Microanatomy of osseous labyrinth and its clinical significance

Objective To observe and measure the adult temporal bone labyrinth in order to provide anatomical data for clinical surgery.Methods Thirty adult temporal bone specimens were obtained for observation and measurement.Results(1) The posterior semicircular canal was the longest,followed by the lateral semicircular canal while the anterior semicircular canal was the shortest.(2) The vertex spacing of semicircular canals was(10.86±1.87) mm(9.66-11.32 mm) between the anterior and posterior canal,(9.37±1.61) mm(8.64-11.02 mm) between the anterior and the lateral canal,and(7.35± 0.99) mm(6.36-8.40 mm) between the posterior and lateral canal.(3) The dura mater's distance to the lateral semicircular canal,posterior semicircular canal edge,and to the ampulla of the superior semicircular canal was(4.07±1.26)mm(2.1-6.6 mm),(12.60±2.73) mm(8.2-19.0 mm),(15.02±3.69) mm(7.8-21.3 mm),respectively.Conclusion The results of this study provide the anatomical basis for clinical lateral skull base approach to resection of petrous apex and petroclival tumors.