First of all, don't wait until you think your child is "old enough" for braces before you start looking for an orthodontist. Kids should receive a checkup by age 7 to see how their teeth are coming in.
However, getting braces means making a big commitment to one orthodontist for several years, so don't be afraid to search around for the best fit, even if you've already had a consult with another doctor at an earlier age. The right orthodontist can make the entire process much easier.
Questions to ask your potential office:
How many orthodontists work in this office?
What's the scope of the plan?
When is the best time in my child's life for treatment?
What exactly needs to be done?
What are my options?
What will the consequences be if I don't do this treatment now?
How frequent will the visits be?
How long will the entire process take?
How does the office work to emphasize good oral care at home?
What are your office hours? (Many orthodontists keep limited hours, which means that working parents have to skip work and kids have to be taken out of school.)
How long have you been in practice?
How much will this cost?
How is my treatment cost determined?
Does your quote include all costs from beginning to end?
Are there additional fees during the treatment?
What follow-up care, such as retainers, is included after the braces are removed?
Do you provide references from past or current patients?
In addition to interviewing the orthodontist, be sure to pay attention to the entire office. Do the hygienists seem friendly? Is the office staff easy to work with? Are they flexible about scheduling?
Finally, ask parents of other patients a few questions about their experience. For example:
Will the doctor spend an extra five minutes with a kid who is a bit careless or impatient to help make their experience better?
How accessible is the orthodontist and his/her office for advice?
How do they handle emergencies?