He is completely 'toothless'.
a 'toothless' whale
a 'toothless' smile
(..) guy you met at the bar the other night. I don't recall meeting anyone who matched that description. I think I'd remember. Oh, all right, you got me. It's the ugly, obnoxious, toothless loser... who got hammered and wouldn't leave you alone all night. Oh, Will! I remember. (..)1997 Good Will Hunting