gap-toothed

from WordNet (r) 3.0 (2006)

gap-toothed
    adj 1: having widely spaced teeth; "his gap-toothed grin"

from The Collaborative International Dictionary of English v.0.48

Gap-toothed \Gap"-toothed`\ (g[a^]p"t[=oo]tht`), a.
   Having conspicuous interstices between the teeth; as, his
   gap-toothed grin. --Dryden.
   [1913 Webster + WordNet 1.5]