and Supporting Structures: A Finite Element Method Study

The aim of this finite element method (FEM) study was to assess the safety of 125-150 Hz vibrational frequency electric toothbrush on teeth and associated structures. A three-dimensional (3D) geometric model of entire skull having maxilla, mandible, and their dentitions was created using a computed tomography (CT) image of a healthy male patient. Linear static analysis was carried out by applying 15 g of force on anterior part of maxilla and mandible from labial and lingual sides each to calculate the primary displacement (sagittal, vertical, and transversal) and principal stress levels generated on the maxillary and mandibular dentition, on the maxilla and mandible and on the whole skull. A force of 15 g applied to maxillary anterior teeth from labial side caused a mean deflection of 0.003 mm and stress of 0.004 MPa on the teeth and supporting structures. A force of 15 g applied to maxillary anterior teeth from palatal side caused a mean deflection of 0.017 mm and stress of 0.017 MPa on the teeth and supporting structures. A force of 15 g applied to mandibular anterior teeth from labial side caused a mean deflection of 0.078 mm and stress of 0.051 MPa on the teeth and supporting structures. A force of 15 g applied to mandibular anterior teeth from lingual side caused a mean deflection of 0.077 mm and stress of 0.051 MPa on the teeth and supporting structures. For the applied loads and boundary conditions, very small or negligible amount of stresses were observed in maxilla, mandible, and their dentitions. The vibrational frequency of 150 Hz producing 15 g of force did not produce any harmful effects on maxilla, mandible, and their dentitions. Hence, 125-150 Hz of vibrational frequency can be considered optimum. An electric toothbrush using the vibration of 125-150 Hz produces negligible stress on teeth and associated structures.

The development and testing of Thai facial soft tissue thickness data in three-dimensional computerized forensic facial reconstruction.

Forensic facial reconstruction is a useful tool to assist the public in recognizing human remains, leading to positive forensic investigation outcomes. To reproduce a virtual face, facial soft tissue thickness is one of the major guidelines to reach the accuracy and reliability for three-dimensional computerized facial reconstruction, a method that is making a significant contribution to improving forensic investigation and identification. This study aimed to develop a facial soft tissue thickness dataset for a Thai population, and test its reliability in the context of facial reconstruction. Three-dimensional facial reconstruction was conducted on four skulls (2 males and 2 females, with ages ranging between 51 to 60 years). Two main tools of three-dimensional computer animation and modeling software-Blender and Autodesk Maya-were used to rebuild the three-dimensional virtual face. The three-dimensional coordinate (x, y, z) cutaneous landmarks on the mesh templates were aligned homologous to the facial soft tissue thickness markers on the three-dimensional skull model. The final three-dimensional virtual face was compared to the target frontal photograph using face pool comparison. Four three-dimensional virtual faces were matched at low to moderate levels, ranging from 30% to 70% accuracy. These results demonstrate that the facial soft tissue thickness database of a Thai population applied in this study could be useful for three-dimensional computerized facial reconstruction purposes.

Maxillary repositioning using a CAD/CAM wafer and an intraoperative navigation system for bimaxillary orthognathic surgery using segmental Le Fort I osteotomy: A pilot study

ObjectiveThe precision of maxillary repositioning using computer-aided design/computer-aided manufacturing (CAD/CAM)-generated wafers and a surgical navigation system for bimaxillary orthognathic surgery (BMOS) using segmental Le Fort I osteotomy was evaluated. MethodsSix participants with jaw deformities who required BMOS incorporating segmental Le Fort I osteotomy were included. The preoperative simulation was performed using a three-dimensional skull model on the simulation software, and a wafer for maxillary repositioning was prepared by CAD/CAM. Using the CAD/CAM-generated wafer and intraoperative navigation system, the maxillary segments were repositioned to agree with virtual surgical planning. The ideal movements of the preoperative simulation were compared with the actual movements after the surgery, and the errors of the ideal movements with reference to the actual movements were evaluated three-dimensionally at seven evaluation points. ResultsThe largest and smallest median errors calculated from the differences between the ideal and actual 3-D movements were, respectively, 0.65 mm at anterior nasal spine, 0.02 mm at posterior nasal spine. There is no significant difference was observed between ideal and actual movements in either 2-D and 3-D. ConclusionThe clinical accuracy of maxillary repositioning with the CAD/CAM wafer and an intraoperative navigation system in segmental Le Fort I osteotomy was revealed in the present study.

Correlation between head shape and volumetric changes following spring-assisted posterior vault expansion

The aim of the study was to investigate whether different head shapes show different volumetric changes following spring-assisted posterior vault expansion (SA-PVE) and to investigate the influence of surgical and morphological parameters on SA-PVE.Preoperative three-dimensional skull models from patients who underwent SA-PVE were extracted from computed tomography scans. Patient head shape was described using statistical shape modelling (SSM) and principal component analysis (PCA). Preoperative and postoperative intracranial volume (ICV) and cranial index (CI) were calculated. Surgical and morphological parameters included skull bone thickness, number of springs, duration of spring insertion and type of osteotomy.In the analysis, 31 patients were included. SA-PVE resulted in a significant ICV increase (284.1 ± 171.6 cm3, p < 0.001) and a significant CI decrease (−2.9 ± 4.3%, p < 0.001). The first principal component was significantly correlated with change in ICV (Spearman ρ = 0.68, p < 0.001). Change in ICV was significantly correlated with skull bone thickness (ρ = −0.60, p < 0.001) and age at time of surgery (ρ = −0.60, p < 0.001). No correlations were found between the change in ICV and number of springs, duration of spring insertion and type of osteotomy.SA-PVE is effective for increasing the ICV and resolving raised intracranial pressure. Younger, brachycephalic patients benefit more from surgery in terms of ICV increase. Skull bone thickness seems to be a crucial factor and should be assessed to achieve optimal ICV increase. In contrast, insertion of more than two springs, duration of spring insertion or performing a fully cut through osteotomy do not seem to impact the ICV increase. When interpreting ICV increases, normal calvarial growth should be taken into account.

Craniofacial Reconstruction Based on Geodesic Regression Model

<p indent=0mm>Craniofacial reconstruction refers to predicting the corresponding appearance based on the characteristics of an unknown skull. In order to solve the problem of large amount of data, manual work of calibrating feature points and difficulty in defining craniofacial feature points in the process of craniofacial reconstruction, for the three-dimensional skull and skin model represented by a triangular mesh, the craniofacial model is represented by a set of geodesics which are starting from the tip of a nose, thereby craniofacial reconstruction method based on geodesic regression is proposed. First, a set of geodesics is extracted from the nose tip point of the 3D face model; then the skull and the geodesics extracted from the corresponding face model are used as training samples, and the partial least square regression statistical model is used to reconstruct geodesics corresponding to the unknown skull; Finally, the iterative closest point algorithm is used to match the geodesics generated by the geodesic regression method with the facial statistical model to reconstruct the face of the test skull. Craniofacial reconstruction experiments have been conducted on 192 sets of craniofacial data. The reconstruction results based on geodesic regression were compared with the reconstruction results of principal component analysis and partial least squares regression. The experimental results showed that our method can improve the reconstruction accuracy, reduce the reconstruction time, and achieve a good reconstruction effect.

Evaluation of stress distribution in maxilla, mandible, and glenoid fossa after Class III intermaxillary traction: A three-dimensional finite element analysis study

Aim: In this study, we aimed to evaluate the stress distribution on maxilla, mandible, and glenoid fossa after application of Class III intermaxillary anteroposterior orthopedic forces of 150, 250, and 400 gas applied to a three-dimensional (3D) model of the young human dry skull. Methods: A 3D finite element model was developed from the computed tomography images of a growing boy (age, 13 years). ANSYS (version 16.0) software used to simulate Class III force of progressively increasing intensity over maxilla, mandible, and glenoid fossa to quantify the biomechanical reaction with two components, direction and stress. Results: We quantified detailed changes in the maxillofacial sutures, dentition, mandible, and glenoid fossa with bone-anchored maxillary protraction (BAMP) to analyze their effects. Conclusions: As the force increases from 150, 250 to 400 g, stresses are increased on all structures associated except maxillary central incisor which show a decrease in the stresses. Although forces were for maxillary protraction, stress generated at the circummaxillary sutures was minimal. As with any other Class III force, stresses were distributed on whole of condyle, capsular ligament, and minimal at glenoid fossa. This suggests that BAMP has more of mandibular restraining effect.

Three-Dimensional Skull Model for Endoscopic Skull Base Surgical Training

Nebor, Ivanna; Hussein, Ahmed; Montemagno, Kora; Fumagalli, Rebecca; Labiad, Ikrame; Anderson, Zoe; Xu, Alice; Sedaghat, Ahmad; Patil, Yash; Forbes, Jonathan A MD Author Information

Bioanthropological analysis of human occipital condyles using geometric morphometric method.

Sex differences are present in all parts of the body, including the skeletal system. Several methods are used to analyze the sex differences of skeleton, while more recently, a new method called geometric morphometry has been used. The aim of this study was to examine the sexual dimorphism of occipital condyles on human skulls originating from the population of Bosnia and Herzegovina using the geometric morphometric method.Material and methodsThe study was conducted on 214 human skulls of known gender from Bosnian population. For analysis of sexual dimorphism of occipital condyles, we used geometric morphometry, where all the skulls were scanned to obtain three-dimensional skull models. On the obtained models, we marked anthropometric points on occipital condyles in a Landmark Editor program from which we exported data in the form NTSYS file and analyzed it in MorphoJ program.ResultsFirst principal component PC1 describes 26.917% of total variability, the second principal component PC2 describes 20.992% of total variability, while the first eight principal components together describe 100% of total variability. The greatest variability between the male skulls and female skulls was present in the anterior-posterior diameter (length of occipital condyles). Discriminant functional analysis of the shape and size of the occipital condyles was possible with 69.50% accuracy for male skulls and with 60.27% accuracy for female skulls. The size of the occipital condyles showed a statistically significant effect on sexual determination. Discriminant functional analysis of the shape of the occipital condyles without affecting size enabled the determination of gender with with 65.96% accuracy for male skulls and with 63.01% accuracy for female skulls.ConclusionAnalysis of sexual dimorphism of occipital condyles using geometric morphometry showed statistically significant differences in the shape and size of occipital condyles between the sexes. The accuracy of sex determination based on occipital condyles was higher for male gender.

Surface Topography-Based Positioning Accuracy of Maxillary Templates Fabricated by the CAD/CAM Technique for Orthognathic Surgery without an Intermediate Splint

Computer-aided design/computer-aided manufacturing (CAD/CAM)-based maxillary templates can transfer a surgical plan accurately only when the template is positioned correctly. Our study aimed to evaluate the positioning accuracy of the CAD/CAM-based template for maxillary orthognathic surgery using dry skulls. After reconstruction of a three-dimensional (3D) virtual skull model, a surface-based surgical template for Le Fort I osteotomy was designed and fabricated using CAD/CAM and 3D printing technology. To determine accuracy, the deviation of the template between the planned and the actual position and the fitness of the template were evaluated. The mean deviation was 0.41 ± 0.30 mm in the medio-lateral direction, 0.55 ± 0.59 mm in the antero-posterior direction, and 0.69 ± 0.59 mm in the supero-inferior direction. The root mean square deviation between the planned and the actual position of the template was 1.21 ± 0.54 mm. With respect to the fitness of the template, the mean distance between the inner surface of the template and the underlying bone surface was 0.76 ± 0.24 mm. CAD/CAM-based templates showed precise positioning and good fitness. These results suggest that surface topography-based CAD-CAM templates can be considered as an alternative solution in replacing the traditional intermediate splints for the transfer of surgical plans.

An average three-dimensional virtual human skull for a template-assisted maxillofacial surgery.

Although many advances have been made in three-dimensional virtual planning in maxillofacial surgery, facial harmony is still difficult to achieve and is heavily dependent on the surgeon's experience. The aim of the study is to present a method to build up an average three-dimensional virtual human skull to be used as a reference template for bone repositioning and reconstruction during maxillofacial surgical interventions. A total of 20 patients (10 females and 10 males) were selected for the optimal outcome after orthognathic surgery. Postoperative cone-beam computed tomography scans were collected and processed in order to obtain three-dimensional digital models of each skull. For male and female subgroups, the three-dimensional skull models were registered and an average three-dimensional virtual skull model was computed. Deviation color maps were calculated to show differences between each postoperative skull model in the population and the obtained average three-dimensional skull. A clinical use case of genioplasty treatment assisted by the provided average three-dimensional skull template was presented. The overall mean deviation from the average three-dimensional skull model was 1.3 ± 0.6 and 1.6 ± 0.5 mm in male and female subgroups, respectively. For both groups, the greatest deviations were at the area of the mandible, while almost no deviation was found at the zygomatic and orbital areas. In the presented use case, the female average three-dimensional skull model was effectively used for guiding surgical planning. The presented method of obtaining an average three-dimensional virtual human skull may offer the interesting perspective of performing an innovative template-assisted maxillofacial surgery.

Sex Recognition of Skulls in Chinese Uygur.

Objective Logistic regression method was used to establish a multiple regression sex discriminant function to discriminate the complete skull model and the incomplete skull model without frontal bone, occipital bone and mandible of Uygur adults in Turpan, Xinjiang. Methods A total of 117 （60 male and 57 female） three-dimensional skull models were collected by CT. Sixteen cranial measurement indexes were measured and calculated by computer software. The multivariate regression sex discriminant function was established with Logistic regression method and retrospectively tested. Results Among the 16 measurement indexes, except for nose width （x7） and maximum frontal breadth （x13）, the remaining 14 indexes had statistical significance of differences between male and female （P<0.05）. For the discriminant function of complete skull established by eyebrow arch convexity （x4）, mastoid width （x6）, maximum cranial length （x12）, cranial base length （x15）, cranial circumference （x16）, the male and female discrimination accuracy was 90.0% and 94.7%, respectively. For the sex discriminant function of incomplete skull without frontal bone established by mandibular angle width （x10）, mandibular height （x11） and cranial circumference （x16）, the discrimination accuracy of male and female was 85.0% and 84.2%, respectively. For the sex discriminant function of incomplete skull without occipital bone established by the index of eyebrow arch convexity （x4）, the discrimination accuracy of male and female was 80.0% and 73.7%, respectively. For the sex discriminant function of incomplete skull without mandible established by frontal chord （x5） and occipital protrusion angle （x9）, the discrimination accuracy of male and female was 85.0% and 78.9%, respectively. Conclusion The computer software and system developed in our study can achieve sex discrimination of complete skulls and incomplete skulls without frontal bone, occipital bone or mandible.

Three-Dimensional Skull Model with Vascular Structures for Occipital Expansion in Patients with Developed Occipital Emissary Veins

We report the application of a three-dimensional skull model with vascular structures for occipital expansion in a patient who had developed occipital emissary veins. A 15-year-old boy visited a dentist for orthodontic treatment and was diagnosed with midface hypoplasia. He had undergone a ventriculo-peritoneal shunt at the age of 10 months. On visiting our institution, he was diagnosed with exophthalmos, low visual acuity, reversed bite, and developmental retardation. Moreover, he had sleep apnea and was supported with continuous positive airway pressure at night. Computed tomography and magnetic resonance imaging demonstrated brachycephalus, chronic tonsillar herniation, midface hypoplasia, and well-developed occipital emissary veins. We chose occipital expansion for lowering intracranial pressure and created a three-dimensional skull model with vascular structures and shunt tube. On this model, we wrote scalp incision and craniotomy lines avoiding injury to the veins and shunt tube. The operation was completed using this plan. Patients with syndromic craniosynostosis frequently have developed emissary veins and previous shunt operation. The three-dimensional skull model with vascular structures will be expected to reduce the risks of surgery.

The Phenotypes of Spheno-Occipital Synchondrosis in Patients With Crouzon Syndrome.

To characterize the phenotypes of spheno-occipital synchondrosis (SOS) in Chinese patients with Crouzon syndrome. Twelve patients with Crouzon syndrome were included in this retrospective study, and were divided into 2 groups. The first group included 5 patients (5-7-year old), whereas 7 patients were included in the second group (8-11-year old). Two age- and sex-matched control groups were constituted for comparison. All patients and controls were underwent preoperative computed tomography examinations of the craniofacial area, and the three-dimensional skull models, sagittal, and axial images were reconstructed. The density of the SOS region was also calculated. The SOS was partially closed in the first Crouzon patients group, whereas the SOS was open in control groups. The SOS was completely fused SOS in the second Crouzon patients group, whereas the SOS was open or partially closed in control groups. There also were short and hypoplastic sphenoid bone in both Crouzon groups when compared with controls. In addition, the average density of SOS in patients with Crouzon syndrome was higher than the control groups (P <0.01). The SOS begins to prematurely fuse in Chinese patients with Crouzon syndrome, and there are short and hypoplastic sphenoid bone in these patients. Although a definitive role of prematurely fused SOS in Crouzon syndrome cannot be drawn, our finds provide important clues into the mechanisms, and potentially provide a treatment target for midfacial and cranial vault hypoplasia in Crouzon patients.

Customized "In-Office" Three-Dimensional Printing for Virtual Surgical Planning in Craniofacial Surgery.

Virtual surgical planning using three-dimensional (3D) printing technology has improved surgical efficiency and precision. A limitation to this technology is that production of 3D surgical models requires a third-party source, leading to increased costs (up to $4000) and prolonged assembly times (averaging 2-3 weeks). The purpose of this study is to evaluate the feasibility, cost, and production time of customized skull models created by an "in-office" 3D printer for craniofacial reconstruction. Two patients underwent craniofacial reconstruction with the assistance of "in-office" 3D printing technology. Three-dimensional skull models were created from a bioplastic filament with a 3D printer using computed tomography (CT) image data. The cost and production time for each model were measured. For both patients, a customized 3D surgical model was used preoperatively to plan split calvarial bone grafting and intraoperatively to more efficiently and precisely perform the craniofacial reconstruction. The average cost for surgical model production with the "in-office" 3D printer was $25 (cost of bioplastic materials used to create surgical model) and the average production time was 14 hours. Virtual surgical planning using "in office" 3D printing is feasible and allows for a more cost-effective and less time consuming method for creating surgical models and guides. By bringing 3D printing to the office setting, we hope to improve intraoperative efficiency, surgical precision, and overall cost for various types of craniofacial and reconstructive surgery.

Stereolithographic skull models in the surgical planning of fronto-supraorbital bar advancement for non-syndromic trigonocephaly

BackgroundFronto-supraorbital bar advancement in the treatment for trigonocephaly is associated with extensive intraoperative blood loss and compensatory erythrocyte transfusions. Since both are related to the length of surgery, efforts have been focused on optimizing preoperative preparations. The utilization of three-dimensional skull models in surgical planning allows for familiarization with the patient's anatomy, the optimization of osteotomies, the preparation of bone grafts and the selection of fixation plates. MethodsStereolithographic skull models were used in the surgical planning for five patients with non-syndromic trigonocephaly treated in Wilhelmina Children's Hospital in 2012. A comparison group was composed of six patients with non-syndromic trigonocephaly treated by the same surgical team. Once all patients had received surgery, a retrospective chart review was performed to identify the volumes of perioperative blood loss and erythrocyte transfusions and the length of the procedure. Furthermore, the educational value of the models was assessed in a round table discussion with the surgical team and residents. ResultsIn the model group patients were transfused a mean 24 ml/kg (27% of Estimated Blood Volume [EBV]) compared to 16 ml/kg (18% of EBV) in the comparison group (P = 0.359) for a mean perioperative blood loss of 53 ml/kg (60% of EBV) in the model group against 40 ml/kg (41% of EBV) in the comparison group (P = 0.792). The mean length of surgery in the model groups was 256 min versus 252 min in the comparison group (P = 0.995). Evaluation of educational purposes demonstrated that the models had a role in the instruction of residents and communication to parents, but did not improve the insight of experienced surgeons. ConclusionThe usage of stereolithographic skull models in the treatment of non-syndromic trigonocephaly does not reduce the mean volume of perioperative erythrocyte transfusions, the mean volume of perioperative blood loss nor the mean length of the surgical procedure. Nonetheless, the models do facilitate the education of the patient's parents as well as support the training of residents.