At the suggestion of our family dentist, when my son was 2 or so we started taking him along when my husband and I had appointments even though he didn't actually have an appt himself. The point was to start getting him used to the noises and sounds of the office so it wasn't scary when he had his first - for which I believe he was 3 1/2 or 4. Also for 1 or 2 of the visits before he started his own, after I was done, we had him sit in the chair and the hygenist just peeked inside and counted his teeth (kind of a trial run). It all worked great and the only problem he's ever had was taking too long to decide which flavor toothpaste he wanted.
As for when the teeth are coming in, my son also was a late teether and our dentist also concurred that it's better for them to come in later. As one of the other posts mentioned, if they get them in late, he will also loose them late, probably later than many of his friends. We, oops, 'the tooth fairy' just paid him a bit more since he had to wait longer than most.