Evaluation of cortical bone thickness and root proximity at maxillary interradicular sites for mini-implant placement

The purpose of this study was to evaluate the interradicular cortical bone thickness, alveolar process width and root proximity for planning mini-implant placement in the maxillary alveolar process.

Eighty maxillae (right and left sides) of 40 Japanese adult skulls were examined. The samples were imaged and measured using a micro-CT system. Buccal and palatal interradicular cortical bone thickness, alveolar process width, and root proximity were measured in six interradicular sites from distal of central incisor to mesial of second molar. Buccal and palatal interradicular cortical bone thickness and alveolar process width were measured at 10 different vertical levels. Root proximity was measured at four different vertical levels.

Buccal and palatal interradicular cortical bone thickness and alveolar process width tended to increase from crest to base of alveolar process. The buccal interradicular cortical bone thickness between canine and first premolar or between first premolar and second premolar was the greatest, and between central incisor and lateral incisor was the least. The palatal interradicular cortical bone was significantly thicker than the buccal. The root proximity between second premolar and first molar or first premolar and second premolar was the widest and between central incisor and lateral incisor it was the narrowest.

The findings of this study suggest that recommendations when low dose 3D multislice CT or low dose cone beam imaging is not available, the results of this research may be useful in providing indicators for selecting the design of the placement site.