Affiliation:
1. 1 Department of Dental Anatomy and Morphology , Islamic Azad University, Dental Branch Tehran , Iran
2. 2 Private practice Tehran , Iran
3. 3 Department of Orthodontics, School of Dentistry , Shahid Beheshti University of Medical Sciences , Tehran , Iran
Abstract
Abstract
Aim: To determine the possible risk factors for external apical resorption (EARR) of the maxillary incisors.
Methods: Panoramic radiographs of 132 orthodontic patients with a mean age of 16.9 ± 3.6 years were selected from two practice centres in Tehran. The radiographs were taken between 1990 and 2005 and 63.6% of the subjects were female. Mean, standard deviation and distribution of EARR for various variables were assessed. Prevalence significance, as well as differences between frequency distributions of clinical EARR (≥ 1.2 mm) between genders, treatment plans (extraction/ non-extraction), initial overjet and overbite magnitude, and incisor types (centrals/laterals) were evaluated by the chi-squared test. The mean resorption rates on central and lateral incisors were compared using the independent-samples t-test. Associations between EARR with the age, duration of treatment, pretreatment overjet and overbite were assessed by the Pearson’s correlation test. The reliability of the method was determined by remeasuring 117 randomly selected incisors and determining the associations between both sets of measurements with the Pearson’s correlation coefficients.
Results: The prevalence of EARR, and clinical EARR (≥ 1.2 mm) were 91.8% and 44.78% respectively. The average of EARR was 1.377 ± 1.214 mm, or 8.165 ± 8.021% of pretreatment root lengths. The prevalence of clinical EARR was significantly higher in extraction cases, cases with greater initial overjet and on lateral incisors. Using the t-test, significant differences (p < 0.05) were observed between the extent of resorption between genders (higher in females), treatment plans (higher in extraction cases) and incisor types (greater on lateral incisors). Longer treatment times and excessive initial overjet were correlated with higher EARR levels (p < 0.05, r < 0.2).
Conclusions: Factors related to premolar extraction, initial ovejet size, treatment time and being female may be correlated with higher EARR. Clinically significant resorption did not occur more in females.
Reference33 articles.
1. Vlaskalic V, Boyd RL. Root resorptions and tissue changes during orthodontic treatment. In: Bishara SE, editor. Textbook of Orthodontics: Saunders; 2001 p. 463-75.
2. Weltman B, Vig KW, Fields HW, Shanker S, Kaizar EE. Root resorption associated with orthodontic tooth movement: a systematic review. Am J Orthod Dentofacial Orthop 2010;137:462-76; discussion 12A.
3. Linge BO, Linge L. Apical root resorption in upper anterior teeth. Eur J Orthod 1983;5:173-83.
4. Massler M, Perreault J. Root resorption in the permanent teeth of young adults. J Dent Child 1954;21:158-64.
5. Al-Qawasmi RA, Hartsfield JK, Jr., Everett ET, Weaver MR, Foroud TM, Faust DM, et al. Root resorption associated with orthodontic force in inbred mice: genetic contributions. Eur J Orthod 2006;28:13-9.
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献