Among the types of root fractures (horizontal), which location has the best prognosis for healing?

Horizontal root fractures are classified by location: cervical third (near the gingival margin), middle third, and apical third. Apical third fractures have the best prognosis because: the coronal fragment is more stable (longer remaining root), there is less mobility and displacement, healing by calcific tissue (hard tissue union), connective tissue, or bone formation is more likely, and blood supply from the apex can support pulp vitality in both fragments. Cervical third fractures have the worst prognosis because the coronal fragment is short, mobile, and often necrotic due to disrupted blood supply; extraction of the coronal fragment is often required.