OBJECTIVE: To investigate the motion of the normal and reconstructed ossicular chain during changes in static pressure. MATERIAL AND METHODS: Experiments were carried out using seven fresh human temporal bones Using digital photography, movements of the malleus were measured during incremental pressure changes between +500 and -500 daPa with the incus in situ and following its removal. The pattern of movement of the ossicles was recorded in the form of digital video clips. This was carried out with the ossicular chain intact and also when it had been reconstructed with an incus graft and four different types of artificial prosthesis. RESULTS: The lateral to medial movement of the malleus during changes in static pressure is converted into a predominantly superior to inferior movement of the incus. Conventional reconstructions using a graft or prosthesis transmit the malleus movement directly to the stapes so that it is pushed in and out of the oval window. Reconstructions with prostheses which restore the mammalian three-ossicle pattern, by contrast, move in a similar manner to the normal incus. CONCLUSION: Ears reconstructed using conventional techniques are more at risk from pressure changes than those in which a "physiological" method is used.
OBJECTIVE: To investigate the motion of the normal and reconstructed ossicular chain during changes in static pressure. MATERIAL AND METHODS: Experiments were carried out using seven fresh human temporal bones Using digital photography, movements of the malleus were measured during incremental pressure changes between +500 and -500 daPa with the incus in situ and following its removal. The pattern of movement of the ossicles was recorded in the form of digital video clips. This was carried out with the ossicular chain intact and also when it had been reconstructed with an incus graft and four different types of artificial prosthesis. RESULTS: The lateral to medial movement of the malleus during changes in static pressure is converted into a predominantly superior to inferior movement of the incus. Conventional reconstructions using a graft or prosthesis transmit the malleus movement directly to the stapes so that it is pushed in and out of the oval window. Reconstructions with prostheses which restore the mammalian three-ossicle pattern, by contrast, move in a similar manner to the normal incus. CONCLUSION: Ears reconstructed using conventional techniques are more at risk from pressure changes than those in which a "physiological" method is used.
Authors: Marcin Szymanski; Rafał Rusinek; Marek Zadrozniak; Kamal Morshed; Jerzy Warminski Journal: Clin Exp Otorhinolaryngol Date: 2014-11-14 Impact factor: 3.372