Pulp canal obliteration (PCO) occurs more frequently in teeth with open apices which have suffered a severe luxation injury. It usually indicates ongoing pulpal vitality. Extrusion, intrusion, and lateral luxation injuries have high rates of PCO (32, 33) Subluxated and crown- fractured teeth also may exhibit PCO, although with less frequency (34). Additionally, PCO is a common occur- rence following root fractures (35, 36).