Zap Into Radiography Brilliance: ADAA X-Ray Practice Exam 2026 – Light Up Your Future!

In this type of question, you map the star to the universal tooth numbering system. This system numbers teeth from 1 to 32, starting at the upper right third molar (tooth 1) and moving across the upper jaw to the left (tooth 16), then continuing on the lower jaw from left to right (17 to 32). The upper left central incisor—the tooth right at the midline on the left side of the upper jaw—is tooth number 9.

So, if the star is on the upper left central incisor, its universal number is 9. For reference, 11 would be the upper left canine, 14 the upper left second molar, and 24 the lower left central incisor. Therefore, the star in the second example corresponds to tooth number 9.