Dilaceration is defined as:

Correct answer: D. A sharp bend or curve in the root or crown of a tooth

• A. Incomplete root dentin formation describes radicular dentin dysplasia or other developmental dentin defects, not dilaceration.
• B. A horizontal root fracture is a traumatic injury to an erupted tooth, not a developmental anomaly. It is not called dilaceration.
• C. Fusion is the joining of two adjacent developing teeth into a single large tooth; gemination is attempted division of a single tooth. Neither is dilaceration.
• D. CORRECT. Dilaceration refers to a sharp angulation or bend in the root (less commonly the crown) of a tooth, usually resulting from trauma to the primary predecessor that displaces the developing permanent tooth germ. The bend can occur at any level of the root and may complicate endodontic treatment or extraction.