Probably fewer than the number of bitemarks you have seen. I commend him on his practice ethics but take exception with his own leap of logic. His foundation is irrelevant. I don't know of any extraction site that even superficially resembles epithelial injuries on keratinized skin. I find it amazing that dentists will enter into such subjective areas of science and create a degree of certainty for their opinion that is beyond any scientific proof.
Forensic pathologists determine the cause of death.
They can follow a bullet's path into a vital organ and establish cause and effect. Dentist's don't have such biological certainty at their disposal. They have sub-epithelial hemorrhage. In layman's terms, a bruise. I don't believe it is.