A single force applied at which point of a tooth will allow complete translation of the tooth:
**Core Concept**
The question tests the understanding of the **biomechanics of tooth movement**, specifically the type of force application that allows for **translation** of a tooth. This concept is crucial in **orthodontics**, where controlled tooth movement is a key objective.
**Why the Correct Answer is Right**
To achieve complete translation of a tooth, a single force must be applied at the **center of resistance** of the tooth. This allows the tooth to move in a straight line without rotating, as the force is evenly distributed around the tooth's root structure. The center of resistance is typically located at the midpoint of the root.
**Why Each Wrong Option is Incorrect**
**Option A:** Applying force at this point would cause the tooth to rotate rather than translate.
**Option B:** This point is not typically associated with the center of resistance.
**Option D:** Force applied here would also lead to rotation.
**Clinical Pearl / High-Yield Fact**
Remember, for **translation** to occur, the force must be applied at the **center of resistance**, whereas **rotation** occurs when force is applied at a distance from this point.
**Correct Answer: C. Center of Resistance.**