The star marks tooth number 10.

The star marks tooth number 10.

• A. 31
• B. 28
• C. 10
• D. 20

Answer: (C)

Understanding which tooth gets which number in the universal system is the key. In this system, permanent teeth are numbered 1 through 32, starting at the upper right third molar as 1 and continuing across to the upper left third molar as 16, then down to the lower left third molar as 17 and ending at the lower right third molar as 32. The star marks the tooth that is the upper left lateral incisor, which in this system is numbered 10. That’s why 10 is the best answer. The other numbers point to different teeth elsewhere in the mouth.

Understanding which tooth gets which number in the universal system is the key. In this system, permanent teeth are numbered 1 through 32, starting at the upper right third molar as 1 and continuing across to the upper left third molar as 16, then down to the lower left third molar as 17 and ending at the lower right third molar as 32. The star marks the tooth that is the upper left lateral incisor, which in this system is numbered 10. That’s why 10 is the best answer. The other numbers point to different teeth elsewhere in the mouth.