A review on patient-specific facial and cranial implant design using Artificial Intelligence (AI) techniques

Study Design: Inlay cranioplasties following partial craniectomy in tumor or trauma cases and onlay cranioplasties for reconstructions of residual developmental skull anomalies are frequently performed using CAD-CAM techniques. Objective: In this case series, we present a novel cranial implant design, being a combination of 3D-printed titanium grade 23 and calcium phosphate paste (CeTi). Methods: The titanium patient-specific implant, manufactured using selective laser melting, has a latticed border with interconnected micropores. The cranioplasty is miniscrew fixed and its border zone subsequently partially filled with calcium phosphate paste to promote osteoinduction and osteoconduction. From April 2017 to April 2019, 8 patients have been treated with such a CeTi implant. The inlay cranioplasties were each time revision surgeries of complicated cases. Results: All implants were successful after a limited follow-up time (range 18-42 months). There were no dehiscences and no infections, and no complaints of thermal conduction. Conclusions: The proposed CeTi cranial implant combines the strength of titanium implants with the biological integration potential of ceramic implants and seems particularly resistant to infection, probably due to the biofunctionalized titanium surface and the antimicrobial activity of elevated intracellular free calcium levels.

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Evaluation of Patient-Specific Cranial Implant Design Using Finite Elemental Analysis

World Neurosurgery ◽

10.1016/j.wneu.2021.01.102 ◽

2021 ◽

Author(s):

Stijn E.F. Huys ◽

Anke Van Gysel ◽

Maurice Y. Mommaerts ◽

Jos Vander Sloten

Keyword(s):

Elemental Analysis ◽

Implant Design ◽

Patient Specific ◽

Cranial Implant

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Synthetic skull bone defects for automatic patient-specific craniofacial implant design

Scientific Data ◽

10.1038/s41597-021-00806-0 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Jianning Li ◽

Christina Gsaxner ◽

Antonio Pepe ◽

Ana Morais ◽

Victor Alves ◽

...

Keyword(s):

Bone Defects ◽

Third Party ◽

Implant Design ◽

Patient Specific ◽

Solid Base ◽

Skull Bone ◽

Imaging Data ◽

Cranial Implant ◽

Cranial Implants ◽

Craniofacial Implants

AbstractPatient-specific craniofacial implants are used to repair skull bone defects after trauma or surgery. Currently, cranial implants are designed and produced by third-party suppliers, which is usually time-consuming and expensive. Recent advances in additive manufacturing made the in-hospital or in-operation-room fabrication of personalized implants feasible. However, the implants are still manufactured by external companies. To facilitate an optimized workflow, fast and automatic implant manufacturing is highly desirable. Data-driven approaches, such as deep learning, show currently great potential towards automatic implant design. However, a considerable amount of data is needed to train such algorithms, which is, especially in the medical domain, often a bottleneck. Therefore, we present CT-imaging data of the craniofacial complex from 24 patients, in which we injected various artificial cranial defects, resulting in 240 data pairs and 240 corresponding implants. Based on this work, automatic implant design and manufacturing processes can be trained. Additionally, the data of this work build a solid base for researchers to work on automatic cranial implant designs.

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Cranial Implant Design Applying Shape-Based Interpolation Method via Open-Source Software

Applied Sciences ◽

10.3390/app11167604 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7604

Author(s):

Johari Yap Abdullah ◽

Abdul Manaf Abdullah ◽

Low Peh Hueh ◽

Adam Husein ◽

Helmi Hadi ◽

...

Keyword(s):

Open Source ◽

Open Source Software ◽

Interpolation Method ◽

Implant Design ◽

Patient Specific ◽

Dice Similarity Coefficient ◽

Patient Specific Implants ◽

Significant Difference ◽

Cranial Implant ◽

Cranial Implants

Reconstructing a large skull defect is a challenge, as it normally involves the use of sophisticated proprietary image processing and expensive CAD software. As an alternative, open-source software can be used for this purpose. This study aimed to compare the 3D cranial implants reconstructed from computed tomography (CT) images using the open-source MITK software with commercial 3-matic software for ten decompressive craniectomy patients. The shape-based interpolation method was used, in which the technique of segmenting every fifth and tenth slice of CT data was performed. The final design of patient-specific implants from both software was exported to STL format for analysis. The results of the Kruskal–Wallis test for the surface and volume of cranial implants designed using 3-matic and the two MITK techniques showed no significant difference, p > 0.05. The results of the Hausdorff Distance (HD) and Dice Similarity Coefficient (DSC) analyses for cranial implants designed using 3-matic software and the two different MITK techniques showed that the average points distance for 3-matic versus MITK was 0.28 mm (every tenth slice) and 0.15 mm (every fifth slice), and the similarity between 3-matic and MITK on every tenth and fifth slices were 85.1% and 89.7%, respectively. The results also showed that the open-source MITK software is comparable with the commercial software for designing patient-specific implants.

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Surgical Advances in Osteosarcoma

Cancers ◽

10.3390/cancers13030388 ◽

2021 ◽

Vol 13 (3) ◽

pp. 388

Author(s):

Marcus J. Brookes ◽

Corey D. Chan ◽

Bence Baljer ◽

Sachin Wimalagunaratna ◽

Timothy P. Crowley ◽

...

Keyword(s):

Fluorescent Dyes ◽

Imaging Techniques ◽

Intraoperative Imaging ◽

Survival Rates ◽

Computer Navigation ◽

Bone Cancer ◽

Technical Difficulty ◽

Implant Design ◽

Patient Specific ◽

Patient Specific Instruments

Osteosarcoma (OS) is the most common primary bone cancer in children and, unfortunately, is associated with poor survival rates. OS most commonly arises around the knee joint, and was traditionally treated with amputation until surgeons began to favour limb-preserving surgery in the 1990s. Whilst improving functional outcomes, this was not without problems, such as implant failure and limb length discrepancies. OS can also arise in areas such as the pelvis, spine, head, and neck, which creates additional technical difficulty given the anatomical complexity of the areas. We reviewed the literature and summarised the recent advances in OS surgery. Improvements have been made in many areas; developments in pre-operative imaging technology have allowed improved planning, whilst the ongoing development of intraoperative imaging techniques, such as fluorescent dyes, offer the possibility of improved surgical margins. Technological developments, such as computer navigation, patient specific instruments, and improved implant design similarly provide the opportunity to improve patient outcomes. Going forward, there are a number of promising avenues currently being pursued, such as targeted fluorescent dyes, robotics, and augmented reality, which bring the prospect of improving these outcomes further.

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On the effect of antiresorptive drugs on the bone remodeling of the mandible after dental implantation: a mathematical model

Scientific Reports ◽

10.1038/s41598-021-82502-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mehran Ashrafi ◽

Farzan Ghalichi ◽

Behnam Mirzakouchaki ◽

Manuel Doblare

Keyword(s):

Mathematical Model ◽

Bone Density ◽

Bone Remodeling ◽

Dental Implants ◽

Implant Design ◽

Patient Specific ◽

Dental Implantation ◽

Antiresorptive Agents ◽

Antiresorptive Drugs

AbstractBone remodeling identifies the process of permanent bone change with new bone formation and old bone resorption. Understanding this process is essential in many applications, such as optimizing the treatment of diseases like osteoporosis, maintaining bone density in long-term periods of disuse, or assessing the long-term evolution of the bone surrounding prostheses after implantation. A particular case of study is the bone remodeling process after dental implantation. Despite the overall success of this type of implants, the increasing life expectancy in developed countries has boosted the demand for dental implants in patients with osteoporosis. Although several studies demonstrate a high success rate of dental implants in osteoporotic patients, it is also known that the healing time and the failure rate increase, necessitating the adoption of pharmacological measures to improve bone quality in those patients. However, the general efficacy of these antiresorptive drugs for osteoporotic patients is still controversial, requiring more experimental and clinical studies. In this work, we investigate the effect of different doses of several drugs, used nowadays in osteoporotic patients, on the evolution of bone density after dental implantation. With this aim, we use a pharmacokinetic–pharmacodynamic (PK/PD) mathematical model that includes the effect of antiresorptive drugs on the RANK/RANK-L/OPG pathway, as well as the mechano-chemical coupling with external mechanical loads. This mechano-PK/PD model is then used to analyze the evolution of bone in normal and osteoporotic mandibles after dental implantation with different drug dosages. We show that using antiresorptive agents such as bisphosphonates or denosumab increases bone density and the associated mechanical properties, but at the same time, it also increases bone brittleness. We conclude that, despite the many limitations of these very complex models, the one presented here is capable of predicting qualitatively the evolution of some of the main biological and chemical variables associated with the process of bone remodeling in patients receiving drugs for osteoporosis, so it could be used to optimize dental implant design and coating for osteoporotic patients, as well as the drug dosage protocol for patient-specific treatments.

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Dataset Descriptor for the AutoImplant Cranial Implant Design Challenge

Towards the Automatization of Cranial Implant Design in Cranioplasty - Lecture Notes in Computer Science ◽

10.1007/978-3-030-64327-0_2 ◽

2020 ◽

pp. 10-15

Author(s):

Jianning Li ◽

Jan Egger

Keyword(s):

Implant Design ◽

Cranial Implant ◽

Design Challenge

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Unicompartmental Knee Resurfacing: Enlarged Tibio-Femoral Contact Area and Reduced Contact Stress Using Novel Patient-Derived Geometries

The Open Biomedical Engineering Journal ◽

10.2174/1874120701004010085 ◽

2010 ◽

Vol 4 (1) ◽

pp. 85-92 ◽

Cited By ~ 21

Author(s):

Nick Steklov ◽

John Slamin ◽

Sudesh Srivastav ◽

Darryl D’Lima

Keyword(s):

Contact Stress ◽

Contact Area ◽

Polyethylene Wear ◽

Femoral Condyle ◽

Implant Design ◽

Heel Strike ◽

Patient Specific ◽

Computer Assisted ◽

Average Curvature ◽

Standard Deviations

Advances in imaging technology and computer-assisted design (CAD) have recently enabled the introduction of patient-specific knee implant designs that hold the potential to improve functional performance on the basis of patient-specific geometries, namely a patient-specific sagittal and coronal curvature, as well as enhanced bone preservation. The objective of this study was to investigate the use of a novel implant design utilizing a patient specific sagittal J-curve on the femoral component combined with a novel constant, patient-derived femoral coronal curvature and to assess tibio-femoral contact area and contact stress on a femur matched curved tibial polyethylene insert. Mean contact area and standard deviations were 81±5, 96±5 and 74±4 mm2 for the heel strike, toe off and mid-stance positions, respectively. Mean contact stress and standard deviations were 23.83±1.39, 23.27±1.14 and 20.78±0.54 MPa for the heel strike, toe off and mid-stance positions, respectively. Standard deviations of the measurements were small, not exceeding 6-7% confirming the consistency of loading conditions across different flexion angles. The results were comparable to those reported for standard, off-the-shelf fixed-bearing implants with paired femoral and tibial geometries. These data show that a constant coronal curvature can be applied to a patient-specific implant by measuring coronal curvatures across the femoral condyle in each patient and by deriving an average curvature. This novel approach combines unique benefits of patient-specific geometry with proven design concepts for minimizing polyethylene wear.

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