'Stranger Things' Star Gaten Matarazzo Grinnin' Wide, Fake Teeth and All

Gaten Matarazzo isn't shy about his missing teeth on "Stranger Things" ... and he isn't ashamed to admit he rocks dentures in real life.

We got the 13-year-old actor in NYC where he talked about playing Dustin, the show's incredible success and his front teeth. Gaten has cleidocranial dysplasia, which affects tooth and bone development.

He copped to the fact he's got fake chompers, but Gaten also told us about his lesser known talent ... singing our National Anthem.

He kinda does it all, but check out the clip -- there's a reason he won't be singing too much. For now.