Tooth resorption part II - external resorption: Case series
A 16-year-old female patient reported to the department with a chief complaint of discolored tooth #9. Past dental history revealed that the tooth was avulsed about 10 years back and was immediately replanted by the patient's father. On clinical examination, the clinical crown height of tooth #9 was much lesser than the adjacent teeth and the cervical portion of the crown displayed a pinkish hue. A perforation was detected in the cervical third of the crown on the palatal aspect with an endodontic explorer and was seen extending mesially and distally. Profuse bleeding was evident on exploration. On the periapical radiograph, tooth #9 had the appearance of an immature apex with thin incompletely developed parallel root canal walls. The pulp canal space was obliterated by a less radio opaque material resembling bone which appeared to be in continuity with the periapical bone. A large ill defined radioluency was seen in the cervical third of the crown extending extensively in a mesiodistal direction []. Computerized tomography (CT) scan slices revealed the canal configuration of the tooth at the coronal, middle and apical levels. At the coronal level a break in the continuity of the palatal wall was observed that was indicative of a perforation. The canal space showed radio opacity resembling bone [–]. At the middle third of the root, CT slices displayed a continuity of the canal walls [–] and slices in the apical region revealed thin mesial and distal canal walls [].\nFollowing replantation of avulsed immature teeth, in growth of periodontal tissues into the canal space has been observed as an attempt at revascularization. It has been reported that well organized bone, PDL and cementum can grow into the canal space.[] In this case tooth #9 which been replanted had a wide open apex which probably provided an open pathway for the in growth of periodontal tissues following damage to the pulp. The pulpal tissue was replaced by metaplastic bone like tissue that was evident on the radiograph and the CT scan images. The perforation that was present in the cervical third of the crown on the palatal aspect and the presence of granulation tissue indicated it to be a case of external cervical resorption. Though the radiographic appearance also resembles perforating internal resorption, this diagnosis could be ruled out due to the absence of vital apical pulp tissue which is essential for internal resorption to progress. The presence of a weakened coronal tooth structure due to the extensive nature of the resorption process and the obliteration of the canal space with metaplastic bone like tissue signalled a poor prognosis for the tooth which was hence advised an extraction.