According to Zac, he suffered a massive jaw injury four years ago that left his “chin bone hanging off his face” after he slipped at home and smacked his chin on a granite fountain.
The injury caused the masseter muscles, located along the side of the jaw, to grow massively as they compensated for the injury.
While he usually works with a specialist to manage the ongoing impacts of the jaw injury, Zac took time off from his physical therapy in early 2021 and the results were, well, obvious.
“The masseters just grew,” he told the outlet. “They just got really, really big.”
The star, who found fame after being cast in the High School Musical movies, added that he had no idea about the plastic surgery rumours at the time because he largely avoids social media.
“If I valued what other people thought of me to the extent that they may think I do, I definitely wouldn’t be able to do this work,” he said.
It’s not the first time Zac has faced rumours about his appearance.
In 2017 the actor starred in Baywatch and his muscular physique gave rise to new speculation that he was using steroids to boost his gains.
While Zac himself never responded to the allegations, plenty of fitness gurus insisted there was no way he could have built such major muscle mass so quickly without help.
But some fans slammed the rumours, insisting that there was a “double standard” and that no one would be “allowed” to comment on the changes to Zac’s body if he was a woman.