The Hot Girls at the Dentist Office who clean your teeth and tell you to brush more often. They accidentally brush their breasts against you and use the suction too.
A dental hygienist is the cute blonde who cleans your teeth every 6 mos. that you secretely have a crush on.
Otherwise known as "the dentist" or "the dental hygienist", the oral hygienist is the lost art of giving two guys head at the same time, in the sense that the multiple penises represent the dental tools.
Guy 1: dude i totally had a three way last night with this random dude and this chick
Guy 2: oh nice... i think... you didn't cross swords did you?
Guy 1: Are you kidding me, we gave her the oral hygienist, she totally got the fluoride treatment.