LAUSR

AIM To describe four cases of an uncommon type of segmental root development after endodontic revitalization procedures. The formation, development, and prognosis of this phenomenon is discussed, along with the causes and preventive measures. SUMMARY One immature maxillary anterior tooth with an extensive periapical lesion after partial extrusion caused by trauma. Three immature mandibular premolars had extensive periapical lesions after fracture of the dens evaginatus. All four teeth underwent revitalization procedures. During follow-up, an uncommon type of segmental root development was observed in each case, where the apical segment appeared to detach from the body of the root and developed separately. In all cases, the detached apical segments had continuing development with a shape and structure similar to that of a normal root tip. However, development of the root body did not appear to occur. The follow-up time of the present cases were 11, 60, 41, and 67 months, respectively. All four teeth remained intact and functioned normally without symptoms. Cases 2 and 3 displayed positive reactions to electrical pulp tests during follow-up.