subpetrosal

— To avoid injury to the subpetrosal sinuses, the width of the penetration of the clivus in the posterior wall of the sphenoid sinus should be limited within 10.36±0.45 mm from the mid-sagittal line in the plane passing through the lowest, central point of the SF; less than 10.76±0.43mm from the mid-sagittal line, in the plane passing through the aperture of the sphenoid sinus; and 10.55±0.45 mm from the mid-sagittal line.