Zac Efron has cleared up rampant rumors about his alleged plastic surgery, saying that when “jaw-gate” blew up on social media last year, his mom called him to ask if he had undergone an operation. Speaking to Men’s Health, Efron denied having surgery and claimed the changes to the shape of his jaw were due to an injury four years ago. Speculation surrounding the High School Musical star’s appearance began last year, in April, when the 34-year-old appeared in a promotion for Earth Day with Bill Nye. Speaking to Men’s Health, Efron revealed the injury occurred when “he’d been running through his house in socks and slipped, smacking his chin against the granite corner of a fountain.” He said he “lost consciousness, and when he woke up, he recalls, his chin bone was hanging off his face.” Due to the injury, Efron says, the muscles in his jaw—masseters—needed to work harder to compensate. Through work with a specialist and physical therapy, “‘the masseters just grew,’ he says, shrugging. ‘They just got really, really big.’” Efron said he was completely unaware of “jaw-gate” until his mother called and asked “because, though he appreciates that social media can be useful for promoting projects he cares about, he generally avoids it.”