Auricular Research Articles

Ten Top Topics That Neuro-Otologists Think General Practitioners and Family Medicine Specialists Must Know: A Multi-Center Study Using Delphi Method

In order to decrease medical errors and improve organized, targeted education pre- and post-graduation, we intended to detect 10 most important concepts that neuro-otologists believe family physicians and general practitioners must know. A multi-center study based on Delphi’s method was designed and conducted in three stages. Of 31 topics gathered by expert panel, 10 top priorities were ranked based on 50 neuro-otologists’ opinion over the country. Early diagnosis and management of sudden sensorineural hearing loss, foreign body removal from external ear canal, proper management of otitis extern, and management of emergency situations in chronic otitis media gained the highest scores among all. Also, some topics, such as managing serous and acute otitis media, differentiating peripheral vs. central vertigos, and early hearing screening at birth were among top topics, contrary to others, such as surgery in only hearing ears, or hearing losses after COM surgeries. Almost all of the top-ranked topics are among critical/organ saving, or most prevalent medical concerns in all of the world. Sudden deafness, complicated COM, and mis-diagnosing vertigo may be organ/life threatening, while foreign bodies or inflammations of external ear, acute or serous otitis media, and congenital hearing loss are among the most prevalent medical problems worldwide, with numerous malpractices in their diagnosis and management. Regarding educational and practical priorities should be considered a basic step in neurotology field, and targeted programming policies.

A review of Karnapaligata Rogas with possible contemporary correlation and pictorial representation

Shalakya Tantra, one of the Asthangas of Ayurvade deals with anatomical, physiological, pathology, and therapeutic aspects pertaining to Gyanendriyas. The ears are one of the Gyanendriya and hearing is one of the important senses to gain knowledge. It enables us to take forward our existence without limitations and helps us to express, socialize and communicate with the world. The ear is not only the organ of hearing but also maintains balance. In Ayurvedic classics, Karna is the word that represents the organ ear. Karna is divided into 3 parts Bahya Karna (Outer ear), Madhya Karna (Middle ear), and Abhyanthara Karna (Inner ear). Karnapaligata Rogas are those which occur to the outer ear i.e., Bahya Karna. Acharya Susruta laid down the principles of plastic surgery centuries ago, which are relevant even in the present era of advanced plastic surgery. Karna Sandhana is one of the techniques Acharya has mentioned as a treatment modality for Karnapaligata Rogas. This article is aimed to compile various opinions on Karnapaligata Rogas by different Acharya and exhibit the nearest correlation in the contemporary view of the disease.

Salvage re-irradiation in non-melanoma skin cancers: A multicenter analysis

Background and purposeWe conducted a multicentre real-world study to assess the outcomes of radical salvage re-irradiation for non-melanoma skin cancer (nMSC) recurrences following definitive or postoperative radiotherapy. Materials and methodsData on patients treated between 2006 and 2022 with re-irradiation for nMSCs were retrospectively collected from five high-volume brachytherapy centers. The primary endpoint was local control (LC). Secondary endpoints included overall survival, progression-free survival, and adverse events (AEs). The Kaplan-Meier estimator and Cox Proportional-Hazards Model were utilised in the analysis. ResultsA total of 58 patients with a median age of 78.4 years with recurrences of previously irradiated nMSC in the head and neck region were included in the analysis. The majority had cutaneous basal cell carcinoma (BCC; 91.4%), and were irradiated with high-dose-rate brachytherapy (HDR-BT; 91.4%). The most common locations included the nasal region (36.2%) and external ear (18.9%). The 1-year LC was 73.1% and decreased to 41.7% at three years. The size of the re-irradiated lesion was the single independent prognostic factor in Cox analysis (per mm; HR 1.07; 95% CI 1.04–1.11; p < 0.001). Grade 3 or worse AEs were reported in 7 cases (12.1%). ConclusionRe-irradiation for nMSCs, predominantly administered with brachytherapy for radiorecurrent BCC, is associated with high recurrence rates, and the risk of failure significantly increases with the size of the treated lesion. Re-irradiation could be an option for selected elderly patients with small, localised, inoperable recurrences after RT to achieve local control or defer systemic treatment; however, prospective trials are necessary to confirm its safety and efficacy.

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.

Técnica de ressecção lateral do conduto auditivo modificada para o tratamento de estenose auricular em seis equinos

The external ear extends from the pinna to the tympanic membrane, where it is supported and shaped by an arrangement of cartilages including the conchal, annular, scutiform, and external acoustic meatus. Environmental exposure can often lead to diseases of the external ear canal in animals. In horses, otitis primarily occurs due to infestation by ectoparasites, promoting local inflammation and infection. Chronic conditions can result in ear deformation, including auricular canal stenosis. While operative techniques for treating auricular stenosis are known, they are limited to companion animals, with few reports on horses. This study aimed to describe the modified lateral resection technique of the ear canal, which is commonly performed in small animals, for treating auricular canal stenosis in six horses. As a methodology, the intertragic notch was used as a reference for the incision due to species disparity. The ear canal cartilage was dissected, followed by resection of the lateral wall and the cartilaginous flap adhered to the skin. Excess skin was removed, and the ear canal was sutured to the skin with nylon thread. Our results indicated a significant improvement in the treatment of otitis in the treated horses, demonstrating a favorable evolution in the healing process and resolution of bacterial infections in all cases. In conclusion, the use of the modified lateral resection technique of the ear canal was successful in all six treated horses, providing access to clinical treatment of the canal without any occurrences of recurrence or postoperative complications.

Metric and morphological features of the ear in sex classification

BackgroundThe human face can reveal a great deal about a person’s identity. Age, sex, and ethnicity differences can be recognized, classified, and analyzed using facial features, which give a scientific basis for personal identification and recognition. Sex, like age and ethnicity, has a significant influence on outer ear morphology. The shape and size of the auricle, which is one of the defining features of the face, are affected by age, sex, and ethnicity. Variations in the outer ear are known to be sufficient for identification in a forensic case and can help in determining whether the suspect is guilty or not. The aim of this research is to determine whether such metric and morphological features of the ear can be used to estimate sex and how dimorphic they are. After ear measurements with ImageJ 1.52a program, statistical data was recorded and analyzed in SPSS.ResultsThis study, which analyzed 350 people’s facial images, provides significant information for forensic applications. Among the analyzed ear morphology data, the helix and ear lobe form showed sex differences. Except for the T-PCC distance, all measurements differed significantly between sexes.ConclusionsModel 1 has the greatest accuracy rate (88%) among the models created for sex estimation. Sex estimation can be performed as an effective method when the morphological and metric parameters of the ear are analyzed together.

Unilateral crosstalk cancellation via bone conduction: Methods and evaluation

Bone conduction hearing aids (BCHAs) offer an alternative solution for individuals with outer or middle ear issues who cannot benefit from traditional air conduction hearing aids. However, the phenomenon of “crosstalk,” where sound intended for one ear is mistakenly transmitted to the other ear through bone conduction, presents a challenge. This unintended transmission may limit the benefits of binaural hearing that can be achieved using two BCHAs, such as accurately detecting a sound source's direction. In this article, we present a method to suppress “crosstalk” within the human head using an adaptive algorithm to control two audiometric bone transducers.•Our method involves positioning an error sensor at a location considered close to the cochlea, such as the ear canal or the mastoid, and utilizing an adaptive algorithm to estimate the crosstalk compensation filter. This filter generates an anti-signal, which is then transmitted to one of the two transducers, effectively cancelling the crosstalk.•To verify whether the crosstalk cancellation reaches the cochlea in the inner ear, we provide a procedure for measuring hearing thresholds with and without crosstalk cancellation. This acts as a subjective measure of the efficacy of our crosstalk cancellation method.By leveraging an adaptive algorithm, this approach provides personalized cancellation and has the potential to enhance the performance of binaural BCHAs.

Otological problems in ichthyosis: A literature review.

Ichthyoses are a rare group of keratinization disorders characterized by scaling of the skin due to an impaired barrier function. Few studies have addressed ear involvement in patients with ichthyosis, although it is a probably underestimated aspect of the disease. This study aims to provide an overview of the otological manifestations in ichthyosis and propose specific treatment options. Articles were collected using PubMed, EMBASE, and Web of Science. A total of 53 articles were included in this literature review. The most common ear problem in patients with ichthyosis is scale accumulation in the ear canals, which can lead to conductive hearing loss and increases the risk of ear infections. Furthermore, some types of ichthyosis are associated with outer ear malformations. Lastly, sensorineural hearing loss is common in syndromic forms of ichthyosis. Otological problems are present in all types of ichthyoses and their treatment is challenging. The involvement of ear, nose, and throat specialists in the routine care of ichthyosis patients is essential for early identification and treatment of these manifestations. More research is needed to provide more insight into the otological problems in ichthyosis and to ameliorate treatment options.

Risk factors for Microtia and preventive approaches

Microtia is a congenital anomaly that directly affects the external ear. Although the etiology of this pathology is not fully elucidated, there are several factors that are associated with its occurrence, such as genetics, perinatal and maternal conditions. During organogenesis of the outer ear it is important to mention that as anomalies occur before the sixth week of pregnancy, the chances of severe defects or total absence of the outer ear increase. At the genetic level, the etiology of microtia has been related to multiple causes, as well as the identification of genes involved in allelic expression pathways and transcription factors. Furthermore, this anomaly does not always occur alone, but associated with other pathologies such as cleft palate (12.8%), cleft lip and palate (11.5%), anophthalmia/microphthalmia (11.5%), facial asymmetry (10.6%), as well as oculoauriculovertebral spectrum syndromes, Goldenhar syndrome, craniofacial microsomia, Treacher Collins syndrome, Nager, DiGeorge or 22q deletion, Townes-Brock syndrome and branchi oto-renal syndrome. Treatments are based on the aesthetic management of the patient, but also related to the improvement of the patient's hearing ability. Epidemiologically, the prevalence ranges from 0.8 to 17.5 per 10,000 live births. One of the main risk factors for variation in case identification is altitude, genetics and maternal-perinatal factors. This literature review provides a thorough analysis of information for the better understanding, analysis and clinical management of this congenital anomaly.

Cochleo-Vestibular Disorders in Herpes Zoster Oticus: A Literature Review and a Case of Bilateral Vestibular Hypofunction in Unilateral HZO.

The varicella-zoster virus (VZV), a member of the Herpesviridae family, causes both the initial varicella infection and subsequent zoster episodes. Disorders of the eighth cranial nerve are common in people with herpes zoster oticus (HZO). We performed a review of the literature on different databases including PubMed and SCOPUS, focusing on cochlear and vestibular symptoms; 38 studies were considered in our review. A high percentage of cases of HZO provokes cochlear and vestibular symptoms, hearing loss and vertigo, whose onset is normally preceded by vesicles on the external ear. It is still under debate if the sites of damage are the inferior/superior vestibular nerves and cochlear nerves or a direct localization of the infection in the inner ear. The involvement of other contiguous cranial nerves has also been reported in a few cases. We report the case of a patient with single-side HZO presenting clinical manifestations of cochleo-vestibular damage without neurological and meningeal signs; after 15 days, the patient developed a new episode of vertigo with clinical findings of acute contralateral vestibular loss. To our knowledge, only three other such cases have been published. An autoimmune etiology may be considered to explain these findings.

Malignant tumors of the external auditory canal: diagnosis, treatment, genetic landscape, biomarkers, and clinical outcome

Malignant tumors of the external auditory canal (EAC) are rare neoplasms that appear in the head and neck area. A common feature of these malignancies is their rarity, as well as their delayed diagnosis due to the appearance of non-specific symptoms that mimic various benign otologic conditions. The reported histological types of cancer of the external ear are: squamous cell carcinoma, basal cell carcinoma, malignant melanoma, Merkel cell carcinoma, angiosarcoma, adnexal carcinoma (including ceruminous adenocarcinoma and adenoid cystic carcinoma), and lymphoma (Lancet Oncol. 2005;6:411–20. doi: 10.1016/S1470-2045(05)70208-4). Several therapeutic interventions have been proposed, primarily orientated towards the cure of the patient, placing the surgical excision of the lesions at the tip of the spear. Subsequently and depending on the clinical stage and the pathological characteristics of the tumor, radiation, chemotherapy, a combination thereof, or some form of palliative treatment for particularly advanced cases, may be recommended. The aim of all the above-mentioned approaches is the complete resection of the mass with negative surgical margins along with lymph node dissection, the elimination of any residual disease or metastasis, and the improvement of survival. The anatomical complexity of the region will always remain a demanding challenge. Nevertheless, advances in the fields of ear microsurgery, imaging, radiation, molecular biology, and genomics have led to remarkable outcomes compared to the past, with a view to the patient’s quality of life. Large, well-organized, and prospective studies with the participation of multiple centers in contrast to existing retrospective studies with a limited number of patients will help to establish universally accepted guidelines. The exploration of the molecular and genetic background of these cancers in conjunction with the search for new biomarkers and target molecules seems promising for providing upgraded and more personalized treatment modalities for the future.

Characterization of Distinct Chondrogenic Cell Populations of Patients Suffering from Microtia Using Single-Cell Micro-Raman Spectroscopy.

Microtia is a congenital condition of abnormal development of the outer ear. Tissue engineering of the ear is an alternative treatment option for microtia patients. However, for this approach, the identification of high regenerative cartilage progenitor cells is of vital importance. Raman analysis provides a novel, non-invasive, label-free diagnostic tool to detect distinctive biochemical features of single cells or tissues. Using micro-Raman spectroscopy, we were able to distinguish and characterize the particular molecular fingerprints of differentiated chondrocytes and perichondrocytes and their respective progenitors isolated from healthy individuals and microtia patients. We found that microtia chondrocytes exhibited lower lipid concentrations in comparison to healthy cells, thus indicating the importance of fat storage. Moreover, we suggest that collagen is a useful biomarker for distinguishing between populations obtained from the cartilage and perichondrium because of the higher spectral contributions of collagen in the chondrocytes compared to perichondrocytes from healthy individuals and microtia patients. Our results represent a contribution to the identification of cell markers that may allow the selection of specific cell populations for cartilage tissue engineering. Moreover, the observed differences between microtia and healthy cells are essential for gaining better knowledge of the cause of microtia. It can be useful for designing novel treatment options based on further investigations of the discovered biochemical substrate alterations.

Retrospective evaluation of ceruminous gland tumors confined to the external ear canal of dogs and cats treated with biopsy and CO2 laser ablation.

Treatments currently available for ceruminous gland tumors include surgery and radiation therapy, which come with high financial costs and frequent complication and recurrence rates. To evaluate the treatment, response, complication, and recurrence of ceruminous gland tumors confirmed with biopsy and ablated using CO2 laser. Retrospective review of medical records from Iowa State Universityand the University of Illinois between January 1, 2016 and December 31, 2021. Electronic medical records were evaluated for a histopathologically confirmed ceruminous gland tumor via video-otoscopic aided biopsy and subsequent CO2 laser ablation. Signalment, tumor type, size, location within the ear canal, length of time tumor was present before presentation, advanced imaging, and follow-up including recurrence were assessed. Fourteen ceruminous gland adenomas (4 dogs, 10 cats) and 12 ceruminous gland adenocarcinomas (7 dogs, 5 cats) were identified. Bacterial otitis externa was present in 4/26 (15%) animals. Recurrence was identified in 1/14 (7%) ceruminous gland adenomas and 1/12 (8%) ceruminous gland adenocarcinomas. Video-otoscopic aided biopsy and CO2 laser ablation of ceruminous gland tumors in dogs and cats is a viable treatment option with low recurrence and complication rates with CO2 laser ablation.

Prediction of mid-high frequency noise in new energy electric vehicles

Mid-high frequency noise in new energy electric vehicles is a critical factor affecting the comfort of car occupants. Such noise is generated near the electric motor and four tires, transmitted to the cabin through airborne, and finally perceived by the car occupants. Transfer Path Analysis is widely used for predicting cabin noise, but obvious time-consuming problems exist here. In this study, a time-efficient method called Inverse Transfer Path Analysis was used to calculate the mid-high frequency noise Airborne Transfer Function of a new energy electric vehicle. Then, the mid-high frequency noise at the driver’s ear position was predicted through an operational test. The results reveal that this method can accurately and efficiently predict the noise in the cabin. Furthermore, an artificial head was used to calculate the Head-Related Transfer Function from the external ear to the eardrum. This function was used to predict the mid-high frequency noise at the driver’s eardrum position, and the role of the human ear in the propagation of mid-high frequency noise has been analyzed.

Pneumocephalus and meningoencephalitis as a complication of otitis media in a dog

AbstractA 3‐year‐old Maltese dog presented with vestibular signs that worsened after a grass seed was removed from the right external ear canal. Neurological examination was suggestive of a brainstem lesion. Magnetic resonance imaging of the head was performed, and findings were consistent with infectious meningoencephalitis and otogenic pneumocephalus secondary to intracranial extension of right otitis media. A culture of the right middle ear effusion yielded Staphylococcus epidermidis. The dog was euthanased under general anaesthesia due to worsening of the cardiovascular and respiratory parameters. Pneumocephalus in dogs has been described secondary to surgery, trauma, meningocele and meningoencephalocele. To the authors' knowledge, this is the first case report describing otogenic pneumocephalus in a dog.

Literature review of transcutaneous electrical nerve stimulation in peripheral arterial occlusive disease of the lower limbs.

The aim was to evaluate the use of non-invasive transcutaneous electrical stimulation therapies (regardless of location) in PAD of the lower limbs, whatever the disease grade. A review of the literature was carried out via a search of the MEDLINE/PubMed database from 1975 to 2023. The articles were selected via abstracts by checking (1) medical indications: PAD patients with claudication were retained, excluding neurological or venous claudication, PAD whatever the disease grade (intermittent claudication or critical limb ischemia [CLI]) and (2) non invasive electrical stimulations were considered (neuromuscular electrical stimulation and spinal cord stimulation were excluded) whatever the anatomical site. Non-electrical stimuli such as acupuncture and reflexotherapy were excluded. Only 9 items were selected, including 7 studies with TENS treatment on the calf, one with trans-auricular vagus nerve stimulation and one with electro-acupuncture points of stimulation. Even if the mechanisms involved are different, TENS on the calves or in the external ears show an improvement of walking distance in PAD patients with intermittent claudication. The results of the studies show few positive effects in arteriopathy but we should keep vigilant in the technics used since mechanisms are different and not fully understood. Electro-stimulation of the calf and external ear appears to be an easy-to-use and accessible therapeutic option, especially since some PAD patients are still failing to be released from pain, despite the rise of endovascular interventional techniques.

Outer ear reconstruction using 3D technology

Abstract Manufacturing replicas for replacing missing or defective body parts also incorporates 3D technology, including scanning, image processing and printing. In the case of the ears, both aesthetics and functionality play a significant role. Based on these techniques, outer ear replicas were produced using 3D scans of human skulls in a rapid prototyping procedure for actual patients. Hand-held scanners delivered accurate images for post-processing of the mesh and for printing in a cost- and time efficient way. Use cases of patients demonstrate applicability, allowing the technology to be available also for the general population in the future.

Tolerability of Otic Solutions Containing Different Enrofloxacin Concentrations in Dogs with Healthy Ears.

Otitis externa (OE) is a common disease in dogs, and topical medications are the preferred treatment. Compounded solutions of enrofloxacin are commonly used in practice to treat bacterial OE; however, the tolerability of different concentrations of this antibiotic in the ear canals of dogs has not been evaluated. The objective of this study is to determine if a higher concentration of enrofloxacin applied to the external ear canal is clinically tolerated in dogs with healthy ears. Sixteen client-owned dogs with bilateral healthy ears and no previous history of OE were enrolled. Injectable enrofloxacin 2.27% diluted with sterile sodium chloride in 1:1 (11.35 mg/mL) and 2:1 (15 mg/mL) ratios were applied into the dogs' right and left ears, respectively, q 12 hr for 14 days. Based on video otoscopic examination, clinical score for canine OE (OTIS3) results before application were ≤1 for all dogs. During the study and at the conclusion, all scores remained ≤2, which is considered normal. No cytologic inflammatory cells were seen in any of the dogs' ears throughout the study. Different concentrations of enrofloxacin solution applied topically were well tolerated by dogs with healthy ears and can be considered for the treatment of dogs with bacterial OE.

External Ear Anthropometry of Healthy Turkish Young Adults.

The aim of this study was to determine the external ear values in Turkish young adults with 2-dimensional photogrammetry. One hundred males and 100 females aged between 18 and 25 years were included in the study. Individuals were photographed from both sides. Ear length (superaurel-subaurel, spa-sba ), ear width (preaurel-postaurel, pra-pa ), and the angle between the vertical axis of the auricle and the line between spa and sba (ear incline angle, eia ) were measured in these photographs. Also, auricular index ( pra-pa / spa-sba ×100) was calculated. The average values of the spa-sba, pra-pa , eia , and auricular index were found as 65.46±4.68mm, 37.89±3.61mm, 19.40±4.83 degrees, and 57.93±4.53 in males and 60.90±5.35mm, 35.62±3.69mm, 17.95±4.86 degrees, and 58.65±5.29 in females, respectively. While the values of spa-sba ( P =0.001 for the right side and P =0.001 for the left side), pra-pa ( P =0.001 for the right side and P =0.001 for the left side), and eia ( P =0.024 for the right side and P =0.041 for the left side) were statistically higher for males than females, there was no statistically significant difference between the sex and the auricular index ( P =0.404 for the right side and P =0.955 for the left side). Besides, there was no statistically significant difference between the sides for these 4 parameters ( P =0.760, 0.409, 0.225, and 0.521, respectively). The authors believe that the results obtained for Turkish young adults can be used as reference values, which can be used in the diagnosis, follow, or surgical treatment of many diseases, forensic procedures, and planning esthetic surgery procedures.

The Auriculotemporal Nerve and TMJ region: anatomy and function

The studies on the auriculotemporal nerve in humans are limited. However, we considered crucial to investigate the topographic relation between the auriculotemporal nerve and the TMJ region that can explain some of the symptoms in TMDs. The results derived from our experience in the anatomic dissection on 16 adult cadaveric heads were compared with what literature describes from 1971 to 2023. The results confirm the existence of a particular anatomic position of the ATN within the infratemporal fossa in direct contact with the lateral pterygoid muscle and the TMJ capsular region. Therefore, there is evidence of a potential entrapment mechanism involving the ATN caused by an internal derangement of TMJ or a spastic condition of the lateral pterygoid muscle. Through a detailed anatomical description of the ATN the present study aims to offer an explanation to the main sensory and otological symptoms that patients with TMJ disorders often complaint, from facial pain and paresthesias to external ear pruritus.