I need to go to a dentist, "Orthodontics" is derived from the Greek "orthos" ("correct", "straight") 
Oh ok like to straighten teeth?
Exactly, in fact it has a history over 2000 years old
I had no idea it went that far back what else can you tell me?
Well it has origins as a part of medicine
Oh ok so just like Dr.'s
Yup! In fact I have heard archaeologists have discovered mummified ancients with metal bands wrapped around individual teeth
That is crazy to imagine!
Yeah and Orthodontic treatment can focus on dental displacement only
Oh so its limited