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The purpose of this paper is to develop a workflow for design and fabrication of customized surgical guides (CSGs) for placement of the bidirectional extraoral distraction instruments (EDIs) in bilateral mandibular distraction osteogenesis (MDO) surgery to treat the bilateral temporomandibular joint ankylosis with zero mouth opening.

The comprehensive workflow consists of six steps: medical imaging; virtual surgical planning (VSP); computer aided design; rapid prototyping (RP); functional testing of CSGs and mock surgery; and clinical application. Fused deposition modeling, an RP process was used to fabricate CSGs in acrylonitrile butadiene styrene material. Finally, mandibular reconstruction with MDO was performed successfully using RP-assisted CSGs.

Design and development of CSGs prior to the actual MDO surgery improves accuracy, reduces operation time and decreases patient morbidity, hence improving the quality of surgery. Manufacturing of CSG is easy using RP to transfer VSP into the actual surgery.

This study describes an RP-assisted CSGs fabrication for exact finding of both; osteotomy site and drilling location to fix EDI’s pins accurately in the mandible; for accurate osteotomy and placement of the bidirectional EDIs in MDO surgery to achieve accurate distraction.

The computer‐aided design (CAD) and manufacture of custom‐fitting surgical guides have been shown to provide an accurate means of transferring computer‐aided planning to surgery. To date guides have been produced using fragile materials via rapid prototyping techniques such as stereolithography (SLA), which typically require metal reinforcement to prevent damage from drill bits. The purpose of this paper is to report case studies which explore the application of selective laser melting (SLM) to the direct manufacture of stainless steel surgical guides. The aim is to ascertain whether the potential benefits of enhanced rigidity, increased wear resistance (negating reinforcement) and easier sterilisation by autoclave can be realised in practice.

A series of clinical case studies are undertaken utilising medical scan data, CAD and SLM. The material used is 316L stainless steel, an alloy typically used in medical and devices and surgical instruments. All treatments are planned in parallel with existing techniques and all guides are test fitted and assessed on SLA models of the patients' anatomy prior to surgery.

This paper describes the successful application of SLM to the production of stainless steel surgical guides in four different maxillofacial surgery case studies. The cases reported address two types of procedure, the placement of osseointegrated implants for prosthetic retention and Le Fort 1 osteotomies using internal distraction osteogenesis. The cases reported here have demonstrated that SLM is a viable process for the manufacture of custom‐fitting surgical guides.

The cases have identified that the effective design of osteotomy guides requires further development and refinement.

This paper represents the first reported applications of SLM technology to the direct manufacture of stainless steel custom‐fitting surgical guides. Four successful exemplar cases are described including guides for osteotomy as well as drilling. Practical considerations are presented along with suggestions for further development.

This paper aims to provide an overview of applications of medical rapid prototyping (MRP)-assisted customized surgical guides (CSGs) and shows the potential of this technology in complex surgeries. This review paper also reports two case studies from open literature where MRP-assisted CSGs have been successfully used in complex surgeries.

Key publications from the past two decades have been reviewed.

This study concludes that the use of MRP-assisted CSGs improves the accuracy of surgery. Additionally, MRP-assisted CSGs make the surgery much faster, accurate and cheaper than any other technique. The outcome based on literature review and two case studies strongly suggested that MRP-assisted CSGs might become part of a standard protocol in the medical sector to operate the various complex surgeries, in the near future.

Advanced technologies like radiology, image processing, virtual surgical planning (VSP), computer-aided design (CAD) and MRP made it possible to fabricate the CSGs. MRP-assisted CSGs can easily transfer the VSP into the actual surgery.

This paper is beneficial to study the development and applications of MRP-assisted CSGs in complex surgeries.

Electric fields (EFs) are known to influence cell and tissue activity. This influence can be due to thermal or non-thermal effects. While the non-thermal effects are still matter of discussion, thermal effects might be detrimental for cell and tissue viability due to thermal damage, this fact being exploited by applications like hyperthermia and tissue ablation. The paper aims to discuss these issues.

In this work the authors investigate the influence of thermal damage in the consolidation of bone formation during electrostimulation (ES). The authors introduce a mathematical model describing the migration of osteoprogenitor cells, the thermal variation, the thermal damage accumulation and the formation of new bone matrix in an injury (fracture) site.

Numerical results are in agreement with experimental data and show that EFs more intense than 7.5 V/cm are detrimental for the viability of osteoprogenitor cells and the formation of new bone.

The model is suitable to conduct dosimetry studies in support of other different ES techniques aimed at improving bone and soft tissues repair.

This study aims to provide an overview of rapid prototyping (RP) and shows the potential of this technology in the field of medicine as reported in various journals and proceedings. This review article also reports three case studies from open literature where RP and associated technology have been successfully implemented in the medical field.

Key publications from the past two decades have been reviewed.

This study concludes that use of RP-built medical model facilitates the three-dimensional visualization of anatomical part, improves the quality of preoperative planning and assists in the selection of optimal surgical approach and prosthetic implants. Additionally, this technology makes the previously manual operations much faster, accurate and cheaper. The outcome based on literature review and three case studies strongly suggests that RP technology might become part of a standard protocol in the medical sector in the near future.

The article is beneficial to study the influence of RP and associated technology in the field of medicine.

Rapid prototype models are directly integrated into non‐engineering applications such as medicine. Medical models are used to plan complex procedures prior to surgery with potential to optimise patient treatment in the operating theatre. This paper presents results following a 12 month National Health Service Executive research project to assess the feasibility of using rapid prototype medical models. A total of 16 medical models were created. Nine anatomical sites were reconstructed from patient data acquired from five London hospitals. The purpose of the models is described and the commissioning surgeons as part of a questionnaire assessed their usefulness. Future developments are discussed and conclusions about the use of medical models are made.

The purpose of this paper is to describe two different approaches for manufacturing pre-formed titanium meshes to assist prosthetically guided bone regeneration of atrophic maxillary arches. Both methods are based on the use of additive manufacturing (AM) technologies and aim to limit at the minimal intervention the bone reconstructive surgery by virtual planning the surgical intervention for dental implants placement.

Two patients with atrophic maxillary arches were scheduled for bone augmentation using pre-formed titanium mesh with particulate autogenous bone graft and alloplastic material. The complete workflow consists of four steps: three-dimensional (3D) acquisition of medical images and virtual planning, 3D modelling and design of the bone augmentation volume, manufacturing of biomodels and pre-formed meshes, clinical procedure and follow up. For what concerns the AM, fused deposition modelling (FDM) and direct metal laser sintering (DMLS) were used.

For both patients, a post-operative control CT examination was scheduled to evaluate the progression of the regenerative process and verify the availability of an adequate amount of bone before the surgical intervention for dental implants placement. In both cases, the regenerated bone was sufficient to fix the implants in the planned position, improving the intervention quality and reducing the intervention time during surgery.

A comparison between two novel methods, involving AM technologies are presented as viable and reproducible methods to assist the correct bone augmentation of atrophic patients, prior to implant placement for the final implant supported prosthetic rehabilitation.

This study aims to assess the design, manufacturing and surgical implantation of three-dimensional (3D) customized implants, including surgical preoperative planning, surgery and postoperative results, for cranioplasty along with zygomatic and orbital floor implants using additive manufacturing (AM) technics for a 23-year-old female who suffered from severe craniomaxillofacial trauma.

The skull biomodel was produced in polyamide while implants were made of Ti-6Al-4V alloy by AM.

The method enabled perfectly fitting implants and anatomical conformance with the craniomaxillofacial defect, providing complete healing for the patient. Surgical planning using a customized 3D polyamide biomodel was effective. This proved to be a powerful tool for medical planning and manufacturing of customized implants, as complete healing and good craniofacial aesthetic results were observed.

Satisfactory surgical procedures, regarding surgery time reduction and good craniofacial aesthetic results, were achieved. Furthermore, the 3D titanium customized implants represented a favorable alternative for the repair of craniomaxillofacial defects.

This paper aims to fill a research gap by presenting design and 3D printing guidelines and considerations which apply to the development process of patient-specific osteotomy guides for orthopaedic surgery.

Analysis of specific constraints related to patient-specific surgical guides design and 3D printing, lessons learned during the development process of osteotomy guides for orthopaedic surgery, literature review of recent studies in the field and data gathered from questioning a group of surgeons for capturing their preferences in terms of surgical guides design corresponding to precise functionality (materializing cutting trajectories, ensuring unique positioning and stable fixation during surgery), were all used to extract design recommendations.

General design rules for patient-specific osteotomy guides were inferred from examining each step of the design process applied in several case studies in relation to how these guides should be designed to fulfill medical and manufacturing (fused deposition modelling process) constraints. Literature was also investigated for finding other information than the simple reference that the surgical guide is modelled as negative of the bone. It was noticed that literature is focussed more on presenting and discussing medical issues and on assessing surgical outcomes, but hardly at all on guides’ design and design for additive manufacturing aspects. Moreover, surgeons’ opinion was investigated to collect data on different design aspects, as well as interest and willingness to use such 3D-printed surgical guides in training and surgery.

The study contains useful rules and recommendations for engineers involved in designing and 3D printing patient-specific osteotomy guides.

A synergetic approach to identify general rules and recommendations for the patient-specific surgical guides design is presented. Specific constraints are identified and analysed using three case studies of wrist, femur and foot osteotomies. Recent literature is reviewed and surgeons’ opinion is investigated.

The goal of rapid mechanical prototyping is to be able to quickly fabricate complex‐shaped, 3D parts directly from computer‐aided design models. The key idea of this novel technology is based upon decomposition of 3D computer models data into thin cross‐sectional layers, followed by physically forming the layers and stacking them up; “layer by layer technique.” This new method of modeling has raised many attentions in dentistry especially in the field of surgery and implantology. The purpose of this review study is to represent the historical development and various methods currently used for building dental appliances. It is also aimed to show the many benefits which can be achieved by using this new technology in various branches of dentistry.

The major existing resources, including unpublished data on the internet, were considered.

Although, creating 3D objects in a layered fashion is an idea almost as old as human civilization but, this technology has only recently been employed to build 3D complex models in dentistry. It seems that in near future many other methods will develop which could change traditional dental practices. It is advisable to include more unit hours in dental curriculums to acquaint dental students with the many benefits of this novel technology.

It is hard to believe that the routine dental techniques were affected by revolutionary concepts originally theorized by engineering methods. It is a reality that in future, most of the restorative disciplines will be fully revised and the computer methods be evolved to an extent where dentistry can be performed by computer‐assisted methods with optimum safety, simplicity, and reliability.