Anatomic site evaluation of edentulous maxillae for dental implant placement.

PURPOSE

This study evaluated 17 edentulous cadavers for bone quantity and quality of the alveolar process of the maxilla for the purpose of dental implant placement.

MATERIALS AND METHODS

The maxillary arch was divided into four anatomically defined regions for measurements of bone quantity. Bone quality was assessed histologically and described by trabecular bone patterns and tissue composition.

RESULTS

Average bone height with a minimum thickness of 4 mm was as follows: region 1, 12.1 +/- 4.9 mm; region 2, 14.1 +/- 7.2 mm; region 3, 6.1 +/- 2.8 mm; and region 4, 8.5 +/- 2.2 mm. Histological evaluation showed increased trabeculation and thicker cortex in the maxillary anterior area, regions 1 and 2. Region 3, the floor of the maxillary sinus area, had the least amount of bone; however, the quality of bone was superior to that of region 4, the maxillary tuberosity area. Trabecular distance or marrow spaces ranged from 40 microns to 2 mm with larger spaces associated with the posterior maxilla.

CONCLUSIONS

Maxillary tuberosity is the least desirable site for the placement of implants in the maxilla. The area corresponding to the first and second molars had the least bone thickness. All measures of bone preservation need to be considered, especially in this area.