How Are Teeth Numbered in the Human Mouth?

If you've been to a dentist office, you may have seen a diagram of teeth with numbers around them. Or your doctor may have shown you which teeth needed to be fixed according to a number. According to the American Dental Association (ADA) the Universal/National System is used in the United States to number adult teeth. This system numbers adult teeth from left to right on the top and bottom of the mouth.

Upper Molars

• Your upper teeth are numbered 1 through 16. Your left wisdom tooth, called the third molar, is number 1, and your right wisdom tooth is numbered 16. The second and first molars are numbered 2 and 3 on the left and 14 and 15 on the right.

Other Upper Teeth

• Your second and first bicuspid are numbered 4 and 5 on the right and 13 and 12 on the left. Your cuspids, or canine teeth, are numbered 6 and 11. Your lateral incisors are numbered 7 and 10. Your front teeth, or central incisors, are numbers 8 and 9.

Bottom Molars

• Your bottom teeth are numbered from 17 to 32. Your third molar is 32 on the left side and 17 on the right. The other molars are numbered 30 and 31 on the left and 18 and 19 on the right.

Other Bottom Teeth

• Your bicuspids are numbered 28 and 29 on the left and 20 and 21 on the right. You cuspids are numbered 22 and 27. Your lateral incisors are numbered 23 and 26, and your central incisors are 24 and 25.

Primary Teeth

• The system for identifying primary, or baby, teeth is similar to the system for identifying adult teeth. The only difference is that uppercase letters A-T are used to identify the teeth instead of numbers.