Epithelial migration in the external auditory canal and the movement of the chondro-osseous junction.

Epithelial migration occurs in a lateral direction from the tympanic membrane to the external auditory canal. The underlying mechanism which determines the direction of this laterally directed movement has not been elucidated. This study attempts to analyze whether migration is stimulated at the chondro-osseous junction, the very place where squamous cells stop migrating and desquamate. Active movement of the junction is postulated as a stimulus for the migratory process. Such movement may be caused by contraction of the peri-auricular muscles which attach to the cartilaginous canal. In this study, eight guinea pigs underwent unilateral facial nerve section in order to paralyze the peri-auricular muscles and thus diminish active movement of the junction. Migration times were determined for both operated and unoperated ears. No significant difference was noted between the two groups. One may conclude that paralysis of the peri-auricular muscles does not alter the time taken for skin migration in the external auditory canal.