What tooth number is the star on?

What tooth number is the star on?

• A. 18
• B. 3
• C. 9
• D. 21

Answer: (C)

The star is in a position that points to the upper left central incisor. In the universal numbering system, you start at the upper right third molar and move across the upper arch to the upper left third molar, counting from 1 to 16. The upper left central incisor is the ninth tooth in that sequence. So the star’s location corresponds to tooth nine. The other numbers would place the star on different teeth (such as a molar on the upper right or teeth on the lower arch), which wouldn’t match the star’s position.

The star is in a position that points to the upper left central incisor. In the universal numbering system, you start at the upper right third molar and move across the upper arch to the upper left third molar, counting from 1 to 16. The upper left central incisor is the ninth tooth in that sequence. So the star’s location corresponds to tooth nine. The other numbers would place the star on different teeth (such as a molar on the upper right or teeth on the lower arch), which wouldn’t match the star’s position.