Patient-Specific Augmentation Rhinoplasty Using a Three-Dimensional Simulation Program and Three-Dimensional Printing

Polymers in 3D printing of external maxillofacial prostheses and in their retention systems

Maxillofacial defects, arising from trauma, oncological disease or congenital abnormalities, detrimentally affect daily life. Prosthetic repair offers the aesthetic and functional reconstruction with the help of materials mimicking natural tissues. 3D polymer printing enables the design of patient-specific prostheses with high structural complexity, as well as rapid and low-cost fabrication on-demand. However, 3D printing for prosthetics is still in the early stage of development and faces various challenges for widespread use. This is because the most suitable polymers for maxillofacial restoration are soft materials that do not have the required printability, mechanical strength of the printed parts, as well as functionality. This review focuses on the challenges and opportunities of 3D printing techniques for production of polymer maxillofacial prostheses using computer-aided design and modeling software. Review discusses the widely used polymers, as well as their blends and composites, which meet the most important assessment criteria, such as the physicochemical, biological, aesthetic properties and processability in 3D printing. In addition, strategies for improving the polymer properties, such as their printability, mechanical strength, and their ability to print multimaterial and architectural structures are highlighted. The current state of the prosthetic retention system is presented with a focus on actively used polymer adhesives and the recently implemented prosthesis-supporting osseointegrated implants, with an emphasis on their creation from 3D-printed polymers. The successful prosthetics is discussed in terms of the specificity of polymer materials at the restoration site. The approaches and technological prospects are also explored through the examples of the nasal, auricle and ocular prostheses, ranging from prototypes to end-use products.

Paradigm Shift in Rhinoplasty with Virtual 3D Surgery Software and 3D Printing Technology

Most Asians have a nose with a short columella and a low dorsum; augmentation rhinoplasty using implants is commonly performed in Asian countries to achieve a taller and more well-defined nasal dorsum. However, the current knowledge is insufficient to fully understand the various subjective desires of patients, reflect on them during surgery, or to objectively analyze the results after surgery. Advances in digital imaging technologies, such as 3D printing and 3D scanning, have transformed the medical system from hospital-centric to patient-centric throughout the medical field. In this study, we applied these techniques to rhinoplasty. First, we used virtual 3D plastic surgery software to enable surgical planning through objectified numerical calculations based on the visualized data of the patient's medical images rather than simple virtual plastic surgery. Second, the customized nasal implant was manufactured by reflecting the patient's anatomical shape and virtual 3D plastic surgery data. Taken together, we describe the surgical results of applying these rhinoplasty solutions in four patients. Our experience indicates that high fidelity and patient satisfaction can be achieved by applying these techniques.

Sutures positioning technique enhances the predictability and concordance between preoperative simulation and actual outcomes in rhinoplasty

BACKGROUND

The predictability and concordance between simulated and actual outcomes in rhinoplasty are uncertain. Here, we introduce a suture positioning technique (SPT), a simple and low-cost method to minimize the gap between the simulated and actual outcomes of rhinoplasty.

METHODS

Seventy patients were enrolled in this study between January 2018 and January 2021. Preoperative simulations were performed using Adobe Photoshop. The control group underwent surgery using simulation and intuition. In the SPT group, sutures were used to assist in the preoperative identification of the ideal nasal tip position. The SPT effectiveness was tested by measuring the nasal parameters and using the patient's subjective satisfaction questionnaire at T1 (Time 1, immediately postoperatively) and T2 (Time 2, at least 1 year postoperatively).

RESULTS

The intraclass correlation coefficient test showed a satisfactory correlation between simulation and postoperative outcomes in both groups. However, the SPT group had a higher correlation than the control group, especially for the nasal length (16% higher at T1 and 15% higher at T2). The mean absolute difference (MAD) between the outcomes and simulation indicated that the MAD of nasal tip projection between T2 and simulation and MAD of nasal length between T1 (or T2) and simulation were statistically significant between groups. Additionally, the SPT group was more satisfied with the postoperative outcomes and were consistent with the preoperative simulation.

CONCLUSION

This study demonstrated the effectiveness of SPT in intraoperative quality control. This technique may be adopted by surgeons to achieve good concordance between simulated and actual surgical outcomes.

Emerging 3D bioprinting applications in plastic surgery

Plastic surgery is a discipline that uses surgical methods or tissue transplantation to repair, reconstruct and beautify the defects and deformities of human tissues and organs. Three-dimensional (3D) bioprinting has gained widespread attention because it enables fine customization of the implants in the patient's surgical area preoperatively while avoiding some of the adverse reactions and complications of traditional surgical approaches. In this paper, we review the recent research advances in the application of 3D bioprinting in plastic surgery. We first introduce the printing process and basic principles of 3D bioprinting technology, revealing the advantages and disadvantages of different bioprinting technologies. Then, we describe the currently available bioprinting materials, and dissect the rationale for special dynamic 3D bioprinting (4D bioprinting) that is achieved by varying the combination strategy of bioprinting materials. Later, we focus on the viable clinical applications and effects of 3D bioprinting in plastic surgery. Finally, we summarize and discuss the challenges and prospects for the application of 3D bioprinting in plastic surgery. We believe that this review can contribute to further development of 3D bioprinting in plastic surgery and provide lessons for related research.

Update on Rhinoplasty Research Trends: A Bibliometric Analysis

BACKGROUND

Rhinoplasty is one of the most commonly performed aesthetic surgical procedures. The current study aimed to use bibliometric analysis to qualitatively and quantitatively evaluate rhinoplasty research and determine the research trends and hotspots in this field.

METHODS

Publications on rhinoplasty research were extracted from the web of science core collection database. VOSviewer1.6.18 was used to analyze the co-authorship, co-occurrence, the citations of countries, institutions, authors, and hotspot keywords, and the journals in which the studies were published.

RESULTS

On April 8, 2022, 11,130 records of rhinoplasty research published between 1945 and 2021 were collected. Most of the retrieved studies were original research articles (n = 8309, 74.65%), and 1950 (17.52%) papers were available in an open-access format. The annual publication output increased annually. Research groups in the USA were the main contributors and had a strong academic reputation in this field. University of California System was the institution with the greatest contribution (4.17%, with 464 publications). Plastic and Reconstructive Surgery (1248 publications, 11.21%) published the most research in this field and was also the most frequently co-cited journal (33,894 citations, total link strength [TLS]: 722,672). R. J. Rohrich (140 publications) was the most prolific author and the most frequently co-cited author (2562 citations, TLS: 56,624). The following rhinoplasty research hotspots were identified: cleft rhinoplasty, nasal reconstruction, nasal tip, revision rhinoplasty, septorhinoplasty, nasal prosthesis, hyaluronic acid, and preservation rhinoplasty.

CONCLUSION

Our results provide a general overview of the major directions in rhinoplasty research. Preservation rhinoplasty, rib graft, nonsurgical rhinoplasty, hyaluronic acid, FACE-Q, fillers, and three-dimensional technology may be future research hotspots.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Simulation and Artificial Intelligence in Rhinoplasty: A Systematic Review

BACKGROUND

Rhinoplasty is one of the most popular cosmetic procedures. The complexity of the nasal structure and the substantial aesthetic and functional impact of the operation make rhinoplasty very challenging. The past few years have witnessed an increasing implementation of artificial intelligence (AI) and simulation systems into plastic surgery practice. This review explores the potential uses of AI and simulation models in rhinoplasty.

METHODS

Five electronic databases were searched: PubMed, CINAHL, EMBASE, Scopus, and Web of Science. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis as our basis of organization.

RESULTS

Several simulation models were described to predict the nasal shape that aesthetically matches the patient's face, indicate the implant size in augmentation rhinoplasty and construct three-dimensional (3D) facial images from two-dimensional images. Machine learning was used to learn surgeons' rhinoplasty styles and accurately simulate the outcomes. Deep learning was used to predict rhinoplasty status accurately and analyze the factors associated with increased facial attractiveness after rhinoplasty. Finally, a deep learning model was used to predict patients' age before and after rhinoplasty proving that the procedure made the patients look younger.

CONCLUSION

3D simulation models and AI models can revolutionalize the practice of functional and aesthetic rhinoplasty. Simulation systems can be beneficial in preoperative planning, intra-operative decision making, and postoperative evaluation. In addition, AI models can be trained to carry out tasks that are either challenging or time-consuming for surgeons.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Progress of 3D Printing Techniques for Nasal Cartilage Regeneration

Once cartilage is damaged, its self-repair capacity is very limited. The strategy of tissue engineering has brought a new idea for repairing cartilage defect and cartilage regeneration. In particular, nasal cartilage regeneration is a challenge because of the steady increase in nasal reconstruction after oncologic resection, trauma, or rhinoplasty. From this perspective, three-dimensional (3D) printing has emerged as a promising technology to address the complexity of nasal cartilage regeneration, using patient's image data and computer-aided deposition of cells and biomaterials to precisely fabricate complex, personalized tissue-engineered constructs. In this review, we summarized the major progress of three prevalent 3D printing approaches, including inkjet-based printing, extrusion-based printing and laser-assisted printing. Examples are highlighted to illustrate 3D printing for nasal cartilage regeneration, with special focus on the selection of seeded cell, scaffolds and growth factors. The purpose of this paper is to systematically review recent research about the challenges and progress and look forward to the future of 3D printing techniques for nasal cartilage regeneration.Level of Evidence III This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

The usefulness of patient-specific 3D nasal silicone implant using 3D design and order form

PURPOSE

The need for customized implants has continuously increased, but patient-specific silicone implants are not yet commonly used in the plastic surgery market. We sought to validate the effectiveness of a 3D customized nasal implant design in terms of design and lead time compared with a manually customized implant by a surgeon.

MATERIALS AND METHODS

Based on the computed tomography (CT) findings of 15 patients who planned rhinoplasty, a surgeon wrote order forms reflecting the surgical plan and subsequently designed implants manually using epoxy on a 3D printed skull. Separately, engineers analyzed the CT findings and designed 3D implants based on the order forms.

RESULTS

Epoxy designs were 3D-scanned, converted into a stereolithography format and compared with 3D implant designs to assess which method had a smaller margin of error as per the preoperative order form. Moreover, the lead time in all steps are compared. Nasion thickness, tip thickness, glabella starting point, glabella width, radix width, and total volume were comparatively analyzed. In all parameters, the error rate of the 3D design is relatively lower than that of the epoxy design. The former also had a lower total volume and a faster manufacturing time.

CONCLUSION

With novel 3D customized nasal implants, the limitations of ready-made silicone implants are addressed, and it is now possible to preoperatively design implants more accurately, quickly, and conveniently.

3D Virtual Planning for Rhinoplasty Using a Free Add-On for Open-Source Software

BACKGROUND

Rhinoplasty is one of the most frequent aesthetic surgeries; the procedure can be challenging for inexperienced surgeons, and positive outcomes depend on good communication with the patient, proper planning, and precise execution. Three-dimensional (3D) technology has emerged to address these issues, but specific software for 3D planning tends to be expensive.

OBJECTIVES

This study presents a simple, low-cost method for 3D simulation to plan rhinoplasty.

METHODS

This preliminary report describes 3D rhinoplasty planning in a series of 3 cases employing free software and an add-on especially developed for rhinoplasty (Blender and RhinOnBlender, respectively). The photogrammetry protocol, which can be performed easily with a smartphone, is described in detail along with all the steps in 3D planning.

RESULTS

The software and add-on automated the process, making the tool environment accessible to surgeons who are not familiar with graphic design software. The surgeries were uneventful in all cases, and the patients were satisfied with the outcomes.

CONCLUSIONS

3D graphic technology has provided significant advances in health research, improvement, and teaching for surgeons and communication between surgeons and patients. Free open-source software and add-ons are excellent options that offer proven utility, affordability, and ease of utilization to healthcare providers.

Three-dimensional Printing in Plastic Surgery: Current Applications, Future Directions, and Ethical Implications

Background

Three-dimensional printing (3DP) is a rapidly advancing tool that has revolutionized plastic surgery. With ongoing research and development of new technology, surgeons can use 3DP for surgical planning, medical education, biological implants, and more. This literature review aims to summarize the currently published literature on 3DP's impact on plastic surgery.

Methods

A literature review was performed using Pubmed and MEDLINE from 2016 to 2020 by 2 independent authors. Keywords used for literature search included 3-dimensional (3D), three-dimensional printing (3DP), printing, plastic, surgery, applications, prostheses, implants, medical education, bioprinting, and preoperative planning. All studies from the database queries were eligible for inclusion. Studies not in English, not pertaining to plastic surgery and 3DP, or focused on animal data were excluded.

Results

In total, 373 articles were identified. Sixteen articles satisfied all inclusion and exclusion criteria, and were further analyzed by the authors. Most studies were either retrospective cohort studies, case reports, or case series and with 1 study being prospective in design.

Conclusions

3DP has consistently shown to be useful in the field of plastic surgery with improvements on multiple aspects, including the delivery of safe, effective methods of treating patients while improving patient satisfaction. Although the current technology may limit the ability of true bioprinting, research has shown safe and effective ways to incorporate biological material into the 3D printed scaffolds or implants. With an overwhelmingly positive outlook on 3DP and potential for more applications with updated technology, 3DP shall remain as an effective tool for the field of plastic surgery.

Biofabrication of a shape-stable auricular structure for the reconstruction of ear deformities

Bioengineering of the human auricle remains a significant challenge, where the complex and unique shape, the generation of high-quality neocartilage, and shape preservation are key factors. Future regenerative medicine–based approaches for auricular cartilage reconstruction will benefit from a smart combination of various strategies. Our approach to fabrication of an ear-shaped construct uses hybrid bioprinting techniques, a recently identified progenitor cell population, previously validated biomaterials, and a smart scaffold design. Specifically, we generated a 3D-printed polycaprolactone (PCL) scaffold via fused deposition modeling, photocrosslinked a human auricular cartilage progenitor cell–laden gelatin methacryloyl (gelMA) hydrogel within the scaffold, and cultured the bioengineered structure in vitro in chondrogenic media for 30 days. Our results show that the fabrication process maintains the viability and chondrogenic phenotype of the cells, that the compressive properties of the combined PCL and gelMA hybrid auricular constructs are similar to native auricular cartilage, and that biofabricated hybrid auricular structures exhibit excellent shape fidelity compared with the 3D digital model along with deposition of cartilage-like matrix in both peripheral and central areas of the auricular structure. Our strategy affords an anatomically enhanced auricular structure with appropriate mechanical properties, ensures adequate preservation of the auricular shape during a dynamic in vitro culture period, and enables chondrogenically potent progenitor cells to produce abundant cartilage-like matrix throughout the auricular construct. The combination of smart scaffold design with 3D bioprinting and cartilage progenitor cells holds promise for the development of clinically translatable regenerative medicine strategies for auricular reconstruction.

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First application of human auricular cartilage progenitor cells for bioprinting.

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Dual-printing of hybrid ear-shaped constructs with excellent shape fidelity over time.

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Strategy and design ensured adequate deposition of cartilage-like matrix throughout large auricular constructs.

Computational technology for nasal cartilage-related clinical research and application

Surgeons need to understand the effects of the nasal cartilage on facial morphology, the function of both soft tissues and hard tissues and nasal function when performing nasal surgery. In nasal cartilage-related surgery, the main goals for clinical research should include clarification of surgical goals, rationalization of surgical methods, precision and personalization of surgical design and preparation and improved convenience of doctor-patient communication. Computational technology has become an effective way to achieve these goals. Advances in three-dimensional (3D) imaging technology will promote nasal cartilage-related applications, including research on computational modelling technology, computational simulation technology, virtual surgery planning and 3D printing technology. These technologies are destined to revolutionize nasal surgery further. In this review, we summarize the advantages, latest findings and application progress of various computational technologies used in clinical nasal cartilage-related work and research. The application prospects of each technique are also discussed.

3D Printing as a Significant Achievement for Application in Posttraumatic Surgeries - A Literature Review

BACKGROUND

3D printing is increasingly used in many fields of medicine. The broadening of knowledge in this field and the cooperation of doctors and engineers increase the interest in this technology and results in attempts to implement it at every stage of the treatment.

OBJECTIVE

The review aims to summarize the current literature on the use of 3D printing technology in the treatment of post-trauma patients.

METHODS

A review of available scientific publications in PubMed regarding 3D printing and its application in the context of posttraumatic procedures was carried out. Clinical Trials and Reviews from the period 2014-2019 (6-year period) were taken into consideration. The database was searched for "Printing", "ThreeDimensional" [MAJR] [MeSH Term]. Finally, 48 studies have been included in our review article.

RESULTS

3D printing technology has a number of applications in patients who have suffered injuries. 3D printing has found application in the preparation of procedures, accurate visualization of occurring injuries and complications, education of doctors and patients, prototyping, creation of synthetic scaffolding, production and implementation of target implants and rehabilitation.

CONCLUSION

3D printing is increasingly used in providing for posttraumatic patients. It is necessary to conduct further research in this area and to provide development opportunities regarding biopolymers and bioprinting. It is also necessary to improve cooperation between doctors and engineers and to create new centres that can comprehensively use 3D printing - from imaging diagnostics to the production of implants and their surgical use.

Clinical Application of a Patient-Specific, Three-Dimensional Printing Guide Based on Computer Simulation for Rhinoplasty

BACKGROUND

A practical application of three-dimensional printing technology has been considered a difficult area in rhinoplasty. However, the patient-specific three-dimensionally printed rhinoplasty guide based on the simulation program the authors developed could be a solution for minimizing the gap between simulation and actual surgical results. The aims of this study were to determine how a three-dimensional rhinoplasty guide based on three-dimensional simulation would link the patient to the surgeon to investigate its effectiveness.

METHODS

Fifty patients who underwent rhinoplasty between January of 2017 and February of 2018 were included in this study. The patients were consulted about the desired shape of their nose based on preoperative three-dimensional photography. The confirmed three-dimensional simulation was sent to a manufacturing company for three-dimensionally printed rhinoplasty guides. In the guide group, rhinoplasty was performed based on the three-dimensionally printed rhinoplasty guide, and in the control group, procedures were performed based on the surgeon's intuition.

RESULTS

The intraclass correlation coefficient test for comparing the simulated and postoperative measurements showed higher correlation in the three-dimensional printing guide group: higher correlation 11.3 percent in nasal tip projection, 21.6 percent in dorsum height, and 9.8 percent in nasolabial angle. The postoperative result of the nasal dorsum had a statistically significant difference between the two groups (p < 0.05).

CONCLUSIONS

This study demonstrated the usefulness of the three-dimensionally-printed rhinoplasty guide, which delivers the preoperative simulated image in the actual clinical practice of rhinoplasty. This approach could cause a paradigm shift in simulation-based rhinoplasty.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Definition of "Gender Angle" in Caucasian Population

INTRODUCTION

The goal of this study report is to define the "gender angle," a new angle which represents the masculine or feminine nasal shape, for performing a gender-oriented rhinoplasty. The use of the "gender angle" in Caucasian patients will help the plastic surgeon in the search for a suitable nose for the patient's face and above all for the search for maximum patient satisfaction.

MATERIALS AND METHODS

The study population was obtained from Caucasian patients who had undergone rhinoplasty between January 1986 and September 2016 at our department. Patients answered the Italian version of the FACE-Q outcome instrument on post-rhinoplasty satisfaction with their nose. Anthropometric measurements were taken retrospectively by AutoCAD for MAC on a photograph of the profile view taken postoperatively at the last follow-up.

RESULTS

A total of 1774 (706 male and 1068 female) patients satisfied the inclusion criteria and were finally enrolled in this study. We identified a gender-specific angle ranging from 168° to 182° for the male nose and from 160° to 178° for the female nose. We subdivided all study patients into 3 ranges of angles as follows: male nose, range 1 = 168°-172°, range 2 = 173°-177°, range 3 = 178°-182°; female nose, range 1 = 160°-166°, range 2 = 167°-171°, range 3 = 172°-178°. All study patients completed the FACE-Q rhinoplasty postoperative module. Analysis was performed of the FACE-Q results and the angle obtained for each nose. The most satisfactory angle range for male patients was range 3 (P = 0.01) and for the female patients was range 2 (P = 0.01).

CONCLUSIONS

The "gender angle" might be a parameter that effectively provides the optimal cosmetic result for male and female patients who undergo rhinoplasty.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors - www.springer.com/00266 .

In-House Manufacture of Sterilizable, Scaled, Patient-Specific 3D-Printed Models for Rhinoplasty

BACKGROUND

Rhinoplasty relies on clear patient communication and precise execution of a three-dimensional (3D) plan to achieve optimal results. As 3D imaging and printing continue to grow in popularity within the medical field, rhinoplasty surgeons have begun to leverage these resources as an aid to preoperative planning, patient communication, and the technical performance of this challenging operation.

OBJECTIVES

Utilizing departmentally available resources and open-access 3D imaging platforms, we have developed an affordable, reproducible protocol for rapid in-house virtual surgical planning (VSP) and subsequent manufacture of 3D-printed rhinoplasty models.

METHODS

Preoperative 3D photographic images underwent virtual rhinoplasty using a freely available 3D imaging and sculpting program (BlenderTM [Version 2.78, Amsterdam, The Netherlands]). Once the ideal postoperative result was digitally achieved, scaled, sterilizable, and patient-specific 3D models of the preoperative and ideal postoperative result were manufactured in-house using a departmentally owned 3D printer.

RESULTS

3D-printed models have successfully been manufactured and employed for 12 patients undergoing rhinoplasty. The average time to prepare a set of pre- and postoperative models was 3 hours, while the printing process required 18 to 24 hours per model. Each set of surgical models can be manufactured at a total materials cost of approximately $5.00.

CONCLUSIONS

We describe an affordable means to construct sterilizable, scaled, patient-specific 3D-printed models for rhinoplasty. This technique may become of increasing interest to academic and cosmetic centers as hardware costs of 3D printers continue to fall.

LEVEL OF EVIDENCE: 4

The Application of Three-Dimensional Simulation Program and Three-Dimensional Printing in Secondary Rhinoplasty

BACKGROUND

In recent years, efficacy of 3-dimensional (3D) simulation, in preoperative planning of aesthetic and reconstructive surgeries and prediction of the postoperative result, has been reported in many clinical studies. Especially in rhinoplasty, it can be used not only for prediction the outcome but also for fabricating implants that will strictly match with the anatomical needs of patient.

CLINICAL REPORT

A 30-year-old male after traffic accident visited emergency room complaining on painful swelling and contour deformity of nose. Under the diagnosis of nasal bone fracture and deviated nose, he had been admitted to our hospital. Considering his medical history of rhinoplasty, which was performed in the local aesthetic clinic 6 years ago, the authors decided to perform the operation with 3D simulation program and 3D printed implant. There were no specific complications, such as hematoma, infection, or necrosis. Patient was discharged on fourth postoperation day.

DISCUSSION

There is no doubt that creating an ideal dorsal aesthetic line is critically important in rhinoplasty. Therefore creating individual implants for certain patient's anatomical nasal structure is highly significant in the rhinoplasty. Although usefulness of primary rhinoplasty using patient-specific 3D implant is introduced in previous study, the authors successfully applied the patient-specific 3D implant to patient who has fracture of nasal bone and primary rhinoplasty history. It means that the patient-specific implants are stable and can be used not only in primary rhinoplasty patients but also for the patients who had primary rhinoplasty previously.