Which numbers indicate the lower right molars from first to third?

• A. 30, 31, 32
• B. 28, 29, 30
• C. 21, 22, 23
• D. 27, 28, 29

Answer: (A)

Understanding this relies on the universal numbering system for permanent teeth. In this system, numbers increase as you move from the front to the back within a single quadrant. For the lower right quadrant, the sequence from the front to the back goes central incisor as 25, then lateral incisor 26, canine 27, first premolar 28, second premolar 29, first molar 30, second molar 31, and third molar 32. So the three molars in that quadrant, in order from front to back, are first molar (30), second molar (31), and third molar (32). That exact progression corresponds to the given set. Other sequences would mix in premolars or incisors or refer to teeth in a different quadrant, which is why they don’t fit.