A 16 film radiographic survey consists of the 12 film survey and the addition
High-Yield Explanation
4 film survey requires 2 anterior occlusal and 2 bitewing radiographs.
8 film survey requires 4 posterior, 2 anterior occlusal and 2 bitewing radiographs.
12 film survey requires 4 IOPAs for posterior teeth, 4 canine IOPAs, 2 incisor IOPAs and 2 bitewing radiographs.
16 film survey requires 4 permanent molar radiographs additional to the 12 film survey.
Ref: Principles and practice of Pedodontics by Arathi Rao