Characterization of Acellular Cartilage Matrix-Sodium Alginate Scaffolds in Various Proportions.

The development of three-dimensional (3D) bioprinting technology has provided a new solution to address the shortage of donors, multiple surgeries, and aesthetic concerns in microtia reconstruction surgery. The production of bioinks is the most critical aspect of 3D bioprinting. Acellular cartilage matrix (ACM) and sodium alginate (SA) are commonly used 3D bioprinting materials, and there have been reports of their combined use. However, there is a lack of comprehensive evaluations on ACM-SA scaffolds with different proportions. In this study, bioinks were prepared by mixing different proportions of decellularized rabbit ear cartilage powder and SA and then printed using 3D bioprinting technology and crosslinked with calcium ions to fabricate scaffolds. The physical properties, biocompatibility, and toxicity of ACM-SA scaffolds with different proportions were compared. The adhesion and proliferation of rabbit adipose-derived stem cells on ACM-SA scaffolds of different proportions, as well as the secretion of Collagen Type II, were evaluated under an adipose-derived stem cell chondrogenic induction medium. The following conclusions were drawn: when the proportion of SA in the ACM-SA scaffolds was <30%, the printed structure failed to form. The ACM-SA scaffolds in proportions from 1:9 to 6:4 showed no significant cytotoxicity, among which the 5:5 proportion of ACM-SA scaffold was superior in terms of adhesiveness and promoting cell proliferation and differentiation. Although a higher proportion of SA can provide greater mechanical strength, it also significantly increases the swelling ratio and reduces cell proliferation capabilities. Overall, the 5:5 proportion of ACM-SA scaffold demonstrated a more desirable biological and physical performance.

Proteomic dataset for decellularization of porcine auricular cartilage.

OBJECTIVES: Osteoarthritis (OA) is a major concern in the United States and worldwide. Development and validation of robust decellularization techniques is critical in generating suitable bioscaffolds for future OA treatment options. DATA DESCRIPTIONS: In the present study, proteins from porcine auricular cartilage before and after decellularization were extracted, digested, and identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The data represents protein profiles of both non-decellularized and decellularized porcine auricular cartilage. This data is intended to be useful to scientists who are interesting in generating biomaterials for potential relevant clinical applications using decellularized cartilage tissue.

Profiling of Long Non-Coding RNAs in Auricular Cartilage of Patients with Isolated Microtia.

Introduction: Microtia is the second most common maxillofacial birth defect worldwide. However, the involvement of long non-coding RNAs (lncRNAs) in isolated microtia is not well understood. This study aimed at identifying lncRNAs that regulate the expression of genes associated with isolated microtia. Methods: We used our microarray data to analyze the expression pattern of lncRNA in the auricular cartilage tissues from 10 patients diagnosed with isolated microtia, alongside 15 control subjects. Five lncRNAs were chosen for validation using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: We identified 4651 differentially expressed lncRNAs in the auricular cartilage from patients with isolated microtia. By Gene Ontology/Kyoto Encyclopedia of Genes and Genomes pathway (GO/KEGG) analysis, we identified 27 differentially expressed genes enriched in pathways associated with microtia. In addition, we predicted 9 differentially expressed genes as potential cis-acting targets of 12 differentially expressed lncRNAs. Our findings by qRT-PCR demonstrate significantly elevated expression levels of ZFAS1 and DAB1-AS1, whereas ADIRF-AS1, HOTAIRM1, and EPB41L4A-AS1 exhibited significantly reduced expression levels in the auricular cartilage tissues of patients with isolated microtia. Conclusions: Our study sheds light on the potential involvement of lncRNAs in microtia and provides a basis for further investigation into their functional roles and underlying mechanisms.

The Ram Graft: Using One Complete Piece of Conchal Cartilage for Nasal Tip Reconstruction in East Asians.

SUMMARY: Adequate nasal tip projection remains a challenge in aesthetic rhinoplasty for East Asians. Various surgical techniques have been developed to reshape the nasal tip using auricular cartilage. In this article, we introduce the new ram graft to increase nasal tip projection by using one complete piece of conchal cartilage. Between 2019 and 2021, 19 patients who underwent nasal tip reconstruction using ram grafts were reviewed in a single hospital. The complication rate, satisfaction rate, and changes in nasolabial angle and nasal proportion were recorded. Nineteen patients with a mean age (± SD) of 28.9 ± 6.1 years underwent nasal tip reconstruction. The mean follow-up time was 15.4 ± 6.6 months. Nasolabial angle increased from 87.4 ± 10.0 degrees to 91.2 ± 10.2 degrees ( P > 0.05). Sixteen of 19 patients (84.2%) were satisfied with their results. The nasal length-to-nasal tip projection-to-dorsal height-to-radix height ratio is 2:0.8:0.62:0.19 preoperatively and 2:0.92:0.77:0.35 postoperatively. Complications including alloplast-related infection (two of 19) and septal extension graft-related decrease of nasal tip projection (one of 19) were recorded. By using one complete piece of conchal cartilage, the ram graft is a simple and effective approach to increase nasal tip projection for East Asians. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Brent Technique of Repair Versus Nagata Auricular Reconstruction for Microtia Reconstruction: A Systematic Review and Meta-Analysis.

BACKGROUND: Up to 17.4 in every 10,000 births are affected by microtia, but no consensus exists on a gold standard technique for autogenous repair. In this study, the authors compare 2 common methods-the Brent and Nagata autogenous costal cartilage ear reconstruction techniques. A systematic review of the literature and a quantitative meta-analysis to compare the outcomes of these 2 approaches were performed. The outcomes analyzed included rates of infection, necrosis, cartilage exposure, cartilage resorption, hematoma, wire extrusion, and hypertrophic scar. METHODS: A MEDLINE database systematic review with the following keywords: microtia, Brent, and Nagata was performed. Case reports and articles without original data or patient outcomes were excluded. Inclusion methods for study selection are outlined in Supplemental Digital Content 1, http://links.lww.com/SCS/F461 , below. The prevalence of outcomes for each study was analyzed through meta-analysis of proportions using Stata. RESULTS: A total of 536 potential studies were retrieved for review. Twelve of these studies met inclusion criteria. Four studies utilized the Brent method of repair with the inclusion of 563 ear reconstructions. Nine studies implemented the Nagata technique in 2304 reconstructions. Two studies directly compared the Brent (327 ears) and Nagata (471 ears) techniques. The calculated rate and 95% confidence intervals are summarized in Supplemental Digital Content 2, http://links.lww.com/SCS/F461 . There were no statistically significant differences in complication rates between the Brent and Nagata microtic reconstruction techniques identified in this study. CONCLUSIONS: The Brent and Nagata microtia reconstruction techniques have no difference in the risk of infection, necrosis, cartilage exposure, cartilage resorption, hematoma, wire extrusion, or hypertrophic scars.

Optimal surgical timing for ear reconstruction with autologous cartilage: Analysis of the computed tomography scan characteristics of the ribs.

BACKGROUND: The approach to constructing the cartilage framework for ear reconstruction is sufficiently established. However, there is still no consensus about the age of initiation of surgical treatment. This study aims to assess the development and growth of the costal cartilage to determine the best age to perform ear reconstruction surgery. METHODS: Out of 107 patients, we used presurgical treatment data for 40 patients and medical records for 67 patients aged 5-40. Computed tomography (CT) scans were performed, and average parameters were calculated (length, width, thickness, cartilage density, and standard deviation in Hounsfield units) of the cartilaginous part of the 6th, 7th, 8th, and 9th ribs. RESULTS: The required values were reached at 9-10 years old. CONCLUSION: The criteria for starting surgical treatment in the Russian population was determined by the width of the 6th-7th ribs synchondrosis, which must be equal to the width of a healthy auricle, and the length of the 8th rib should be longer than 9 cm. Therefore, the optimal age for ear reconstruction with autologous costal cartilage is 10 years and older. However, reconstruction can be made earlier in specific cases, according to height and weight and the preoperative CT scan.

Age-Related Histologic and Biochemical Changes in Auricular and Nasal Cartilages.

OBJECTIVE: Analyze age-related changes in histologic features and biochemical properties of human auricular cartilage and two subsites of nasal cartilages (quadrangular cartilage and dorsal septal articulation with upper lateral cartilages). STUDY DESIGN: Prospective cross-sectional study of nasal and auricular cartilages from seventy-three (73) live donors. METHODS: Auricular cartilage (AC), quadrangular cartilage (QC), and dorsal septal cartilage articulation (DSA) with the upper lateral cartilage (ULCs) were collected intraoperatively. Histochemical staining was used: Safranin O for glycosaminoglycans (GAGs), Verhoeff's for elastin, and Masson's trichrome for collagen. ImageJ2 software was used to calculate cell count and percent stained for each cartilage type. R studio "ggplot" package was used to visualize age versus cell count or percent stained. RESULTS: Participant ages ranged from 20 to 77 years, average 46.5 years. There was a significant decline in GAGs with age for the DSA subsite, (n = 64, p < 0.001). Significant increase in collagen content with age was observed for DSA subsite (n = 66, p < 0.001) and the QC subsite (n = 64, p < 0.05). There was a statistically insignificant decline in elastin with age (n = 41, p = 0.309) for AC. Cell count declined with age at all cartilage subsites. CONCLUSION: Our findings confirm that there were age-related decreases in cartilage glycosaminoglycan content, and chondrocyte cell count in both auricular and nasal cartilages. We have also confirmed that collagen content increases with age for both auricular and nasal cartilage. The histologic findings while not statistically significant in all comparisons, provides additional evidence that there is some loss of structural integrity and flexibility in nasal and auricular cartilage with aging. LEVEL OF EVIDENCE: NA Laryngoscope, 134:1220-1226, 2024.

Application of 3D printing in ear reconstruction with autogenous costal cartilage: A systematic review.

PURPOSE: In recent years, 3D printing technology has been employed as a production method that builds materials layer upon layer, providing notable advantages in terms of individual customization and production efficiency. Autologous costal cartilage ear reconstruction has seen substantial changes due to 3D printing technology. In this context, this research evaluated the prospects and applications of 3D printing in ear reconstruction education, preoperative planning and simulation, the production of intraoperative guide plates, and other related areas. METHODOLOGY: All articles eligible for consideration were sourced through a comprehensive search of PubMed, the Cochrane Library, EMBASE, and Web of Science from inception to May 22, 2023. Two reviewers extracted data on the manufacturing process and interventions. The Cochrane risk of bias tool and Newcastle-Ottawa scale were used to assess the quality of the research. Database searching yielded 283 records, of which 24 articles were selected for qualitative analysis. RESULTS: The utilization of 3D printing is becoming increasingly widespread in autogenous costal cartilage ear reconstruction, from education to the application of preoperative design and intraoperative guide plates production, possessing a substantial influence on surgical training, the enhancement of surgical effects, complications reduction, and so forth. CONCLUSION: This study sought to determine the application value and further development potential of 3D printing in autologous costal cartilage ear reconstruction. However, there is a lack of conclusive evidence on its effectiveness when compared to conventional strategies because of the limited number of cohort studies and randomized controlled trials. Simultaneously, the evaluation of the effect lacks objective and quantitative evaluation criteria, with most of them being emotional sentiments and ratings, making it difficult to execute a quantitative synthetic analysis. It is hoped that more large-scale comparative studies will be undertaken, and an objective and standard effect evaluation system will be implemented in the future.

Comparison of Polypropylene and Polydioxanone in the Hemitransdomal Suture: A Novel Rabbit Ear Cartilage Model.

BACKGROUND: Lower lateral cartilage reshaping is one of the basic steps in rhinoplasty. Hemitransdomal suture is frequently used for dome narrowing. Different suture materials can be used for hemitransdomal suture. In this study, we investigated the effectiveness of polypropylene and polydioxanone in hemitransdomal suture by designing a new experimental model in the rabbit ear cartilage. METHODS: Twelve young adult male New Zealand White rabbits were used. The bipedicled inverted-U-shaped cartilage was elevated in each ear of the rabbits. Two hemitransdomal sutures were applied using 5-0 polypropylene on one ear and 5-0 polydioxanone on the other ear randomly. A 5 mm high cartilage mound was created with two hemitransdomal sutures on each side. The sample size was twelve both in the polypropylene group and the polydioxanone group (n = 12). All animals were sacrificed after three months. Cartilage mound heights were measured. The samples were examined histologically regarding fibroadipose tissue, inflammation, foreign body granuloma, cartilage degeneration, and the presence of inclusion cyst. RESULTS: Cartilage mound height was significantly higher in the polypropylene group than in the polydioxanone group at the end of the third month [3.75 mm (± 0.68) vs. 3.03 mm (± 0.69); p < 0.05]. There was no significant difference between the two groups in histological analysis (p > 0.05). CONCLUSIONS: Polypropylene suture may be more effective in maintaining the shape given to the dome by hemitransdomal sutures in rhinoplasty. No Level Assigned 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 Table of Contents or the online Instructions to Authors www.springer.com/00266.

Effects of hardness and dimension of pinna and auricular hematoma on detection threshold of cartilage conduction.

In cartilage conduction (CC), a vibrator is presented onto the cartilage of the ear instead of the bony parts of the head used in ordinary bone conduction (BC). Because the auricle cartilage is softer and lighter than the bone, it doesn't require as much pressure as BC, which may cause discomfort (or pain) in the area where a BC transducer is being pressed. However, CC is a relatively new technology, and whether the less dense characteristics of cartilage, which varies from person to person, result in a better sound perception is still being studied. In this paper, we focused on investigating how the hardness and size of the auricle or pinna affect the effectiveness of CC. We used pure-tone hearing thresholds to evaluate this objectively. We also measured the thresholds of CC in subjects with auricular hematoma or "cauliflower ear" (misshapen ears commonly caused by close contact sports) to see if it affected CC differently. Our results indicate that the hardness and size of the auricle affect CC thresholds and that subjects with auricular hematoma have different perceptual characteristics compared to the normal ear group. These differences are believed to be caused by changes in hardness and mass.

BMP9 is a potent inducer of chondrogenesis, volumetric expansion and collagen type II accumulation in bovine auricular cartilage chondroprogenitors.

Reconstruction of the outer ear currently requires harvesting of cartilage from the posterior of the auricle or ribs leading to pain and donor site morbidity. An alternative source for auricular reconstruction is in vitro tissue engineered cartilage using stem/progenitor cells. Several candidate cell-types have been studied with tissue-specific auricular cartilage progenitor cells (AuCPC) of particular interest. Whilst chondrogenic differentiation of competent stem cells using growth factor TGFß1 produces cartilage this tissue is frequently fibrocartilaginous and lacks the morphological features of hyaline cartilage. Recent work has shown that growth factor BMP9 is a potent chondrogenic and morphogenetic factor for articular cartilage progenitor cells, and we hypothesised that this property extends to cartilage-derived progenitors from other tissues. In this study we show monoclonal populations of AuCPCs from immature and mature bovine cartilage cultured with BMP9 produced cartilage pellets have 3-5-fold greater surface area in sections than those grown with TGFß1. Increased volumetric growth using BMP9 was due to greater sGAG deposition in immature pellets and significantly greater collagen accumulation in both immature and mature progenitor pellets. Polarised light microscopy and immunohistochemical analyses revealed that the organisation of collagen fibrils within pellets is an important factor in the growth of pellets. Additionally, chondrocytes in BMP9 stimulated cell pellets had larger lacunae and were more evenly dispersed throughout the extracellular matrix. Interestingly, BMP9 tended to normalise the response of immature AuCPC monoclonal cell lines to differentiation cues whereas cells exhibited more variation under TGFß1. In conclusion, BMP9 appears to be a potent inducer of chondrogenesis and volumetric growth for AuCPCs a property that can be exploited for tissue engineering strategies for reconstructive surgery though with the caveat of negligible elastin production following 21-day treatment with either growth factor.

Combining bioengineered human skin with bioprinted cartilage for ear reconstruction.

Microtia is a congenital disorder that manifests as a malformation of the external ear leading to psychosocial problems in affected children. Here, we present a tissue-engineered treatment approach based on a bioprinted autologous auricular cartilage construct (EarCartilage) combined with a bioengineered human pigmented and prevascularized dermo-epidermal skin substitute (EarSkin) tested in immunocompromised rats. We confirmed that human-engineered blood capillaries of EarSkin connected to the recipient's vasculature within 1 week, enabling rapid blood perfusion and epidermal maturation. Bioengineered EarSkin displayed a stratified epidermis containing mature keratinocytes and melanocytes. The latter resided within the basal layer of the epidermis and efficiently restored the skin color. Further, in vivo tests demonstrated favorable mechanical stability of EarCartilage along with enhanced extracellular matrix deposition. In conclusion, EarCartilage combined with EarSkin represents a novel approach for the treatment of microtia with the potential to circumvent existing limitations and improve the aesthetic outcome of microtia reconstruction.

Total rebuilding of the ear after unsatisfactory initial microtia reconstruction: 30-year experience using autogenous costal cartilage framework.

BACKGROUND: This study describes the author's experience with long-term follow-up analysis of secondary procedures in patients with unsatisfactory initial microtia reconstruction. METHODS: A total of 134 patients who underwent secondary operations between 1992 and 2021 were reviewed by examining medical records and photographic data. A total of 110 patients followed between 6 months and 26 years (average 33.2 months) were included for evaluation of aesthetic outcomes. RESULTS: Primary reconstruction was performed with costal cartilage in 113 patients, porous polyethylene implant in 7 patients, silicone implant in 6 patients, and others in 8 patients. The major external features at the time of the secondary reconstruction were lump (91 cases), deficient convolution (19 cases), and no framework with scarred mastoid skin (22 cases). All secondary reconstructions were performed with an autogenous costal cartilage framework. The framework was covered using temporoparietal fascia flap techniques in 118 patients, mastoid skin coverage technique in 12 patients, and others in 4 patients. One major complication (exposure of cartilage framework due to partial necrosis of fascial flap) and three minor complications (loss of moderate-sized full-thickness skin, grafted on the fascia) were recorded. The average score given for aesthetic outcomes, rated on a four-point Likert scale (i.e., 1 = poor, 2 = fair, 3 = good, and 4 = excellent) was 3.17 (median 3.00). A total of 42% of the patients were rated excellent and 36% were rated good.

Quemaduras del pabellón auricular: membrana amniótica frente a cura oclusiva para prevención de condritis / Burns of the auricular pavillion: amniotic membrane versus occlusive cure for chondritis prevention

Introducción y objetivo: Prevenir la condritis es un pilar importante en el tratamiento de las quemaduras del pabellón auricular teniendo en cuenta que, en la actualidad, no existe un protocolo de manejo frente a esta patología y sus posteriores complicaciones. El presente estudio pretende analizar la literatura disponible acerca del manejo de las quemaduras auriculares y comparar el uso de membrana amniótica frente a la cura oclusiva en un grupo de pacientes con quemadura en pabellón auricular para prevenir la deformidad de oreja en coliflor como secuela. Material y método: Revisión de la literatura sobre las diversas formas de tratamiento de las quemaduras auriculares y estudio en un grupo de pacientes de la Unidad de Quemados de la Subred Integrada de Servicios en Salud Norte E.S.E. UHMES Simón Bolívar de Bogotá, D.C., Colombia, con quemaduras en pabellones auriculares a los que se les aplicó membrana amniótica para cubrir las lesiones con el fin de disminuir el riesgo de condritis y la consecuente deformidad en coliflor, entre otras complicaciones. Resultados: De la revisión de la literatura obtenemos una comparativa del uso de tratamientos conservadores frente a quirúrgicos y en el estudio sobre pacientes tratados con membrana amniótica observamos una importante disminución en la respuesta inflamatoria local, dolor, frecuencia de curaciones y por lo tanto, menor estancia hospitalaria. Conclusiones: Nuestro trabajo aporta revisión bibliográfica y experiencia propia comparativa de interés para la prevención de la condritis postquemadura auricular y contribuye a protocolizar el tratamiento de este tipo de lesiones a fin de evitar sus secuelas. Nivel de evidencia científica 4c Terapéutico.(AU)

Background and objective: Preventing chondritis is an important pillar in the treatment of burns of the auricular pavilion because, currently, there is no management protocol for this pathology and its subsequent complications. The present study aims to analyze the available literature on the management of auricular burns, and to compare the use of amniotic membrane versus occlusive treatment in a group of patients with burns in the auricular pavilion to prevent cauliflower ear. Methods: Literature review of the different ways of treatment for ear burns and study in a group of patients from the Burn Unit of the Integrated Subred of Health Services North E.S.E. Simón Bolívar (UHMES) from Bogotá D.C Colombia, with burns on the auricular pavilion to which amniotic membrane was applied to cover up the injuries in order to reduce the risk of chondritis and the consequent cauliflower deformity, among other complications. Results: From the literature review, we obtain a comparison between the use of conservative treatments versus surgical procedures and, in the study of patients treated with amniotic membrane, we observed a significant decrease in the local inflammatory response, pain, frequency of wound healing, and therefore, shorter hospital stay. Conclusions: Our study provides a bibliographic review and our own comparative experience, both of interest for the prevention of post-auricular burn chondritis and contributes to create protocols for treatment of this type of injury in order to avoid its sequelae.Level of evidence 4c Terapeutic.(AU)

A Scarless Method for Correcting Tanzer Group IIB-Constricted Ear Without Cartilage Grafting.

Tanzer group IIB-constricted ear is described as a deformity of the helix, antihelix, or scapha. Deficiency of the auricular skin and cartilage is a key point in the reconstruction of the cartilaginous framework. Traditionally, the treatment of a constricted ear mainly includes 2 aspects: correction of cartilage deformity and restoration of skin volume deficiency. By mimicking the suspension principle of a cable bridge, our technique only requires adjustment of the spatial directions and mechanical forces between the 2 flaps to achieve an aesthetic effect. The authors were able to avoid harvesting the costal cartilage. The desired ear shape was obtained immediately postoperatively. Therefore, Vaseline gauze was not applied and was modeled along the scapha and antihelix. Expansion of the ear was remarkable in both horizontal and vertical lengths. Our technique causes less damage, less scarring, shorter operation time, fewer complications, faster rehabilitation, and no delays.

Chondrocyte-laden gelatin/sodium alginate hydrogel integrating 3D printed PU scaffold for auricular cartilage reconstruction.

Clinically, modified autologous rib cartilage grafts and commercial implants are commonly used for intraoperative repair of auricular cartilage defects caused by injuries. However, scaffold implantation is often accompanied by various complications including absorption and collapse, resulting in undesirable clinical outcomes. Three-dimensional printed auricular cartilage scaffolds have the advantage of individual design and biofunctionality, which attracted tremendous attention in this field. In this study, to better simulate the mechanical properties of auricular cartilage, we tested PU treated by ultrasonication and high temperature for 30 min (PU-30) or 60 min (PU-60). The results indicated that the compression modulus of PU-30 was 2.21-2.48 MPa, which similar to that of natural auricular cartilage (2.22-7.23 MPa) and was chosen for subsequent experiments. And the pores of treated PU were filled with a gelatin/sodium alginate hydrogel loaded with chondrocytes. In vivo analysis using a rabbit model confirmed that implanted PU-30 scaffold filled with chondrocytes contained hydrogel successfully integrated with normal auricular cartilage, and that new cartilage was generated at the scaffold-tissue interface by histological examination. These findings illustrate that this engineered scaffold represents a potential strategy for repair of ear cartilage damage in clinical.

Bioengineered human tissue regeneration and repair using endogenous stem cells.

We describe a general approach to produce bone and cartilaginous structures utilizing the self-regenerative capacity of the intercostal rib space to treat a deformed metacarpophalangeal joint and microtia. Anatomically precise 3D molds were positioned on the perichondro-periosteal or perichondral flap of the intercostal rib without any other exogenous elements. We find anatomically precise metacarpal head and auricle constructs within the implanted molds after 6 months. The regenerated metacarpal head was used successfully to surgically repair the deformed metacarpophalangeal joint. Auricle reconstructive surgery in five unilateral microtia patients yielded good aesthetic and functional results. Long-term follow-up revealed the auricle constructs were safe and stable. Single-cell RNA sequencing analysis reveal early infiltration of a cell population consistent with mesenchymal stem cells, followed by IL-8-stimulated differentiation into chondrocytes. Our results demonstrate the repair and regeneration of tissues using only endogenous factors and a viable treatment strategy for bone and tissue structural defects.

An Innovative Stent Consisting of Expanded Polytetrafluoroethylene and Ear Cartilage in Rhinoplasty For Asians: Application I of Dai's Exogenous Extension Stent Concept.

BACKGROUND: Restricted ventilation is common after rhinoplasty with an endogenous extension stent. The authors proposed an exogenous extension stent concept for Asian rhinoplasty patients to avoid this problem. Herein, we introduce an innovative stent in rhinoplasty for Asians, which is an application of this concept. METHODS: An L-shaped expanded polytetrafluoroethylene is hand-carved, and the long arm is placed at the nose back to improve the flatness of the nose, while the short arm supports the nasal column to raise the nose tip. The prosthesis does not occupy nasal volume and therefore theoretically does not affect nasal ventilation. The fan-shaped ear cartilage was placed at the nasal tip to prevent visualization of the nasal tip. The safety and effectiveness of this method were verified through 20 years of clinical practice. The difficulty of learning and popularizing the method was tested through the course of rhinoplasty among 22 plastic surgeons. RESULTS: After 20 years of clinical practice, it was found that this stent could not only effectively improve the nasal dorsum and tip morphology, but also did not actually affect the nasal volume and thus did not affect the nasal ventilation of patients. Among the trainees in plastic surgery, we found that it was not difficult to learn this method of rhinoplasty and the trainees could complete the prosthesis carving well after standardized training. CONCLUSION: This stent consisting of expanded polytetrafluoroethylene and ear cartilage is suitable in rhinoplasty for Asians with significant advantages, one of which is that it has no risk of resulting in restricted nasal ventilation. LEVEL OF EVIDENCE: Level IV.

The Promise of Regenerative Medicine in the Reconstruction of Auricular Cartilage Deformities.

There are many physiologic and psychologic challenges associated with ear cartilage deformities which are incredibly distasteful to patients, particularly children. The development of regenerative medicine (RM) sciences has opened up a new window for the reconstruction of auricular cartilage because it allows the creation of a structure similar to the auricular in appearance and function. As part of this review, we discuss the role that each RM tool, including tissue engineering, cells, and biomolecules, plays in developing engineered auricular tissue. In previous studies, it was shown that the simultaneous use of natural and synthetic biomaterials as well as three-dimensional printing techniques could improve the biological and mechanical properties of this tissue. Another critical issue is using stem cells and differentiated cartilage cells to produce tissue-specific cellular structures and extracellular matrix. Also, the importance of choosing a suitable animal model in terms of handling and care facilities, physiologic similarities to humans, and breed uniformity in the preclinical assessments have been highlighted. Then, the clinical trials registered on the clinicaltrials.gov website, and the commercialized product, called AuriNovo, have been comprehensively explained. Overall, it is important to provide engineered auricular cartilage structures with acceptable safety and efficacy compared with standard methods, autologous cartilage transplantation, and prosthetic reconstruction in RM.