Dwarfs vs Dwarves

In watching Snow White and the Seven Dwarfs I was surprised by the spelling of "Dwarfs". I always thought the plural of dwarf was dwarves. As it turns out both versions can be used. The term dwarves was popularize by J.R.R. Tolkien's Lord of the Rings. Since then many other games and movies have used the plural dwarves. When referring to the medical condition, it is more appropriate to use dwarfs.

As wikipedia states:
"Regarding the plural, Tolkien wrote in 1937 that 'I am afraid it is just a piece of private bad grammar, rather shocking in a philologist; but I shall have to go with it.' "



http://whatsthediff.net/featured/whats-the-difference-between-dwarf-and-midget/
https://en.wikipedia.org/wiki/Dwarf_(mythology)#cite_note-GILLIVER-MARSHALL-WEINER-104-108-3