Trigonocephaly?

My son is six months old, about a month ago or so we noticed this ridge on his four head. We’ve looked back at pictures of him at birth and it is there so we believe he was born with it, but as he’s grown it has become more noticeable. Googling pointed to something called Trigonocephaly.

We’ve asked our pediatrician about it at the last 2 appointments and she said it was normal but both times she was in and out of the room in less than 30 seconds so we didn’t feel too assured.

If anyone’s had any experience with this or if your little one has something similar I’d really appreciate any input.