Final answer:
The tooth is composed of a crown and a root, and the prognosis of a traumatized tooth depends on the type of fracture. A vertical fracture of the root has the poorest prognosis, while other types may still have potential for recovery with appropriate treatment.
Step-by-step explanation:
The tooth is composed of two main parts: the crown and the root. The crown is the visible part of the tooth above the gum line, while the root is embedded within the maxilla and mandible. When a tooth is traumatized, the prognosis for its recovery depends on the type and extent of the fracture.
In the given options, the fracture with the poorest prognosis for a traumatized tooth is a vertical fracture of the root (option A). This type of fracture involves a complete break in the root of the tooth, which can lead to significant damage and potential loss of the tooth.
On the other hand, horizontal fractures (options B and E) and coronal fractures (options C and D) may still have some potential for recovery depending on the extent of the damage and appropriate treatment.