Auricular Research Articles

External ear malformations and cardiac and renal anomalies: A systematic review and meta-analysis.

External Ear Malformations (EEM) continue to be a common malformation seen in the pediatric patient population. This study aims to further elucidate the correlation between EEM and cardiac and renal anomalies. A systematic review and meta-analysis to study the incidence of cardiac and renal anomalies associated with syndromic and isolated (EEM). The literature search spanned multiple databases, including Google Scholar, PubMed, Scopus, Web of Science, and MEDLINE. Studies must be focused on EEM and cardiac and/or renal anomalies. Only articles written in English were included. General study characteristics, number of EEM patients, number of cardiac and renal anomalies and whether cases were syndromic were extracted from the studies. Of 1,058 initial studies, 33 were included for meta-analyses. Mean JBI score for all included studies was 92.06%, indicating acceptable study quality. Interrater reliability was high, with a Cohen kappa score for all studies of 0.94. The resulting pooled prevalence of cardiac abnormalities was 20% [95% CI:13-28%], while renal abnormalities were 13% [95% CI: 7-20%]. The most common anomalies were VSD (3.725%) and renal agenesis (2.04%). The presence of syndrome data across studies was not a significant modifier of prevalence rates. Primary limitation is due to heterogeneity in individual study methodology and reporting standards. These results highlight a higher prevalence of cardiac-related conditions than renal anomalies in patients with both syndromic and non-syndromic EEM in the included studies, underscoring the need for thorough clinical evaluations.

Preliminary evidence supporting use of UK consensus definitions for necrotising otitis externa

BackgroundInfections of the external ear canal (EAC) exist as a spectrum of disease from severe otitis externa (SOE) to necrotising otitis externa (NOE), but distinguishing between these is challenging. The UK consensus case definition (UKCCD) was established in 2022, but had not yet been assessed in clinical practice. MethodsAll consecutive adult patients undergoing CT to investigate a diagnosis of possible NOE between November 2018 and October 2019 were prospectively included in the cohort. Clinical diagnosis at baseline and the end of 12 months follow-up were compared to the diagnosis defined by UKCCD. Results55 patients were included in the analysis. 27 % (15/55) had an initial clinical diagnosis of NOE, of which 47 % (7/15) did not have changes on CT consistent with NOE. Only 9 % (5/55) patients had an MRI scan performed within 7 days of the baseline CT. At the end of 12 months, 9 % (5/55) patients had a change in diagnosis to or from NOE. All cases diagnosed as NOE by UKCCD had a clinical diagnosis of ‘NOE’ at baseline, while no cases clinically diagnosed as NOE were mislabelled by UKCCD as ‘not NOE’. All cases that had a change of diagnosis in the 12-month period or had an initial CT with no changes consistent with NOE, were captured by the UKCCD category of ‘possible NOE’. Median duration of antibiotics of clinically defined NOE cases were 14 days of intravenous (IQR: 7.3–23.8), 28 days of oral (IQR: 21.0–40.3), and 49.5 days combined (IQR: 29.8–67.3). ConclusionUKCCD has excellent clinical concordance with clinical diagnosis. Further work is warranted to assess its utility for risk stratification of patients presenting with severe infections of the EAC in a larger cohort.

Sound Measurements in Pulsatile Tinnitus: A Review in 171 Patients.

To evaluate the diagnostic application of external ear canal sound measurements in pulsatile tinnitus (PT). Retrospective chart review on a prospective series of sound measurements. Tertiary referral center. A cohort of 171 PT patients with sound measurements during diagnostic workup for PT (2016-2023). The percentages of PT patients per pathology and diagnosis, with PT objectified by sound measurements. In 57% of the patients, an identifiable etiology that could explain the PT was identified using various imaging modalities. The PT could be detected with a sound measurement in the ear canal in 48% of these patients. In absence of an identifiable etiology, an objective PT was found in only 15% of the cases. PT was more often detected for patients with arterial pathologies than venous or nonvascular pathologies (73% vs 50% and 22%, respectively). Particularly, in PT patients with a DAVF, an objective PT was found for all patients (100%). The sound measurements were found to be more sensitive than auscultation in detecting bruits in PT patients. A sound recording can objectify PT in almost half of the cases with a diagnosis as determined by imaging. In patients where the PT cannot be detected, arterial pathologies (particularly DAVFs) are less likely. Combined with a thorough clinical evaluation and proper imaging studies, sound measurements can be of added value in the clinical pathway of PT patients.

The Prevalence and Awareness of Congenital External Ear Deformity among the School-Age Group: A Cross-Sectional Study.

Congenital outer ear deformities stem from a sequence of disturbances during fetal auricular cartilage embryonic development. A significant gap exists in understanding their prevalence among the school-age group in Saudi Arabia. This cross-sectional study aims to address this knowledge gap to raise awareness about the impact of such disorders. This cross-sectional study targeted parents of children in the school-age group. A multistage cluster sampling technique was employed to ensure the representation of schools. A self-administered Google form survey was used. Data were analyzed using IBM SPSS Statistics for Windows, Version 28.0 (IBM Corp., Armonk, NY). Our study revealed that the majority were males (56.2%), aged 6 to 10 years (49.3%), and attended primary school (69.5%). Chronic illnesses were present in 7.1% of children, with hearing impairment most prevalent (25.9%). Congenital ear deformities affected 2.7% of children, primarily Stahl's ear (35.4%). Limited knowledge about these deformities was observed among respondents (30.3%), yet a significant majority (73.9%) expressed belief in the potential of community awareness to decrease deformity prevalence. The awareness levels were impacted by parental education but showed no significant association with the child's age, gender, or presence of chronic diseases. Our study underscores the noteworthy occurrence of congenital ear deformities among the school-age group, coupled with a notable lack of awareness. Parental education emerges as a key factor influencing awareness levels. It is imperative to prioritize initiatives to bolster awareness and early detection to promote child health.

Issues Concerning the Mechanisms of Bone Conduction.

Air and bone conduction thresholds are used to differentiate between conductive and sensori-neural hearing losses because bone conduction is thought to bypass the conductive apparatus, directly activating the inner ear. However, the suggested bone conduction mechanisms involve the outer and middle ears. Also, normal bone conduction thresholds have been reported in cases of lesions to the conduction pathway. Therefore, further investigation of bone conduction mechanisms is required.

A Step-by-Step Surgical Technique to the Posterior Auricular "Revolving Door" Flap for Conchal Tumor Excision: A Guide for the Surgical and Dermatological Trainee.

Skin cancer is the most common malignancy worldwide and the auricle is particularly vulnerable to the effects of cumulative sun exposure. Reconstruction of auricular defects after skin cancer excision remains a vexing surgical challenge owing to the complex three-dimensional- anatomy of the external ear, particularly in the conchal bowl. The postauricular island "revolving door" flap is a reliable single-stage method for reconstructing anterior auricular and conchal defects. While the revolving door flap is well known in the literature, a clear description of how to use the flap to reconstruct an anterior auricular conchal bowl defect is lacking. Herein, we present a step-by-step description of the surgical technique, using surgical photos of a patient who presented with basal cell carcinoma on their anterior auricular concha.

Evaluation of the Curative Effects of Surgical Intervention in Cases of Congenital Malformation of the Ossicular Chain in Children.

Purpose: Congenital malformation of the ossicular chain results in challenges with hearing and language development in children. We aimed to analyze the clinical characteristics, prognosis, and surgical treatments of different types of congenital ossicular chain malformations in children. Methods: Eight cases (10 ears) treated between October 2019 and February 2022 were analyzed retrospectively. Patients were divided according to the location of the ossicular chain malformation and whether it was complicated by external ear malformation. Imaging, audiological examination, intraoperative exploration of the middle ear, and postoperative outcomes were recorded. Results: Group 1 incudostapedial joint deformity): 6 ears/60%; Group 2 (simple incus deformity): 2 ears/20%; Group 3 (simple malleus deformity): 2 ears/20%; Group A (with external ear malformations): 4 ears/40%; Group B (without external ear malformations): 6 ears/60%. The average hearing threshold before and after the operation was 51.25 ± 12.88 and 31.94 ± 12.96 dB, respectively. There were differences in the intervention effects of different malformed sites (Group 1: t = 5.139, P = .004; Group 2: t = 13.500, P = .047; Group 3: t = 15.000, P = .042). The effect of the intervention in cases of malformation with mobile stapes footplates was better than that with immobile stapes footplates (t = 4.082, P = .027). The effect of the intervention without external ear malformations was better than that with external ear malformations (t = 7.706, P = .001). Conclusions: The intervention yielded superior results in cases of malformation with mobile stapes footplates compared to those with immobile stapes footplates. Different intervention strategies should be determined through precise deformity assessments, with the degree of stapes mobility serving as a crucial factor in improving the prognosis.

Anthropometric Measurements of External Ear of Medical Students in Rupandehi District of Nepal

Anthropometric Measurements of External Ear of Medical Students in Rupandehi District of Nepal

Treacher Collins Syndrome 2 caused by a novel pathogenic variant in PLOR1D: clinical report and literature review

Objective: To investigate the clinical features, molecular etiology, and treatment of a family with Treacher Collins Syndrome 2 (TCS2). Methods: Information of the proband (female, 8 years old) including medical history and family history was collected. Physical examination and examinations concerning laboratory, audiology, and radiology were performed on the proband. Physical examination was also performed on the family members. Genomic DNA of proband was extracted for whole exome sequencing, and then the genomic DNA of family members was extracted for Sanger sequencing. POLR1D and TCS2 related literatures published before August 31,2023 were searched and sifted in PubMed and CKNI databases. The clinical characteristics of TCS2 were summarized. Results: The proband had poor hearing since childhood, with pure tone audiometry indicating conductive hearing loss. She had a smaller jaw, bilateral preauricular fistulas and cup-shaped ear deformities. Temporal bone CT scan revealed deformities in the left external ear canal, bilateral middle ear and inner ear. A bone-conduction hearing aid device was surgically implanted, resulting in restoration of almost normal hearing levels. The proband's mother also had a slightly smaller jaw. Genetic analysis revealed a novel heterozygous variant NM_015972.4:c.38_47del in the POLR1D gene in the proband, which was inherited from her mother. A review of the literature revealed no clear evidence of genotype-phenotype correlation in TCS2. Conclusions: Molecular diagnosis plays a vital role in the diagnosis of TCS2. Patients with normal facial phenotype may be carriers of pathogenic variants in the POLR1D gene and have the risk of passing it to the offsprings with complete penetrance. Proper bone conductive hearing devices can improve the quality of life of TCS2 patients.

Audio-Vestibular Evaluation of Pediatric Pseudo-Conductive Hearing Loss: Third Window Syndromes.

Conductive hearing loss caused by external or middle ear problems prevents the transmission of sound waves from the external auditory canal to the cochlea, and it is a common condition, especially in pediatric patients aged 1-5 years. The most common etiological factors are otitis media and cerumen during childhood. In some patients, external and middle ear functions and structures may be normal bilaterally despite the air-bone gap on the audiogram. This condition, which is often a missed diagnosis in children, is defined as a pseudo-conductive hearing loss (PCHL) caused by third window syndromes (TWSs) such as semicircular canal dehiscence, inner ear malformations with third window effect, and perilymphatic fistula. In this review of the literature, the authors emphasize the pitfalls of pediatric audio-vestibular evaluation on TWSs as well as the key aspects of this evaluation for the differential diagnosis of PCHL brought on by TWSs. This literature review will provide audiologists and otologists with early diagnostic guidance for TWSs in pediatric patients.

Exploration of technique for preservation of external-middle ear structure in surgery of jugular foramen paraganglioma （appended 2 case reports）

Objective:To investigate the feasibility and effect of the modified surgery of the classic infratemporal fossa type A approach for the surgical treatment of jugular foramen paraganglioma with preservation of the external and middle ear structures. Methods:The medical data of 2 patients with jugular foraminal paraganglioma treated by sublabyrinthic-transmastoid approach were retrospectively analyzed. The clinical feature, degree of tumor resection, postoperative facial nerve function and hearing retention, and the incidence of postoperative complications were evaluated. Results:Two patients were both female, and were pathologically confirmed as paraganglioma. The tumor of case 1 was staged as C2De1, and case 2 as C1De1. Tumors were completely resected in both patients. Case 1 suffered infection after surgery, with residual tympanic membrane perforation and mixed deafness. Case 2 developed mild facial paralysis（grade Ⅱ） after surgery, and recovered after symptomatic treatment. There was no tumor residue or recurrence during half a year of follow-up. Conclusion:Surgical treatment of certain paragangliomas in the jugular foramen with a combined sublabyrinthic-transmastoid and upper neck approach might achieve both complete resection of the tumor and preserving the structure and function of the outer-middle ear. This procedure is suitable for paragangliomas restricted in the jugular foramen area, with no or limited involvement of the internal carotid artery（C1 or C2）, and with no or mild hearing loss.

First report on the occurrence of psoroptic mange in llamas (Lama glama) of the Andean region.

An outbreak of Psoroptes sp.-caused mange was detected in a llama herd of Larcas, Jujuy province, Argentina. Infested llamas showed alopecia, erythema, hyperpigmentation, hyperkeratosis, and inflammation of the ear pinnae, as well as crusts and serous, serosanguineous, or purulent drainage with unpleasant smell in the external ear canal. Microscopic evaluation of skin scrapings revealed 0.5- to 0.7-mm-long acari identified as Psoroptes sp. based on their morphology. Histology showed a typical allergic reaction with perivascular to periadnexal mixed inflammatory infiltrate. Phylogenetic tree analysis showed that the cytochrome c oxidase subunit I gene sequences analyzed from the sampled acari clustered into a single P. ovis clade including sequences isolated from rabbits and bighorn sheep, with P. natalensis as a sister taxon that infested bighorn sheep from the USA. Phylogenetic analysis of cytochrome b sequences showed three well-supported clades, one of which contained the sequences of the Larcas llamas and US bighorn sheep isolates. This is the first report on P. ovis infestation of llamas raised in their original location. Investigations on mange etiological agents acting on South American camelids and their distribution are necessary to implement control strategies to mitigate the negative impacts of these parasitic infections.

External Auditory Canal Erosion at the 6 O'clock Spot.

To report a common site of external ear canal erosion in multiple pathologies, located inferiorly at 6 o'clock. Otology patients who came in 2023 for treatment of external auditory canal erosions. This clinical capsule is an observational report of the external canal's propensity to erosion at the 6 o'clock location. Patient treatments were canalplasty, mastoidectomy, and medical management. Documentation of the propensity to erosion at the 6 o'clock location in the external auditory canal. Locations of the niduses of prior series of external auditory canal pathologies are documented. Eight patients are presented with external auditory canal erosion in 10 ears originating at the 6 o'clock position medial to the bony-cartilaginous junction. No other patient with spontaneous canal erosion presented with their nidus of pathology in another canal location. (A review of 42 case series of 291 patients found that keratosis obturans and bisphosphonate-induced osteonecrosis tended to arise from the same 6 o'clock lateral bony canal location, while 26% of necrotizing otitis externa cases arose there.). The "6 o'clock spot" in the external canal is a common location of canal erosion for spontaneous wax and keratin collections and may be the precursor to keratosis obturans, bisphosphonate-induced osteonecrosis of the ear canal, and necrotizing otitis externa.

Clinical outcome of cats with suppurative otitis media and intact tympanum submitted to myringotomy: retrospective findings from 26 cases.

The efficacy of medical treatment associated with single myringotomy in cats with suppurative otitis media (OM) and intact tympanum was retrospectively evaluated. Patients' records were retrieved from cats with suppurative OM. Cats were included in this retrospective study based on fluid content within the tympanic cavity on imaging, intact tympanum on otoendoscopic examination and neutrophils on ear bulla exudate cytological examination. A total of 26 cats with middle ear suppurative otitis were included. Just over half of the cats (54%) presented bilateral involvement. Clinical signs included head tilt (13/26), otalgia (9/26), Horner's syndrome (7/26), external ear discharge (5/26), and nystagmus and facial paralysis (1/26). Cocci were identified on cytological examination in 18/40 samples and rods in 2/40. Bacterial culture results were positive in 15/40 samples, with Pseudomonas species (4/15), Pasteurella multocida (3/15), Staphylococcus felis (3/15), Staphylococcus schleiferi (2/15), Staphylococcus canis (2/15), Escherichia coli (2/15), Staphylococcus pseudintermedius (1/15) and Serratia marcesens (1/15) isolation. After myringotomy and gentle flushing of middle ear bullae (0.5-2 ml saline per ear), all cats were treated with oral corticosteroids and a 1-month course of systemic antibiotics according to sensitivity testing. In total, 19 (73%) cats were clinically healed 60-240 days after treatment. One cat was euthanased because of failure to eradicate a Pseudomonas species infection. Another cat died a few hours after the procedure. The five remaining cats were cured after ventral bulla osteotomy. OM without an aural polyp is a frequent diagnosis in cats, but data on medical treatment are scarce. This simple therapeutic technique, single myringotomy procedure and mild ear flushing, offers a practical, safe and efficient first-line treatment of suppurative OM with an intact tympanum in cats with or without neurological signs.

Effect of ear cleaning on treatment outcome for canine otitis externa.

Ear cleaning is often recommended for management of canine otitis externa (OE). Few invivo studies evaluate how ear cleaning affects treatment outcome. To determine the effect of ear cleaning on canine OE by comparing treatment outcome in cleaned versus noncleaned ears. Twenty-three client-owned dogs with ceruminous or purulent OE. Forty ears were randomised to one of two groups: 20 ears were wiped with dry or saline-moistened gauze (grp1), and 20 external ear canals received manual cleaning (grp2) with a commercial product. One millilitre of a commercial otic suspension containing hydrocortisone aceponate, miconazole nitrate and gentamicin sulfate was applied to affected ears every 24 h for five days. Cytological scores, modified otitis index score (OTIS3), pruritus Visual Analog Scale (PVAS), modified PVAS and client questionnaire were compared on Day (D)0 and D7. There were no statistical differences between cytological scores, modified OTIS3, PVAS, modified PVAS or client assessments between groups at D7. Both groups had significant reduction in all treatment parameters from D0 to D7 with the exception of cytological rod scores that were only significantly decreased in cleaned ears. There was a significant difference in OTIS3 before and after cleaning on D0. Both groups achieved successful outcome regardless of cleaning. Ear cleaning may be more important when rod-shaped bacteria are present.

Otomycosis: Epidemio-Clinical and Therapeutic Profile at the Fousseyni DAOU Hospital in Kayes, Mali

Introduction: Otomycosis is a relatively common pathology of the external ear canal, its prevalence is estimated to be 5 to 10% of all otitis externa [1,2, 3]. There are no data on otomycosis at the Kayes Hospital, hence the interest of this study. Methodology: This was a descriptive study with retrospective data collection that spanned the period from January 1, 2021 to December 31, 2023. All patients with clinically suspected otomycosis on otoscopy, otoendoscopy and/or confirmed on mycological examination and with usable medical records were included. Results: We recorded 1156 cases of otitis externa, including 384 cases of otomycosis, i.e. a frequency of 33.2%. Females were the most represented at 51.6% (n=198) with a sex ratio of 0.93. The mean age was 37 years with extremes of 7 and 77 years. The reasons for consultation were: otalgia 44.8% (n=172), pruritus 35.2% (n=135), otorrhea 20% (n=77). The main contributing factors were cleaning the ear with cotton swab, 57.8% (n=221), wearing a turban 26.3% (n=101), and using antibiotic and corticosteroid drops 9.6% (n=37). The otologic examination revealed whitish or blackish deposits, purulent otorrhea and inflammation of the external auditory canal. Mycological examination found yeasts 42.3% (n=122) and molds 57.2% (n=163). Treatment was based on topical antifungals and antibiotics in 69% (n=265) and the combination of antifungal and antihistamine in 31% (n=119). Conclusion: Otomycoses are benign, chronic infectious pathologies. Their occurrence is multifactorial. Cleaning with the cotton swab and wearing the turban were the main causes. Keywords: Otomycosis, Fousseyni DAOU Hospital in Kayes.

The Effects of Viral Infections on the Molecular and Signaling Pathways Involved in the Development of the PAOs.

Cytomegalovirus infection contributes to 10-30% of congenital hearing loss in children. Vertebrate peripheral auditory organs include the outer, middle, and inner ear. Their development is regulated by multiple signaling pathways. However, most ear diseases due to viral infections are due to congenital infections and reactivation and affect healthy adults to a lesser extent. This may be due to the fact that viral infections affect signaling pathways that are important for the development of peripheral hearing organs. Therefore, an in-depth understanding of the relationship between viral infections and the signaling pathways involved in the development of peripheral hearing organs is important for the prevention and treatment of ear diseases. In this review, we summarize the effects of viruses on signaling pathways and signaling molecules in the development of peripheral auditory organs.

Prevalence of group B Streptococcus colonisation in mother–newborn dyads in low-income and middle-income south Asian and African countries: a prospective, observational study

Rectovaginal group B Streptococcus (GBS) colonisation in pregnant individuals at the time of labour is a major risk factor for invasive GBS disease by age 7days (early-onset disease). We aimed to investigate the prevalence of rectovaginal GBS colonisation at the time of labour among pregnant women and vertical transmission to their newborns across selected low-income and middle-income African and south Asian countries. This prospective, observational study was undertaken at 11maternity and obstetric care facilities based in Ethiopia, Kenya, Mozambique, Nigeria, Mali, South Africa, Bangladesh, India, and Bhutan. HIV-negative pregnant women aged 18-45years who were in the early stages of labour and at least 37weeks' gestation were eligible for inclusion. Lower vaginal and rectal swabs and urine were collected from the women, and swabs of the umbilicus, outer ear, axillary fold, rectum, and throat were obtained from their newborns, for GBS culture. Standardised sampling and culture using direct plating and selective media broth for detection of GBS colonisation was undertaken at the sites. Serotyping of GBS isolates was done in South Africa. The primary outcome was the prevalence of rectovaginal GBS among pregnant women, analysed in participants with available data. This study is registered with the South African National Clinical Trials Register, number DOH-27-0418-4989. 6922pregnant women were enrolled from Jan 10, 2016, to Dec 11, 2018, of whom 6514 (94·1%; 759-892per country) were included in the analysis; data from Bhutan were not included in the study due to issues with specimen collection and processing. Overall, the prevalence of maternal GBS colonisation was 24·1% (95% CI 23·1-25·2; 1572of 6514); it was highest in Mali (41·1% [37·7-44·6]; 314of 764) and lowest in Ethiopia (11·6% [9·5-14·1]; 88of 759). Theoverall rate of vertical transmission of GBS from women with rectovaginal GBS colonisation was 72·3% (70·0-74·4; 1132of 1566); it was highest in Mozambique (79·2% [73·3-84·2]; 168of 212) and lowest in Bangladesh (55·8%, 47·5-63·8; 77of 138). The five most common GBS colonising serotypes were Ia (37·3% [34·9-39·7]; 586of 1572), V(28·5% [26·3-30·8]; 448of 1572), III (25·1% [23·0-27·3]; 394of 1572), II (9·2% [7·8-10·7]; 144of 1572), and Ib(6·5% [5·4-7·8]; 102of 1572). There was geographical variability in serotype proportion distribution; serotype VIIwas the third most common serotype in India (8·6% [5·3-13·7]; 15of 174) and serotype VI was mainly identified in Bangladesh (5·8% [3·0-11·0]; eight of 138) and India (5·7% [3·2-10·3]; ten of 174). Our study reported a high prevalence of GBS colonisation in most settings, with some geographical variability even within African countries. Our findings suggest that serotypes not included in current multivalent capsular-polysaccharide GBS vaccines prevail in some regions, so vaccine efficacy and post-licensure effectiveness studies should assess the effect of vaccination on maternal GBS colonisation given the potential for replacement by non-vaccine serotypes. Bill & Melinda Gates Foundation.

3D Computational Modeling of Blast Wave Transmission in Human Ear From External Ear to Cochlear Hair Cells: A Preliminary Study.

Auditory disabilities like tinnitus and hearing loss caused by exposure to blast overpressures are prevalent among military service members and veterans. The high-pressure fluctuations of blast waves induce hearing loss by injuring the tympanic membrane, ossicular chain, or sensory hair cells in the cochlea. The basilar membrane (BM) and organ of Corti (OC) behavior inside the cochlea during blast remain understudied. A computational finite element (FE) model of the full human ear was used by Bradshaw etal. (2023) to predict the motion of middle and inner ear tissues during blast exposure using a 3-chambered cochlea with Reissner's membrane and the BM. The inclusion of the OC in a blast transmission model would improve the model's anatomy and provide valuable insight into the inner ear response to blast exposure. This study developed a microscale FE model of the OC, including the OC sensory hair cells, membranes, and structural cells, connected to a macroscale model of the ear to form a comprehensive multiscale model of the human peripheral auditory system. There are 5 rows of hair cells in the model, each row containing 3 outer hair cells (OHCs) and the corresponding Deiters' cells and stereociliary hair bundles. BM displacement 16.75 mm from the base induced by a 31 kPa blast overpressure waveform was derived from the macroscale human ear model reported by Bradshaw etal. (2023) and applied as input to the center of the BM in the OC. The simulation was run for 2 ms as a structural analysis in ANSYS Mechanical. The FE model results reported the displacement and principal strain of the OHCs, reticular lamina, and stereociliary hair bundles during blast transmission. The movement of the BM caused the rest of the OC to deform significantly. The reticular lamina displacement and strain amplitudes were highest where it connected to the OHCs, indicating that injury to this part of the OC may be likely due to blast exposure. This microscale model is the first FE model of the OC to be connected to a macroscale model of the ear, forming a full multiscale ear model, and used to predict the OC's behavior under blast. Future work with this model will incorporate cochlear endolymphatic fluid, increase the number of OHC rows to 19 in total, and use the results of the model to reliably predict the sensorineural hearing loss resulting from blast exposure.

Hemifacial microsomia – a review of the literature of current hypotheses of pathogenesis, and possible therapeutic methods

<b>Introduction:</b> Hemifacial microsomia (HFM) is the second most common congenital craniofacial anomaly.<b>Aim:</b> The aim of this study is to review data related to HFM.<b>Materials and methods:</b> Materials for the review were selected based on an analysis of publications published in the last 10 years.<b>Results:</b> There are three possible models of pathogenesis – vascular abnormalities, Meckel’s cartilage damage, and abnormal development of cranial neural crest cells – caused by genetic, maternal, and external factors. Symptoms results from disorders of structures originating from the first, and second branchial arches, most commonly resulting in mandibular hypoplasia, microtia or anotia, hypoplasia of the auditory ossicles, facial nerve paralysis, and soft tissue deficiency. The severity of the disorder varies greatly, depending on the number of structures involved, and the degree of penetration. The most common classification system (Orbit, Mandible, Ear, Nerve, Soft tissue; OMENS) has recently been proposed to assess the temporomandibular joint disc, and to assess disturbances originating from another structures. Other classifications such as FACIAL or ICHOM criteria have also been developed. The approach to treating each case should be individualized, primarily focusing on reconstructing the underdeveloped mandible, orthodontic treatment, creating the external ear, and filling soft tissue deficiencies.<b>Discussion:</b> The complexity of the condition is noted, as well as the need for interdisciplinary patient care.<b>Conclusions:</b> Through analysis of existing research, and clinical data, significant information regarding etiology, symptoms, possible classification systems, and therapeutic options has been gathered.