periosadist

periosadist \'per-ē-ō-sād,sad-əst\ n, pl -s (2008) 1 : a person who obtains advanced credentialing in the field of periodontology in order to inflict great physical pain on others for gratification

usage:

"That periosadist took all my money, hacked my gums to bits, and now I can't chew my food!"

"Ever since that periosadist got through with me, I have to take my meals through a straw!"