Ridge alterations post-extraction in the esthetic zone: a 3D analysis with CBCT

Abstract: Dimensional alterations of the facial bone wall following tooth extractions in the esthetic zone have a profound effect on treatment out-comes. This prospective study in 39 patients is the first to investigate three-dimensional (3D) alterations of facial bone in the esthetic zone dur-ing the initial 8 wks following flapless tooth extraction. A novel 3D analysis was carried out, based on 2 consec-utive cone beam computed tomogra-phies (CBCTs). A risk zone for signif-icant bone resorption was identified in central areas, whereas proximal areas yielded only minor changes. Correlation analysis identified a facial bone wall thickness of ≤ 1 mm as a critical factor associated with the extent of bone resorption. Thin-wall phenotypes displayed pronounced ver-tical bone resorption, with a median bone loss of 7.5 mm, as compared with thick-wall phenotypes, which decreased by only 1.1 mm. For the first time, 3D analysis has allowed for doc-umentation of dimensional alterations of the facial bone wall in the esthetic zone of humans following extrac-tion. It also characterized a risk zone prone to pronounced bone resorp-tion in thin-wall phenotypes. Vertical bone loss was 3.5 times more severe than findings reported in the existing literature. Key Words: bone remodeling, bone resorption, three-dimensional imaging