Comparative Analysis of the Bone Dimensional Changes after Extraction of Maxillary Molars: A CBCT Study
Abstract: Aims & Hypotheses: The goals of this retrospective CBCT study were to: (1) compare the area of the alveolar process before and after molar extraction; (2) compare the height and width of the alveolar process before and after molar extraction, and (3) identify the pattern of bone remodeling according to the initial relation between the molar roots, alveolar bone position, and the sinus ca... read morevity. Three hypotheses were proposed: (1) there are significant dimensional bone changes at the site of maxillary molars following extraction; (2) the magnitude of the dimensional bone change is associated with root divergence, and (3) the magnitude of the dimensional bone change is associated with initial bone position. Materials & Methods: Twenty-five teeth samples from 17 subjects were analyzed with two CBCT scans (before and after the molar extraction). Then, the scans were segmented to reconstruct 3D models. Two models were superimposed in computer planning software using specific anatomical landmarks. The MB-P, Mid-P, and DB-P cross-section planes were established to measure the dimensional change in horizontal bone width, vertical bone height, and the area of the alveolar bone. Results: Overall, the average reduction in horizontal bone width was 65.10%. The average reduction in vertical bone height and the area of alveolar bone were 35.23% and 18.89%, respectively. The associations of bone change with either root divergence or initial bone location were not statistically significant (p > 0.05). Conclusions: Despite all the limitations of this study, the results showed that after maxillary posterior tooth extraction, dimensional changes in the alveolar process occurred in both the vertical and horizontal directions. The vertical changes in the majority of the subjects were attributable to remodeling of the alveolar bone, and only two subjects presented signs of sinus pneumatization.
Thesis (M.S.)--Tufts University, 2018.
Submitted to the Dept. of Posthodontics.
Advisor: André de Souza.
Committee: Hans-Peter Weber, Matthew Finkelman, Gabriela Lagreca, and Panos Papaspyridakos.
Keyword: Dentistry.read less