Rapid Prototyping Services, Professional manufacturer of CNC Prototyping and 3D Prototyping in China. 

fabrication of patient specific genioplasty surgical template using investment casting.

by:Tuowei     2019-09-07
Manufacturing of abstract materials (AM)
It is one of the best techniques for manufacturing customized medical models.
This technology is best suited to the medical industry.
Depending on the anatomy of the patient, the design and size of the surgical template varies from patient to patient.
AM provides the flexibility to design patient-specific surgical templates using patient CT scan data.
Medical processing software converts medical data into 3d cad data.
This 3D CAD data is used to design patient-specific surgical templates.
This surgical template data is then converted into an anSTL file format to make a medical model using an AM machine.
The original surgical template was made using FDM machines and is easy to obtain, which is used for pre-surgical planning.
After obtaining satisfactory results in pre-operation planning, the same STL file is made using pouring resin.
The Castableresin model is used for the preparation of casting process molds.
The mold is then used to produce the final surgical template for the medical grade ss316.
Compared to the same model made using the metal AM system, the cost of the final metal surgical template is reduced by 30%.
The main advantage of this process is that we have obtained patient-specific templates in a traditional way of approval, but the cost is reduced.
Key words: manufacturing of additive materials;
Computer-aided design (CAD); Genioplasty;
Surgical template;
The 3D printing medical model has a history of more than 25 years.
In the early days, this technology was called Rapid Prototyping (RP).
As the name suggests, these products are used primarily as prototypes in many industries, one of which is medical care.
When the technology was introduced in 1980s, there were very few machines around the world.
In those days, the cost of these machines is very high, and the choice of materials is very limited ([1]).
The machine of technological progress becomes affordable for ordinary people, especially for machines that integrate deposition models (FDM)technique.
There is a wide range of materials to choose from.
The beauty of 3D printing technology is that every model made by a 3D printer can be customized ([2]).
This is good for most healthcare industries.
In the case of the medical industry, tailor-made medical models such as surgical templates or implants are required for almost every patient ([3]).
In 1895, with the discovery of X, the medical industry has developed for the first time.
Ray by William Rosing
This helps to analyze the bone anatomy of the patient at that time.
The X-rays provide only the 2d anatomy of the patient and only the bone information of the patient.
In order to overcome this situation, this CT scanner is-
Light around the gantry tube.
Depending on the number of transmitters and receivers, the specifications of the CT scanner vary ([4-6]).
In the first days, there used to be a double slice CT scanner, and now technological advances have made it possible to scan 256 slices of CT.
Usually, CT scanners are used to obtain the bone anatomy of the patient, while MRI is used to obtain the soft tissue information of the patient ([7]).
In the early stages of the AM model, they are only used for pre-surgical planning, but in the current period AM is able to produce direct implants according to the specific requirements of the patient ([8]).
Although this technology is so advanced, there are still problems in determining the availability of certified medical implant manufacturers, machines, the time and cost of implants or templates.
These processes need to be streamlined.
In order to overcome the medical approval of the AM medical model, an alternative method has been identified in the current work, which takes advantage of the maximum advantages of AMtechnology and traditional casting processes.
There are several processes under the AM roof, classified according to the technology or materials used.
In a broad sense, it can be classified according to the raw materials used, whether liquid, powder or solid.
Among these technologies, the readily available technology is fdmtechnology, where solid filaments are used as raw materials.
Since the technology is readily available and affordable, it is widely used to make pre-surgical models for planning.
Good strength;
These models can be used for functional testing as well as for pre-surgery planning, just like for a simulated operation.
The medical model can be cut according to the operation plan.
Genioplastic is one of the complex operations in oral and facial surgery.
The use of surgical templates makes genioplasty easier.
In Gene plastic surgery, the anterior jaw is cut and moved according to the patient\'s requirements.
Use CT or X-to identify the cutting area of the bone
Light data is very difficult.
The designed template provides the greatest advantage to mark the area of fit on the lower jaw, and the miniature plate also bends before surgery using an AM medical model.
The procedure followed by the casting of the patient-specific surgical template is shown in the following flow chart (Figure 1). [
Figure 1 slightly]
Acquisition of patient CT data the patient\'s CT data was obtained using a Somatom 128 slice CT scanner and a 3D facial scan.
The best reconstruction parameters are used to reconstruct the collected images.
CT scan data for patients shown in Figure 2 below.
The Munich data of the patient was processed using the medical processing software MIMICS to obtain the 3D CADbone anatomy of the patient.
The 3D CAD data of the patient is shown in Figure 2b below.
From dic data, bone anatomy of patients separated using Hounsfield unit values, in simulations, HU values of bones start from 226 to 3071.
In the MIMICS software, the soft tissue HU value is less than 30. [
Figure 2:
Developing patient 3D CAD data from the patient\'s complete skeletal anatomy. Use area growth, edit mask and other operations to separate interface areas.
This study is to develop a special template for gene shaping, where the previous and lower mandible is the region of instrest.
The patient\'s 3D CAD jaw is shown in figure 3 below ([4]).
The development of patient-specific templates uses mandible\'s 3D CAD data. . [
Figure 3 slightly]
Design of patient-specific surgical templates are designed to be accurately installed along the lower jaw of the patient\'s profile, as shown in figure 4 abelow.
The purpose of this template is to obtain perfect symmetry during bone cutting.
In addition, it is expected that the reduction will be 30 [degrees]
Make this angle a 30 [degrees]
The chamfer is created at the edge of the template for Saw or drill to follow this angle without any deviation, the template is designed to avoid important structures, such as the mental nerves and roots on both sides.
Figure 4b below shows a 3D CAD image of the template with the patient\'s lower jaw. [
Figure 4 slightly]
Surgical simulation or virtual surgical planning MIMCS software provides the flexibility to perform a virtual surgery that can cut and locate bones as planned to analyze the results shown in figure 5.
After the expected results are obtained, the design of the template is completed, otherwise the iteration will be repeated.
Since this is just a virtual operation, the same procedure is performed using a physical AM medical model.
In order to perform the most suitable pre-planning surgeryFDM model and for case studies of the current manufacturing model, the 3D CAD data of the model is converted to STL file format. [
Figure 5 Slightly]
STL file format is a neutral file format for all ammachine.
Processing STL files using pre-processing software, generating machine-specific code to make an AM medical model or template.
In the sudy Flashforge finder of the current finite difference technology, it is used to make a pateient-specific medical model and surgical template for pre-planning, as shown in Figure 6 below.
Flashprint is a pre-processing software for flashforge finder machines. PLA(PolyLacticAcid)
Whether it is used to make the material of the lower jaw of the patient, whether the lower jaw orthopedic surgery has been performed, and whether the patient-specific surgical template has been manufactured.
In order to make the model, FDM provides the flexibility of filament in multiple colors.
These models have good advantages and can be used as functional prototype models.
The biggest advantage of finite difference is easy to use and low cost. [
Figure 6 slightly]
Follow the manufacture of patient-specific metal SS316 templates currently studying the investment casting process, and make patient-specific surgical templates with SS316 Medical Metal surgical templates.
The first step to follow in investment casting is to prepare a pattern that can evaporate and should be an exact replica of the final product.
As shown in Figure 7a, cast resin patterns for patient-specific surgical templates for casting were prepared with SLAprocess.
This pattern is used to make the mold and since the mold cannot be opened, it can only be used once to remove the final part mold that needs to be destroyed.
The advantage of this process is that any complex model can be easily manufactured.
In order to make the mold, the casting mode is to immerse the slurry of fine-grained silica, adhesive and water into it.
This slurry forms a ceramic layer on the casting pattern.
When the ceramic coating is thick enough, as shown in Figure 4b, it is allowed to dry.
In order to evaporate the pattern, this mold is heated at 150 [degrees]
C, forming the cavity of investment casting.
The ceramic mold is heated to 1000 [degrees]
C. strengthen the mold and discharge any cast resin remaining.
When it is still hot, the molten SS316 is poured into the mold so that the molten metal flows easily to every minute feature of the mold.
This pouring of metal to the hot mold will also improve the dimensional accuracy, because the mold and the casting will shrink together when cooling.
Figures 7c and 7d show the final SS316 patient-specific surgical template that can be used for surgery.
These metal templates can be sterilized with high pressure for surgery. [
Figure 7 Slightly]
Conclusion The additive manufacturing technology is most suitable for the low volume model of manufacturing customization.
One of the biggest obstacles to the MetalAM system is medical grade certification, cost and material selection, and a hybrid approach has been adopted to overcome these obstacles.
This model is made with a low cost AM system and is easily accessible to everyone.
It is also easy to obtain the final required metal surgical template through traditional investment casting.
The advantage of using this hybrid technology is the medical grade SS316 currently in use, but this method allows the model to be made with any material.
This procedure provides the greatest benefits for custom parts, especially in the case of manufacturing custom surgical templates and implants in the medical industry. References (1. )
Liang Jiaqiang (Cai\'s CK)2000)
Rapid prototyping.
Principles and Applications of manufacturing.
World Science. (2. )
Gibson I am Xiang Road, Zhou SP, Xiang WL, Beh SL, etc. (2004)
Use rapid prototyping technology to assist medical applications.
The Protoss of the Protoss. (3. )
Krishna LSR, Manmadhachary A, Reddy PB, Venkatesh S (2011)
Use selective laser sintering to develop the best pre-planning for oral surgery.
International Journal of Engineering, Science and Technology, 3: 185-196. (4. )
Madha Chari A, Kumar YR, Krishna and L (2016)
Improve the accuracy, surface smoothing and material adaptation of the RPmedical model STL file.
Process 21: 46-55. (5. )
Oh, toy E (2014)
3D imaging technology: literature review.
€ 8: 132-140. (6. )
Banerjee, Touro, Ghosh, pan sugar P (2013)
Preliminary investigation of CT scans in patients with multiple trauma.
Computer Tomography 2: 46-progress51. (7. )
Malyala SK in Kumar YR (2017)
Optimization of computer tomography reconstruction parameters by additive manufacturing. BiolMed (Aligarh)9: 377. (8. )
Mala SK, Mala Dhaka RIA, Kumar YR, Alvara (2017)
Manufacturing of a special AM medical model for patients with complex surgery.
Today\'s materials: litigation 4: 1134-1139.
Santosh Kumar Malyala (1*)Ravi Kumar Y (1), Rakesh K (2)
Antalya Chuck lavasi (3)(1)
Department of Mechanical and Electronic Engineering, National Institute of Technology, Telangana Warangal, India (2)
Department of Mechanical Engineering, Bheema Institute of Technology and Science,. P, India (3)
Raichur oral and Maxillo facial surgery, nawardaa dantar College, Karnataka, India (*)
Correspondent author: Santosh Kumar Malyala, Department of Mechanical Engineering, Telangana National Institute of Technology
506004, India, Tel: 91 9963343361; E-
Email: msantoshpdd @ gmail
Com received date: June 01, 2017;
Acceptance Time: July 19, 2016;
Date of Publication: July 26, 2017 Copyright :[c]
2017 Malyala SK, etc.
This is an open
Attachments distributed under the terms of the Creative Commons license are permitted to be used, distributed and reproduced without restriction on any media, provided that the original author and source are credited.
Custom message
Chat Online
Chat Online
Chat Online inputting...