Characteristic features of trabecular bone in edentulous maxillae

Following tooth loss, the maxillary alveolar ridge is affected by extensive resorption and its cancellous bone substance undergoes intense remodeling processes. This is particularly important for endosseous implant surgery as the primary stability and thus the prognosis of endosseous implants depends on the cancellous bone density and structure of the alveolar ridge. To analyze the structure of alveolar trabecular bone, 156 sections were obtained from 52 edentulous maxillae (29 female, 23 male; mean age: 72.5 years) from the lateral incisor, first premolar, and first molar regions. The structural histomorphometric analysis was performed on cancellous bone of the section surfaces using semiautomatic image analysis. The following parameters were measured: trabecular bone volume, trabecular number, trabecular thickness, trabecular plate separation and trabecular interconnection. All examined parameters showed an extreme range of variation. A difference of more than 45% between the highest (= 51.93%) and the lowest (= 6.73%) trabecular bone volumes was found. Furthermore, the measurements showed that trabecular bone volume, thickness and number were distinctly lower in the molar region than in the incisal and premolar regions. Significant sex-specific differences were found in all investigated regions, female maxillae showing a smaller amount and a lower connectivity of cancellous bone than male maxillae.