Evaluation of Alveolar Bone Microstructure around Impacted Maxillary Canines Using Fractal Analysis in Dravidian Population: A Retrospective CBCT Study

Abstract

The aim of this study was to assess alveolar bone microstructure around impacted maxillary canines derived from fractal analysis. The present study was a retrospective cone-beam computed tomography (CBCT) study. In total, 61 scans (25 males, 36 females; age range - 12-28 years) were analyzed. About 64 × 64-pixel regions of interest (ROI) in the maxillary alveolar process containing trabecular bone between the premolars were selected. ImageJ software was utilized to process images and bone density was assessed by determining bone surface area (BSA) and bone marrow surface area (BMSA) for the impacted and nonimpacted sides separately. Selected fractals were plotted in a histogram using box-counting method and the results were tabulated. Paired t-tests were used to determine significant differences between the groups and gender differences. For both buccally and palatally impacted maxillary canines, BSA was increased, BMSA decreased in the region of the impacted canine and the difference was statistically significant (p <0.05) in both genders. Bone fractal dimension (FD) values were greater in the region of the impacted canine for both buccally (1.47 > 1.21) and palatally (1.53 > 1.43) displaced canines, while bone marrow FD values were greater in the region of the nonimpacted canine for both buccally (1.37 > 1.28) and palatally displaced canines (1.41 > 1.33). Females had significantly higher BMSA than males around impacted canines (p <0.05). Denser bone microstructure was noted around impacted canines when compared with fully erupted canines. No gender-related differences were noted for BSA, whereas BMSA was higher in females implying lower bone density when compared with males. Retrospective evaluation of bone microstructure surrounding unerupted/impacted canines can provide analytical information about treatment prognosis and anchorage considerations. With FD analysis of CBCT images, BSA and BMSA can be measured and bone density estimated in a reliable manner.