Statistical analysis of shape of auricular concha for mass customization of OTC hearing aids / Análisis estadístico de la forma de la concha auricular para la personalización masiva de audífonos de venta libre

SUMMARY: A detailed data of shape of auricular concha is currently not available. Therefore, this study constructed a framework to statistically analyze the shape of the auricular concha based on a database of 3D scanned images. The 3D models of the auricular concha from 308 study participants are converted into compatible NURBS surfaces generated through 795 data points to perform a requisite statistical analysis. Subsequently, the shape of the auricular concha of the participants is grouped into 29 clusters with a modified hierarchical clustering algorithm. Finally, a wear trial and simulation test are carried out to validate the wear comfort of a designed OTC hearing aids based on the average shape of each cluster. The experimental results show that the average shape obtained as per the cluster is capable of representing the common geometric properties of their corresponding members, and could thus be used as a reference in designing mass-customized OTC hearing aid. The method in this study is superior to conventional methods that rely on sparse results for shape analysis because it takes into account the intricate geometric shape of the auricular concha. The quantitative description of conchal morphometry will be beneficial for plastic surgeons, and for the ergonomic design of ear-related products.

RESUMEN: Actualmente no se dispone de datos específicos de la forma de la concha auricular. Por lo tanto, este estudio construyó un marco para analizar estadísticamente la forma de ella a partir de una base de datos de imágenes escaneadas en 3D. Los modelos 3D de la concha auricular de 308 participantes del estudio se convirtieron en superficies NURBS compatibles generadas a través de 795 puntos de datos para realizar un análisis estadístico requerido. Posteriormente, la forma de la concha auricular de los participantes se agrupó en 29 grupos con un algoritmo de agrupamiento jerárquico modificado. Finalmente, se llevó a cabo una prueba de uso y una prueba de simulación para validar la comodidad de uso de unos audífonos OTC diseñados en función de la forma promedio de cada grupo. Los resultados experimentales mostraron que la forma promedio obtenida de la concha auricular, según el grupo, es capaz de representar las propiedades geométricas comunes de sus miembros correspondientes y, por lo tanto, podría usarse como referencia en el diseño de audífonos OTC personalizados en masa. El método de este estudio es superior a los métodos convencionales que se basan en resultados escasos para el análisis de forma, porque tiene en consideración la intrincada forma geométrica de la concha auricular. La descripción cuantitativa de la morfometría de la concha auricular será beneficiosa para los cirujanos plásticos y para el diseño ergonómico de productos relacionados con el oído.

Comparative assessment of auricular measurements in young males and females / Evaluación comparativa de las medidas auriculares en hombres y mujeres jóvenes

SUMMARY: Personal identification is mostly done by facial assessment. The auricle plays a key role in the evaluation and recognition of the craniofacial complex. The aim of this study was to provide normative database using the measurements of the auricle among young males and females by anthropometric methods. Anthropometric measurements were taken from 115 participants, (56 men and 59 women) between 18-30 years old. Participants werestudents at Yasar Dogu Faculty of Sport Sciences of Ondokuz Mayis University. Each participant signed an informed consent form and then participated to the study. We found that the mean length of the right and left auricles were 58.30-58.52 mm, the mean width of the right and left auricles were 30.04-29.73 mm, the mean length of right and left lobules were 16.05-16.45 mm, and the mean width of the right and left lobules were 17.61-18.76 mm in female participants. The mean length of right and left auricles were 62.33-62.49 mm, the mean width of the right and left auricles were 33.60-33.96 mm, the mean length of right and left lobules were 18.49-18.11 mm, and the mean width of the right and left lobules were 19.19-20.47 mm in male participants. The data obtained from the present study may be useful for further studies. Also, the results may be useful for reconstructive surgeons to analyze the size and shape of the auricle.

RESUMEN: La identificación personal se realiza principalmente mediante evaluación facial. El pabellón auricular tiene un papel clave en la evaluación y el reconocimiento del complejo craneofacial. El objetivo de este estudio fue proporcionar una base de datos normativa utilizando las medidas de la oreja entre hombres y mujeres jóvenes por métodos antropométricos. Se tomaron medidas antropométricas de 115 participantes, (56 hombres y 59 mujeres) entre 18 y 30 años. Los participantes eran estudiantse de la Facultad de Ciencias del Deporte Yasar Dogu de la Universidad Ondokuz Mayis. Cada participante firmó un formulario de consentimiento informado y luego participó en el estudio. Encontramos que en las mujeres la longitud media de las aurículas derecha e izquierda era de 58,30-58,52 mm, el ancho medio de las aurículas derecha y izquierdas era de 30,04 a 29,73 mm, la longitud media de los lóbulos derecho e izquierdo era de 16,05 a 16,45 mm y el ancho medio de los lóbulos derecho e izquierdo era de 17,61 a 18,76 mm. En los hombres, la longitud media de las aurículas derecha e izquierda era de 62,33-62,49 mm, el ancho medio de las aurículas derecha e izquierda era de 33,60-33,96 mm, la longitud media de los lóbulos derecho e izquierdo era de 18,49-18,11 mm, y el ancho medio de los lóbulos derecho e izquierdo era de 18,49-18,11 mm. Los datos obtenidos del presente estudio pueden ser útiles para estudios posteriores. Además, los resultados pueden ser útiles para que los cirujanos reconstructivos analicen el tamaño y la forma del pabellón auricular.

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.

Respuesta al comentario de la Dra. F. Valotta / No disponible

No disponible

[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.

Anatomy of the Intertragic Notch of the Auricle May Protect the Ear Canal from Fluids as a Built-In Overflow Spout at an Appropriate Position.

To observe the utility of the intertragic notch during rain showers, an anatomic replica of the human auricle was studied under an artificial shower system with a video recorder. During the shower, water trickled out through the intertragic notch naturally, avoiding the ear canal. This study finds one utility of the intertragic notch may be the prevention of water flowing into the ear canal during rain showers.

Effect of Body Mass Index on Auricular Morphology and Auditory Functions.

In this study, we aimed to investigate the relationship between the body mass index (BMI) and the morphometric properties of auricula and its acoustic gain characteristics. A total of 45 participants between 18 and 45 years of age were enrolled into the study. Participants' height and weight measurements were recorded for the BMI calculation. On both sides, the morphometric properties of the auricula were measured and recorded. Additionally, the participants were subjected to multidirectional dynamic real ear measurements (REMs) to specify the intensity and frequency values of the maximum hearing gain. Participants consisted of 24 women and 21 men. The mean BMI was 23.42. The mean auricular area was 22.70 cm2. Statistically significant positive correlation was found between the auricular area and BMI (r = 0.427, P = .03). The mean postauricular sulcus angle was 20.99°. The mastoid-helix distance was 16.07 mm. There was no statistically significant correlation between BMI level and postauricular sulcus angle and mastoid-helix distance (P > .05). The mean dynamic REM measurement was evaluated. The maximum acoustic gain at anterior, lateral, and posterior vectorial stimulation was calculated as 20.9, 24.2, and 20.7 dB Sound Presure Level (SPL), respectively. Statistically significant negative correlation was found between the three directions acoustic gain level and BMI in the statistical examination (r = -0.365, r = -0.386, r = -0.453, respectively, and P < .05 for all). The results of acoustic gain frequency were 2967.4, 2963, and 2934 Hz, respectively. There was no statistically significant correlation between acoustic gain frequency and BMI (P > .05). When participants were grouped according to their BMI, participants with a BMI >25 had a statistically significantly bigger auricular area and lower maximum acoustic gain when compared with those with BMI <25 (P < .05). We found that the auricular area increased with BMI. We think that this is related to soft tissue thickening of the auricula related to high BMI. In addition, we found that the acoustic gain level decreased inversely with BMI. We believe that the decrease in acoustic gain is due to the increase of acoustic resistance after the increase of soft tissue thickness. In conclusion, we think that BMI has a negative effect on auditory function according to findings in our study.

The testing of an artificial modified bacterial cellulose auricle skeleton in an animal model.

The aim of this study was to assess whether modified bacterial cellulose can be used for an artificial auricle skeleton. INTRODUCTION: The auricle is a part of the external ear. It consists of skin, cartilage, muscles and adipose tissue. The cartilage gives shape to the structure. There are several indications for reconstruction, such as congenital anomalies, mechanical injuries, and burns, and a range of methods have been proposed for the complete reconstruction of the auricle. MATERIAL AND METHODS: A bacterial cellulose membrane, at least 25 mm in thickness, was produced in vitro by Acetobacter xylinum culture. The entire artificial human auricle skeleton was made to scale to allow its implantation into an animal model - Wistar rats. Forty rats were divided into four groups of 10 animals. Each group was assigned a different resection time: 14 days, 30 days, 90 days or 720 days. After each resection, an examination of the artificial skeleton and the tissues surrounding it was conducted. The surgical procedure was based on the Nagata technique. RESULTS: Resection after 14, 30, 90 and 720 days shows the progression of the healing process and integration of the artificial skeleton into the animal body. There are no signs of change in the shape or structure of the skeleton. DISCUSSION: Several surgical techniques and biotechnological methods have been developed over the past few years to improve the results of facial reconstruction. Other approaches can be used to create auricle cartilage, based on scaffolds and chondrocytes. CONCLUSION: My findings indicate that modified bacterial cellulose can be used to form an effective artificial auricle which appears to maintain its shape and elasticity, with no signs of degradation.

Mean Auricular Index of the External Ear in Medical Students of a Medical College in Nepal.

INTRODUCTION: The human ear is divided into external, middle and internal ear. The auricle helps in the clinical diagnosis of congenital anomalies and syndromes. The aim of this study is to determine the mean auricular index from the right and left ears, mean measurements of left and right ear and sex-related dimensions of the ear. METHODS: A descriptive cross-sectional study was conducted in medical students studying at a tertiary care hospital during the period of 1st April 2019 to 20th May 2019 after ethical clearance from the institutional review committee. Simple random sampling was done. Data were collected, entered in Statistical Package for Social Sciences version 20 and point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. RESULTS: Out of total measurements done, we found the mean auricular index was found to be for right ear 51.75±4.51mm and for left ear 54.0996±4.95682mm at 95% CI (51.75-52.37) and (53.42654.766) respectively. The mean ear length, mean ear breadth, mean lobular length and mean lobular breadth were 57.62±5.03mm, 29.72±2.79mm, 19.32±2.60mm and 20.89±3.06mm on the right side and 57.89±4.89mm, 31.21±2.95mm, 19.38±2.55mm and 21.25±2.81mm on the left side respectively. CONCLUSIONS: The mean auricular index of the external ear of medical students was within the normal range as compared to the other studies conducted.

Fabrication and characterization of 3D-printed elastic auricular scaffolds: A pilot study.

OBJECTIVE: Aesthetic reconstruction of the external ear is challenging due to the complex anatomical shape of the auricle. Recently, artificial scaffolds such as Medpor (Stryker, Kalamasoo, MI, USA) have become widely used in ear reconstruction. However, the Medpor scaffold is stiffer than the natural ear, which may lead to discomfort, and moreover has uniform design for every patient. In this study, we investigated whether three-dimensional (3D)-printed artificial polyurethane (PU) scaffolds are suitable for auricular reconstruction. METHODS: PU scaffolds were fabricated using 3D printing according to a design derived from a digital imaging and communications in medicine (DICOM) image of the human auricle. The microstructure of the scaffolds was observed using scanning electron microscopy, and the porosity was examined. Cell proliferation on the scaffolds was assessed in vitro using tonsil-derived mesenchymal stem cells to evaluate the biocompatibility of the scaffolds. The scaffolds were implanted in C57BL/6 mice, and histological analysis was performed. RESULTS: The structural study revealed that the 3D-printed porous PU scaffolds have rectangular microstructure with regular pitch and line, as well as high porosity (56.46% ± 10.22%) with a pore diameter of 200 µm. The mechanical properties of the 3D-printed PU scaffolds were similar to those of the human auricle cartilage. Cell proliferation on the PU scaffolds was greater than that on Medpor scaffolds. Histological evaluation demonstrated that the porous parts of the PU scaffolds became filled with collagen and vascular tissue. CONCLUSION: Elastic, porous PU scaffolds can be obtained using 3D printing, have biomechanical properties similar to those of the natural ear, and are suitable for use in auricular reconstruction. LEVEL OF EVIDENCE: NA Laryngoscope, 129:351-357, 2019.

Reevaluation of the earlobe types in Koreans.

The shape of the earlobes has a variety of genetic significance. This study analyzed the frequencies of the earlobe shapes in the Korean population. Data were collected on randomly selected 500 males and 500 females in Daegu Metropolitan City, with all participant ages being in their twenties. Obtuse angled earlobes accounted for 41.2% of the earlobes observed, while acute angled earlobes prevalence was calculated at 38.8% and right angled earlobe was 20.0% of the total (sexes combined). In men, the acute angled earlobe was the most frequent type (43.0%), while the obtuse angled earlobe was the most frequent type in females (45.2%). These differences were statistically significant (p = 0.015). Overall, attached type earlobe (61.2%) was more frequent than free type earlobe. The attached type earlobe was more common in both sex groups (57.0% in male and 65.4% in female), and the proportion was significantly higher for females (p = 0.006). In conclusion, the findings in this study suggest that the attached earlobe type is the most common among Koreans, and the proportion of earlobe types among males and females is significantly different. Further studies are needed to understand the genetic background of earlobe types among Koreans.

Entropy analysis of frequency and shape change in horseshoe bat biosonar.

Echolocating bats use ultrasonic pulses to collect information about their environments. Some of this information is encoded at the baffle structures-noseleaves (emission) and pinnae (reception)-that act as interfaces between the bats' biosonar systems and the external world. The baffle beam patterns encode the direction-dependent sensory information as a function of frequency and hence represent a view of the environment. To generate diverse views of the environment, the bats can vary beam patterns by changes to (1) the wavelengths of the pulses or (2) the baffle geometries. Here we compare the variability in sensory information encoded by just the use of frequency or baffle shape dynamics in horseshoe bats. For this, we use digital and physical prototypes of both noseleaf and pinnae. The beam patterns for all prototypes were either measured or numerically predicted. Entropy was used as a measure to compare variability as a measure of sensory information encoding capacity. It was found that new information was acquired as a result of shape dynamics. Furthermore, the overall variability available for information encoding was similar in the case of frequency or shape dynamics. Thus, shape dynamics allows the horseshoe bats to generate diverse views of the environment in the absence of broadband biosonar signals.

Externalization of remote microphone signals using a structural binaural model of the head and pinna.

In a remote microphone (RM) system, a talker speaks into a microphone and the signal is transmitted to the hearing aids worn by the hearing-impaired listener. A difficulty with remote microphones, however, is that the signal received at the hearing aid bypasses the head and pinna, so the acoustic cues needed to externalize the sound source are missing. The objective of this paper is to process the RM signal to improve externalization when listening through earphones. The processing is based on a structural binaural model, which uses a cascade of processing modules to simulate the interaural level difference, interaural time difference, pinna reflections, ear-canal resonance, and early room reflections. The externalization results for the structural binaural model are compared to a left-right signal blend, the listener's own anechoic head-related impulse response (HRIR), and the listener's own HRIR with room reverberation. The azimuth is varied from straight ahead to 90° to one side. The results show that the structural binaural model is as effective as the listener's own HRIR plus reverberation in producing an externalized acoustic image, and that there is no significant difference in externalization between hearing-impaired and normal-hearing listeners.

A morphometric study of auricular concha in the population of young Chinese adults / Estudio morfométrico de la concha auricular en una población de jóvenes adultos chinos

SUMMARY: A detailed data of concha is currently not available. Therefore, the present study aimed to determine twelve morphometric measurements of concha, to investigate its sexual dimorphism and bilateral asymmetry, and to establish basic shapes of concha for both sexes and sides. The study sample comprised of 310 young Chinese aged 18-28 years. 141 left and 141 right ear impressions for females, 169 left and 169 right ear impressions for males were collected and scanned. The 3D coordinates of seven landmarks on each auricular concha were obtained using 3D scanning technology and curvature theory. From the landmarks, twelve morphometric measurements of concha were calculated and analyzed. The conchal morphometry exist significantly sexual dimorphism in this study sample. On average, all measurements were larger in males than in females regardless of the sides. There was significantly bilateral asymmetry among left and right conchae in both sexes. Some measurements were larger in the right sides and some measurements were larger in the left sides, but the bilateral difference in both measurements found to be less than 1mm. Additionally, the basic shapes of concha for both sexes and sides were established on the basis of the mean 3D coordinates of each landmark and the mean value of each measurement. The anthropometric method of this study could overcome the difficulty in locating landmarks of auricle complex structures, and attain a higher level of accuracy in the procedure of measurement. The quantitative description of conchal morphometry will be beneficial for plastic surgeons, and for the ergonomic design of hearing aids.

RESUMEN: Actualmente no existen datos detallados de la concha auricular. Por lo tanto, el presente estudio tuvo como objetivo determinar doce medidas morfométricas de la concha auricular, investigar su dimorfismo sexual y asimetría bilateral, y establecer formas básicas de la concha para ambos sexos y lados. La muestra del estudio estaba compuesta por 310 jóvenes chinos de 18 a 28 años de edad. Se recolectaron y escanearon 141 impresiones de la oreja izquierda y 141 de la oreja derecha en mujeres; 169 impresiones de la oreja izquierda y 169 de la oreja derecha en hombres. Las coordenadas 3D de siete hitos en cada concha auricular se obtuvieron utilizando la tecnología de exploración 3D y la teoría de la curvatura. A partir de los hitos, se calcularon y analizaron doce medidas morfométricas de concha. La morfometría conchal indica la existencia significativa de dimorfismo sexual en esta muestra. En promedio, todas las mediciones fueron mayores en los hombres que en las mujeres, independientemente de los lados. Se observó una asimetría bilateral significativa entre las conchas izquierda y derecha en ambos sexos. Algunas medidas eran mayores en el lado derecho y otras medidas eran mayores en el lado izquierdo, pero la diferencia bilateral en ambas medidas fue menor a 1 mm. Además, las formas básicas de concha para ambos sexos y lados se establecieron sobre la base de las coordenadas 3D medias de cada punto de referencia y el valor medio de cada medición. El método antropométrico de este estudio podría superar la dificultad de localizar los hitos de las estructuras del complejo auricular y lograr un mayor nivel de precisión en el procedimiento de medición. La descripción cuantitativa de la morfometría conchal será util para los cirujanos plásticos y para el diseño ergonómico de audífonos.

Alcohol consumption, smoking and development of visible age-related signs: a prospective cohort study.

BACKGROUND: Visible age-related signs indicate biological age, as individuals that appear old for their age are more likely to be at poor health, compared with people that appear their actual age. The aim of this study was to investigate whether alcohol and smoking are associated with four visible age-related signs (arcus corneae, xanthelasmata, earlobe crease and male pattern baldness). METHODS: We used information from 11 613 individuals in the Copenhagen City Heart Study (1976-2003). Alcohol intake, smoking habits and other lifestyle factors were assessed prospectively and visible age-related signs were inspected during subsequent examinations. RESULTS: The risk of developing arcus corneae, earlobe crease and xanthelasmata increased stepwise with increased smoking as measured by pack-years. For alcohol consumption, a high intake was associated with the risk of developing arcus corneae and earlobe crease, but not xanthelasmata. CONCLUSIONS: High alcohol consumption and smoking predict development of visible age-related signs. This is the first prospective study to show that heavy alcohol use and smoking are associated with generally looking older than one's actual age.

Horseshoe bats and Old World leaf-nosed bats have two discrete types of pinna motions.

Horseshoe bats (Rhinolophidae) and the related Old World leaf-nosed bats (Hipposideridae) both show conspicuous pinna motions as part of their biosonar behaviors. In the current work, the kinematics of these motions in one species from each family (Rhinolophus ferrumequinum and Hipposideros armiger) has been analyzed quantitatively using three-dimensional tracking of landmarks placed on the pinna. The pinna motions that were observed in both species fell into two categories: In "rigid rotations" motions the geometry of the pinna was preserved and only its orientation in space was altered. In "open-close motions" the geometry of the pinna was changed which was evident in a change of the distances between the landmark points. A linear discriminant analysis showed that motions from both categories could be separated without any overlap in the analyzed data set. Hence, bats from both species have two separate types of pinna motions with apparently no transitions between them. The deformations associated with open-close pinna motions in Hipposideros armiger were found to be substantially larger compared to the wavelength associated with the largest pulse energy than in Rhinolophus ferrumequinum (137% vs 99%). The role of the two different motions in the biosonar behaviors of the animals remains to be determined.

A Morphometric Study of the Newborn Ear and an Analysis of Factors Related to Congenital Auricular Deformities.

BACKGROUND: The incidence of neonatal ear deformities varies widely in the literature, and the incidence of those that correct spontaneously is largely unknown. To address these questions, the authors analyzed the auricles of 1500 newborns from the Pearl River Delta within the first 7 days of life and again at 30 days of age. METHODS: Using a combination of direct measurement and digital image measurement, the authors measured physiognomic ear length, physiognomic ear breadth, morphologic ear length, vertical distance between head and ear, and auriculocephalic angle of the newborns. The first measurement was within 1 week of birth, whereas the second measurement was performed for the same newborns 1 month after birth. RESULTS: Among 1500 newborns, 862 had various forms of auricular deformities. The incidence of neonatal auricular deformity in the Pearl River Delta area was 57.46 percent, and the self-healing rate was 31.55 percent by the 30-day follow-up. Seven factors were found to be statistically significant: mother's delivery situation, mother's hepatitis history, abnormal pregnancy, abnormal labor, cephalopelvic disproportion, premature rupture of membranes, and neonatal weight. Birth by cesarean delivery and mother with no abnormal pregnancy or no history of hepatitis were protective factors against the newborn's auricular deformity. CONCLUSIONS: Newborns have a high incidence of auricular deformities, and different types of auricular deformities have distinct incidences. Auricular deformities are caused by the interactions of a number of factors. There were large differences in the self-healing rates of different types of auricular deformities. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Morphological variability of the earlobe in a Spanish population sample.

This article shows the morphological variability of the earlobe in a Spanish population of European origin. The frequencies of four lobe characteristics (attachment, contour, modeling, and size) and their degree of expression were studied. The relationship among the characteristics and the differences involving sex and laterality were also considered. The least frequent morphology, and of main use in solving forensic cases, was the very small size with triangle-pulled contour into the skin and crossed-discontinuous modeling. The most frequent morphology, and most clinically useful, was the medium-sized lobe with free-arched contour and eminent or cross-continuous modeling. The characteristics were all symmetric. Size and modeling showed sexual dimorphism. Some characteristics were associated with each other: attachment with contour and modeling and the contour with modeling and size. The least frequent peculiarities were sharp lobe and virgule. The literature is scarce on this matter, practically non-existent for some characteristics, especially modeling and peculiarities. For the first time, the associations of the ear characteristics were analyzed, and this information could be applied to forensic identification.

Innervation of the Human Cavum Conchae and Auditory Canal: Anatomical Basis for Transcutaneous Auricular Nerve Stimulation.

The innocuous transcutaneous stimulation of nerves supplying the outer ear has been demonstrated to be as effective as the invasive direct stimulation of the vagus nerve for the treatment of some neurological and nonneurological disturbances. Thus, the precise knowledge of external ear innervation is of maximal interest for the design of transcutaneous auricular nerve stimulation devices. We analyzed eleven outer ears, and the innervation was assessed by Masson's trichrome staining, immunohistochemistry, or immunofluorescence (neurofilaments, S100 protein, and myelin-basic protein). In both the cavum conchae and the auditory canal, nerve profiles were identified between the cartilage and the skin and out of the cartilage. The density of nerves and of myelinated nerve fibers was higher out of the cartilage and in the auditory canal with respect to the cavum conchae. Moreover, the nerves were more numerous in the superior and posterior-inferior than in the anterior-inferior segments of the auditory canal. The present study established a precise nerve map of the human cavum conchae and the cartilaginous segment of the auditory canal demonstrating regional differences in the pattern of innervation of the human outer ear. These results may provide additional neuroanatomical basis for the accurate design of auricular transcutaneous nerve stimulation devices.

The Existence of a Natural Plica at the Anatomical Base of the Antihelix and its Surgical Importance to Address Protruding Ears: An Anatomicosurgical Study.

BACKGROUND: Protruding ears represent the main abnormality of the external ear, which has required numerous anatomic and surgical studies. Most studies give attention to the absence of the antihelix as the anatomic defect responsible for the clinical deformity of the lateral aspect of the ear that leads to its anteversion. The reason for this study is the controversial origin of the fold of the antihelix within the auricle framework, a field of interest for aesthetic otoplasty. The current study examined the medial surface of the cartilaginous ear frame from cadaver specimens with right morphology to investigate the starting point of the fold of the antihelix. This allowed for verification of a natural plica at the anatomic base of this antihelical fold, which to date has not had its topography described morphologically. It is acknowledged that relevant literature makes no reference to this innominate natural plica at the origin of the antihelix, whose anatomic and surgical importance is related in this report. This study aimed to show that the existence of a natural plica at the base of the antihelix in ear framing represents a landmark between normal and protruding ear morphology. METHODS: For 8 years, 118 ears were carefully investigated within rigid ethical principles based on a thorough review of the pertinent literature. The study investigated 16 selected cadaver specimens and 102 protruding ears dissected by the senior author including 49 bilateral cases (26 males and 23 females) and 4 unilateral cases (2 males and 2 females). Bifacial anthropometric measurements by calipers were used for documentation. RESULTS: A natural plica at the base of the antihelix was found in all cadaver ears selected with right morphology, whereas it was totally absent in every surgically treated protruding ear irrespective of color, gender, age, or ethnic origin. Ambilateral measures of the antihelix eminence certify the study object in normal specimens as well as its lack in abnormal ones. CONCLUSION: Technical and topographic knowledge that a natural plica exists at the anatomic base of the antihelix is a valuable key point in recognizing the normal external ear. In addition, the making of a natural plica is the first and most effective factor in the reconstruction of the antihelical fold and its absolute absence results in the pathologic condition for protruding ears. 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 A3 online Instructions to Authors. http://www.springer.com/00266 .