A. Ruprecht, D.D.S., M.Sc.D., F.R.C.D.(C)
Answer: Film bending and "Cone-cutting."
There is a blank area (less dense) along the posterior aspect of the image. This is due to “cone-cutting” using a rectangular collimated PID. There is a crescent-shaped dense line over the image of the distal root of the first molar. This is due to bending of the film, possibly with a fingernail.
