Pterygoid point (Ptm) is a cephalometric point representing the radiolucent foramen of:

 # Pterygoid point (Ptm) is a cephalometric point representing the radiolucent foramen of:

A. Magnum

B. Ovale

C. Rotundum

D. Spinosum

The correct answer is C. Rotundum.

Pterygomaxillary Fissure (Ptm): 

• A bilateral teardrop-shaped area of radiolucency 

• The anterior shadow of which is the posterior surfaces of the tuberosities of the maxilla. 

• The PTM point is the intersection of the inferior border of the foramen rotundum with the posterior wall of the pterygomaxillary fissure.