Fractal Dimension Analysis of Periapical Alveolar Architecture in Endodontically Treated Teeth Before and After Orthodontic Treatment: A Retrospective Split-Mouth Study

Purpose: To assess periapical trabeculation of endodontically treated mandibular first molars before (T0) and after (T1) orthodontic treatment using fractal dimension (FD) analysis, and the effect of sex on these changes.
Methods: The study included 32 patients (15 males and 17 females, mean age 17.32±1.71 years). The study group consisted of endodontically treated teeth, and their healthy contralateral counterparts served as controls. FD analysis was performed on 40×40 pixel ROIs from panoramic radiographs at T0 and T1. Paired t-tests were used for comparisons between the study group and their contralateral controls, as well as for T0–T1 comparisons. Independent t-tests were used to evaluate sex-related differences (p<0.05).
Results: FD values of the study group were significantly lower than controls at T0 and T1 (p<0.001), with a greater T0–T1 increase in the study group. At T0, female FD values were significantly lower than males in the study group (p=0.014), but this difference was not significant at T1 (p>0.05). Significant T0–T1 FD increases were observed in both sexes and groups (p<0.05).
Conclusion: Periapical trabeculation during the healing of endodontically treated teeth was not adversely affected by orthodontic treatment, and sex-related differences tend to balance over time.

Keywords: Endodontically treated teeth, alveolar bone, periapical healing, orthodontic treatment; fractal dimension analysis