As a former Dental Assistant I can tell you why.
A. Most operatories don't have enough room for 3 adults and a child. Both the assistant and doctor have to be able to move around, hard to do if you are there.
B. Alot of parents nervous about the dentist and kids are VERY intuitive! If you are nervous, they are nervous. Believe it or not, most kids do BETTER without their parents in the room! AND most dentists are compassionate people, they understand the fear! Believe me, there is nothing worse than a parent that clutches their child...OH SWEEETIE IT'S OK THEY WON'T HURT YOUUUUUU! *sob*! OY.
C. At 3 a dental exam consists of the doctor looking at the teeth, doing a quick count to see if he has all his teeth. Seeing if he has any plaque. IF there are issues he will usually refer you to a pediatric dentist. There usually are no x-rays. If you brush his teeth twice a day there should be no reason to do a "cleaning".
I would recommend;
Janda, James M DDS - Prairie Point Dental Inc
Address: 3015 E New York St # A10, Aurora, IL 60504
Phone: ###-###-####
Address: 1112 S Washington St # 203, Naperville, IL 60540
Phone: ###-###-####
Not only is he great with the kids but his staff are all REALLY great people! Give them a try.
No offense but I a so TIRED of people not trusting others! Yes, there are pediphiles out there but do you have to be afraid of EVERYONE?? This isn't even directed just at you, it is directed at all moms that are like this today. I mourn the day when you trusted your doctor, your dentist, your neighbor. How did we EVER survive?? *sigh*