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Journal of Morphology Oct 2022The morphology of the mammalian middle ear-including the size, shape, and stiffness of individual ossicles-controls their vibrational response to sound and, is closely...
The morphology of the mammalian middle ear-including the size, shape, and stiffness of individual ossicles-controls their vibrational response to sound and, is closely related to an animal's auditory capabilities. While the relationship between middle ear morphology and hearing frequency has been explored in living carnivorans, the size and shape of ossicles in fossil carnivorans have been sparsely documented. In this study, we present the first morphological data on four iconic carnivoran taxa from the Rancho La Brea Tar Pits: Smilodon fatalis, Panthera atrox, Canis dirus, and Arctodus simus. These data are contextualized with samples of extant felids, canids, and ursids to determine the extent to which the ossicles of these iconic fossil taxa resemble their living relatives. Six, five, and seven linear measurements were taken from the malleus, incus, and stapes, respectively. Comparisons of geometric means reveal that the ossicles of fossil canids and felids are similar in size to living analogs, but those of A. simus are significantly larger than those of any living ursid. Further, principal components analyses demonstrate close morphological affinities between fossil and extant taxa within canids and felids, and again, a greater disparity between fossil and extant ursids. Canids and ursids occupy distinct regions of the morphospace, yet both overlap the morphological range spanned by felids. While some elements-for example, the stapes-require further specimens to facilitate more nuanced interpretations of variation, our findings underscore the need for concerted efforts towards identifying and preserving these bones within fossil assemblages.
Topics: Animals; Ear, Middle; Felidae; Fossils; Mammals; Principal Component Analysis
PubMed: 36041006
DOI: 10.1002/jmor.21506 -
Annals of Translational Medicine Nov 2022Currently, the optimum surgical approach for treating adherent otitis media is debatable. The traditional treatment is usually performed by microscopic tympanoplasty...
BACKGROUND
Currently, the optimum surgical approach for treating adherent otitis media is debatable. The traditional treatment is usually performed by microscopic tympanoplasty combined with temporal myofascial tympanic tube placement. In recent years, the application of whole ear endoscopic surgery in the treatment of middle ear diseases has gradually increased, otoendoscopy has been used in the operation of adhesive otitis media, but its safety and effectiveness are still controversial.
METHODS
This study retrospectively analyzed 17 patients with adhesive otitis media treated by endoscopic ear surgery (EES) in our hospital from January 2018 to July 2021 over a 6-month period post-surgery. Of the 17 patients, 8 were males and 9 were females (mean age, 53 years; age range, 24-70 years). There were 12 and 5 cases of adhesive otitis media involving the left and right ear, respectively. The patients had follow-up evaluations 1 week, 2 weeks, 1 month, 3 months, and 6 months after surgery.
RESULTS
A total of 17 patients with adhesive otitis were enrolled, including 1 patient with Dornhoffer stage II; 6 patients with stage III; and 10 patients with stage IV. Adhesive otitis media was combined with middle ear cholesteatoma in 4 patients (24%). Fourteen patients (82%) had disruption or interruption of the ossicular chain (8 malleus, 14 incus, and 4 stapes lesions), 11 of whom had artificial ossicular chain reconstruction [8 with partial ossicular reconstruction prosthesis (PORP) and 3 with total ossicular reconstruction prosthesis (TORP) implantation]. All patients had good tympanic membrane and graft morphology, no invaginations, and no perforations. The mean postoperative air-conduction hearing threshold [49.06±22.15 dB hearing level (dB HL)] and mean air-bone gap (19.94±10.00 dB HL) were significantly improved compared with the preoperative values (65.29±21.53 and 32.53±8.21 dB HL, respectively; P<0.05). No recurrences, secondary cholesteatomas, or secondary surgeries were reported.
CONCLUSIONS
EES seems to be a safe and effective surgical method for the management of adhesive otitis media. The study has limitations due to its small sample size and lack of controlled studies. It still needs to be proven in clinical randomized controlled trials.
PubMed: 36544640
DOI: 10.21037/atm-22-4831 -
Medicina (Kaunas, Lithuania) Sep 2023: The diagnosis of cholesteatoma is usually clinic, and the only efficient treatment is surgical. High-resolution computed tomography (HRCT) is not considered absolutely...
: The diagnosis of cholesteatoma is usually clinic, and the only efficient treatment is surgical. High-resolution computed tomography (HRCT) is not considered absolutely necessary for the management of an uncomplicated cholesteatoma, but unsuspected situations from a clinical point of view can be discovered using the scans, warning the surgeon. Our objective is to compare HRCT scan information with intraoperative findings in patients with cholesteatoma and analyze the usefulness of a preoperative HRCT scan from a surgical point of view. : This is a prospective descriptive study conducted in the Department of Otolaryngology, Victor Babes University of Medicine and Pharmacy Timisoara, Romania, from May 2021 to April 2022. It was carried out on 46 patients with a clinical diagnosis of cholesteatoma who were consequently operated on in our department. All patients received full clinical and audiological examinations. In all cases, an HRCT scan was performed preoperatively as a mandatory investigation. Preoperative HRCT scans were analyzed, and their findings were compared to the intraoperative notes. The two sets of observations were analyzed using standard statistical methods. : Extensive cholesteatoma was the most common type of disease, involving 46% of the patients, followed by pars flaccida cholesteatoma (35%) and pars tensa cholesteatoma (19%). Eroded scutum was the most frequent lesion involving 70% of the patients, followed by incus erosion (67%). Comparison of the HRCT and intraoperative findings revealed a very good correlation for tegmen tympani erosion, sigmoid plate erosion, scutum and malleus erosion, and a moderate-to-good correlation for lateral semicircular canal erosion, incus and stapes erosion, and fallopian canal erosion. : HRCT is a valuable tool in the preoperative assessment of cholesteatoma, helping in making surgical decisions. It can accurately predict the extent of disease and is helpful for detecting unapparent dangerous situations. However, it is not very accurate in detecting fallopian canal and stapes erosion.
Topics: Humans; Cholesteatoma, Middle Ear; Ear, Middle; Tomography, X-Ray Computed; Prospective Studies; Ambulatory Care Facilities; Retrospective Studies
PubMed: 37893430
DOI: 10.3390/medicina59101712 -
Ear, Nose, & Throat Journal Jun 2020Our aim was to investigate the relationship between facial canal dehiscence (FCD) and surgical findings and procedures in patients with cholesteatoma. A total of 186...
Our aim was to investigate the relationship between facial canal dehiscence (FCD) and surgical findings and procedures in patients with cholesteatoma. A total of 186 patients (118 males, 39.2 ± 15 years) who underwent surgery for advanced cholesteatoma between 2013 and 2018 were included in the study. The relationship between FCD and surgical findings was investigated via the surgical registries. The prevalence of FCD was 36.6% (68/186). The prevalence of FCD was 44%, and 13.2% for the patients who underwent canal wall down mastoidectomy (62/141) and canal wall up mastoidectomy (6/45), respectively ( < .001). Facial canal dehiscence was detected in 73.9% of the 23 patients who had a lateral semicircular canal (LSCC) defect ( < .001), in 61.9% of 21 patients who had a tegmen tympani defect, and in 58.1% of the 31 patients who had erosion on the posterior wall of the external auditory canal (EAC; < .05). The prevalence of FCD was 3.1% in patients with isolated incus erosion, 59.1% in patients with erosion of malleus and incus, 60.7% in patients with erosion of stapes suprastructure and incus, and 43.2% in patients with whole ossicular chain deformation ( < .001). The defects on LSCC, EAC, tegmen tympani, and malleus and incus might be cautionary findings for the presence of FCD during cholesteatoma surgery.
Topics: Adult; Cholesteatoma, Middle Ear; Ear Ossicles; Facial Nerve; Facial Nerve Injuries; Female; Humans; Incidental Findings; Male; Mastoidectomy; Middle Aged; Retrospective Studies; Semicircular Canal Dehiscence; Semicircular Canals
PubMed: 31203653
DOI: 10.1177/0145561319856886 -
Medical Hypotheses Sep 2019There is large support in literature linking tinnitus to dental occlusion and temporomandibular joint disorders (TMD). However, there is no model to explain such a link....
There is large support in literature linking tinnitus to dental occlusion and temporomandibular joint disorders (TMD). However, there is no model to explain such a link. This hypothesis explains how the fusimotor system of the muscles innervated by the trigeminal motor nucleus is affected by inadequacies in the occlusion of the teeth that cause changes in posture and movement of the mandible. Reptile to mammal evolution shows that stomatognathic structures underwent changes related to mastication. Among several changes, there was the appearance of a new articulation between the mandible and skull: the temporomandibular joint. The bones of the old reptile joint, quadrate-articular, have detached from the mandible and are part of the middle ear bone chain. The former becomes the incus and the latter the malleus. This bone change also carried the tensor tympani and its trigeminal motor innervation. Inadequate occlusal contacts give rise to an adapted function of the mandible and the most common compensatory muscular response is hypertonia involving all mandibular muscles, including the tensor tympani. A fundamental clinical feature that demonstrates the involvement of the trigeminal fusimotor system is the characteristic pain by palpation, but no pain on the mandibular movement. Muscle pain is always felt in the dermatome innervated by the mandibular branch of the trigeminal nerve, which carries the motor fibers, reported as tightening, similar to cramp, and has regular behavior in intensity, duration and frequency. In addition, the patient has increased musculature volume, detected by palpation of certain anatomical landmarks, but with loss of functional efficiency. The neuromotor control of the mandibular movements is poor and when asked to make lateral jaw movement touching the teeth, it is common to observe that the patient moves the lips, eyes, and even turns the head in the same direction as the movement. There is also difficulty eating hard foods and talking fast. Tongue biting while chewing is frequent, meaning that these non-physiological events surpass protective reflex circuits. The report of ear pain, tinnitus, blocked ear sensation and sudden hearing loss is common in such patients, compatible with the tonic contraction of the tensor tympani. The fusimotor system hypothesis is able to explain all events related to the symptoms and helps to establish a correct diagnosis for certain types of hearing disorders.
Topics: Biological Evolution; Dental Occlusion; Humans; Hyperkinesis; Mandible; Mastication; Models, Theoretical; Movement; Temporal Muscle; Temporomandibular Joint; Temporomandibular Joint Disorders; Tensor Tympani; Tinnitus; Tooth; Trigeminal Motor Nucleus
PubMed: 31383322
DOI: 10.1016/j.mehy.2019.109280 -
Journal of Anatomy Aug 2022The vascular supply of the human auditory ossicles has long been of anatomical and clinical interest. While the external blood supply has been well-described, there is...
The vascular supply of the human auditory ossicles has long been of anatomical and clinical interest. While the external blood supply has been well-described, there is only limited information available regarding the internal vascular architecture of the ossicles, and there has been little comparison of this between individuals. Based on high-resolution micro-CT scans, we made reconstructions of the internal vascular channels and cavities in 12 sets of ossicles from elderly donors. Despite considerable individual variation, a common basic pattern was identified. The presence of channels within the stapes footplate was confirmed. The long process of the incus and neck of the stapes showed signs of bony erosion in all specimens examined. More severe erosion was associated with interruption of some or all of the main internal vascular channels which normally pass down the incudal long process; internal excavation of the proximal process could interrupt vascular channels in ossicles which did not appear to be badly damaged from exterior inspection. An awareness of this possibility may be helpful for surgical procedures that compromise the mucosal blood supply. We also calculated ossicular densities, finding that the malleus tends to be denser than the incus. This is mainly due to a lower proportion of vascular channels and cavities within the malleus.
Topics: Aged; Ear Ossicles; Ear, Middle; Humans; Incus; Malleus; Tomography, X-Ray Computed
PubMed: 35357009
DOI: 10.1111/joa.13661 -
Laryngoscope Investigative... Dec 2022The association between the chorda tympani nerve (CTN) and atresiaplasty has not been investigated. This study aimed to describe the course of the CTN observed during...
OBJECTIVES
The association between the chorda tympani nerve (CTN) and atresiaplasty has not been investigated. This study aimed to describe the course of the CTN observed during atresiaplasty for congenital aural atresia (CAA) and explore the feasibility of CTN preservation.
METHODS
In this retrospective study, six consecutive patients who underwent atresiaplasty in a tertiary academic center were included. The course of the tympanic segment of the CTN and its preservation feasibility were evaluated. Atresiaplasty was performed using an anterior approach. The average Jahrsdoerfer score was 8.7 points (range, 8-9 points).
RESULTS
The CTN was located in the atretic plate in all patients. It emerged from an average of 5.6 mm (range, 5.2-6.1) inferior to the incus buttress and crossed the middle ear in an anterior-superior direction. The distance between the neck of the malleus and the CTN varied in the absence of the malleus handle. However, when the malleus handle developed, the CTN passed between the incus and the malleus handle. The CTN was preserved in two of the six patients. They had a Jahrsdoerfer score of 9 and grade I microtia.
CONCLUSION
The CTN was located in the atretic plate, emerging from an average distance of 5.6 mm inferior to the incus buttress. The incus buttress might serve as a good anatomical landmark to identify and preserve the CTN. CTN preservation is feasible in atresiaplasty candidates with a Jahrsdoerfer score of 9 and auricular deformity of grade I.
LEVEL OF EVIDENCE
4.
PubMed: 36544945
DOI: 10.1002/lio2.938 -
Anatomical Record (Hoboken, N.J. : 2007) Nov 2023Echolocation is the primary sense used by most bats to navigate their environment. However, the influence of echolocating behaviors upon the morphology of the auditory...
Echolocation is the primary sense used by most bats to navigate their environment. However, the influence of echolocating behaviors upon the morphology of the auditory apparatus remains largely uninvestigated. While it is known that middle ear ossicle size scales positively with body mass across mammals, and that peak call frequency scales negatively with body mass among bats, there are still large gaps in our understanding of the degree to which allometry or ecology influences the morphology of the chiropteran auditory apparatus. To investigate this, we used μCT datasets to quantify three morphological components of the inner and middle ear: ossicle size, ossicle shape, and cochlear spirality. These data were collected across 27 phyllostomid species, spanning a broad range of body sizes, habitats, and dietary categories, and the relationships between these variables and ear morphology were assessed using a comparative phylogenetic approach. Ossicle size consistently scaled with strong negative allometry relative to body mass. Cochlear spirality was significantly (p = .025) associated with wing aspect ratio (a proxy for habitat use) but was not associated with body mass. From a morphological perspective, the malleus and incus exhibited some variation in kind with diet and call frequency, while stapes morphology is more closely tied to body size. Future work will assess these relationships within other chiropteran lineages, and investigate potential morphological differences in the middle and inner ear of echolocating-vs-non-echolocating taxa.
Topics: Animals; Phylogeny; Chiroptera; Ear, Inner; Echolocation; Incus
PubMed: 36823766
DOI: 10.1002/ar.25178 -
Cell Stem Cell Feb 2021The tympanic membrane (TM) is critical for hearing and requires continuous clearing of cellular debris, but little is known about homeostatic mechanisms in the TM...
The tympanic membrane (TM) is critical for hearing and requires continuous clearing of cellular debris, but little is known about homeostatic mechanisms in the TM epidermis. Using single-cell RNA sequencing, lineage tracing, whole-organ explant, and live-cell imaging, we show that homeostatic TM epidermis is distinct from other epidermal sites and has discrete proliferative zones with a three-dimensional hierarchy of multiple keratinocyte populations. TM stem cells reside in a discrete location of the superior TM and generate long-lived clones and committed progenitors (CPs). CP clones exhibit lateral migration, and their proliferative capacity is supported by Pdgfra+ fibroblasts, generating migratory but non-proliferative progeny. Single-cell sequencing of the human TM revealed similar cell types and transcriptional programming. Thus, during homeostasis, TM keratinocytes transit through a proliferative CP state and exhibit directional lateral migration. This work forms a foundation for understanding TM disorders and modeling keratinocyte biology.
Topics: Epidermal Cells; Epidermis; Humans; Keratinocytes; Stem Cells; Tympanic Membrane
PubMed: 33181078
DOI: 10.1016/j.stem.2020.10.006 -
Indian Journal of Otolaryngology and... Sep 2023Previous studies of the middle ear in Chronic Otitis Media have focussed on radiological assessment of temporal bone; endoscopic studies were focussed on perforation...
UNLABELLED
Previous studies of the middle ear in Chronic Otitis Media have focussed on radiological assessment of temporal bone; endoscopic studies were focussed on perforation size and location. The malleus handle (manubrium) is a constant ossicular feature visible on otoendoscopy. It's relative position may indicate the previously documented differences in ossicular chain and middle ear cleft development relative to the tympanic ring and inner ear capsule between affected ear and contralateral ear.
DESIGN
descriptive.
SETTING
hospital based.
SUBJECTS
84 patients with unilateral mucosal chronic otitis media.
METHODS
each patient underwent Otoendoscopy and the findings were recorded through a camera connected to a laptop. Using image j software these images were analysed. Participants were of mean age of 35 years with left preponderance, and no gender preponderance was found. In our study, majority of the perforations were small sized perforations. The malleus handle foreshortening was about 92.6% compared to unaffected ear which was statistically insignificant. There was a significant inter group difference in the distance between the tip of the manubrium and the inferior annulus-which was decreased in affected ears and in the distance from the lateral process to the anterior tympanic ring-which was increased in affected ears. There was no difference in the malleo scutal angles. These differences were not dependent on the site or size of the perforation. The differences we found between ears were unexpected. The significance of the differences in the shape of the tympanic membrane between affected and unaffected ears in unilateral mucosal COM need further study. We did not find a statistically significant difference in the malleo-scutal angles between ears.
PubMed: 37636676
DOI: 10.1007/s12070-023-03797-z