Computed tomography evaluation of jaw atrophies before and after surgical bone augmentation

Purpose: The aim of the study was to evaluate by Computed Tomography (CT) scan technique the alveolar ridges reconstructed through osseous grafting procedures (onlay bone grafts or sinus lift and grafting) for dental implant placement, and to test its suitability to differentiate pre-operative and post-operative conditions in reconstructed areas. Methods: Seventy-four CT cross-sections from 16 mandibles and 113 CT cross-sections from 18 maxillae from patients treated with autogenous bone grafts, performed via either vertical or horizontal autogenous bone block grafting or sinus lift procedure and grafting, and implant positioning, from January 2000 through December 2004, were analyzed and listed according to a residual ridge resorption evaluation. Maxillary and mandibular measurements were recorded and compared by Wilcoxon tests to highlight statistically significant differences. Data were subjected to Pearson's chi-square (?2) test, with YATES correction when necessary, to show frequency differences between pre-operative and post-operative conditions. Results: The comparison between pre-operative and post-operative CT cross-sections showed statistically significant differences both in maxillary and mandibular posterior regions subjected to vertical onlay grafts; no statistically significant differences, instead, were found in the anterior region of the maxilla. Clinical Significance: The presented 3D CT scan evaluation of jaw atrophies could be applied to the recognition of bone height useful for implant positioning. Future maxillomandibular atrophy evaluation schemes should include the three-dimensional relationship between the maxilla and the mandible, as well as volumetric considerations.