Assembling a functional tympanic membrane: signals from the external acoustic meatus coordinate development of the malleal manubrium

Development ◽  
2000 ◽  
Vol 127 (19) ◽  
pp. 4127-4136 ◽  
Author(s):  
M. Mallo ◽  
H. Schrewe ◽  
J.F. Martin ◽  
E.N. Olson ◽  
S. Ohnemus
Keyword(s):  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Essential Role ◽  
Acoustic Pressure ◽  
Developmental Process ◽  
Terrestrial Mammals ◽  
Ear Ossicles ◽  
Membrane Vibrations

In terrestrial mammals, hearing starts with the perception of acoustic pressure by the tympanic membrane. Vibrations in this membrane are then transduced into the inner ear by the ossicle chain of the middle ear, composed of the malleus, incus and stapes. The proper connection of the ossicle chain with the tympanic membrane, provided by the insertion of the manubrium of the malleus into the eardrum, is essential for the functionality of the hearing apparatus. We describe here the mechanisms regulating the development of the manubrium and its integration into the tympanic membrane. We show that the external acoustic meatus (EAM), which eventually forms the outer epithelium of the tympanic membrane, plays an essential role in this developmental process. Histological and expression analyses indicate that the manubrium develops close to the EAM with a similar temporal sequence. In addition, when the middle ear ossicles are allowed to develop in vitro under conditions that do not support further EAM development, the manubrium develops only up to the stage of its induction at the time of explantation. Moreover, genetically or teratogenically derived alterations in the EAM also have an effect on manubrial development. Finally, we show that the EAM is the source of two quite opposite activities, one that induces chondrogenesis and another that represses it. The combination of these two activities results in the proper positioning of the manubrium.

Common drugs used in ENT

2009 ◽  
pp. 347-350
Author(s):  
Rogan Corbridge ◽  
Nicholas Steventon
Keyword(s):  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Otitis Externa ◽  
Round Window ◽  
Acid Reflux ◽  
Tympanic Membrane Perforation ◽  
Active Infection ◽  
Middle Ear Mucosa ◽  
Membrane Perforation

Drugs used in the ear 348 Drugs used in the nose 349 Drugs used in the treatment of acid reflux 350 This group of drugs is widely used for the treatment of otitis externa. Otitis externa 2 drops tds for 10 days Presence of grommet or tympanic membrane perforation due to aminoglycoside ototoxicity in the inner ear. Risk thought to be low in the presence of active infection where the middle-ear mucosa is swollen and the antibiotic is unlikely to reach the inner ear via the round window...

scholarly journals Study on the Prosthesis Structural Design and Vibration Characteristics Based on the Conduction Effect of Human Middle Ear

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wu Ren ◽  
Huijuan Yan ◽  
Yi Yu ◽  
Jinghong Ren ◽  
Jinlong Chang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Transmission Function ◽  
Ossicular Chain ◽  
Sound Signal ◽  
Sound Perception ◽  
Response Characteristics ◽  
Middle Ear Prosthesis

As a bridge from the sound signal in the air to the sound perception of the inner ear auditory receptor, the tympanic membrane and ossicular chain of the middle ear transform the sound signal in the outer ear through two gas-solid and solid-liquid conversions. In addition, through the lever principle formed by three auditory ossicle structure, the sound was concentrated and amplified to the inner ear. However, the sound transmission function of the middle ear will be decreased by disease, genetic, or trauma. Hence, using middle ear prosthesis to replace the damaged ossicles can restore the conduction function. The function realization of middle ear prosthesis depends on the vibration response of the prosthesis from the tympanic membrane to the stapes plate on the human auditory perception frequency, which is affected by the way the prosthesis combined with the tympanic membrane, the material, and the geometric shape. In this study, reasonable prosthetic structures had been designed for different types of ossicular chain injuries, and the frequency response characteristics were analyzed by the finite element method then. Moreover, in order to achieve better vibration frequency response, a ball structure was designed in the prosthesis to simulate its amplification function. The results showed that the middle ear prostheses constructed by different injury types can effectively transfer vibration energy. In particular, the first- and second-order resonant frequencies and response amplitudes are close to each other when ball structure models of different materials are added. Instead, the resonance frequency of the third stage formed by aluminum alloy ball materials is larger than that of the other two, which showed good response features.

Inner ear pathology in osteogenesis imperfecta congenita

1980 ◽  
Vol 94 (7) ◽  
pp. 697-705 ◽  
Author(s):  
Makoto Igarashi ◽  
Austin I. King ◽  
C. Willy Schwenzfeier ◽  
Tsuneo Watanabe ◽  
Bobby R. Alford
Keyword(s):  
Osteogenesis Imperfecta ◽  
Inner Ear ◽  
Temporal Bone ◽  
Middle Ear ◽  
Stria Vascularis ◽  
Bony Labyrinth ◽  
Congenital Form ◽  
Basal Zone ◽  
Ear Ossicles ◽  
Osteogenesis Imperfecta Congenita

AbstractThis temporal bone report describes the inner ear deformities which were found in addition to the bony pathology in a case of osteogenesis imperfecta congenita. The labyrinthine pathology includes anomalously positioned and enlarged vestibular spaces, the existence of a scala communis (on one side) and the existence of hematoxylin dark-stained material in the basal zone of the stria vascularis.The appearance of temporal bone reports of osteogenesis imperfecta congenita is sporadic. Friedmann (1974)described changes in the bony capsule in one case of osteogenesis imperfecta congenita Zajtchul and Lindsay(1975)reported three cases of the congenital form of osteogenesis imperfecta with their temporal bone findings. Within recent years, Altmann reported three cases in 1962, Bretlau and Jorgensen reported one case in 1969, Bergstrom and others reported one case in 1972, and Bergstrom described the temporal bone findings in four infants in 1977. The pathologic description of the temporal bone in osteogenesis imperfecta congenita has been focused more or less on the structures of the bony labyrinth and the middle ear ossicles, with a brief description of the inner ear. In this report, we describe anomalous inner ear structures in osteogenesis imperfecta congenita.

scholarly journals Direct Analysis of Pathogenic Structures Affixed to the Tympanic Membrane during Chronic Otitis Media

2018 ◽  
Vol 159 (1) ◽  
pp. 117-126 ◽  
Author(s):  
Guillermo L. Monroy ◽  
Wenzhou Hong ◽  
Pawjai Khampang ◽  
Ryan G. Porter ◽  
Michael A. Novak ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Tympanic Membrane ◽  
Otitis Media ◽  
Middle Ear ◽  
Mucosal Surface ◽  
Microbial Infection ◽  
Oct Imaging

Objective To characterize otitis media–associated structures affixed to the mucosal surface of the tympanic membrane (TM) in vivo and in surgically recovered in vitro samples. Study Design Prospective case series without comparison. Setting Outpatient surgical care center. Subjects and Methods Forty pediatric subjects scheduled for tympanostomy tube placement surgery were imaged intraoperatively under general anesthesia. Postmyringotomy, a portable optical coherence tomography (OCT) imaging system assessed for the presence of any biofilm affixed to the mucosal surface of the TM. Samples of suspected microbial infection–related structures were collected through the myringotomy incision. The sampled site was subsequently reimaged with OCT to confirm collection from the original image site on the TM. In vitro analysis based on confocal laser scanning microscope (CLSM) images of fluorescence in situ hybridization–tagged samples and polymerase chain reaction (PCR) provided microbiological characterization and verification of biofilm activity. Results OCT imaging was achieved for 38 of 40 subjects (95%). Images from 38 of 38 (100%) of subjects observed with OCT showed the presence of additional microbial infection–related structures. Thirty-four samples were collected from these 38 subjects. CLSM images provided evidence of clustered bacteria in 32 of 33 (97%) of samples. PCR detected the presence of active bacterial DNA signatures in 20 of 31 (65%) of samples. Conclusion PCR and CLSM analysis of fluorescence in situ hybridization–stained samples validates the presence of active bacteria that have formed into a middle ear biofilm that extends across the mucosal layer of the TM. OCT can rapidly and noninvasively identify middle ear biofilms in subjects with severe and persistent cases of otitis media.

scholarly journals The Role of Pseudoephedrine Tablets Versus Xylometazoline Spray in Otic Barotrauma Prevention During Flights

2018 ◽  
Vol 69 (11) ◽  
pp. 3199-3202
Author(s):  
Ruxandra Oana Iana ◽  
Dragos Cristian Stefanescu ◽  
Viorel Zainea ◽  
Razvan Hainarosie
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Tympanic Membrane ◽  
Eustachian Tube ◽  
Middle Ear ◽  
Severe Pain ◽  
Air Pressure ◽  
Membrane Rupture ◽  
Common Complaint

Otalgia during airplane flights is a common complaint among patients. This occurs due to the changes in air pressure during take-off and landing that affect middle ear and inner ear. The eustachian tube is responsible with equalizing pressure but in many cases, it happens insufficiently leading to mild to severe pain, hearing loss, tympanic membrane rupture and even inner ear lesions. The aim of this paper is to asses the efficacy of two decongestants, oral pseudoephedrine versus topical xylometazoline in preventing otic barotrauma.

A preliminary investigation of four-dimensional ultrasound for evaluation of middle ear ossicles: An in vitro study

2010 ◽  
Vol 74 (9) ◽  
pp. 1028-1033 ◽  
Author(s):  
Evan J. Propst ◽  
Jeremy D. Prager ◽  
Janet M. Adams ◽  
Ellis M. Arjmand ◽  
J. Paul Willging ◽  
...  
Keyword(s):  
Middle Ear ◽  
Preliminary Investigation ◽  
In Vitro Study ◽  
Vitro Study ◽  
Ear Ossicles

Contraindications to the Small Hole Stapedectomy

1981 ◽  
Vol 90 (6) ◽  
pp. 636-639 ◽  
Author(s):  
Brown Farrior
Keyword(s):  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Fluid Pressure ◽  
Internal Auditory Canal ◽  
Air Pressure ◽  
Small Hole ◽  
Excessive Pressure ◽  
Pressure Changes

A small hole stapedectomy with an unprotected piston is contraindicated in an ear subjected to excessive pressure changes whether these are excessive fluid pressure changes which occur in the inner ear or excessive air pressure changes in the middle ear. Excessive fluid pressure changes in the inner ear may be the result of an overly patent aqueduct of the cochlea or a permeable internal auditory canal. These excessive fluid pressure changes may produce fistulas or a dilated blister around the piston called a tented piston. Excessive air pressure changes in the middle ear will produce excessive excursions of the tympanic membrane which may result in vertigo or a dislocated piston.

scholarly journals Simultaneous 3D imaging of sound-induced motions of the tympanic membrane and middle ear ossicles

2013 ◽  
Vol 304 ◽  
pp. 49-56 ◽  
Author(s):  
Ernest W. Chang ◽  
Jeffrey T. Cheng ◽  
Christof Röösli ◽  
James B. Kobler ◽  
John J. Rosowski ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
3D Imaging ◽  
Ear Ossicles

Organ Culture of the Mammalian and Avian Embryo Otocyst

1977 ◽  
Vol 86 (3) ◽  
pp. 371-380 ◽  
Author(s):  
I. Friedmann ◽  
M. Giselle Hodges ◽  
P. N. Riddle
Keyword(s):  
Organ Culture ◽  
Inner Ear ◽  
Middle Ear ◽  
Defined Medium ◽  
Avian Embryo ◽  
Vestibular Apparatus ◽  
Chemically Defined Medium ◽  
Organ Cultures ◽  
Cochlear Duct

The use of a chemically defined medium supplemented with serum has proved most suitable for the growth of the isolated embryonic otocyst in vitro. Complete differentiation of the cochlear duct and of the vestibular apparatus ensued and is described. The system is reliable for organ cultures of both the avian and mammalian otocyst and for the study of various lesions affecting the inner ear and middle ear.

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