Atlas & Axis, Vertebrae AP, Open mouth

40" VGD

8x10 LW

upright, arms @ sides, shoulders same plane

open mouth wide, upper occlusal plane to mastoid tip ┴ IR

Center MSP to ML VGD

┴ MP open mouth

right, face up, 2" in from mid 10" IR border

4x5

softly phonate "ah" to avoid tongue shadow

do not keep in final, strained position too long, remove dentures

AP atlas + axis through open mouth

dens, atlas, axis, + C1+C2 articulations superimpos occlusal surface upper incisors + skull base, wide open mouth, tongue shadow not over atlas + axis, mand rami equidistant dens