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European Annals of Otorhinolaryngology,... May 2017The Eustachian (auditory) tube and tympanomastoid cavities form an anatomic and functional whole that cannot easily be divided, and is therefore known as the... (Review)
Review
The Eustachian (auditory) tube and tympanomastoid cavities form an anatomic and functional whole that cannot easily be divided, and is therefore known as the "tubotympanic system". The system has been the focus of several studies, with complex and sometimes contradictory results, making an overview of its functioning difficult to obtain. The objective of the present article is to review the current state of knowledge, as an indispensable preliminary to understanding tubotympanic system dysfunction, and notably the development of chronic otitis. The system as a whole is covered by mucosa, which provides continuity, although with certain particularities from one area to another, and plays a primordial role. Thus, under physiological conditions, gas diffusion across the tympanomastoid mucosa largely ensures the equilibrium of pressure between the middle ear and outside environment, the tube orifice being very little involved. Under large rapid change in atmospheric pressure, the aeration function of the Eustachian tube comes into play, governed by a reflex mechanism. The system also has other functions that are essential to good middle-ear functioning: protection against nasopharyngeal secretions and pathogens and against certain physiological noises; middle-ear cavity clearance by mucociliary transport of pathogens, partly related to submucosal gland secretion; and immune defense.
Topics: Chronic Disease; Ear, Middle; Eustachian Tube; Humans; Mastoid; Mucociliary Clearance; Otitis Media, Suppurative; Tympanic Membrane Perforation
PubMed: 28461039
DOI: 10.1016/j.anorl.2017.03.010 -
The Journal of the Acoustical Society... Apr 2021The mouse is an important animal model for hearing science. However, our knowledge of the relationship between mouse middle-ear (ME) anatomy and function is limited. The...
The mouse is an important animal model for hearing science. However, our knowledge of the relationship between mouse middle-ear (ME) anatomy and function is limited. The ME not only transmits sound to the cochlea in the forward direction, it also transmits otoacoustic emissions generated in the cochlea to the ear canal (EC) in the reverse direction. Due to experimental limitations, a complete characterization of the mouse ME has not been possible. A fully coupled finite-element model of the mouse EC, ME, and cochlea was developed and calibrated against experimental measurements. Impedances of the EC, ME, and cochlea were calculated, alongside pressure transfer functions for the forward, reverse, and round-trip directions. The effects on sound transmission of anatomical changes such as removing the ME cavity, pars flaccida, and mallear orbicular apophysis were also calculated. Surprisingly, below 10 kHz, the ME cavity, eardrum, and stapes annular ligament were found to significantly affect the cochlear input impedance, which is a result of acoustic coupling through the round window. The orbicular apophysis increases the delay of the transmission line formed by the flexible malleus, incus, and stapes, and improves the forward sound-transmission characteristics in the frequency region of 7-30 kHz.
Topics: Acoustic Stimulation; Acoustics; Animals; Cochlea; Ear, Middle; Mice; Round Window, Ear; Sound; Stapes
PubMed: 33940924
DOI: 10.1121/10.0004218 -
Ear and Hearing 2019
Topics: Databases, Factual; Diagnostic Techniques, Otological; Ear, Middle; Humans; Reference Values
PubMed: 31651606
DOI: 10.1097/AUD.0000000000000790 -
Nagoya Journal of Medical Science Feb 2017The inner and middle ear are connected mainly through round and oval windows, and inflammation in the middle ear cavity can spread into the inner ear, which might induce... (Review)
Review
The inner and middle ear are connected mainly through round and oval windows, and inflammation in the middle ear cavity can spread into the inner ear, which might induce a disturbance. In cases with intractable otitis media, attention should also be paid to symptoms related to the inner ear. In this paper, middle ear inflammation and related inner ear disturbances are reviewed with a focus on representative middle ear diseases (such as acute otitis media, chronic otitis media, otitis media with anti-neutrophil cytoplasmic antibody-associated vasculitis, eosinophilic otitis media, cholesteatoma with labyrinthine fistula, and reflux-related otitis media). Their clinical concerns are then discussed with reference to experimental studies. In these diseases, early diagnosis and adequate treatment are required to manage not only middle ear but also inner ear conditions.
Topics: Ear, Inner; Ear, Middle; Humans; Inflammation; Otitis Media
PubMed: 28303055
DOI: 10.18999/nagjms.79.1.1 -
Acta Oto-laryngologica Feb 2022Ear canal and middle ear tumors are rare and exhibit variability in histology and clinical manifestation. Surgical resection remains the treatment of choice, but...
BACKGROUND
Ear canal and middle ear tumors are rare and exhibit variability in histology and clinical manifestation. Surgical resection remains the treatment of choice, but individualized approach is needed to preserve function when possible.
AIMS/OBJECTIVES
To review the management and outcome of ear canal and middle ear tumors at an academic referral center.
MATERIALS AND METHODS
Helsinki University Hospital (HUS) patient files were searched for clinically and histologically confirmed ear canal and middle ear tumors over a 14-year period. The minimum follow-up time was 2 years.
RESULTS
Eighty-seven patients with 88 tumors were identified. There were 20 (23%) benign external auditory canal (EAC), 36 (41%) benign middle ear space (MES), 29 (33%) malignant EAC, and 3 (3%) malignant MES tumors. Most (92%) tumors were managed with primary resection. Thirty-five percent of the operatively managed patients had a residual or a recurrent tumor.
CONCLUSIONS AND SIGNIFICANCE
EAC and MES tumors show great diagnostic and histologic heterogeneity with need for individualized investigative and treatment approaches. In benign tumors, we advocate aggressive local surgical control without sacrificing vital structures. In malignant tumors, we recommend local surgical control with or without adjunct RT.
Topics: Ear Canal; Ear Neoplasms; Ear, Middle; Humans; Neoplasm Recurrence, Local; Retrospective Studies
PubMed: 35148225
DOI: 10.1080/00016489.2022.2032824 -
Journal of Anatomy Feb 2016The mammalian ear is a complex structure divided into three main parts: the outer; middle; and inner ear. These parts are formed from all three germ layers and neural... (Review)
Review
The mammalian ear is a complex structure divided into three main parts: the outer; middle; and inner ear. These parts are formed from all three germ layers and neural crest cells, which have to integrate successfully in order to form a fully functioning organ of hearing. Any defect in development of the outer and middle ear leads to conductive hearing loss, while defects in the inner ear can lead to sensorineural hearing loss. This review focuses on the development of the parts of the ear involved with sound transduction into the inner ear, and the parts largely ignored in the world of hearing research: the outer and middle ear. The published data on the embryonic origin, signalling, genetic control, development and timing of the mammalian middle and outer ear are reviewed here along with new data showing the Eustachian tube cartilage is of dual embryonic origin. The embryonic origin of some of these structures has only recently been uncovered (Science, 339, 2013, 1453; Development, 140, 2013, 4386), while the molecular mechanisms controlling the growth, structure and integration of many outer and middle ear components are hardly known. The genetic analysis of outer and middle ear development is rather limited, with a small number of genes often affecting either more than one part of the ear or having only very small effects on development. This review therefore highlights the necessity for further research into the development of outer and middle ear structures, which will be important for the understanding and treatment of conductive hearing loss.
Topics: Animals; Ear, External; Ear, Middle; Hearing; Mammals
PubMed: 26227955
DOI: 10.1111/joa.12344 -
Journal of Anatomy Feb 2016Middle ear surgery is strongly influenced by anatomical and functional characteristics of the middle ear. The complex anatomy means a challenge for the otosurgeon who... (Review)
Review
Middle ear surgery is strongly influenced by anatomical and functional characteristics of the middle ear. The complex anatomy means a challenge for the otosurgeon who moves between preservation or improvement of highly important functions (hearing, balance, facial motion) and eradication of diseases. Of these, perforations of the tympanic membrane, chronic otitis media, tympanosclerosis and cholesteatoma are encountered most often in clinical practice. Modern techniques for reconstruction of the ossicular chain aim for best possible hearing improvement using delicate alloplastic titanium prostheses, but a number of prosthesis-unrelated factors work against this intent. Surgery is always individualized to the case and there is no one-fits-all strategy. Above all, both middle ear diseases and surgery can be associated with a number of complications; the most important ones being hearing deterioration or deafness, dizziness, facial palsy and life-threatening intracranial complications. To minimize risks, a solid knowledge of and respect for neurootologic structures is essential for an otosurgeon who must train him- or herself intensively on temporal bones before performing surgery on a patient.
Topics: Ear Diseases; Ear, Middle; Hearing Loss; Humans
PubMed: 26482007
DOI: 10.1111/joa.12389 -
Journal of Morphology Aug 2019The evolution of the various hearing adaptations is connected to major structural changes in nearly all groups of vertebrates. Besides hearing, the detection of... (Review)
Review
The evolution of the various hearing adaptations is connected to major structural changes in nearly all groups of vertebrates. Besides hearing, the detection of acceleration and orientation in space are key functions of this mechanosensory system. The symposium "show me your ear - the inner and middle ear in vertebrates" held at the 11th International Congress of Vertebrate Morphology (ICVM) 2016 in Washington, DC (USA) intended to present current research addressing adaptation and evolution of the vertebrate otic region, auditory ossicles, vestibular system, and hearing physiology. The symposium aimed at an audience with interest in hearing research focusing on morphological, functional, and comparative studies. The presented talks and posters lead to the contributions of this virtual issue highlighting recent advances in the vertebrate balance and hearing system. This article serves as an introduction to the virtual issue contributions and intends to give a short overview of research papers focusing on vertebrate labyrinth and middle ear related structures in past and recent years.
Topics: Animals; Ear, Inner; Ear, Middle; Hearing; Vertebrates
PubMed: 30117612
DOI: 10.1002/jmor.20880 -
Diving and Hyperbaric Medicine Mar 2021Middle ear barotrauma (MEBt) is the most common medical complication in diving, posing a serious risk to dive safety. Given this prevalence and the continuing growth of...
INTRODUCTION
Middle ear barotrauma (MEBt) is the most common medical complication in diving, posing a serious risk to dive safety. Given this prevalence and the continuing growth of the diving industry, a comprehensive overview of the condition is warranted.
METHODS
This was a survey study. An anonymous, electronic questionnaire was distributed to 7,060 recipients: professional divers of the Finnish Border Guard, the Finnish Rescue Services, and the Finnish Heritage agency; and recreational divers registered as members of the Finnish Divers' Association reachable by e-mail (roughly two-thirds of all members and recreational divers in Finland). Primary outcomes were self-reported prevalence, clinical characteristics, and health effects of MEBt while diving. Secondary outcomes were adjusted odds ratios (OR) for frequency of MEBt with respect to possible risk factors.
RESULTS
A total of 1,881 respondents participated in the study (response rate 27%). In total, 81% of the respondents had experienced MEBt while diving. Of those affected, 38% had used medications and 1% had undergone otorhinolaryngology-related surgical procedures due to MEBt. Factors most associated with MEBt were poor subjective success in Valsalva ('occasionally' versus 'always' successful: OR 11.56; 95% CI 7.24-18.47) and Toynbee ('occasionally' versus 'always' successful: OR 3.51; 95% CI 1.95-6.30) manoeuvres.
CONCLUSIONS
MEBt is common in both recreational and professional divers, having affected 81% of the respondents. The main possible risk factors include poor success in pressure equalisation manoeuvres.
Topics: Acoustic Impedance Tests; Barotrauma; Diving; Ear, Middle; Eustachian Tube; Finland; Humans
PubMed: 33761540
DOI: 10.28920/dhm51.1.44-52 -
Philosophical Transactions of the Royal... Feb 2017One of the most amazing transitions and innovations during the evolution of mammals was the formation of a novel jaw joint and the incorporation of the original jaw... (Review)
Review
One of the most amazing transitions and innovations during the evolution of mammals was the formation of a novel jaw joint and the incorporation of the original jaw joint into the middle ear to create the unique mammalian three bone/ossicle ear. In this review, we look at the key steps that led to this change and other unusual features of the middle ear and how developmental biology has been providing an understanding of the mechanisms involved. This starts with an overview of the tympanic (air-filled) middle ear, and how the ear drum (tympanic membrane) and the cavity itself form during development in amniotes. This is followed by an investigation of how the ear is connected to the pharynx and the relationship of the ear to the bony bulla in which it sits. Finally, the novel mammalian jaw joint and versatile dentary bone will be discussed with respect to evolution of the mammalian middle ear.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
Topics: Animals; Biological Evolution; Birds; Ear, Middle; Mammals; Reptiles
PubMed: 27994124
DOI: 10.1098/rstb.2015.0483