External apical root resorption after nonextraction orthodontic treatment with labial vs. lingual fixed appliances.

Abstract

The aim of this retrospective study is to compare external apical root resorption (EARR) after labial and lingual fixed orthodontic treatment, as detected with panoramic radiographs. Sixty subjects were divided into two groups according to the treatment type: lingual (30patients) and labial (30patients) fixed orthodontic treatment. Panoramic radiographs which were obtained at the beginning of treatment (T0) and at the end of the treatment (T1) were evaluated. The maxillary and mandibular central and lateral incisors, as well as canine crown and root lengths were measured for T0 and T1. Crown to root ratios were used to determine EARR. Data were evaluated using analysis of variance and χ2 analysis. In all, 5patients (16.7%) in the lingual group and 7patients (23.3%) in the labial group had aminimum of one tooth with severe EARR, while 9patients (30%) in the lingual group and 14patients (46.7%) in the labial group had no EARR. A total of 26teeth (7.2%) in the lingual group and 34teeth (9.4%) in the labial group developed severe EARR; however, 184 teeth (51.1%) in the lingual group and 202 teeth (56.1%) in the labial group did not reveal any EARR. No statistically significant difference was found for the resorption rates between the treatment groups (p > 0.05). Although not statistically significant, there was a higher percentage of severe EARR in the mandible within the labial group. Both lingual and labial orthodontic techniques showed statistically similar root resorption rates. EARR is amultifactorial issue and individual predispositions must also be taken into consideration.