**Core Concept**
Tooth movement relapse is a common concern in orthodontic treatment, particularly if the teeth do not have sufficient retention to maintain their new position. The stability of tooth movement depends on the type of tooth movement and the duration of orthodontic treatment.

**Why the Correct Answer is Right**
Tooth movement relapse is most likely to occur in cases of tipping or bodily movement without sufficient retention. Tipping involves the rotation of the tooth around a fulcrum, whereas bodily movement involves the translation of the tooth in a specific direction. Without retention, the tooth may return to its original position over time due to the forces of the surrounding bone and periodontal ligament. This is because tipping movements do not alter the length of the periodontal ligament fibers, whereas bodily movements do, and the periodontal ligament fibers tend to return to their original position if not retained.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is too vague and does not provide any specific information about tooth movement relapse.
**Option B:** This option is incorrect because it does not specify the type of tooth movement that is most likely to relapse.
**Option C:** This option is incorrect because it is a distractor and does not relate to tooth movement relapse.

**Clinical Pearl / High-Yield Fact**
To prevent tooth movement relapse, orthodontists often use retention appliances such as Hawley retainers or Essix retainers for a specified period after orthodontic treatment.

**Correct Answer:** C.