Fractal Analysis of Trabecular Bone Before and After Orthodontic and Surgical Extrusion: A Retrospective Case–Control Study

The present study explores bone healing patterns induced by orthodontic (OE) and surgical extrusion (SE) of structurally compromised teeth, where extrusion techniques are commonly used in rehabilitation. Changes in the trabecular bone were assessed by means of fractal analysis (FA) of consecutive periapical radiographs. (2) The present study is a retrospective case–control study. Pre- and post-treatment periapical radiographs from 44 adults undergoing orthodontic (OE) or surgical extrusion (SE) were retrieved. The radiographs were taken at T0 (pre-treatment), T1 (post-treatment), T2 (3-month follow-up), and T3 (6-month follow-up). Bone density (fractal dimension, FD) was analyzed in the apical and proximal bone regions (ROIs) of the extruded teeth, and both intra-group and inter-group differences were examined. (3) In all the regions of interest (ROIs), statistically significant intra-group differences in terms of bone density (FD) for both groups were found. In the OE group, the FD value increased, respectively, at T1, T2, and T3 in the apical ROI, compared to T0. For the proximal ROI, nearly the same trend was observed, respectively, at T1, T2, and T3 versus T0. As for the SE group, a statistically significant increase in the apical ROI was noted at T1, T2, and T3 when compared to T0. The same trend was registered in the proximal ROI compared to T0. However, no statistically significant inter-group differences in FD were detected between the two groups. (4) Orthodontic extrusion and surgical extrusion both resulted in an increased bone density (FD) despite the different healing patterns. Further prospective studies with a longer follow-up in this field are required.