Abstract
Immature permanent teeth suffering from root resorption as results of dental trauma, ectopic eruption of the neighboring tooth, auto-transplantation, and cysts, were clinically analysed to investigate their prognosis. The material included 59 teeth from 41 patients, aged 7 to 12 at the primary visit.
External and internal root resorption occured due to the trauma. The follow-up examination varied from 2 to 19 years, with average of 9 years. It was possible to recognize five types of root resorption.
Transient external resorption was observed in 5 vital teeth following root frature, luxation and albeolar bone fracture. This resorption showed small superficial resorption lacunae, and was repaired with hard tissue (Type I).
Another 46 teeth had endodontic therapy. Internal root resorption was radiographically characterized by an oval shaped increase in the size of the pulp chamber, associated with inflammation in the pulp or process to pulp necrosis in 4 teeth. After the start of endodontic therapy, resorption stopped (Type II).
External root resorption was observed in 42 teeth. In 13 teeth, resorption area of both root and albeolar bone was seen with pulpitis or pulp necrosis. By means of endodontic therapy, resorption was arrested (Type III). In some of them, the resorption lacunae were repaired with deposition of hard tissue.
However, in 11 teeth which had suffered displacement injuries, albeolar bone fracture, and avulsion, continuous extensive resorption was oberved. Endodontic therapy and endodontic surger had a slight influence on this resorption (Type IV).
In 18 teeth, dento-albeolar ankylosis was recognized by the infra-occlusion, and endodontic therapy showed little effect on the resorptive process (Type V). The radiographs revealed disappearance of the normal periodontal space and continuous replacement of root substance with bone, with or without radiolusency. As delayed findings, tunneling resortption and merginal bone loss were observed. In 5 teeth infrapositioning ceased. Besides this, the auto-transplanted tooth had the exetrnal reorption type III.
The root resorption in seven teeth resulted from ectopic eruption of the neighbouring canines or second premolars in patients with extensive crowding in the upper jaw other than the dental trauma. A folliculr dental cyst was also suspected to absorb the mesial root of its neighbouring mandibular first molar. When the suspected causes were removed, this resorption ceased in all the 8 teeth.
