When does the hook or notch on the upper corner incisor typically appear and disappear?

When does the hook or notch on the upper corner incisor typically appear and disappear?

• A. 7-8
• B. 11-12
• C. 5-6
• D. 8-9

Answer: (A)

Hooks on the upper corner incisor form when the permanent tooth has erupted and the bite hasn’t yet worn away the notch. In horses, this typically happens around seven to eight years old. As the teeth continue to wear with age, the hook is worn down and usually disappears by about nine to ten years. So the best fit for when it appears is the seven-to-eight-year window. The other age ranges are either too early for the hook to appear or refer to a disappearance that starts later than the onset.

Hooks on the upper corner incisor form when the permanent tooth has erupted and the bite hasn’t yet worn away the notch. In horses, this typically happens around seven to eight years old. As the teeth continue to wear with age, the hook is worn down and usually disappears by about nine to ten years. So the best fit for when it appears is the seven-to-eight-year window. The other age ranges are either too early for the hook to appear or refer to a disappearance that starts later than the onset.