When should children get their first dental X-ray?

The American Dental Association recommends that parents take children to a dentist no later than their first birthday and then at intervals recommended by their dentist. How often your child's teeth will need to be x-rayed will depend on his or her present oral health, age, risk for disease, and any signs or symptoms of oral disease. Because their teeth and jaw are still developing and are more likely to be affected by tooth decay, children may require x-rays more often than adults.

The dentist will review your child's history, examine his mouth and then decide whether or not x-rays are needed. 

There is no specific time when children should get their first dental x-ray. You should take your child for his first dental visit soon after he gets his first baby tooth or turns 1, whichever comes first. But when he gets his first x-ray will depend on his situation. If he's starting to get cavities early, his dentist may want an x-ray. Often, though, dentists don't give a child an x-ray until the first permanent tooth comes in, around age 5 or 6. An x-ray at that time can help determine if the permanent teeth are coming in correctly.