Evaluation of the effect of class II fixed orthodontic treatment on the periradicular bone structure of endodontically treated mandibular molar teeth using fractal dimension analysis

Aim: The aim of this study was to investigate whether changes in periradicular tissues with orthodontic movement of root canal-treated teeth differ from those without root canal treatment using fractal dimension analysis (FA). Methodology: A retrospective archive study was performed using panoramic radiographs taken before (T1) and after (T2) fixed orthodontic treatment. Panoramic radiographs of a total of 32 mandibular 1st and 2nd molar teeth were divided into groups: Group 1 (n:17), the control group, comprised radiographs of mandibular 1st or 2nd teeth without root canal treatment, and Group 2 (n:15) comprised radiographs of 1st or 2nd mandibular molars with root canal treatment. Fractal analyses were performed in four different regions—the periapical, bifurcation, mesial periapical, and distal periapical regions—of the mandibular molar teeth included in the study for a total of 128 analyses. Results: In the control group, orthodontic treatment did not make a statistically significant difference to the fractal dimension values in the four regions of the tooth (p > 0.05). In the endodontically treated group, the fractal dimension values of the mesial periapical regions increased statistically significantly after orthodontic treatment (p < 0.05). Conclusion: The FA values of this study showed that more biological interaction occurred in the root canal treatment group and in the mesial periapical region. Thus, it is important to keep orthodontic force within the tooth’s physiological limits to avoid damaging the tooth in the periapical areas where stress accumulates during orthodontic treatment. How to cite this article: Küçükkaraca E, Sarıçam E. Evaluation of the effect of class II fixed orthodontic treatment on the periradicular bone structure of endodontically treated mandibular molar teeth using fractal dimension analysis. Int Dent Res 2023;13(S1):38-43. https://doi.org/10.5577/idr.2023.vol13.s1.6 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.