Which type of tooth fracture is characterized by a "J-shaped lesion"?

A "J-shaped lesion" specifically refers to the appearance associated with vertical tooth fractures, particularly those that involve the dentin and/or pulp. This type of fracture is characterized by a jagged or curved line that resembles the letter "J," often extending from the crown of the tooth down towards the root.

In vertical fractures, the crack typically follows the long axis of the tooth, which distinguishes it from horizontal, coronal, and transversal fractures. Understanding the morphology of dental fractures is crucial for diagnosis and treatment planning, as the management of a vertical fracture may differ significantly from that of other types of fractures. For example, vertical fractures may require endodontic intervention or even extraction, while other fracture types may often be treated with restorative measures.

Each other fracture type mentioned represents a different clinical presentation and mechanism of injury, contributing to their distinct diagnostic features.