Robot-Automated Cartilage Contouring for Complex Ear Reconstruction: A Cadaveric Study.

OBJECTIVES/HYPOTHESIS: Auricular reconstruction requiring manual contouring of costal cartilage is complex and time consuming, which could be facilitated by a robot in a fast and precise manner. This feasibility study evaluates the accuracy and speed of robotic contouring of cadaver costal cartilage. METHODS: An augmented robot with a spherical burr was used on cadaveric rib cartilage. Using a laser scanner, each rib section was converted to a three-dimensional model for preoperative planning. A model ear was also scanned to define a carving path for each piece of cartilage. After being contoured, each specimen was compared against the preoperative plan utilizing deviation maps to analyze topographic accuracy. Contouring times of the robot were compared with 13 retrospectively reviewed cases (2006-2017) by an experienced surgeon. RESULTS: Scanning the cartilage sections took 24.8 ± 6.8 seconds. Preoperative processing took an additional 29.9 ± 8.9 seconds for the preparation of the contouring path. Once the path was prepared, the robot contoured the specimens with a root mean square error of 0.54 mm and a mean absolute deviation of 0.40 mm. The average time to contour the specimens with the robot was 13 ± 2 minutes compared to 71 ± 6 minutes for the manual contouring in the reviewed cases. CONCLUSIONS: The accuracy of the robotic system was high, with submillimeter deviations from the preoperative plan. The robot required <20% of the contouring time compared to the experienced surgeon. This represents a fast and accurate alternative to hand-contouring costal cartilage grafts for auricular reconstruction. Laryngoscope, 131:1002-1007, 2021.

Hybrid Three-Dimensional-Printed Ear Tissue Scaffold With Autologous Cartilage Mitigates Soft Tissue Complications.

OBJECTIVES/HYPOTHESIS: To analyze the use of highly translatable three-dimensional (3D)-printed auricular scaffolds with and without novel cartilage tissue inserts in a rodent model. STUDY DESIGN: Preclinical rodent animal model. METHODS: This prospective study assessed a single-stage 3D-printed auricular bioscaffold with or without porcine cartilage tissue inserts in an athymic rodent model. Digital Imaging and Communications in Medicine computed tomography images of a human auricle were segmented to create an external anatomic envelope filled with orthogonally interconnected spherical pores. Scaffolds with and without tissue inset sites were 3D printed by laser sintering bioresorbable polycaprolactone, then implanted subcutaneously in five rats for each group. RESULTS: Ten athymic rats were studied to a goal of 24 weeks postoperatively. Precise anatomic similarity and scaffold integrity were maintained in both scaffold conditions throughout experimentation with grossly visible tissue ingrowth and angiogenesis upon explantation. Cartilage-seeded scaffolds had relatively lower rates of nonsurgical site complications compared to unseeded scaffolds with relatively increased surgical site ulceration, though neither met statistical significance. Histology revealed robust soft tissue infiltration and vascularization in both seeded and unseeded scaffolds, and demonstrated impressive maintenance of viable cartilage in cartilage-seeded scaffolds. Radiology confirmed soft tissue infiltration in all scaffolds, and biomechanical modeling suggested amelioration of stress in scaffolds implanted with cartilage. CONCLUSIONS: A hybrid approach incorporating cartilage insets into 3D-printed bioscaffolds suggests enhanced clinical and histological outcomes. These data demonstrate the potential to integrate point-of-care tissue engineering techniques into 3D printing to generate alternatives to current reconstructive surgery techniques and avoid the demands of traditional tissue engineering. LEVEL OF EVIDENCE: NA Laryngoscope, 131:1008-1015, 2021.

[Anthropometric measurements of moderate concha-type microtia after auricular cartilage unfolding].

OBJECTIVE: To explore the anthropometric changes of the auricle after auricular cartilage unfolding in moderate concha-type microtia patients, so as to provide the basis to help evaluate surgical timing and prognostic. METHODS: A total of 33 children with moderate concha-type microtia, who were treated with auricular cartilage unfolding between October 2016 and September 2018 and met the inclusive criteria, were included in the study. There were 24 boys and 9 girls with an average age of 1.4 years (range, 1-3 years). Sixteen cases were left ears and 17 cases were right ears. The follow-up time was 12-23 months (mean, 17.5 months). The affected auricular detailed structures were observed and quantitatively analyzed before operation and at immediate after operation. The width, length, and perimeter of auricle before operation and at immediate after operation and at last follow-up were noted with three dimensional-scanning technology. The normal auricle was noted as control. RESULTS: There were (7.5±1.0) and (11.3±0.8) structures of the affected auricle at pre- and post-operation, respectively, showing significant difference between pre- and post-operation ( t=23.279, P=0.000). The length, width, and perimeter of the affected auricle constantly increased after operation, and there were significant differences between pre-operation and immediately after operation and between immediately after operation and last follow-up ( P<0.05). The differences of length, width, and perimeter of the affected auricle between immediately after operation and last follow-up were (3.13±1.44), (2.44±0.92), and (8.50±3.76) mm, respectively. And the differences of length, width, and perimeter of the normal auricle between pre-operation and last follow-up were (3.16±1.54), (2.35±0.86), and (9.79±4.60) mm, respectively. There was no significant difference in the differences of length, width, and perimeter between the affected auricle and the normal auricle ( P>0.05). CONCLUSION: The auricular cartilage unfolding in treatment of the moderate concha-type microtia can receive more ear structures and increase auricle sizes, which make it possible for free composite tissue transplantation. In addition, the affected and the contralateral normal auricles have a very similar growth rate and it offers the theoretical foundation for the early treatment for moderate concha-type microtia.

Butterfly tragal cartilage for repair of focal canal wall defects.

BACKGROUND: Meato-mastoid fistula is a connection between the external auditory canal and the mastoid cavity. It may be iatrogenic or pathological. The repair of these focal canal wall defects is necessary to prevent retraction pockets or sequential cholesteatoma and attain relief from otorrhoea. AIM/OBJECTIVE: To study the effectiveness of an innovative technique for repair of meato-mastoid fistula (less than or equal to 10mm in size) in the bony external auditory canal. MATERIAL AND METHODS: We performed a retrospective review of 5 surgeries performed in our hospital between January 2017 and December 2017 for the repair of posterior bony canal wall defects. Active ear disease was ruled out before the repair. We used full-thickness butterfly tragal cartilage graft for the repair of these fistulae. All our surgeries were endoscopic and sutureless. RESULTS: The butterfly tragal cartilage graft was in situ at the repair site and viable on examination at 2 years follow-up, in all our cases. CONCLUSION AND SIGNIFICANCE: Small posterior canal wall defects can be successfully repaired using this technique. The method is minimally invasive and cosmetic, with good patient compliance. The curling property of the cartilage graft is exploited effectively in this method of repair.

[Experimental studies on the repair and restitution of cartilage by cartilage acellular extracellular matrix and adipose tissue-derived stem cells].

Objective: To investigate the effects of the repair and restitution of ear-shaped cartilage by adipose tissue-derived stem cells(ADSC) and cartilage acellular extracellular matrix. Methods: ADSC were extracted by digesting with collagenase type II from the adipose tissue from 32 patients with adiposity whose fats were drawn, and were cultured and subcultured in vitro. The natural biological scaffolds were prepared by acellular method using porcine ear cartilage, and then the second generation ADSC(5.0×10(7)/ml) were inoculated on the preformed natural bio-scaffold scaffold by culturing in vitro for 3 days to form a cell scaffold complex. 32 New Zealand white rabbits were randomly divided into the experimental groups, the control group A, the control group B and the control group C. All New Zealand white rabbits were modeled by ear cartilage defects. The cell scaffolds composite was implanted into the experimental group of the ear cartilage defects of rabbits, the ADSC were implanted into the control group A, the cartilage acellular extracellular matrix scaffold was implanted into the control group B and the control group C was modeled only by ear cartilage defects. After 16 weeks, the animals were sacrificed and the repair effect was observed by gross appearance and histological examinations including HE, Toluidine blue staining, Safranin O and typeⅡ collagen staining. Its were quantitatively analyzed by positive staining results of type Ⅱ collagen. Ear cartilage tissue elasticity was detected. SPSS 17.0 software was used to analyze the data. Results: The cartilage defects in the experimental group were repaired well by general shape observation and those in the control group was filled in with granulation tissue. There were significant differences between the experimental group and the control group in the wet weight(P<0.05). HE staining showed that cartilage cavities formed in articular cartilage defects, and only the fibrous tissue was filled with the ear cartilage defect in the control groups. In the repair area, Toluidine blue staining, Safranin O and type Ⅱ collagen staining were positive in the experimental group, and negative in the control groups. There was no significant difference between the experimental group and the normal ear cartilage in the ear cartilage elastic constant detection(P>0.05). Conclusions: The mechanics and histology of rabbit ear neonatal cartilage constructed by ADSC combined with cartilage acellular matrix are close to normal ear cartilage. Cartilage acellular matrix material combined with adipose-derived stem cells has good repair and reconstruction ability for ear cartilage defects, which possesses potential clinical application value.

Impact of cartilage graft size on success of tympanoplasty / Impacto do tamanho do enxerto de cartilagem no sucesso da timpanoplastia

Abstract Introduction: In the last decade, there has been an increasing use of cartilage grafts in the primary repair of tympanic membrane perforations. The major advantages of cartilage are its stiffness and its very low metabolic requirements, which make it particularly suitable for difficult conditions, such as subtotal perforations, adhesive otitis and reoperation. Objective: To analyze the impact of different perforation sizes requiring different sizes of cartilage on the anatomical and functional outcome after tympanoplasty. Methods: Through this prospective non-controlled, non-randomized study, 50 patients underwent cartilage type 1 tympanoplasty (20 females and 30 males), with a mean age of 19.3 ± 9.8 years. According to size of perforation, patients were subdivided into three groups, Group I had perforation >50% of tympanic membrane area, in Group II patients the perforations were 25-50% of tympanic membrane area, and in Group III the perforations were ≤25% of tympanic membrane. All patients had pre and postoperative Pure Tone Average and Air Bone Gap frequencies (0.5, 1, 2, 4 kHz). All patients were followed up at least 12 months after operation. Results: The anatomical success rate among all patients was 92%, all groups showed statistical significant improvement between pre and postoperative air bone gap, no significant correlation between size of cartilage graft and degree of air bone gap improvement was noticed among the three groups. Conclusion: Size of a cartilage graft has no impact on degree of hearing improvement or anatomical success rate after tympanoplasty.

Resumo Introdução: Na última década, tem havido um interesse crescente no uso de enxertos de cartilagem como opção para o reparo de perfurações primárias de membrana timpânica. As principais vantagens da cartilagem são a sua rigidez e o metabolismo braditrófico, o que a torna particularmente adequada para condições difíceis, tais como perfurações subtotais, otite adesiva e reoperações. Objetivo: Analisar o impacto de diferentes tamanhos de perfuração, portanto diferentes tamanhos de cartilagem, sobre o desfecho anatômico e funcional da timpanoplastia. Método: Através deste estudo prospectivo, não controlado, não randomizado, 50 pacientes foram submetidos a timpanoplastia de cartilagem tipo 1 (20 mulheres e 30 homens), com idade média de 19,3 ± 9,8 anos. De acordo com o tamanho da perfuração, os pacientes foram subdivididos em três grupos, Grupo I com perfuração > 50% da área da membrana timpânica, Grupo II com perfuração de 25%-50% da área da membrana timpânica, Grupo III com perfuração ≤ 25% da membrana timpânica. Todos apresentavam Audiometria tonal pura pré e pós-operatório - gap Aéreo-Ósseo para frequências testadas (0,5, 1, 2, 4 kHz). Todos os pacientes foram acompanhados por pelo menos 12 meses após a cirurgia. Resultados: A taxa de sucesso anatômico entre todos os pacientes foi de 92%, todos os grupos apresentaram melhoria estatisticamente significante entre pré e pós-operatório nos três grupos, não houve correlação significante entre o tamanho do enxerto de cartilagem e observou-se algum grau de melhoria do gap nos 3 grupos. Conclusão: O tamanho do enxerto de cartilagem não tem impacto sobre o grau de melhoria da audição ou na taxa de sucesso anatômico após timpanoplastia.

Costal and Auricular Cartilage Grafts for Nasal Reconstruction: An Anatomic Analysis.

OBJECTIVES: The aim of this study was to measure the length, width, and surface area of costal and auricular cartilage harvested for grafting in rhinoplasty and nasal reconstruction. We also compared the sizes of ear cartilage grafts harvested from the anterior and posterior approaches. METHODS: Fifty-eight nasal reconstructive surgeries requiring rib or ear cartilage were performed by 2 facial plastic surgeons from February 2015 through January 2016. Among the 57 cases that met inclusion criteria, they comprised of 33 costal cartilage grafts and 24 auricular cartilage grafts (17 via anterior approach and 7 via posterior approach). RESULTS: The mean length, width, and surface area for the auricular cartilage grafts were 3.39 cm, 1.22 cm, and 4.38 cm2, respectively. The mean length, width, and surface area of the costal cartilage grafts were 4.21 cm, 1.46 cm, and 17.87 cm2, respectively. The differences in length, width, and surface area between the anterior versus posterior approach groups were all statistically significant. CONCLUSIONS: In our study, ear cartilage grafts harvested from the posterior approach had significantly greater length, width, and surface area. While this analysis has several limitations, it sets quantitative norms for costal and auricular cartilage harvest that can aid in surgical planning.

[The anatomical structure similarity research on auricular cartilage and nasal alar cartilage].

OBJECTIVE: There are many scaffold materials of repairing nasal alar cartilage defects. Auricuiar cartilage was used extensively in terms of its abundant tissues, good elasticity, little donor-site malformation, good plasticity etc. The authors dissected auricular cartilage and nasal alar cartilage, measured cartilage's morphous data and found some similar territories with nasal alar cartilage in the structure of auricular cartilage. METHOD: An anatomical study was performed using 10 adult cadavers acquired through Plastic Surgery Hospital, Peking Union Medical College, Beijing, China. Seven male and three female cadav-ers were included in the study. Harvest 20 auricular cartilage specimens and 20 nasal alar cartilage specimens. Then, Computed Tomography Scan on the auricular cartilage and nasal alar cartilage were performed. The datas were imported into mimics and three-dimensional reconstructions of the auricular cartilage and nasal alar cartilage were carried on. RESULT: Parts of the auricular cartilage, such as conchal fossa, tragus, intertragic notch, and cymba of auricular concha, curs of helix and curs of helix, triangular fossa, are ana-tomically similar to nasal alar cartilage. CONCLUSION: This study reports the anatomy of auricular cartilage and nasal alar cartilage, found some territories in the auricular cartilage, such as conchal fossa, tragus, intertragic notch, and cymba of auricular concha, curs of helix and curs of helix, triangular fossa, are anatomically similar to nasal alar cartilage. This research provides the anatomical basis that auricular cartilage was used to repair the nasal cartilage defect.

Conditions for seeding and promoting neo-auricular cartilage formation in a fibrous collagen scaffold.

BACKGROUND: Carved autologous costal cartilage and porous polyethylene implants (Medpor) are the most common approaches for total ear reconstruction, but these approaches may have inconsistent cosmetic outcomes, a high risk of extrusion, or other surgical complications. Engineering ear cartilage to emulate native auricular tissue is an appealing approach, but often the cell-seeded scaffolds are susceptible to shrinkage and architectural changes when placed in vivo. The aim of this study was to assess the most favorable conditions for in vitro pre-culture of cell-seeded type I collagen scaffolds prior to in vivo implantation. METHODS: Sheep auricular chondrocytes were seeded into this type I collagen scaffold. The cell-seeded constructs were cultured in either static or dynamic conditions for two days or two weeks and then implanted into nude mice for another six weeks. The harvested constructs were evaluated histologically, immunohistochemically, and biochemically. RESULTS: Robust neo-cartilage formation was found in these collagen scaffolds seeded with auricular chondrocytes, which was comparable to native cartilage morphologically, histologically, and biochemically. Culture under dynamic conditions prior to implantation improved the neo-cartilage formation histologically and biochemically. CONCLUSION: Dynamic culture of this cell-seeded fibrous collagen material could permit predictable engineered auricular cartilage and a promising approach for external ear reconstruction.

Anatomic analysis of the conchal bowl cartilage.

PURPOSE: The conchal bowl is a portion of auricular cartilage commonly used as an autologous graft for various maxillofacial procedures. Few studies have attempted to describe the anatomy of this region in detail, particularly in relation to the curvature of the conchal bowl. The present study has provided detailed information about the anatomy of the auricular cartilage in the conchal bowl region that could assist in the surgical design of graft harvesting. MATERIALS AND METHODS: A total of 35 pairs of cadaver ears without gross deformity (15 male, 20 female; aged 39 to 99 years) were dissected to completely expose the cartilage skeleton. Each cartilage was stabilized, and the conchal bowl was mapped. The starting reference point was defined as the intersection of the lateral border of the antihelix and the superiormost aspect of the inferior crux. A prefabricated grid was then used to imprint a 4 × 5 matrix of pinpoint ink spots on the surface of each cartilage, with 6-mm increments between each spot. The grid's y and x axes were then aligned with the landmarks above. Next, a MicroScribe 3-dimensional digitizer (ghost3d.com) was used to capture the 3-dimensional coordinates for each point on the ear's surface and the coordinates were transferred into an Excel spreadsheet. After digitization, a Boley gauge was used to measure the thickness of the cartilage at each premarked spot. The gathered data points and measurements were examined to describe our parameters of interest (ie, depth, thickness, and curvature). RESULTS: The average maximum conchal bowl depth was 10.5 ± 3.0 mm in the female ears and 10.7 ± 2.5 mm in the male ears. In general, the conchal bowl depth at each point did not differ significantly between the males and females. The mean cartilage thickness ranged from 0.77 to 1.79 mm (mean 1.15 ± 0.26) in the females and 0.95 to 1.45 mm (mean 1.25 ± 0.23) in the males. Both genders showed an increase in the conchal bowl depth from inferiorly to superiorly and from posteriorly to anteriorly. The cartilage thickness also increased from posteriorly to anteriorly; however, the exact shape is complex. CONCLUSIONS: A detailed understanding of the facial anatomy is important in the practice of facial surgery. The results we have presented will provide surgeons with information on the overall dimensions, thickness, and curvature of the conchal bowl that could allow more advantageous donor site selection.

Development of scaffold-free elastic cartilaginous constructs with structural similarities to auricular cartilage.

External ear reconstruction with autologous cartilage still remains one of the most difficult problems in the fields of plastic and reconstructive surgery. As the absence of tissue vascularization limits the ability to stimulate new tissue growth, relatively few surgical approaches are currently available (alloplastic implants or sculpted autologous cartilage grafts) to repair or reconstruct the auricle (or pinna) as a result of traumatic loss or congenital absence (e.g., microtia). Alternatively, tissue engineering can offer the potential to grow autogenous cartilage suitable for implantation. While tissue-engineered auricle cartilage constructs can be created, a substantial number of cells are required to generate sufficient quantities of tissue for reconstruction. Similarly, as routine cell expansion can elicit negative effects on chondrocyte function, we have developed an approach to generate large-sized engineered auricle constructs (≥3 cm(2)) directly from a small population of donor cells (20,000-40,000 cells/construct). Using rabbit donor cells, the developed bioreactor-cultivated constructs adopted structural-like characteristics similar to native auricular cartilage, including the development of distinct cartilaginous and perichondrium-like regions. Both alterations in media composition and seeding density had profound effects on the formation of engineered elastic tissue constructs in terms of cellularity, extracellular matrix accumulation, and tissue structure. Higher seeding densities and media containing sodium bicarbonate produced tissue constructs that were closer to the native tissue in terms of structure and composition. Future studies will be aimed at improving the accumulation of specific tissue constituents and determining the clinical effectiveness of this approach using a reconstructive animal model.

Predicting skin deficits through surface area measurements in ear reconstruction and adult ear surface area norms.

Ear reconstruction is one of the most challenging procedures in plastic surgery practice. Many studies and techniques have been described in the literature for carving a well-pronounced framework. However, just as important as the cartilage framework is the ample amount of delicate skin coverage of the framework. In this report, we introduce an innovative method of measuring the skin surface area of the auricle from a three-dimensional template created from the healthy ear.The study group consisted of 60 adult Turkish individuals who were randomly selected (30 men and 30 women). The participant ages ranged from 18 to 45 years (mean, 31.5 years), and they had no history of trauma or congenital anomalies. The template is created by dividing the ear into aesthetic subunits and using ImageJ software to estimate the necessary amount of total skin surface area required.Reconstruction of the auricle is a complicated process that requires experience and patience to provide the auricular details. We believe this estimate will shorten the learning curve for residents and surgeons interested in ear reconstruction and will help surgeons obtain adequate skin to drape over the well-sculpted cartilage frameworks by providing a reference list of total ear skin surface area measurements for Turkish men and women.

Comparison of different autografts for aural cartilage in aesthetic rhinoplasty: is the tragal cartilage graft a viable alternative?

Auricular cartilage is an important source of grafts for various reconstructive procedures such as aesthetic rhinoplasty. The purpose of this investigation was to compare tragal cartilage with auricular cartilage harvested from the concha and scapha, and describe its clinical viability, indications, and morbidity in rhinoplasty. A total of 150 augmentation rhinoplasties with a total of 170 grafts were included. The donor sites were tragus (n=136), concha (n=26), and scapha (n=8). The time needed to harvest the grafts, the donor site morbidity, and the indications for operation were recorded. The anthropometric changes to 4 auricular variables after the cartilage had been harvested were analysed and compared with those on the opposite side in 48 patients using Student's paired t-test. Intraobserver reliability was assessed using Pearson's intraclass correlation. The mean (SD) harvesting time was 27 (8) min for the concha, 4.5 (1.4) min for the tragus, and 5.7 (1.6) min for the scapha. The largest graft was taken from the concha (28×19 mm), followed by the tragus (20×12 mm), and the scapha (18×6 mm). The grafts were placed at the following sites: tip grafts (n=123), columella struts (n=80), shield (n=20), rim (n=17), and dorsal onlay (n=15). Harvesting tragal cartilage is safe, simple, fast, and has a low morbidity, but it can affect the patient's ability to wear earphones. Tragal cartilage is a good alternative for nasal reconstruction if a graft of no longer than 20 mm is required.

Progression of growth in the external ear from birth to maturity: a 2-year follow-up study in India.

BACKGROUND: This study aimed to follow the growth dynamics of auricular dimensions from birth to the age of 18 years. The norms of dimensions at different ages, the peak growth period and the maturity age of the dimensions are essential information to Physicians for early clinical diagnosis or for deciding the optimal time for surgery to correct abnormalities. METHODS: For this study, 2,147 children belonging to central Indian population were measured in at least three sequential sessions. Eight dimensions including the physiognomic length and width of the ear and its morphologic width; conchal length, width, and depth; and lobular length and width were measured using anthropometric technique. Three new dimensions (tragal length and height and maximum width of the antihelix) were introduced in the study. Three indices (auricular, conchal, and lobular) also were derived. RESULTS: Most dimensions exhibited very rapid growth during the first 3-6 months of infancy and thereafter proceeded at a slow pace until adulthood. The smaller dimensions (conchal depth, tragal height, and maximum width of the antihelix) increased continuously throughout the growth period. At birth, most of the dimensions were 52-76 % of their adult size, while tragal length and height were less than half their adult size. Unlike the other dimensions, the lobule length was smaller in males, probably due to the higher frequency of hypoplastic and bow-shaped lobules among them. The width dimensions matured earlier, at 5.6-11 years, whereas the maturity age of lengths varied from 12 to 16 years. CONCLUSIONS: The data generated in the current study will be useful to Physicians as a guideline in correcting auricular deformity and in constructing age progression charts of the external ear. Knowledge concerning the maturation age of the ear will help law enforcement authorities in deciding when to use it for establishing personal identification. 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 .

The perichondrium in auricular melanomas: implications for surgical management.

OBJECTIVE: Auricular melanomas are now considered less aggressive than originally thought, but those located on the conchal bowl and posterior ear can create particular challenges for reconstruction. Given the paucity of cases, no standardized recommendations exist for tumor resection. In this study, we provide a pathologic basis in support of conservative tumor resection along the perichondrial plane. STUDY DESIGN: Case series with review of pathology and medical records. SETTING: Academic tertiary referral center. SUBJECTS AND METHODS: We retrospectively reviewed all ear melanomas from the archives of Yale Dermatopathology and Surgical Pathology laboratories between 1987 and 2009. Cases of melanoma in situ or malignant melanoma of the earlobe were excluded. RESULTS: Fifty-one cases were included in the study. Patients' age ranged from 26 to 94 years, with a mean (SD) of 58.9 (17.5) years. The male to female ratio was of 5.4:1. Melanomas were distributed similarly between right and left ears, at 52% and 48%, respectively. The most common location was the helix (74.5%). The Breslow depth ranged from 0.19 to 11 mm, with a mean (SD) of 1.64 (1.6) mm. The lesion-perichondrium distance ranged from 0 to 8.12 mm, with a mean (SD) of 1.11 (1.1) mm. Notably, the perichondrium was not invaded in any of the cases. CONCLUSION: Based on the histopathologic characteristics of our cases, the perichondrium can be considered an effective barrier and therefore a biological plane for wide local resection in some cases of auricular melanomas, allowing surgeons to achieve negative margins without necessarily sacrificing underlying cartilage.

Relationship between the canthal-tragus distance and the puncture point in temporomandibular joint arthroscopy.

This study investigated whether a relationship exists between the length of the canthal-tragus line and the distance from the tragus at which the puncture point for arthroscope insertion should be made. On one side of 11 cadaver heads, a puncture point was marked 7 mm from the midtragus and 2 mm below the canthal-tragus line. On the other side, the distances were 10 mm and 2 mm, respectively. The arthroscope trocar and cannula were inserted at the marked points. The anatomical location of the arthroscope after insertion was confirmed by open dissection with the arthroscope in place. Following dissection, the canthal-tragus line was measured on each side of the cadaver's head. For measurements > 70 mm, puncture points 10 mm from the midtragus led to insertion of the arthroscope inside the upper joint compartment. For measurements < or = 70 mm, puncture points 7 mm from the midtragus led to insertion of the arthroscope inside the upper joint compartment. This suggests that for canthal-tragus distances of > 70 mm, the arthroscope should be inserted 10mm from the midtragus and for distances < or = 70 mm it should be inserted at 7 mm for the greatest likelihood of entering the upper joint compartment of the TMJ.

Histomorphological transformation of the auricular cartilage after carbon dioxide laser-assisted Mustardé otoplasty. An experimental study.

In an experiment on ten rabbits, 8 W carbon dioxide (CO(2)) laser evaporation of the perichondrium, together with one-third to one-half of the thickness of the auricle cartilage, was performed. Subsequently, the auricle was bent in the middle of the vaporized area, the corresponding surfaces of which were then apposed and fixed to each other with mattress sutures. Three months later the auricle specimen was harvested for histopathological evaluation. This revealed that the partially laser-ablated cartilage had grown together in the form of a solid cartilaginous column. The regeneration process, originating from chondroblasts as well as from perichondrium cells, was strongly stimulated by the laser energy delivered.

The role of the antitragicus muscle in plical folding of the pinna.

BACKGROUND: The antitragicus is one of six intrinsic muscles of the external ear. This study examined the anatomical variations of the muscle and its association with prominent ears. METHODS: Twenty-seven consecutive patients presenting for correction of prominent ears were recruited into the study. In each case, the antihelical fold was assessed preoperatively by a single investigator. A standard anterior cartilage scoring otoplasty was performed, and the presence and quality of the antitragicus muscle were assessed by a second investigator. For statistical analysis, the qualitative assessment of the fold and the muscle was given a numerical value. It was then possible to plot the qualitative assessment of the fold against the muscle, and correlations between muscle and fold were calculated. RESULTS: The presence of the muscle was associated with an absent antihelical fold, whereas a well-defined antihelical fold was associated with an absent muscle (p < 0.0001). CONCLUSIONS: The authors propose that the presence of a well-formed antitragicus muscle, which exerts an anterior pull on the cauda helicis, contributes to the poor development of the antihelical fold.

Tissue-engineered cartilage as a graft source for laryngotracheal reconstruction: a pig model.

OBJECTIVE: To evaluate the feasibility of using tissue-engineered cartilage for laryngotracheal reconstruction in the pig model. DESIGN: Auricular cartilage was harvested from 3 young swine. The cartilage was digested, processed, and suspended and a cell culture was obtained. The cells were then suspended in 3 mL of a 30% solution of a biodegradable polymer (Pluronic F-127) (polyethylene oxide/polypropylene oxide copolymer) at a cellular concentration of 50 x 10(6) cells/mL. This suspension was then implanted subcutaneously into each pig's dorsum. Eight weeks after implantation, the cartilage was harvested with the surrounding perichondrial capsule. An anterior cartilage graft laryngotracheal reconstruction was performed. Bronchoscopy was performed at 3 postoperative weeks to demonstrate airway patency. The animals were killed at 3 months, and specimens were obtained for histological analysis. SETTING: An animal research facility. SUBJECTS: Three young Yorkshire swine. RESULTS: All 3 pigs survived to the 3-month postoperative interval with no evidence of stridor or airway distress. Interval bronchoscopy revealed a normal patent airway with a mucosalized graft. Histopathologic analysis revealed incorporation of the tissue-engineered cartilage graft in the cricoid area, which correlated with results of bronchoscopic evaluation. CONCLUSION: Tissue-engineered auricular cartilage served as a viable graft in the pig model and might be an alternative cartilage source for laryngotracheal reconstruction.