What is the ideal overbite for a normal occlusion?

• A. 40%
• B. 50%
• C. 60%
• D. 30%

Answer: (B)

Overbite measures how much the upper incisors vertically overlap the lower incisors. In a normal occlusion, the upper incisors should cover about half the height of the lower incisors when the jaws are closed, which is roughly 50%. This amount provides a balance between esthetics and function: enough incisal coverage to protect the lower teeth and contribute to stable anterior guidance, without causing a deep bite or hindering jaw movement. A shallower overlap, around 30–40%, reduces incisal protection and can affect esthetics and bite stability; a deeper overlap, around 60% or more, creates a deep bite with potential trauma to the palatal tissues and adverse effects on posterior teeth during closure. Therefore, about 50% is considered the ideal overlap for normal occlusion.