[Fortuitous discovery of a voluminous mandibular cyst in a child].

In a five and a half year-old child, a voluminous mandibular cyst was discovered by a dental check-up. The originality of this case consisted in the great volume of this asymptomatic lesion and the anterior localization in the mandible. Treatment was surgical, conserving the deciduous teeth and the underlying germs.

CD1 hearing-impaired mice. II. Group latencies and optimal f2/f1 ratios of distortion product otoacoustic emissions, and scanning electron microscopy.

In our companion paper (Le Calvez et al., 1998), the levels of distortion product otoacoustic emissions (DPOAE) were collected in the ears of CD1 mice with progressive degeneration of cochlear outer hair cells (OHC). Their comparison to standard functional measurements such as auditory-evoked brainstem responses (ABR) showed that CD1 ears could be classified as normal or impaired in a frequency-specific manner using DPOAE levels.

[Decalcified, lyophilized, sterile heterotopic porcine ossicular xenografts. Experimental evaluation in the guinea pig].

Using the guinea pig middle ear model, we assessed decalcified, lyophylized, sterile heterotopic porcine ossicular xeno-implants based on a histology (optic and electron scan microscope) and immunologic (immunofluorscence) methods. Implants were placed in the middle ear and others in the dorsal subcutaneous area. Allo-implants were compared as controls.

Ultrastructural changes in the hydropic cochlea of the guinea-pig.

Transmission electron microscopy of the cochlear organ of Corti in experimental endolymphatic hydrops revealed two principal features. Starting 1 month after induction of hydrops, osmiophilic inclusions thought to represent lipofuscin accumulation were frequently observed in the subcuticular cytoplasm of the outer hair cells along the length of the cochlea. Starting 3 months after induction of hydrops the efferent terminals on the outer hair cells appeared to be vacuolated.

Neuronal degeneration of primary cochlear and vestibular innervations after local injection of sisomicin in the guinea pig.

This paper reports on a dynamic study of the morphological changes within the cochlear and vestibular ganglia of the guinea pig after local application of Sisomicin in the inner ear. The treatment leads to a rapid, complete and irreversible destruction of the sensory cells in the cochlear and vestibular neuroepithelia. A progressive degeneration of the type I and type II afferent neurons, presenting a decreasing gradient from the base towards the apex of the cochlea, is rapidly observed and becomes almost complete as early as 15 days after the peripheral injury.