Auricular Research Articles

Prevalence and Etiology of Otomycosis in West Libya

Fungal otitis media is a frequently case facing otolaryngologists due to its recurrence and long-Fungal otitis media is a frequent condition faced by otolaryngologists due to its recurrence and long-term treatment period. The infection starts in the outer ear canal and may reach the inner ear. The aim of this study was to isolate and identify the fungal species causing inflammation of the auditory canal, identify the main causes and contributing factors to the spread and increased incidence of ear fungal infection, and determine the relationship between otomycosis occurrence and age, gender, and diabetes. Additionally, the study aimed to compare the incidence of otomycosis among different areas. A total of 205 ear swabs were collected from patients visiting national clinics and hospitals. The samples were cultured on Sabouraud dextrose agar and Czapek-Dox agar and incubated at 30°C for a week. Nine fungal species belonging to four genera were isolated: Aspergillus spp., Alternaria spp., Penicillium spp., and Candida spp. The current study showed a predominance of Aspergillus spp. isolates, with a rate of 82.67%, making it the main cause of fungal ear infection; however, Penicillium spp. was the least prevalent. Among the fungal species, A. niger was dominant, with a prevalence rate of 41.16%. The prevalence of ear infection was higher in females (62.82%) than in males (37.17%), and the infection was most common in the age group from one to twenty years (39.35%), while it was less frequent in older age groups. In coclusion, The study concluded that otomycosis is widely prevalent in western Libya, with Aspergillus niger as the predominant etiological agent.

Otoplasty and Ear Reconstruction Complications.

Prominauris, often known as prominent ears, is one of the most frequent congenital deformities of the head and neck. Therefore, otoplasty has gained significant popularity and is now one of the most performed procedures in the field of facial plastic surgery.Reconstructing and correcting ear abnormalities remains a challenging procedure in facial plastic and reconstructive surgery. These deformities, whether congenital or acquired, have a substantial influence on patients' lives and inflict psychological harm. Addressing the deformity and tissue loss will improve the overall quality of life.Throughout history, various surgical techniques have been reported for treating external ear abnormalities. While most of these surgeries are considered safe, a comprehensive preoperative evaluation and understanding of the different techniques and risks can minimize potential complications.

A Preliminary Evaluation of Potential Perceptual Contributions from the Skull

ABSTRACT An experiment was conducted to test the common assumption that amplification produced by the outer and middle ear for air-conducted (AC) signals renders the perceptual contributions from bone conduction (BC) through the skull negligible under typical, free-field listening conditions. To evaluate this possibility, simulated BC signals reflecting varying levels of attenuation were mixed with the original version of the signal (i.e., in place of the AC signal). To simulate the BC signals, a sawtooth wave (F 0 = 43.06 Hz; maximum frequency = 5,000 Hz) was filtered using existing measurements from individual skulls as a bank of third-octave bands. The resulting signals were mixed with the original sawtooth, such that the relative peak amplitude of BC signals was −8, −20, −32, or −44 dB to the original signal. Listeners completed a 4IAX discrimination task to determine if they could detect the presence of the simulated BC signals (X) relative to the original sawtooth in isolation (A). Discrimination sensitivity (d´) tended to remain high at −8 dB and −20 dB conditions, and, as hypothesized, decreased with greater attenuation. However, d´ remained reliable (>1) for more than a quarter of the skulls, even in the −44 dB attenuation condition. This was despite the fact that third-octave bands below 3,150 Hz exceeded the combination of the expected levels of gain that are observed from AC and the measured attenuation from BC. Furthermore, remaining bands at or above 3,150 Hz reflected similar intensities for BC signals regardless of whether or not they were discriminated in the −44 dB condition. Taken together, these findings raise the possibility that at least a subset of human skulls might make audible contributions under typical (free-field) listening conditions, and certainly when the AC signal is reduced (such as when the ears are covered).

Air–Bone Gap in Meniere’s Disease: A Case Series and Literature Review

Background/Objectives: An air–bone gap (ABG) on audiometry is usually secondary to a conductive hearing loss. However, persistent and repeatable ABGs on audiometry in the absence of external or middle ear pathology is thought to arise from inner ear disorders including Meniere’s Disease (MD). In this paper, we aim to showcase this interesting finding occurring in MD with an associated literature review. Methods: Using retrospective review and analysis of case notes, we describe eight cases of persistent ABG on audiometry in MD. All other causes for the ABG were explored and excluded with the aid of objective audiological testing. Results: ABG can occur in a small sub-set of the MD population. In our case series, the ABG was typically found to affect the low frequencies. Higher frequencies appear to be spared. However, a detailed history, examination and battery of objective tests are required to ensure that all other causes of the ABG are reliably considered and excluded prior to attributing it to the inner ear. The finding of an ABG in MD may be dependent on the stage of the disease. Further research is required to determine the underlying cause of the ABG and its potential applications to help guide treatment.

Ear Reconstruction following Mohs Micrographic Surgery

AbstractRelative to other regions of the body, the ear has a high risk of developing cutaneous malignancies that often necessitate Mohs micrographic surgery (MMS) for removal. This procedure can create defects that are immediately noticeable if left untreated. Reconstructive techniques are often needed to restore the appearance of the affected ear and its symmetrical relationship to the contralateral ear. However, achieving optimal aesthetic results can be challenging due to the subtle intricacies of the external ear. Therefore, careful planning and execution should be implemented prior to managing the acquired defect. Additionally, depending on the size and location of the defect, various options aligning with the reconstructive ladder can provide desired outcomes. The purpose of this article was to highlight and discuss the different techniques used in ear reconstruction following MMS.

The Scutulum and the Pre-Auricular Aponeurosis in Bats.

The external ear in eutherian mammals is composed of the annular, auricular (pinna), and scutellar cartilages. The latter extends between the pinnae, across the top of the head, and lies at the intersection of numerous auricular muscles and is thought to be a sesamoid element. In bats, this scutulum consists of two distinct regions, (1) a thin squama that is in contact with the underlying temporalis fascia and (2) a lateral bossed portion that is lightly tethered to the medial surface of the pinna. The planar size, shape, and proportions of the squama vary by taxa, as does the relative size and thickness of the boss. The origins, insertions, and relative functions of the auricular muscles are complicated. Here, 30 muscles were tallied as to their primary attachment to the pinnae, scutula, or a pre-auricular musculo-aponeurotic plate that is derived from the epicranius. In contrast to Yangochiroptera, the origins and insertions of many auricular muscles have shifted from the scutulum to this aponeurotic plate, in both the Rhinolophidae and Hipposideridae. We propose that this functional shift is a derived character related primarily to the rapid translations and rotations of the pinna in high-duty-cycle rhinolophid and hipposiderid bats.

Middle Ear Malformations

Middle ear malformations (MEMs) represent a diverse group of congenital anomalies with significant implications for auditory function. These malformations, which occur in approximately 0.5 to 3% of conductive hearing loss cases, can arise from various genetic and environmental factors. They often manifest unilaterally and may occur in isolation or as part of a syndromic condition. MEMs are closely associated with abnormalities of the external ear and less frequently with inner ear anomalies.Embryologically, the middle ear develops from the first and second pharyngeal arches, with interactions between the ectoderm and endoderm contributing to the formation of essential structures such as the tympanic membrane, ossicles and Eustachian tube. Disruptions in these developmental processes can lead to a spectrum of MEMs, ranging from minor defects to severe malformations affecting multiple middle ear components.Clinical management of MEMs requires a multidisciplinary approach, involving otolaryngologists, pediatricians, and audiologists. Early intervention with appropriate hearing aids, including conventional hearing aids and bone conduction devices, is essential to mitigate the impact of conductive hearing loss on speech and language development, particularly in children.Surgical planning involves comprehensive preoperative assessment, including high-resolution computed tomography imaging to evaluate middle ear anatomy, the facial nerve course, and vascular anomalies. Traditional surgical approaches such as stapesplasty and tympanoplasty remain mainstays for correcting specific middle ear defects, while advances in technology have expanded the role of active middle ear implants in treating special cases.In conclusion, MEMs represent a heterogeneous group of congenital anomalies with diverse etiologies and clinical implications. A thorough understanding of their embryological basis, genetic underpinnings, and surgical management strategies is crucial for optimizing outcomes in affected individuals.

The Critical Thing about the Ear's Sensory Hair Cells.

The capabilities of the human ear are remarkable. We can normally detect acoustic stimuli down to a threshold sound-pressure level of 0 dB (decibels) at the entrance to the external ear, which elicits eardrum vibrations in the picometer range. From this threshold up to the onset of pain, 120 dB, our ears can encompass sounds that differ in power by a trillionfold. The comprehension of speech and enjoyment of music result from our ability to distinguish between tones that differ in frequency by only 0.2%. All these capabilities vanish upon damage to the ear's receptors, the mechanoreceptive sensory hair cells. Each cochlea, the auditory organ of the inner ear, contains some 16,000 such cells that are frequency-tuned between ∼20 Hz (cycles per second) and 20,000 Hz. Remarkably enough, hair cells do not simply capture sound energy: they can also exhibit an active process whereby sound signals are amplified, tuned, and scaled. This article describes the active process in detail and offers evidence that its striking features emerge from the operation of hair cells on the brink of an oscillatory instability-one example of the critical phenomena that are widespread in physics.

Efficacy of 1.5% levofloxacin otic solution in treating acute otitis externa: A post hoc analysis of ENT103-3001, a multicenter randomized double-blind parallel-group placebo-controlled phase III study in otitis media with persistent otorrhea

ObjectiveIn this post hoc analysis, we aimed to evaluate the efficacy of 1.5% levofloxacin (LVFX) otic solution for the treatment of acute otitis externa (AOE) in patients with nonintact tympanic membrane (NTM) accompanied by chronic suppurative and acute otitis media. MethodsDigital endoscopic images of the tympanic membrane and cavity were evaluated. In addition, the full analysis set from the original ENT103-3001 study was analyzed to determine the efficacy of the 1.5% LVFX otic solution in treating patients with otitis media with persistent otorrhea. AOE was diagnosed by a study-specific blinded independent review committee (BIRC) in the present study, which reviewed the presence of inflammatory findings, such as edema, erosion, and/or erythema (redness), in the external ear canal on the digital endoscopic images acquired at screening. The improvement in the inflammatory findings in each diseased ear was evaluated by examining the digital endoscopic images acquired at the end of treatment (EOT; including study discontinuation) and follow-up (F/U) visits. Data regarding residual purulent otorrhea at EOT and F/U visits were assessed by the BIRC of the ENT103-3001 study. Similarly, otological symptoms at EOT were recorded in the patients’ diaries, and the bacterial eradication rates were used from the ENT103-3001 study. Improvement was defined as the resolution of the inflammatory findings and purulent otorrhea. ResultsAmong the 201 patients with otitis media, 161 patients had AOE (LVFX group, 82; placebo group, 79). The difference (95% confidence interval) between the groups at EOT was 27.3% (12.7, 40.3), and the proportion of patients showing improvement in all inflammatory findings in the external ear canal in the LVFX group (47.6%, 39/82) was significantly higher than that in the placebo group (20.3%, 16/79; Fisher's exact test, p < 0.001). Similarly, the bacterial eradication rate in the LVFX group (94.3%, 66/70) was also significantly higher than that in the placebo group (10.3%, 7/68; Fisher's exact test, p < 0.001). ConclusionThe use of 1.5% LVFX otic solution resulted in a significantly higher rate of improvement in inflammatory findings in the external ear canal and bacterial eradication rate, indicating its efficacy. Thus, 1.5% LVFX otic solution may be an effective treatment for chronic suppurative otitis media and acute otitis media, as well as AOE with NTM.

Occurrence and Phenotypic Antimicrobial Resistance of &lt;i&gt;Escherichia Coli&lt;/i&gt; and &lt;i&gt;Salmonella Enterica&lt;/i&gt; as Well as Coliform Load Recovered from Healthy Dogs in Tamale Metropolis, Ghana

Salmonella enterica and Escherichia coli are vital bacteria associated with infections in both humans and animals. Their presence in dogs expose humans to the risk of infections. This study determined the occurrence and phenotype antimicrobial resistance of Salmonella enterica and Escherichia coli recovered from healthy dogs in the Tamale Metropolis, Ghana. The study also examined coliform loads in these dogs. A total of 120 samples from five different parts (anus, mouth, nose, inner ear and outer ear) of apparently 24 healthy dogs were examined. Isolation and antimicrobial resistance of Salmonella enterica and Escherichia coli were determined according to the Bacteriological Analytical Manual and the Disc Diffusion methods, respectively. The occurrence of Salmonella enterica was highest at 41.7% and lowest at 8.33% while Escherichia coli in the dogs was highest at 62.5% and lowest at 16.7%. The coliform load was highest at 3.7 log cfu/cm2 and lowest at 3.1 log cfu/cm2 . The Salmonella enterica isolates were highly resistant to teicoplanin (100%) and tetracycline (89.5%), but susceptible to gentamicin (68.4%). The MAR index ranged from 0.1 to 0.7 and the resistance pattern TecTeCCro (resistant to teicoplanin, tetracycline, chloramphenicol and ceftriaxone) was the most common. For Escherichia coli, they were highly resistant to teicoplanin (84.6%) and tetracycline (73.1%), but susceptible to gentamicin (80.8%), ceftriaxone (88.5%) and chloramphenicol (92.3%). The MAR index ranged from 0.0 to 0.6 and the resistannce pattern Tec (resistant to only tetracycline) was the most common. In conclusion, this showed that apparently healthy dogs were sources of Salmonella enterica and Escherichia coli. The Salmonella enterica and Escherichia coli isolates showed varied resistances to antibiotics.

Audiological and Subjective Benefits in a Child with Microtia and Atresia After Sequential Bilateral Implantation with Active Bone Conduction Devices: A Case Study

Background: With bilateral hearing loss, the main problems for the patient are speech understanding in noise and, especially in asymmetrical hearing loss, an inability to correctly localize sound sources. There are multiple methods of treatment and rehabilitation for people with conductive hearing loss, and one of them is to use an active bone conduction implant. This case study is designed to evaluate the auditory benefits and sound localization accuracy with active bilateral bone conduction implants—in comparison to unilateral ones—in a patient with congenital bilateral conductive hearing loss caused by a congenital malformation. We assess subjective and audiological benefits (functional, directional hearing, speech comprehension in quiet and noise). Case report: This study describes the results in a 15-year-old patient with bilateral congenital malformation of the outer ears and associated conductive hearing loss who was treated with two Bonebridge active bone conduction implants. Speech recognition ability, hearing thresholds, and sound localization were tested under three conditions: unaided, unilateral on the right-side, and bilateral on both sides. The patient filled in an Abbreviated Profile of Hearing Aid Benefit questionnaire (APHAB) to evaluate limitations in daily life caused by hearing impairment. The results show an improvement in free-field hearing thresholds and the ability to discriminate speech, both in quiet and in noise after implantation. Subjectively, the patient had significantly fewer problems with two implants than with one (or with no implant) in terms of hearing in everyday situations. Conclusions: Unilateral use of the Bonebridge device in a patient with congenital bilateral conductive hearing loss did not provide full benefits. However, bilateral implantation improved speech understanding in noise and sound localization.

First photon-counting detector computed tomography in the living crocodile: a 3D-Imaging study with special reference to amphibious hearing.

Crocodiles are semi-aquatic animals well adapted to hear both on land and under water. Currently, there is limited information on how their amphibious hearing is accomplished. Here, we describe, for the first time, the ear anatomy in the living crocodile using photon-counting detector computed tomography (PCD-CT) and 3D rendering. We speculate on how crocodiles, despite their closed ear canals, can use tympanic hearing in water that also provides directional hearing. A Cuban crocodile (Crocodylus rhombifer) underwent photon-counting detector computed tomography (PCD-CT), under anesthesia and spontaneous respiration. In addition two seven-month-old C. rhombifer and a juvenile Morelet´s crocodile (Crocodylus moreletii) underwent micro-computed tomography (µCT) and endoscopy. One adult Cuviérs dwarf caiman (Paleosuchus palpebrosus) was micro-dissected and video-recorded. Aeration, earflap, and middle ear morphology were evaluated and compared after 3D modeling. PCD-CT and µCT with 3D rendering and segmentation demonstrated the anatomy of the external and middle ears with high resolution in both living and expired crocodiles. Based on the findings and comparative examinations, we suggest that the superior earflap, by modulating the meatal recess together with local bone conduction, may implement tympanic hearing in submerged crocodiles, including directional hearing.

Drug-induced congenital abnormalities of the outer ear

Drug-induced congenital abnormalities of the outer ear

A Comparison of 226- and 1000-Hz Probe Tone Tympanometry With Myringotomy Findings in Infants.

This study aimed to verify the diagnostic value of tympanometry with 226- and 1000-Hz probe tones in infants by comparing tympanometry results with the gold standard of the middle ear state assessed by myringotomy. Furthermore, clinically useful predictors for false peaked tympanograms despite the presence of middle ear fluid should be identified. Pre-operative 226- and 1000-Hz tympanograms were retrospectively compared with intraoperative findings of the tympanic cavity after myringotomy in 111 infants (217 ears) aged ≤ 12 months. In addition to the shape of tympanograms, demographic and clinical characteristics, the results of other audiometric measurements, and the viscosity of middle ear fluid, if present, were evaluated in several subgroups. The sensitivity and specificity of 1000-Hz tympanometry for middle ear effusion (MEE) detection were 97%-98% and 71%-84%, respectively, whereas standard tympanometry with a 226-Hz probe tone achieved a poor sensitivity of 43%-61% and a specificity of 81%-97%. Younger age, low viscosity of the middle ear fluid, and female sex were associated with an increased risk of false peaked 226-Hz tympanograms despite MEE. Furthermore, larger equivalent outer ear canal volumes were linked to false peaked 226-Hz tympanograms. The comparison of myringotomy findings and 226- and 1000-Hz tympanometry confirms the superiority of high-frequency tympanometry in infants younger than 12 months. Although this study identified some vague predictors of potentially false peaked 226-Hz tympanograms, the assessment of the middle ear state by 226-Hz tympanometry remains unreliable in young infants.

PETAL – LIKE OTOPLASTY IN THE TREATMENT OF PROTRUDING EARS

Introduction. Approximately 5% of humanity suffers from inborn protruding ears, and usually this condition causes marked psychosomatic disorders. Despite years of experience gained in aesthetic surgery, optimal technique of otoplasty is yet to be elaborated. The Aim of the Research. To develop a method of surgical correction of congenital bulging ears in order to optimize the immediate and long-term results of otoplasty. Material and methods. We have analysed the outcomes of 120 patients operated for congenital protruding ears at Lviv City Cosmetologic Hospital between 2020 and 2023. Distance between mastoid process and the concha exceeding 20 mm, and auriculo-cephalic angle over 30° were used as objective criteria of protruding ears. Surgical improvement of tall concha and increased auriculo-cephalic angle were identified as key vectors in elaboration of the original otoplasty technique. Results of the Research. With local anaesthesia, an S-shaped incision is made to the depth of perichondrium of posterior surface of the cartilage of the ear. Once subcutaneous dissection is completed, preoperative markup is transferred with injection needles from anterior surface to posterior surface of the conchal cartilage. A full depth arch-shaped incision of conchal cartilage is made. Perichondrium and skin of anterior surface of the concha are mobilized with a raspatory, from the chondral «petal» to the margin of external meatus. Basis of the chondral «petal» is dissected by 2/3 of its depth along the vertical axis between the pedicle of the helix, and the antitragus. In order to reliably fix the auricula, the cartilage is stitched to the mastoid process with three mattress sutures on the ventral surface of the «petal». Finally, excessive skin is carefully resected, and the wound is closed with continuous suture, with dead space elimination for hematoma prevention. Our technique has the following significant advantages: Unique conchal cartilage is kept entirely, therefore it can be used as auto-transplant in the future. The technique does not significantly affect the rheology of auricula. With this technique correction and modification of antihelical curve and radius is possible; if necessary, width of auricula can be corrected, and auricular height to width ratio can be modified. The proposed «petal» technique significantly reduces the rate of postoperative complications, such as recurrent protruding ears. Postoperatively, the size of external meatus is not reduced, hence no hearing deterioration. The outcomes of the technique we have developed were assessed 6 months after otoplasty as good, satisfactory and unsatisfactory. Good outcome: preservation of symmetry and anatomical «standard» of both auriculas, no recurrence throughout follow-up, and no impairment of sensation in the external ear. Satisfactory outcome: anatomical «standard» of the organ is preserved, with permissible error of up to 3 mm in the symmetrical points on the right and left auriculas, not requiring additional correction. Conclusions. 98 (81,3%) patients operated by the proposed «petal» technique assessed their otoplasty outcome as good, 17 (14,3%) of patients assessed the outcome of surgery as satisfactory. 5 (4,3%) patients were not satisfied with the outcome of surgery. These patients were operated during the early period of development of the technique.

Drug-associated congenital anomalies of the external ear identified in the United States food and drug administration adverse event reporting system database

Congenital anomalies of the external ear can have a significant impact on a child’s development and quality of life. While genetic factors play a crucial role in the etiology of these anomalies, environmental factors such as drug exposure during pregnancy may also contribute to their occurrence. This study aims to investigate the association between drug exposure and congenital anomalies of the external ear using data from an adverse drug reaction report database. Using OpenVigil 2.1, we queried the FAERS database to retrieve adverse event reports from the first quarter of 2004 to the first quarter of 2024. To identify relevant cases, we used Medical Dictionary for Regulatory Activities terms focusing on congenital anomalies of the external ear. Drug generic names were sourced from the DrugBank database. To assess safety signals and rank drugs by their signal strength, we conducted a disproportionality analysis, generating reporting odds ratios (ROR) and proportional reporting ratios (PRR). A total of 20,754,281 AE reports were identified in the FAERS database from Q1 2004 to Q1 2024, of which 1763 were related to congenital anomalies of the external ear. Valproic acid (122 cases) was associated with the most cases, followed by mycophenolate mofetil (105 cases) and lamotrigine (65 cases). According to the disproportionality analysis, the top five drugs with the highest ROR and PRR were primidone (ROR: 397.05, 95% CI 147.21, 1070.9; PRR: 388.71, 95% CI 145.89, 1035.7), valproic acid (ROR: 239.46, 95% CI 123.75, 463.37; PRR: 236.42, 95% CI 123.82, 451.43), tapazole (ROR: 198.35, 95% CI 63.49, 619.67; PRR: 196.25, 95% CI 62.97, 611.67), nevirapine (ROR: 138.24, 95% CI 82.9, 230.51; PRR: 137.23, 95% CI 82.44, 228.44), and sebivo (ROR: 117.1, 95% CI 48.51, 282.67; PRR: 116.37, 95% CI 48.17, 281.12). This study identified several drugs significantly associated with congenital anomalies of the external ear in the FAERS database using disproportionality analysis. The findings can help healthcare professionals better recognize and manage drug-induced congenital anomalies of the external ear, particularly when prescribing high-risk medications. Further research is needed to elucidate the mechanisms underlying these associations and develop strategies for preventing and mitigating drug-induced congenital anomalies of the external ear.

Antimicrobial and antibiofilm effect of promethazine on bacterial isolates from canine otitis externa: an in vitro study

Otitis externa is an inflammatory disease of the external ear canal of complex and multifactorial etiology associated with recurrent bacterial infection. This study aimed to assess the antimicrobial and antibiofilm activity of promethazine against bacterial isolates from dogs with otitis externa, as well as the effect of this compound on the dynamics of biofilm formation over 120 h. Planktonic bacterial susceptibility to promethazine was evaluated to determine the minimum inhibitory concentrations (MIC). The minimum biofilm eradication concentration (MBEC) was also determined by broth microdilution. To evaluate the effect on biofilm growth, promethazine was tested at three concentrations MIC, MIC/2 and MIC/8, with daily readings at 48, 72, 96 and 120 h. The MICs of promethazine ranged from 48.83 to 781.25 μg mL−1. Promethazine significantly (P < 0.05) reduced mature biofilm biomass, with MBECs ranging from 48.8 to 6250 μg mL−1 and reduced (P < 0.01) biofilm formation for up to the 120-h, at concentrations corresponding to the MIC obtained against each isolate. Promethazine was effective against microorganisms associated with canine otitis externa. The data suggest that promethazine presents antimicrobial and antibiofilm activity and is a potential alternative to treat and prevent recurrent bacterial otitis in dogs. These results emphasize the importance of drug repurposing in veterinary otology as an alternative to reduce antimicrobial resistance.

Effects of the earplug and external ear hardness of the direct transmissions induced by high-level impulse noises

The performances of Hearing Protection Devices (HPD) facing high-level impulse noises is limited by the transmission through the protector. This transmission can be evaluated by measuring the earplug's displacement along the ear canal axis. Previous measurements highlighted a displacement proportional to the peak acoustic pressure in the protected ear canal. To better understand the consequences on the HPD performances, this evaluation requires to be extended. Thus, various configurations are studied with Acoustic Test Fixture (ATF) external ears and earplugs of low and medium hardness. The earplug's peak displacements have been measured with a laser-vibrometer and the acoustic pressure with the ATF microphone. The impulse waves employed to excite the earplugs ranged from 150 dB to 180 dB peak. A medium hardness earplug inserted in a low hardness ear led to the worst performances with a plug displacement of 200 µm and a peak noise reduction of 17.8 dB(SPL) for an impulse noise of 177 dB(SPL). For the best case, a maximum displacement of 66 µm and peak noise reduction of 28.8 dB(SPL) have been measured. These results suggest new perspectives to improve the HPDs but also their evaluation through the choice of judicious ATF materials that conform to biological tissues.

Comparative performance of video-otoscopy and CT in the diagnosis of external ear disease in cats.

The aim of the study was to compare CT with video-otoscopy for detecting external ear canal masses in cats and to describe CT features of feline external ear disease. This retrospective study evaluated the external ear canals of cats that underwent both CT and video-otoscopy. Two blinded observers reviewed the CT scans and their findings were compared with video-otoscopy results evaluated by one blinded observer. Of the 32 examined ears, 13 had an external ear canal mass detected by both CT and video-otoscopy. No false positives were identified. All 19 ears without masses were correctly identified as true negatives, resulting in perfect agreement for mass detection (kappa = 1.000). On histopathology, 9/13 masses were diagnosed as polyps, 1/13 masses was diagnosed as carcinoma, 2/13 did not undergo histopathology and 1/13 masses seen on video-otoscopy was diagnosed as otitis externa with granulomatous tissue formation. Of the 16 cats examined, 12 had a mass in the external ear canal diagnosed by video-otoscopy: six domestic shorthairs, five Maine Coons and one Oriental Shorthair cat. Of these cats, 11 had a unilateral mass and one had a bilateral mass. There was very low agreement between CT and video-otoscopy for ear canal wall enhancement and erythema (kappa = 0.033), as well as for ear canal thickening and stenosis (weighted kappa = 0.056). There was no significant difference between chronic and non-chronic clinical signs in terms of the presence of ear canal wall mineralisation (P = 0.223). There is high agreement between video-otoscopy and CT in detecting external ear canal masses in cats. However, there is very low agreement between CT and video-otoscopy for ear canal wall enhancement, erythema, thickening and stenosis. The presence of external ear canal mineralisation did not correlate with the chronicity of clinical signs.

Lentigo Maligna and Lentigo Maligna Melanoma of the External Ear: Clinical and Dermoscopic Features of 19 Patients.

External ear lentigo maligna/lentigo melanoma (LM/LMM) represents approximately 1%-4% of all primary cutaneous melanomas. Over the past 20 years, dermoscopy has proven highly effective in early detection of LM/LMM, with recent studies identifying perifollicular linear projections (PLP) as a specific diagnostic criterion for early LM. However, in clinical practice, LM and LMM turn out to be very difficult to distinguish based on dermoscopic findings. Therefore, our retrospective monocentric study aimed to investigate dermoscopic characteristics, as well as the epidemiological and clinical data of 19 patients diagnosed with the external ear (EE) LM/LMM at the Oncologic Dermatology Unit in Bologna. Dermoscopic images were obtained using the FotoFinder Medicam 800HD, and specific criteria validated by the International Dermoscopy Society (IDS) for atypical pigmented facial lesions were assessed. Fisher's exact test was primarily used for statistical comparisons. As results, most of the patients were male (74%) with an average age (± SD) at diagnosis of 69.8 (± 15.1) years old. LMM appeared more commonly observed in elderly patients as compared to LM (mean 71.6 vs. 66.7, p = 0.514), presenting as pigmented macule (89.5%) of the ear lobule (23.9%). A statistically significant difference (p = 0.01) of tumour' diameter between LMM and LM was reported with the first resulting more than twice the size of the latter. Concerning dermoscopic findings, asymmetric pigmented follicles, obliteration of the follicular openings and grey circles were more frequently observed in LMM compared to LM (63.2% vs. 31.6%; 63.2% vs. 26.3%; 47.4% vs. 15.8%, respectively).