Incisor root resorption due to ectopic maxillary canines: a long-term radiographic follow-up.

OBJECTIVE: To document the long-term fate of maxillary incisors with resorbed roots after correction of the associated ectopic canines. MATERIALS AND METHODS: The subjects were recruited from 107 children and adolescents age 9-15 years (mean 12.5 years) at initial registration, with 156 ectopically positioned maxillary canines. The children were referred to the specialist orthodontic clinic for consultation because of the risk of incisor root resorption. Of 51 patients contacted, 16 failed to attend. Eight of the remaining 35 were excluded because their lateral incisors had been extracted, leaving 27 subjects for follow-up registration. At initial consultation, all subjects had undergone radiographic examination, including computed tomography (CT) scans. At the follow-up consultation, the radiographic examination was limited to intraoral films. RESULTS: No resorbed incisor was lost during the 2- to 10-year follow-up period. The resorptive lesions had undergone repair in 13 teeth, remained unchanged in 12 teeth and progressed in 7 teeth. In the 13 teeth exhibiting signs of repair, no resorption was detectable in 11 teeth and minor resorption was detected in 2 lateral incisors. At the initial registration, severe or moderate resorption had been diagnosed in 12 lateral and 5 central incisors, compared with 11 lateral and 6 central incisors at follow-up. In 10 subjects initially diagnosed with resorption of 13 incisors, the lesions were no longer discernible on intraoral radiographs at follow-up. CONCLUSIONS: Even in cases of severe resorption, the incisor roots show good long-term healing. Incisors with root resorption can be used in an orthodontic appliance system.

How a computerized tomography examination changed the treatment plans of 80 children with retained and ectopically positioned maxillary canines.

The purpose of this study was to analyze treatment outcome and treatment planning before and after a computerized tomography (CT) investigation of children with retained and ectopically positioned maxillary canines. Intraoral and panoramic radiographs, computerized tomographs, and, in some cases, lateral head films were taken of 80 children with 113 retained maxillary canines. The incisor roots of 39 of the 80 children had some measure of resorption. Forty-two children with retained maxillary canines also had a space deficiency. Diagnosis and a treatment plan were originally based on extraoral and intraoral photos, study models, the anamnesis, the status on the patient's charts, conventional radiography, and, if available, lateral head films. Approximately one year later, the same examiner drew up a new treatment plan based on the same records but with a supplemental CT examination. The treatment plans of 35 (43.7%) of the 80 children were modified to reflect this new information. Of those patients with root resorption on the incisors adjacent to retained canines, more than half (53.8%) of the treatment plans were altered. Without the CT investigation, 11 children would not have been treated for resorption that had exposed the pulp of an incisor root and 13 who had no root resorption on their incisors would have had one or both lateral incisors extracted. The treatment plans of the latter were changed to nonextraction or extraction of premolars. A CT investigation is an important source of information for treatment planning for children with retained or ectopically erupting maxillary canines.

Does the canine dental follicle cause resorption of permanent incisor roots? A computed tomographic study of erupting maxillary canines.

We performed computed tomography (CT) on 107 children and adolescents aged 9-15 years with 176 unerupted maxillary canines (152 erupting ectopically and 24 erupting normally) to determine whether there is an association between widened dental follicles of the maxillary canines and resorption of the adjacent incisors during eruption. Contiguous axial (transverse) CT scans were obtained through the maxilla in the region of the canines. The width and shape of the dental follicles were recorded, as were any contacts between the follicles and the crowns of the maxillary canines and neighboring incisors. Fifty-eight lateral incisors (38%) and 14 central incisors (9%) had some type of root resorption. The position of the maxillary canine in relation to the root of the lateral incisor varied greatly, as did the width and shape of the canine dental follicle. Follicle width ranged from 0.5 mm to 7.0 mm. The mean +/- SD width of dental follicles was, on average, larger for the ectopically positioned canines (2.9 +/- 0.8 mm) than for the normally erupting canines (2.5 +/- 0.8 mm) (P < or = .01). We found that during eruption, the follicle of the erupting maxillary canine frequently resorbed the periodontal contours of adjacent permanent teeth but not the hard tissues of the roots. We concluded that the dental follicle did not cause root resorption of permanent teeth. Resorption of neighboring permanent teeth during maxillary canine eruption was most probably an effect of the physical contacts between the erupting canine and the adjacent tooth, active pressure during eruption, and cellular activities in the tissues at the contact points, all of which are part of the eruptive mechanism. The findings also confirm an association between root resorption of deciduous canines and the dental follicles of erupting permanent canines.