The incudostapedial articulation in Down's syndrome (trisomy 21): a temporal bone study.

Hypothesis: Anomaly in the incudostapedial articulation (IS) may be responsible for persistent conductive hearing loss (HL) in Down's syndrome (DS) patients. Our goal was to perform a detailed histopathologic assessment of the role of the IS joint in the conductive HL.

Background: In addition to other disabilities, 38% to 78% of patients with Down's syndrome (Trisomy 21) have CHL, some of which are persistent despite maximum treatment.

The pathogenesis of acquired cholesteatoma of the human middle ear: support for the migration hypothesis.

Hypothesis: That acquired cholesteatoma of the human middle ear and mastoid process can be caused by migration of squamous epithelium from the tympanic membrane.

Objective: To provide histologic evidence in humans of the potential for medial epithelial migration toward the middle ear.

Background: The origin of cholesteatomas of the middle ear complex of humans is still not clearly understood.

Selective inner hair cell loss in prematurity: a temporal bone study of infants from a neonatal intensive care unit.

Premature birth is a well-known risk factor for sensorineural hearing loss in general and auditory neuropathy in particular. However, relatively little is known about the underlying causes, in part because there are so few relevant histopathological studies. Here, we report on the analysis of hair cell loss patterns in 54 temporal bones from premature infants and a control group of 46 bones from full-term infants, all of whom spent time in the neonatal intensive care unit at the Hospital de Niños in San Jose, Costa Rica, between 1977 and 1993.

Anatomy of the distal incus in humans.

The anatomy of the distal incus, including the lenticular process, was examined in histological sections from 270 normal cadaveric human temporal bones aged between less than 1 month and 100 years. All but nine of these sectioned specimens showed signs of a bony connection between the long process of the incus and the flattened plate of the lenticular process, and in 108 specimens a complete bony attachment was observed in a single 20 microm section. In these 108 ears, the bony lenticular process consisted of a proximal narrow "pedicle" connected to a distal flattened "plate" that forms the incudal component of the incudo-stapedial joint.

The incudostapedial articulation: new concepts.

Hypothesis: To study the detailed anatomy of the incudostapedial joint (ISJ).

Background: Detailed study of the anatomy of the ISJ has been surprisingly neglected and continues to be controversial.

Methods: We studied the joint in 86 temporal bones from 51 subjects, aged 12 to 104 years, by light microscopy and three-dimensional images of computer-based reconstructions.