The type of anchorage in which two groups of teeth move in equal and opposite direction is called as
**Core Concept**
The question is testing the understanding of different types of anchorage in orthodontics. Anchorage refers to the resistance to tooth movement, and various types of anchorage are used to achieve specific orthodontic goals. The correct type of anchorage is used when two groups of teeth need to move in equal and opposite directions.
**Why the Correct Answer is Right**
Class II anchorage is a type of anchorage where two groups of teeth move in equal and opposite directions. This is achieved by using a Class II elastics or a Class II headgear, which provides a force to the teeth on one side of the dental arch, causing them to move in one direction, while the teeth on the other side of the arch move in the opposite direction. The Class II anchorage is useful in cases where there is a significant discrepancy between the upper and lower dental arches. The mechanism of Class II anchorage involves the use of elastic forces to move the teeth in opposing directions, taking advantage of the natural elasticity of the periodontal ligament and the surrounding bone.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a recognized type of anchorage in orthodontics.
**Option B:** This option is not related to the type of anchorage being described.
**Option C:** This option might be a distractor, but it is not a specific type of anchorage used in orthodontics.
**Clinical Pearl / High-Yield Fact**
One important aspect of orthodontic anchorage is understanding the concept of reciprocal anchorage, where the movement of one group of teeth is opposed by the movement of another group of teeth, often using elastic forces. This concept is crucial in designing effective orthodontic treatment plans.
**Correct Answer:** C.