When viewing an ap projection of the upper cervical spine open mouth technique you notice that the base of the skull is superimposed over the dens. what position error caused this?

It is possible that the error is due to patient’s neck was extended too far.

There are certain rules for the patient positioning during the open-mouth technique. For example, patient’s shoulders should be at equal distances from the image receptor to avoid rotation and the head should be positioned so the skull and the lower margin of the upper incisors are perpendicular (90 degrees) to the image receptor.

i have to report this, it doesn't relate to biology

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this