I believe it was around 8 - 10 when Mom stopped coming into the room. Of course I was the 5th of 6 kids (the 4th and final boy) so she knew about when it would start to become embarrassing for me to have her there, and we all went to the same pediatrician, so she also knew about what age he would prefer to see us alone.
That does not mean, however, she would have any compunction about pulling down my drawers if I needed a suppository or other type of treatment, (Creams, ointments, etc) although rectal temps stopped at about age 6 - 7. Nor would she hesitate to yank down my pants and put me over her knee to give a spanking if the occasion called for it. (Which, thankfully, it didn't often. The mere threat of a spanking was enough to make us toe the line.)