The fact that Dr. Feinstone cut his wife's tongue out for cheating him presented clearly as her mutilated is shown throughout the movie. A brief shot of drilling her mouth is in the opening credits.
Brief shots of bloody mouths are shown throughout Dr. Feinstone's psychotic episodes throughout the movie.
Dr. Feinstone encounters the current dentist, Dr. Burns in Paradise and violently confronts him for doing poor dental work on him. Dr. Burns is backed into a corner and then falls down the stairs. When Dr. Feinstone goes to check his vitals he was dead on impact as he has no pulse and blood is shown coming from his forehead.
Dr. Feinstone is shown cutting into his arm in detail in a few scenes to try to battle his violent impulses. Blood is shown everytime this happens.
After a passing tourist discovers Dr. Feinstone's real identity. This makes him frightened and he attempts to quickly leave his office. The doctor worried he will be reported, begins to choke the man and proceeds to stab him in the ear canal with a dental needle. The man's pale dying face is shown with foam coming from his mouth. The doctor then buries him in his backyard.
Dr. Feinstone sadistically performs dental torture on a woman who knows about his real identity. He knocks her out with nitrous oxide and she awakens taped to the dentist chair. Graphic close-ups of her bloody mouth being poked, drilled and slit are shown. A man who comes to the office attempts to help her, but the doctor beats him, stabs him with a hammer and then smashes in his skull. His blood is shown to be leaking on the floor. He then proceeds to play a game called truth or tooth, where if the lady lies to him she gets a tooth pulled. It is implied that he later kills the woman as well but the act is not shown. Overall that is most violent and disturbing scene in the movie.
After Jamie, the doctor's new girlfriend finds Brooke attempting cut his tongue out she knocks her away and goes to call the police. In the procress, she sees a bloody hammer on the ground and foot sticking out of the closet. When she opens the closet door she finds the bloody and dismembered corpses of her friends who the doctor killed earlier in the movie. Their fatal wounds are shown in great detail.
A man is shot many times with a nail gun at the end of the film but does not die. His injuries shown soon afterward though. The scene of him pulling the nails out of his face was done for a dark comic effect.