With activators, lower incisors are capped to control the forward displacement of the lower arch.

With activators, lower incisors are capped to control the forward displacement of the lower arch.

• A. capped, forward
• B. uncapped, backward
• C. inclined, vertical
• D. aligned, transverse

Answer: (A)

Functional appliances guide the mandible forward to influence growth and tooth positions. To manage how the lower front teeth respond as the jaw is advanced, the lower incisors are capped. That cap acts as a protective guide, limiting excessive forward tipping (proclination) of these teeth and helping control the forward displacement of the lower dental arch while the appliance encourages anterior jaw position. If the lower incisors were not capped, forward movement and tipping could occur more readily, undermining the intended control. The other descriptors relate to different directions of change (vertical or transverse) and don’t describe this sagittal control mechanism.

Functional appliances guide the mandible forward to influence growth and tooth positions. To manage how the lower front teeth respond as the jaw is advanced, the lower incisors are capped. That cap acts as a protective guide, limiting excessive forward tipping (proclination) of these teeth and helping control the forward displacement of the lower dental arch while the appliance encourages anterior jaw position. If the lower incisors were not capped, forward movement and tipping could occur more readily, undermining the intended control. The other descriptors relate to different directions of change (vertical or transverse) and don’t describe this sagittal control mechanism.