[Position and position variations of the canal system of the temporal bone in frontal section]

Estimated are: 1. The axis of the internal acoustic meatus to the horizontal plane in adults and postnatal changes. 2. Eight coronal sections of the temporal bone have been selected to localize the canal systems and structures in the petrous part of the temporal bone and their variations. 3. Described are the different parts of the facial canal, the carotic canal, the auditive tube, the tensor tympani muscle, the major petrosal nerve, and its distances to the carotic canal, the cochlea, the internal acoustic meatus, the supra- and infracochlear cells, the fenestra vestibuli, the fossa jugularis, the canaliculus cochleae, the vestibulum and the semicircular canals. This report includes the development of the supravestibular and other mastoideal cells in the neighbourhood of the canal systems of the petrous bone and the vestibular aqueduct and sac. Estimated are also the distances between the different canal systems. 4. The investigations are discussed with our earlier researches and the results of other researchers and its diagnostic in clinical importance.