Both Marion Ross and Kaitlin Olsen had recurring roles on The Drew Carey Show (as Drew's mom and co-worker, respectively)
Henry Winkler and Marion Ross have previously starred together in Happy Days (Fonzie and Marion Cunningham respectively).
Kaitlin Olson from It's Always Sunny in Philadelphia guest stars as Oliver's girlfriend Debbie.
The song that the MedTones sing is "Sh'boom (Life Could Be A Dream)" by the Chords which is the standard for all doowop. It was a huge hit in 1954, reaching toward the top of the charts before the Crew-Cuts covered it.
Oliver: (to Regina)You spent all night with a medical journal memorizing all the bones in the human hand.
A challenge results about the number of bones 27 according to Regina vs 26 according to Oliver. Regina wins this one, there are actually 27.