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At least 829 records · Page 46Linked to original sources
PubMed1996

Otocephalus: histopathology and three-dimensional reconstruction.

Otocephaly is a lethal malformation of the first and second branchial arches, which consists of ventromedial displacement of the external ear structures (synotia), mandibular aplasia (agnathia), absence of the tongue (aglossia), and microstomia. We present the first complete description of the temporal bone findings in a case of otocephalus. A three-dimensional computer-assisted reconstruction of the right temporal bone was performed, allowing a unique graphic analysis. An extremely low-lying middle fossa tegmen was noted with malrotation of the middle ear structures. Severe ossicular malformations were also found. An anomalous course of the internal carotid artery was noted with indentation of the basal turn of the cochlea. All three layers of the otic capsule were incompletely developed. Cochlear bony dehiscences were noted. These findings are consistent with early arrest of fetal development and malrotation caused by lack of growth pressure from the mandibular arch. Implications of these findings in the embryologic development of the ear are discussed.

Abnormalities, Multiple↗
PubMed1977

Surgical treatment of hemifacial microsomia. (First and second branchial arch syndrome).

A review of 17 patients operated upon for unilateral hemifacial microsomia, and followed for up to 18 years, clarifies several principles of management. The management is facilitated by dysplasia predominance grouping, with the major functional deformity dictating the sequence of repair. Our surgical goals are: (1) provision of adequate upper airway; (2) preservation of normal teeth and adequate alveolar bone to achieve proper dental occlusion; (3) restoration of binaural hearing; (4) external ear construction; (5) acceptable facial symmetry; (6) balanced facial animation; and (7) a child with an acceptable self-image.

Abnormalities, Multiple↗
PubMed1990

Right-sided microtia and conductive hearing loss with variable expressivity in three generations.

Familial cases of microtia and meatal atresia are rare, and both dominant and recessive inheritance have been suggested. We here report a family with right-sided external ear malformations and conductive hearing loss in a grandfather, his daughter and granddaughter. The grandfather and the granddaughter both had microtia and meatal atresia, whereas the daughter had a normal outer ear except for a narrow meatus and auricular appendages. The pedigree suggests autosomal dominant inheritance with variable expressivity.

Adult↗
PubMed2000

Hearing impairment in 18q deletion syndrome.

The 18q-syndrome is associated with hearing impairment in 50-80 per cent of cases. The hearing loss may be sensorineural or conductive. A high proportion of cases are associated with narrow or stenosed external auditory canals. This may be a useful clinical pointer to the syndrome. Two cases with impaired hearing are presented in this paper including one case with complex external ear and middle ear malformations. The clinical and audiological features in each case are described.

Adolescent↗
PubMedDate not supplied

Volume-pressure properties of round and oval windows. A quantitative study on human temporal bone.

A model study was carried out on human temporal bones to assess quantitatively the displacement of the round and oval windows when different pressure levels were applied to the external ear canal and inside the middle ear. It was found that the major displacements of the window membranes occurred in the pressure range of +/- 20 cm H2O in the intact middle ear. An additional increase in the middle ear pressure up to +/- 70 cm H2O caused a minor displacement of the window membranes.

Aged↗
PubMed1988

[Otologic signs and early diagnosis of Turner syndrome. Reevaluation of 30 cases].

In most occasions the Turner's syndrome is diagnosed on the basis of severe growth retardation. But the possibility of an effective treatment of short stature requires earlier a diagnosis. Among the other signs, the importance of ORL signs is underestimated. A group of 30 patients has been analysed to determine their precise extension. The external ears are frequently prominent, low-set and/or posteriorly rotated. Frequency and chronicity of otitis media is highlighted by hypoacousy of the transmission type. The perception pathology is far less common and seems being independent of middle ear pathology. A abnormal development of the 1st branchial arch is likely to explain the auricular pathology in view of the frequently associated anomalies of the palate and the dental articulation. One must clearly consider the diagnosis of Turner syndrome in the case of chronic auricular pathology associated with low linear velocity in a young girl allowing for earlier diagnosis.

Adolescent↗
PubMed1988

Directional hearing in the barn owl (Tyto alba).

The acoustical properties of the external ear of the barn owl (Tyto alba) were studied by measuring sound pressure in the ear canal and outer ear cavity. Under normal conditions, pressure amplification by the external ear reaches about 20 dB between 3-9 kHz but decreases sharply above 10 kHz. The acoustic gain curve of the outer ear cavity alone is close to that of a finite-length exponential horn between 1.2-13 kHz with maximum gain reaching 20 dB between 5-9 kHz. Pressure gain by the facial ruff produces a maximum of 12 dB between 5-8 kHz and decreases rapidly above 9 kHz. The directional sensitivity of the external ear was obtained from pressure measurements in the ear canal. Directivity of the major lobe is explained, to a first approximation, by the sound diffraction properties of a circular aperture. Aperture size is based on the average radius (30 mm) of the open face of the ruff. Above 5 kHz, the external ear becomes highly directional and there is a 26 degree disparity in elevation between the acoustic axis of the left and right ear. In azimuth, directivity patterns are relocated closer to the midline as frequency increases and the acoustic axis moves at a rate of 20 degree/octave between 2-13 kHz. Movement of the axis can be explained, to a first approximation, by the acoustical diffraction properties of an obliquely truncated horn, due to the asymmetrical shape of the outer ear cavity. The directional sensitivity of the barn owl ear was studied by recording cochlear microphonic (CM) potentials from the round window membrane. Between 3-9 kHz, CM directivity patterns are clearly different to the directivity patterns of the external ear; CM directionality is abruptly lost above 10 kHz. Above 5 kHz, CM directivity patterns are characterized by an elongated major lobe containing the CM axis, forming a tilted band of high amplitude but low directionality (CM axial plane), closely bordered by minima or nulls. The highest directionality is found in the CM directional plane, approximately perpendicular to the CM axial plane. The left and right ear axial planes are symmetrical about the interaural midline (tilted 12 degrees to the right of the midline of the head) and inclined by an average of 60 degrees to the left and right respectively. In azimuth, the CM axis moves towards the midline at a rate of 37 degrees/octave as frequency increases from 2-9 kHz, crossing into contralateral space near 7 kHz.(ABSTRACT TRUNCATED AT 400 WORDS)

Acoustic Stimulation↗
PubMed1988

Staphylococcus epidermidis and Staphylococcus aureus in otitis media with effusion.

Bacteriologic investigation of middle ear effusion (MEE), external ear canal, and the nasopharynx was carried out on 458 patients with otitis media with effusion. Staphylococcus epidermidis was the most common bacteria in MEE, even after excluding the contaminants from the external ear canal, which had the same value of minimal inhibitory concentration as the paired MEE. The bacterial agreement of S epidermidis between MEE and the nasopharynx was extremely rare in contrast with Haemophilus influenzae, Streptococcus pneumoniae, and Branhamella catarrhalis, although the organism was also frequently isolated from the nasopharynx. Staphylococcus aureus, having the same minimal inhibitory concentration as that in the nasopharynx, was more frequently found in MEE than S epidermidis. The results suggest that S epidermidis found in MEE is not a pathogen, but rather a contaminant in many instances. Staphylococcus aureus seems to be a causative agent in otitis media with effusion.

Adolescent↗
PubMed2003

Endolymphatic sac tumor (low-grade papillary adenocarcinoma) of the temporal bone.

The entity which has come to be known as an endolymphatic sac tumor (ELST) has, in the past, been known as adenocarcinoma of endolymphatic sac origin, aggressive papillary tumor of the temporal bone and Heffner's tumor. ELSTs arise in the vicinity of the inner ear and may extend to involve both the posterior fossa as well as the middle ear and the external ear canal, which may complicate the differential diagnosis ELSTs are typically seen in adults, with only rare descriptions in pediatric patients. They may be sporadic tumors or they may arise as part of the symptom complex of von Hippel-Lindau disease. Clinical signs at presentation range from a mass in the external ear canal to sensorineural deafness to cranial nerve palsies. Imaging studies reveal a destructive lesion of the petrous bone which is heterogeneous on MR scanning. Light microscopy reveals two chief patterns: a follicular pattern, reminiscent of thyroid parenchyma; and a papillary/solid pattern. Both patterns are often admixed in the same tumor, and the individual tumor cells are cytologically bland. Immunohistochemically, ELSTs are typically keratin-, vimentin- and epithelial membrane antigen-positive; they are often S-100 protein-positive and neuron-specific enolase-positive as well. ELSTs are difficult to extirpate surgically (owing to their locally aggressive nature); nevertheless, surgical excision remains the mainstay of current therapy. These are slow-growing (albeit locally aggressive) tumors which have only rarely been reported to metastasize; as such, they remain principally a problem of local control.

Adenocarcinoma, Papillary↗
PubMed2006

Spontaneous development of otitis media in plasminogen-deficient mice.

Inflammatory conditions of the ear, otitis media, are one of the most common disease entities in children. In this study, the role of the plasminogen (plg)/plasmin system for the spontaneous development of chronic otitis media was investigated by the analysis of plg-deficient mice. Whereas essentially all of the wild-type control mice kept a healthy status of the middle ear, all the plg-deficient mice gradually developed chronic otitis media with various degrees of inflammatory changes during an 18-week observation period. Five bacterial strains were identified in materials obtained from the middle ear cavities of six plg-deficient mice. Morphological studies revealed the formation of an amorphous mass tissue and inflammatory changes in the middle ears of plg-deficient mice. Immunohistochemical studies further indicate a mass infiltration of neutrophils and macrophages as well as the presence of T and B cells in the middle ear mucosa of these mice. Extensive fibrin deposition and an abnormal keratin formation were also observed in the tympanic membrane, the middle ear cavity and external ear canal in these mice. These results suggest that plg plays an essential role in protecting against the spontaneous development of chronic otitis media. Our findings also suggest the possibility of using plg for clinical therapy of certain types of otitis media.

Animals↗
PubMed2002

Mammalian ear specializations in arid habitats: structural and functional evidence from sand cat (Felis margarita).

To test whether structural specializations of sand-cat ears are adaptations to their desert habitats we measured structural and acoustic features of their ears. The area of the external ear's pinna flange is similar to that of domestic cat. The dimensions of the ear canal are about twice domestic cat's, as is the volume of the middle-ear air space. The magnitude of the acoustic input-admittance at the tympanic membrane is about five times larger than that of domestic cat; both the middle-ear cavities and the ossicular chain contribute to the increase. Structure-based models suggest the acoustic admittance looking outward through the external ear is generally larger for sand cat than for domestic cat; the radiation power-efficiency is also larger in sand cat for frequencies below 2 kHz. Hearing sensitivity (estimated from measurements and model calculations) in sand cat is predicted to be about 8 dB greater than in domestic cat for frequencies below 2 kHz. Analysis of attenuation of sound in deserts implies that the increased sensitivity extends sand cat's hearing range beyond domestic cat by 0.4 km at 0.5 kHz. Thus, the structural specializations may provide habitat-specific survival value.

Acoustic Stimulation↗
PubMed2005

Underwater hearing and sound localization with and without an air interface.

HYPOTHESIS: Underwater hearing acuity and sound localization are improved by the presence of an air interface around the pinnae and inside the external ear canals. BACKGROUND: Hearing threshold and the ability to localize sound sources are reduced underwater. The resonance frequency of the external ear is lowered when the external ear canal is filled with water, and the impedance-matching ability of the middle ear is significantly reduced due to elevation of the ambient pressure, the water-mass load on the tympanic membrane, and the addition of a fluid-air interface during submersion. Sound lateralization on land is largely explained by the mechanisms of interaural intensity differences and interaural temporal or phase differences. During submersion, these differences are largely lost due to the increase in underwater sound velocity and cancellation of the head's acoustic shadow effect because of the similarity between the impedance of the skull and the surrounding water. METHODS: Ten scuba divers wearing a regular opaque face mask or an opaque ProEar 2000 (Safe Dive, Ltd., Hofit, Israel) mask that enables the presence of air at ambient pressure in and around the ear made a dive to a depth of 3 m in the open sea. Four underwater speakers arranged on the horizontal plane at 90-degree intervals and at a distance of 5 m from the diver were used for testing pure-tone hearing thresholds (PTHT), the reception threshold for the recorded sound of a rubber-boat engine, and sound localization. For sound localization, the sound of the rubber boat's engine was randomly delivered by one speaker at a time at 40 dB HL above the recorded sound of a rubber-boat engine, and the diver was asked to point to the sound source. The azimuth was measured by the diver's companion using a navigation board. RESULTS: Underwater PTHT with both masks were significantly higher for frequencies of 250 to 6000 Hz when compared with the thresholds on land (p <0.0001). No differences were found in the PTHT or the reception threshold for the recorded sound of a rubber-boat engine for dry or wet ear conditions. There was no difference in the sound localization error between the regular mask and the ProEar 2000 mask. CONCLUSIONS: The presence of air around the pinna and inside the external ear canal did not improve underwater hearing sensitivity or sound localization. These results support the argument that bone conduction plays the main role in underwater hearing.

Acoustic Impedance Tests↗
PubMed1994

[Inheritance of notched ears in Highland cattle].

The present study describes an anomaly of the pinna of the ear and its distribution in Highland Cattle. The investigation is based on a questionnaire survey in farms in Bavaria keeping robust breeds and on registering data in 15 selected farms. In the year 1991, there were registered 548 Highland stud book cows in 108 farms. In four herds animals of the breed Highland Cattle were observed which showed crop ears. Always both ears were affected and this ear defect could be already observed in newborn calves. Crop ears appeared in very different forms. In some cases only small changes of the external ear could be recognized, in more severe cases, grooves in the external ear could be found and in the most severe case, the external ear was totally deformed and drastically reduced in size. In one herd, 45 animals out of the progeny of 46 of one affected breeding bull showed crop ears. The pedigrees indicated that this defect of the ear pinna is inherited and a single autosomal gene with nearly additive (incomplete dominant) action may be involved. Homozygote recessive animals are free from crop ears, animals homozygote for the mutated allele carry totally deformed external ears and heterozygote animals do not show as severe forms of crop ears as homozygote ones.

Animals↗
PubMed2006

[Establishment of composite facial and scalp allograft transplantation model in canine].

OBJECTIVE: To develop an experimental model of composite facial and scalp allograft in canine in order to investigate technical and immunological aspects and functional recovery of facial muscles of this new approach to facial reconstruction. METHODS: (1) Anatomic study: Four mongrel dogs were used for anatomical dissection of the head and neck region and for harvesting flap experiment. (2) Autologous transplantation (group I): Three types composite facial and scalp autologous transplantation were performed in five mongrel dogs. Type I composite tissue flap (group I a n = 2) included bilateral external ear and orbicularis oculi muscle. Type II (group I b n = 1) included single-lateral external ear, orbicularis oculi muscle, external nose upper and lower lip. Type III (group I c n = 2) included single - lateral external ear and orbicularis oculi muscle. (3) Allograft transplantation (group II): In group II a (n = 2), two allograft transplantation were performed with type III composite facial and scalp . In group II b (n = 4), four allograft transplantation were performed with the modified type III composite facial and scalp which included single - lateral external ear, orbicularis oculi muscle and one third of inferior tarsal plate and palpebral conjunctiva. To prevent allograft rejection, Cyclosporin A (CsA) and Methylprednisolone (MP) or Prednisone (PS ) were combined used as immunosuppressive protocol . Dose of CsA was adjusted depending on its blood drug level. Electromyogram (EMG) of orbicularis oculi muscle was carried out at 4 weeks, 6 weeks, 12 weeks and 6 months postoperation. RESULTS: (1) The facial anatomic characteristic of dog is similar to that of human being, external carotid artery and external jugular vein afford good blood supply to composite facial and scalp. (2) The dogs in group I c were long-term surviving with leakage of salivary juice. (3) In group II a (n = 2), one dog presented rejection reaction at 28th day postoperation, the reversal of rejection was achieved by increasing the dose of CsA and prednisone and with topical clobetasol for 2 weeks, the dog survived indefinitely( > 309 days). In group II b (n = 4), there were three dogs survived indefinitely ( > 159 days, > 129 days, > 108 days) without complication, EMG showed the function of orbicularis oculi muscle was gradually improving. CONCLUSION: The modified type III composite facial and scalp allograft transplantation model is an ideal model for facial allograft transplantation study.

Animals↗
PubMed2006

[Bilateral auditory canal squamous cell carcinoma].

Only a small number of cases of bilateral carcinomas of the external ear canal have been described in the literature. We present the first case of a 72 year old male patient with a bilateral squamous cell carcinoma of the external ear canal at a very early stage. A computed tomography of the temporal bone revealed a well-pneumatized mastoid on both sides. Both external ear canals were filled with soft tissue without radiological signs of destruction of the adjacent bone. The carcinomas of the external ear canal were surgically removed using a canal-wall down technique and a selective neck dissection of regions II-IV. Histology confirmed a well differentiated squamous cell carcinoma of the external ear canal without lymph node metastasis on both sides (TNM classification: pT1 G2 N0 M0 R0). Bilateral radiation therapy with 59.4 Gy resulted in stenosis of both ear canals. Hearing rehabilitation was achieved with bone conductive hearing glasses. Diagnosis und therapy of bilateral external ear carcinomas are presented and discussed.

Aged↗