Construction of an Implant-Retained Auricular Prosthesis with the Aid of Contemporary Digital Technologies: A Clinical Report

A Systematic Review of the Application of Computational Technology in Microtia

Microtia is a congenital and morphological anomaly of one or both ears, which results from a confluence of genetic and external environmental factors. Up to now, extensive research has explored the potential utilization of computational methodologies in microtia and has obtained promising results. Thus, the authors reviewed the achievements and shortcomings of the research mentioned previously, from the aspects of artificial intelligence, computer-aided design and surgery, computed tomography, medical and biological data mining, and reality-related technology, including virtual reality and augmented reality. Hoping to offer novel concepts and inspire further studies within this field.

Cost-effective 3D scanning and printing technologies for outer ear reconstruction: current status

Current 3D scanning and printing technologies offer not only state-of-the-art developments in the field of medical imaging and bio-engineering, but also cost and time effective solutions for surgical reconstruction procedures. Besides tissue engineering, where living cells are used, bio-compatible polymers or synthetic resin can be applied. The combination of 3D handheld scanning devices or volumetric imaging, (open-source) image processing packages, and 3D printers form a complete workflow chain that is capable of effective rapid prototyping of outer ear replicas. This paper reviews current possibilities and latest use cases for 3D-scanning, data processing and printing of outer ear replicas with a focus on low-cost solutions for rehabilitation engineering.

Applications of CAD/CAM Technology for Craniofacial Implants Placement and Manufacturing of Auricular Prostheses-Systematic Review

This systematic review was aimed at gathering the clinical and technical applications of CAD/CAM technology for craniofacial implant placement and processing of auricular prostheses based on clinical cases. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, an electronic data search was performed. Human clinical studies utilizing digital planning, designing, and printing systems for craniofacial implant placement and processing of auricular prostheses for prosthetic rehabilitation of auricular defects were included. Following a data search, a total of 36 clinical human studies were included, which were digitally planned and executed through various virtual software to rehabilitate auricular defects. Preoperative data were collected mainly through computed tomography scans (CT scans) (55 cases); meanwhile, the most common laser scanners were the 3dMDface System (3dMD LLC, Atlanta, Georgia, USA) (6 cases) and the 3 Shape scanner (3 Shape, Copenhagen, Denmark) (6 cases). The most common digital design software are Mimics Software (Mimics Innovation Suite, Materialize, Leuven, Belgium) (18 cases), Freeform software (Freeform, NC, USA) (13 cases), and 3 Shape software (3 Shape, Copenhagen, Denmark) (12 cases). Surgical templates were designed and utilized in 35 cases to place 88 craniofacial implants in auricular defect areas. The most common craniofacial implants were Vistafix craniofacial implants (Entific Medical Systems, Goteborg, Sweden) in 22 cases. A surgical navigation system was used to place 20 craniofacial implants in the mastoid bone. Digital applications of CAD/CAM technology include, but are not limited to, study models, mirrored replicas of intact ears, molds, retentive attachments, customized implants, substructures, and silicone prostheses. The included studies demonstrated a predictable clinical outcome, reduced the patient's visits, and completed the prosthetic rehabilitation in reasonable time and at reasonable cost. However, equipment costs and trained technical staff were highlighted as possible limitations to the use of CAD/CAM systems.

Cohesive Zone Modeling of Pull-Out Test for Dental Fiber-Silicone Polymer

BACKGROUND

Several analytical methods for the fiber pull-out test have been developed to evaluate the bond strength of fiber-matrix systems. We aimed to investigate the debonding mechanism of a fiber-silicone pull-out specimen and validate the experimental data using 3D-FEM and a cohesive element approach.

METHODS

A 3D model of a fiber-silicone pull-out testing specimen was established by pre-processing CT images of the typical specimen. The materials on the scans were posted in three different cross-sectional views using ScanIP and imported to ScanFE in which 3D generation was implemented for all of the image slices. This file was exported in FEA format and was imported in the FEA software (PATRAN/ABAQUS, version r2) for generating solid mesh, boundary conditions, and material properties attribution, as well as load case creation and data processing.

RESULTS

The FEM cohesive zone pull-out force versus displacement curve showed an initial linear response. The Von Mises stress concentration was distributed along the fiber-silicone interface. The damage in the principal stresses' directions S11, S22, and S33, which represented the maximum possible magnitude of tensile and compressive stress at the fiber-silicone interface, showed that the stress is higher in the direction S33 (stress acting in the Z-direction) in which the lower damage criterion was higher as well when compared to S11 (stress acting in the XY plane) and S23 (stress acting in the YZ plane).

CONCLUSIONS

The comparison between the experimental values and the results from the finite element simulations show that the proposed cohesive zone model accurately reproduces the experimental results. These results are considered almost identical to the experimental observations about the interface. The cohesive element approach is a potential function that takes into account the shear effects with many advantages related to its ability to predict the initiation and progress of the fiber-silicone debonding during pull-out tests. A disadvantage of this approach is the computational effort required for the simulation and analysis process. A good understanding of the parameters related to the cohesive laws is responsible for a successful simulation.

Use of 3-dimensional imaging and manufacturing for bilateral auricular prostheses: A case series of six patients with congenital auricular defects

The prosthetic reconstruction of unilateral ear deformity is a straightforward procedure which relies on copying the details, position, and symmetry of the existing contralateral ear. However, reconstructing bilaterally missing ears is challenging. The use of 3-dimensional (3D) technology in the prosthetic reconstruction of the bilaterally missing ears of 6 patients is described. The deformity site was created directly by segmenting the patient's digital scan or indirectly via a desktop scanner. Adequate bone quantity and quality for implant retention and optimal implant locations were also identified virtually. The use of 3D technologies has made it more straightforward to accomplish ear symmetry, as well as to validate the orientation and location of the ears reliably with the minimum subjectivity. The printed ears were matched in shape, surface texture, and anatomy. The skin color was straightforward to record and store so that it could be reproduced at a future time. Overall, the digital manufacture of the ears was controlled, consistent, and reproducible.

The cutting edge of customized surgery: 3D-printed models for patient-specific interventions in otology and auricular management-a systematic review

PURPOSE

3D-printing (three-dimensional printing) is an emerging technology with promising applications for patient-specific interventions. Nonetheless, knowledge on the clinical applicability of 3D-printing in otology and research on its use remains scattered. Understanding these new treatment options is a prerequisite for clinical implementation, which could improve patient outcomes. This review aims to explore current applications of 3D-printed patient-specific otologic interventions, including state of the evidence, strengths, limitations, and future possibilities.

METHODS

Following the PRISMA statement, relevant studies were identified through Pubmed, EMBASE, the Cochrane Library, and Web of Science. Data on the manufacturing process and interventions were extracted by two reviewers. Study quality was assessed using Joanna Briggs Institute's critical appraisal tools.

RESULTS

Screening yielded 590 studies; 63 were found eligible and included for analysis. 3D-printed models were used as guides, templates, implants, and devices. Outer ear interventions comprised 73% of the studies. Overall, optimistic sentiments on 3D-printed models were reported, including increased surgical precision/confidence, faster manufacturing/operation time, and reduced costs/complications. Nevertheless, study quality was low as most studies failed to use relevant objective outcomes, compare new interventions with conventional treatment, and sufficiently describe manufacturing.

CONCLUSION

Several clinical interventions using patient-specific 3D-printing in otology are considered promising. However, it remains unclear whether these interventions actually improve patient outcomes due to lack of comparison with conventional methods and low levels of evidence. Further, the reproducibility of the 3D-printed interventions is compromised by insufficient reporting. Future efforts should focus on objective, comparative outcomes evaluated in large-scale studies.

Successful prosthetic salvage of a suboptimal autogenous auricular reconstruction with digital technologies: A report of 3 challenging treatments

The surgical reconstruction of congenitally missing or malformed ears is challenging and involves complicated surgeries. Ear shape, position, and skin color will likely be compromised in patients with relative anatomic symmetry, and it is easier to reproduce these features with a prosthesis. This article describes the prosthetic reconstruction of 3 patients who had received failed or suboptimal surgical reconstruction of their missing or deformed ears. Challenging characteristics included limited soft-tissue availability, skeletal hypoplasia with prominent concavity defect, and bilaterally missing ears with abnormally low hairline. Three-dimensional planning using a software program was used to determine the ideal implant locations and mirror the contralateral ear. The mirrored ear was 3-dimensionally printed with a stereolithography printer. The skin color was reproduced digitally by using the Spectromatch Pro system.

Three-dimensional printing in medicine: a systematic review of pediatric applications

BACKGROUND

Three-dimensional printing (3DP) addresses distinct clinical challenges in pediatric care including: congenital variants, compact anatomy, high procedural risk, and growth over time. We hypothesized that patient-specific applications of 3DP in pediatrics could be categorized into concise, discrete categories of use.

METHODS

Terms related to "three-dimensional printing" and "pediatrics" were searched on PubMed, Scopus, Ovid MEDLINE, Cochrane CENTRAL, and Web of Science. Initial search yielded 2122 unique articles; 139 articles characterizing 508 patients met full inclusion criteria.

RESULTS

Four categories of patient-specific 3DP applications were identified: Teaching of families and medical staff (9.3%); Developing intervention strategies (33.9%); Procedural applications, including subtypes: contour models, guides, splints, and implants (43.0%); and Material manufacturing of shaping devices or prosthetics (14.0%). Procedural comparative studies found 3DP devices to be equivalent or better than conventional methods, with less operating time and fewer complications.

CONCLUSION

Patient-specific applications of Three-Dimensional Printing in Medicine can be elegantly classified into four major categories: Teaching, Developing, Procedures, and Materials, sharing the same TDPM acronym. Understanding this schema is important because it promotes further innovation and increased implementation of these devices to improve pediatric care.

IMPACT

This article classifies the pediatric applications of patient-specific three-dimensional printing. This is a first comprehensive review of patient-specific three-dimensional printing in both pediatric medical and surgical disciplines, incorporating previously described classification schema to create one unifying paradigm. Understanding these applications is important since three-dimensional printing addresses challenges that are uniquely pediatric including compact anatomy, unique congenital variants, greater procedural risk, and growth over time. We identified four classifications of patient-specific use: teaching, developing, procedural, and material uses. By classifying these applications, this review promotes understanding and incorporation of this expanding technology to improve the pediatric care.

A combined digital technique to fabricate an implant-retained auricular prosthesis for rehabilitation of hemifacial microsomia

Implant-retained auricular prostheses provide an excellent treatment option with better retention and stability than a conventionally retained prosthesis. This article presents a technique for auricular reconstruction for a patient with misplaced implants. The scanning process combined the use of an intraoral scanner and a facial scanner to enhance accuracy in space management for different parts of the auricular prosthesis and to reduce sculpting time.

Osseointegrated implant-retained auricular prosthesis constructed using cone-beam computed tomography and a prosthetically driven digital workflow: a case report

Prosthetically driven workflows using CBCT, digital optical scanning, 3D-printed molds and frameworks, and dental implant component attachments to osseointegrated fixtures can produce anatomically accurate, esthetic, durable silicone ear replacements.

Digital surgical planning and placement of osseointegrated implants to retain an auricular prosthesis using implant software with cone-beam computed tomography and 3D-printed surgical guides: A case report

Integration of CBCT imaging with dental implant treatment planning software and 3D-printed surgical guides can facilitate surgical planning for extraoral implant placement. In the current case, this combined planning strategy enabled navigation of challenging osseous anatomy, avoided critical structures, and optimized osseointegration for prosthesis retention.

Simulation of tissue-prosthesis margin interface by using surface scanning and digital design for auricular prostheses

STATEMENT OF PROBLEM

One of the most challenging aspects of auricular prosthesis design and fabrication is ensuring that the prosthesis fits the patient through a range of head and facial movements. Techniques used in conventional prosthetic treatment pathways account for issues of prosthesis fit, but this challenge has not been fully addressed in emerging treatment pathways that use digital technology.

PURPOSE

The purpose of this clinical study was to develop and evaluate a digital workflow by using surface scan data and incorporating the simulation of tissue movement into the design of auricular prostheses that fit the participant through a range of facial movements. An iterative design process was used to develop a design workflow through a sequential case series of participants with auricular prostheses.

MATERIAL AND METHODS

Scan data were acquired from a case series of 5 participants with existing implant-retained auricular prostheses. An iterative design process was used to digitally design auricular prostheses that fit the participants through a range of jaw and facial movements. The fit, shape, and retention of the digitally designed and conventionally made prostheses were assessed and compared. Design considerations were identified and documented through the iterative design process.

RESULTS

A final design workflow was iteratively developed based on the 5 participants. The shapes of the digitally designed prostheses were well matched to nontreatment anatomy overall. Prosthesis fit was variable: Some digitally designed prostheses fit the participant intimately through a range of movements, and others experienced significant gaps between the margins and the tissues.

CONCLUSIONS

An iterative design process provided a method of working toward quality improvement. Although the final design workflow provides a generally successful method of manipulating scan data in the design of auricular prostheses, the prosthesis fit at the anterior margin during facial movements remains variable and requires further development to achieve a consistently acceptable solution.

Three-dimensional printing technologies in the fabrication of maxillofacial prosthesis: A case report

Purpose:

Patients with maxillofacial deformities always seek for aesthetic prosthesis. Recently, three-dimensional printing technologies have been used for dental treatments on such patients.

Case report:

A 24-year-old man reported to the Department of Prosthodontics for replacement of his missing right ear induced by a trauma. A magnet-retained auricular prosthesis was planned for the patient. Three-dimensional scanning was performed on the healthy side by using a three-dimensional optical scanner and the data were mirrored. The mirrored image was then imported to a software and a virtual model of the future prosthesis was obtained for the defect side. A three-dimensional printer was used to fabricate a negative mold for the mirrored image by using additive manufacturing. Initially, an impression of the defect side was made; then, the cast model was obtained in a dental flask. Magnets of the prosthesis were inserted to the acrylic resin framework on the cast model. Room temperature vulcanized silicone elastomer was mixed and poured into the three-dimensionally fabricated mold. Then, the flask was placed over the negative mold firmly. After polymerization of the silicone, the auricular prosthesis was delivered to the patient and the patient was instructed to clean the prosthesis daily.

Conclusions:

Three-dimensional printing technology was used for the fabrication of the patient’s missing ear. This method eliminated the conventional laboratory steps and reduced the number of stages of the fabrication of a silicone prosthesis. The negative mold of the defect side allowed us a direct fabrication of the silicone prosthesis without a need for waxing or flasking procedures.

Developing an In-house Interdisciplinary Three-Dimensional Service: Challenges, Benefits, and Innovative Health Care Solutions

Three-dimensional printing (3DP) technologies have been employed in regular medical specialties. They span wide scope of uses, from creating 3D medical models to design and manufacture of Patient-specific implants and guidance devices which help to optimize medical treatments, patient education, and medical training. This article aims to provide an in-depth analysis of factors and aspects to consider when planning to setup a 3D service within a hospital serving various medical specialties. It will also describe challenges that might affect 3D service development and sustainability and describe representative cases that highlight some of the innovative approaches that are possible with 3D technology. Several companies can offer such 3DP service. They are often web based, time consuming, and requiring special call conference arrangements. Conversely, the establishment of in-house specialized hospital-based 3D services reduces the risks to personal information, while facilitating the development of local expertise in this technology. The establishment of a 3D facility requires careful consideration of multiple factors to enable the successful integration with existing services. These can be categorized under: planning, developing and sustaining 3D service; 3D service resources and networking workflow; resources and location; and 3D services quality and regulation management.

Direct 3D Printing of Flexible Nasal Prosthesis: Optimized Digital Workflow from Scan to Fit

A maxillofacial prosthesis is a successful treatment modality to restore missing facial parts. Digital technologies and 3D printing are employed in constructing facial prostheses such as ears; however, their application is still partial, and final prostheses are usually manufactured conventionally using stone molds. This report aims to introduce a complete digital workflow to construct a nasal prosthesis and compare it to the conventional workflow of a patient requiring a nasal prosthesis. A computer tomography scan showing the defect was exported to specialized software to create 3D reconstructions of the patient's face and underlying bone. The nose was digitally designed restoring facial esthetics, anatomy, shape, and skin color. Different skin tones were digitally matched to skin tissues adjacent to the defect area using the Spectromatch system. The design was 3D printed in flexible and colorful material at 16 μm resolution using a 3D printer. External color pigmentations were applied to the nose for optimum esthetics, and the prosthetic nose was sealed in silicone and left to heat polymerize for 15 minutes. The prosthetic nose was retained in place using biomedical adhesive, and the patient was pleased with it. This report proposes a complete digital workflow to directly design and fabricate a prosthetic nose of acceptable esthetics. Such a workflow can lead to enhanced prosthesis reproducibility and acceptability and may become an effective treatment option for treatment of patients with facial defects.

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.

Additive Manufacturing: A Comparative Analysis of Dimensional Accuracy and Skin Texture Reproduction of Auricular Prostheses Replicas

PURPOSE

The use of computer-aided design/computer-aided manufacturing (CAD/CAM) and additive manufacturing in maxillofacial prosthetics has been widely acknowledged. Rapid prototyping can be considered for manufacturing of auricular prostheses. Therefore, so-called prostheses replicas can be fabricated by digital means. The objective of this study was to identify a superior additive manufacturing method to fabricate auricular prosthesis replicas (APRs) within a digital workflow.

MATERIALS AND METHODS

Auricles of 23 healthy subjects (mean age of 37.8 years) were measured in vivo with respect to an anthropometrical protocol. Landmarks were volumized with fiducial balls for 3D scanning using a handheld structured light scanner. The 3D CAD dataset was postprocessed, and the same anthropometrical measurements were made in the CAD software with the digital lineal. Each CAD dataset was materialized using fused deposition modeling (FDM), selective laser sintering (SLS), and stereolithography (SL), constituting 53 APR samples. All distances between the landmarks were measured on the APRs. After the determination of the measurement error within the five data groups (in vivo, CAD, FDM, SLS, and SL), the mean values were compared using matched pairs method. To this, the in vivo and CAD dataset were set as references. Finally, the surface structure of the APRs was qualitatively evaluated with stereomicroscopy and profilometry to ascertain the level of skin detail reproduction.

RESULTS

The anthropometrical approach showed drawbacks in measuring the protrusion of the ear's helix. The measurement error within all groups of measurements was calculated between 0.20 and 0.28 mm, implying a high reproducibility. The lowest mean differences of 53 produced APRs were found in FDM (0.43%) followed by SLS (0.54%) and SL (0.59%)--compared to in vivo, and again in FDM (0.20%) followed by SL (0.36%) and SLS (0.39%)--compared to CAD. None of these values exceed the threshold of clinical relevance (1.5%); however, the qualitative evaluation revealed slight shortcomings in skin reproduction for all methods: reproduction of skin details exceeding 0.192 mm in depth was feasible.

CONCLUSION

FDM showed the superior dimensional accuracy and best skin surface reproduction. Moreover, digital acquisition and CAD postprocessing seem to play a more important role in the outcome than the additive manufacturing method used.

[Application progress of digital technology in auricle reconstruction]

Objective

To review the application progress of digital technology in auricle reconstruction.

Methods

The recently published literature concerning the application of digital technology in auricle reconstruction was extensively consulted, the main technology and its specific application areas were reviewed.

Results

Application of digital technology represented by three-dimensional (3D) data acquisition, 3D reconstruction, and 3D printing is an important developing trend of auricle reconstruction. It can precisely guide auricle reconstruction through fabricating digital ear model, auricular guide plate, and costal cartilage imaging.

Conclusion

Digital technology can improve effectiveness and decrease surgical trauma in auricle reconstruction. 3D bioprinting of ear cartilage future has bright prospect and needs to be further researched.

Fabrication of three-dimensional scan-to-print ear model for microtia reconstruction

BACKGROUND

Microtia is a congenital deformity of the external ear that occurs in 1 of every 5000 births. Microtia reconstruction using traditional two-dimensional templates does not provide highly detailed ear shapes. Here, we describe the feasibility of using a three-dimensional (3D) ear model as a reference.

MATERIALS AND METHODS

Seven children aged from 11 to 16 (6 grade III and 1 grade II microtia) were recruited from Seoul National University Children's Hospital, Korea. We generated 3D-computer-aided design models of each patient's ear by performing 3D laser scanning for a mirror-transformed cast of their normal ear. The 3D-printed ear model was used in microtia reconstruction surgery following the Nagata technique, and its shape was compared with the casted ear model.

RESULTS

One patient experienced irritation caused by accidently pouring resin into the external auditory meatus, and another had minor skin necrosis; both complications were successfully treated. The average percentage differences of the superior, inferior, anterior, posterior, and lateral views between the casted and 3D-printed ear models were 1.17%, 1.48%, 1.64%, 1.80%, and 5.44%, respectively (average: 2.31%), where the difference between the casted ear models and traditional two-dimensional templates were 16.03% in average.

CONCLUSIONS

Our results show that simple microtia reconstruction can be performed using 3D ear models. The 3D-printed ear models of each patient were consistent and accurately represented the thickness, depth, and height of the normal ear. The availability of the 3D-printed ear model in the operating room reduced the amount of unnecessary work during surgery.

Improved Construction of Auricular Prosthesis by Digital Technologies

Implant-retained auricular prostheses are a successful prosthetic treatment option for patients who are missing their ear(s) due to trauma, oncology, or birth defects. The prosthetic ear is aesthetically pleasing, composed of natural looking anatomical contours, shape, and texture along with good color that blends with surrounding existing skin. These outcomes can be optimized by the integration of digital technologies in the construction process. This report describes a sequential process of reconstructing a missing left ear by digital technologies. Two implants were planned for placement in the left mastoid region utilizing specialist biomedical software (Materialise, Belgium). The implant positions were determined underneath the thickest portion (of anti-helix area) left ear that is virtually simulated by means of mirror imaging of the right ear. A surgical stent recording the implant positions was constructed and used in implant fixtures placement. Implants were left for eight weeks, after which they were loaded with abutments and an irreversible silicone impression was taken to record their positions. The right existing ear was virtually segmented using the patient CT scan and then mirror imaged to produce a left ear, which was then printed using 3D printer (Z Corp, USA). The left ear was then duplicated in wax which was fitted over the defect side. Then, it was conventionally flasked. Skin color was digitalized using spectromatch skin color system (London, UK). The resultant silicone color was mixed as prescribed and then packed into the mold. The silicone was cured conventionally. Ear was trimmed and fitted and there was no need for any extrinsic coloring. The prosthetic ear was an exact match to the existing right ear in shape, skin color, and orientation due to the great advantages of technologies employed. Additionally, these technologies saved time and provided a base for reproducible results regardless of operator.

Rehabilitation of a missing ear with an implant retained auricular prosthesis

Burns can leave a patient with a severely debilitating disability even after treatment. The objectives of burn rehabilitation are to minimize the adverse effects caused by the injury while rehabilitating the patient's physical and psychological well-being, maximizing social integration. Long-term success of maxillofacial prostheses mainly depends on the retention. Extra oral implant retained prostheses have proved to be a predictable treatment option for maxillofacial rehabilitation. Replacement of a severely deformed external ear with burned tissues may be satisfactorily accomplished by a cosmetic prosthesis anchored by implants integrated in the skull. The use of such implants is now a well-recognized method for creating a stable result in maxillofacial rehabilitation. This case report describes a safe, simple and economical method for the rehabilitation of a patient with missing right auricle using an implant supported silicone prosthesis. The implant was placed in the mastoid region of the temporal bone. Reconstruction of the ear was done with auricular silicone prosthesis, retained using magnets incorporated in an autopolymerizing resin shim to decrease the weight of the prosthesis on a single implant. This method eliminates the need of tedious laboratory procedures and exact casting and fitting requirements of a metal substructure while minimizing the overall weight and cost of the prosthesis while maintaining adequate support, esthetics and retention of the prosthesis.

Advantages and disadvantages of 3-dimensional printing in surgery: A systematic review

BACKGROUND

Three-dimensional (3D) printing is becoming increasingly important in medicine and especially in surgery. The aim of the present work was to identify the advantages and disadvantages of 3D printing applied in surgery.

METHODS

We conducted a systematic review of articles on 3D printing applications in surgery published between 2005 and 2015 and identified using a PubMed and EMBASE search. Studies dealing with bioprinting, dentistry, and limb prosthesis or those not conducted in a hospital setting were excluded.

RESULTS

A total of 158 studies met the inclusion criteria. Three-dimensional printing was used to produce anatomic models (n = 113, 71.5%), surgical guides and templates (n = 40, 25.3%), implants (n = 15, 9.5%) and molds (n = 10, 6.3%), and primarily in maxillofacial (n = 79, 50.0%) and orthopedic (n = 39, 24.7%) operations. The main advantages reported were the possibilities for preoperative planning (n = 77, 48.7%), the accuracy of the process used (n = 53, 33.5%), and the time saved in the operating room (n = 52, 32.9%); 34 studies (21.5%) stressed that the accuracy was not satisfactory. The time needed to prepare the object (n = 31, 19.6%) and the additional costs (n = 30, 19.0%) were also seen as important limitations for routine use of 3D printing.

CONCLUSION

The additional cost and the time needed to produce devices by current 3D technology still limit its widespread use in hospitals. The development of guidelines to improve the reporting of experience with 3D printing in surgery is highly desirable.

Psychosocial and quality of life outcomes of prosthetic auricular rehabilitation with CAD/CAM technology

Introduction. The psychosocial and quality of life (QoL) of patients with deformed or missing ears are frequently compromised. The aim of this study is to develop innovative techniques using CAD/CAM technology in prosthetic auricular rehabilitation and provide improvement in the treatment outcomes, including their psychology and QoL. Methods. This is a preliminary clinical cohort study. Six patients requesting for auricular reconstruction were recruited and rehabilitated with implant-supported prosthesis using CAD/CAM technology. Different treatment outcomes including QoL and psychological changes were assessed at different time points. Results. A significant reduction in severity of depressive symptoms (P = 0.038) and an improving trend of satisfaction with life were found at 1 year postoperatively when compared with the preoperative findings. The domain scores in ‘‘Body image”, ‘‘Family/friends/strangers”, and ‘‘Mood” were also significantly higher (P < 0.05) at 1 year postoperatively than 1 week postoperatively. However, only 50% of the patients wear their auricular prosthesis regularly. Conclusion. This preliminary study has confirmed that implant-supported auricular prosthesis could induce improvement in the psychology and QoL with statistically significant differences in the domains of the body image, social interaction, and mood. Our present findings can inform research design and hypotheses generation of future studies.

Complete integration of technology for improved reproduction of auricular prostheses

The accurate reproduction of the form and surface details of missing body structures is an essential part of any successful prosthetic rehabilitation. It helps mask the prosthesis and gives confidence to the patient. This clinical report details the integration of multiple in-house digital technologies of laser scanning, rapid prototyping, and digital color scanning and formulating to improve the shape, texture, orientation, and color of auricular prostheses for 3 patients with missing unilateral ears. A structured light laser scanner was used to digitize the patient's nondefect ear. The digitized data were then manipulated in specialist software and mirrored to reflect the opposing side. A rapid prototyping machine was used to manufacture a 3-dimensional (3D) model of the soft tissue required. This 3D mirrored ear model allowed the accurate reproduction of missing soft tissue. A color spectrometer was used to accurately reproduce the skin tones digitally and physically.