gap-toothed 
adjective
Having or showing gaps between the teeth: he gave a gap-toothed grin a gap-toothed waitress...
- With trademark good-natured stoicism, he flashed a gap-toothed grin, drank a can of Coke, and played bass with a red string around his wrist, a gift from some Tibetan friends who've been chanting for his recovery.
- In the meantime, we keep in touch through the gadgets that have shrunk the world so much that I can see my niece's gap-toothed grin from 11,000 miles away, within hours of her teeth being kissed out.
- The one with the freckles and the gap-toothed grin.