Quantitative Assessment of the Edentulous Posterior Maxilla for Implant Therapy: A Retrospective Cone Beam Computed Tomographic Study.

Abstract

Dimensional changes of the alveolar bone are often noted in horizontal and vertical planes as a sequel to tooth extraction, particularly in the maxillary posterior region due to alveolar bone resorption combined with pneumatization of the sinus. The aim of this retrospective study was to quantitatively assess the maxillary residual alveolar ridge using cone beam computed tomography (CBCT) scans. A total of 349 edentulous sites from 250 CBCTs were evaluated. The apico-coronal bone height and bucco-palatal crest width were measured in sagittal and coronal slices, respectively. Additionally, the obliqueness of the sinus floor at the edentulous sites was also evaluated. One hundred and twelve (55.45%) of the molar and 74 (54.42%) of the premolar sites had a horizontal ridge dimension < 6mm, whereas 137 (67.83%) of the molar and 61 (44.86%) of the premolar sites showed an apico-coronal height < 8mm. Furthermore, 183 (54.14%) of the evaluated sites had an oblique sinus floor morphology. Additional augmentative procedures are thus required in a high percentage of the population at the edentulous maxillary posterior site for rehabilitation using a standard dimension implant. This study stresses on the need for a three-dimensional CBCT prior to implant surgery for proper treatment planning.