Which statement about eruption timing is true: second premolars erupt later than first premolars by about one year?

• A. They erupt earlier
• B. They erupt around the same time
• C. They erupt about one year later
• D. They erupt after the second molars

Answer: (C)

In eruption timing, premolars follow a set sequence in the mixed dentition. The first premolars come into the mouth before the second premolars, so there is typically a gap between them. Clinically, this gap is about one year, with first premolars erupting around ages 10–11 and second premolars about a year later, around 11–12. This timing reflects the development and eruption pathway of the teeth: the second premolars need the proper space and root development to be ready to erupt after the first premolars.

So the statement that second premolars erupt about one year later than first premolars is the best answer. The alternatives don’t fit because they imply the premolars erupt earlier, at roughly the same time, or after the second molars, which contradicts the typical eruption sequence and timing.