Evaluation of apical root resorption occurrence in orthodontic patients treated with fixed braces depending on selected clinical parameters

An aim of the work was analysis of the possible connections between the selected clinical parameters and external apical root resorption (EARR) in patients after orthodontic treatment.

The study comprised 101 persons, who underwent complex orthodontic treatment with the use of fixed braces (straight-arch technique).

The teeth chosen for measurement of resorption level were central and lateral incisors of mandible and maxilla, as well as maxillary first molars, which are the most susceptible to root resorption. The roots were measured on the basis of the dental radiographs taken before and at the end of treatment. The measurements were made on digital radiographs with the use of diagnostic software (Planmeca Romexis® Viewer), which allows the image filters ensure the highest precision when localizing roots end points. Proportional measurements of the chosen teeth were made with the use of Linge’s method and Linge’s method modified by Brezniak et al. For further analysis, the persons taking part in the study were divided into two groups depending on the presence of postorthodontic EARR or its lack, resulting from radiographic measurements: a control group comprising 61 patients without EARR (with 0.90 ≤ rRCR ≤ 1.00) and a study group including 40 patients with EARR (rRCR < 0.90). In statistical analysis there was used verification of statistical hypotheses based on the following tests: Pearson’s chi-squared test, Student’s t-test, Mann-Whitney U test.

On the basis of the made analyses and achieved results, it was found out that age, sex, type of skeletal malocclusion, increased overjet and overbite do not constitute risk factors for EARR occurrence. Excessive proclination of central and lateral incisors of mandible and maxilla predisposes to shortening the roots of these teeth during orthodontic treatment with fixed braces (p < 0.01).