Effect of Alveolar Process and Basal Bone Features on Post-Extraction Dimensional Changes

To evaluate the effect of specific phenotypical and anatomical features of the alveolar process and basal bone on post-extraction dimensional changes.

Patients requiring the extraction of a single maxillary non-molar tooth were enrolled. A comprehensive panel of baseline anatomical characteristics, including sagittal root position (SRP) class, was recorded. Linear and volumetric bone changes and the need for ancillary bone augmentation (NBA) were assessed after a 14-week healing period.

Records from 65 patients were included. Facial bone thickness (FBT) ≤ 1 mm was associated with significantly greater dimensional changes and greater NBA compared to sites presenting FBT > 1 mm (88.46% vs. 35.13%; p < 0.002). Bone remodelling and NBA were highest in SRP Class IV (100%), with lower frequencies in Class I (60%) and Class II (43.5%). Sites with roots outside the bony housing showed significantly more remodelling and NBA (89.47% vs. 43.18%; p < 0.001). Sites with a basal bone width narrower than the alveolar processes exhibited significantly greater bone remodelling and a higher prevalence of NBA compared to sites where the basal bone was wider (88.89% vs. 50%; p = 0.09). Socket entrance dimensions, distance from the coronal aspect of the facial bone to adjacent boundaries and root volume showed a comparable trend towards increased dimensional changes and grafting.

Certain site-specific features appear to significantly affect post-extraction alveolar ridge remodelling and the subsequent NBA to facilitate implant therapy.