My kids' 1st 2 dentists did that. The one they go to now lets me go back if I want to. Most of the time the kids ask me to stay in the waiting room though. When they didn't have the option of me going back, they'd be anxious. But since they have the choice now, they'd prefer to go alone. And they know I'm right in the next room if they need me (small office). None of the rooms have doors (just the waiting room and the bathroom have doors)