Stranger Things' Gaten Matarazzo undergoing "big" surgery No. 4 for cleidocranial dysplasia

E! Online

"Surgery number 4! This is a big one!" the 17-year-old actor captioned an image on Instagram. Matarazzo is undergoing surgery for cleidocranial dysplasia (CCD), a birth defect that affects the growth of the bones and teeth that often leaves sufferers without them.