Measurement of the zygomatic region for the optimal placement of quad zygomatic implants.

BACKGROUND: The zygomatic implant is suggested to be placed in zygomatic areas with the largest thickness, but regions to obtain the largest bone-to-implant contact (BIC) were unknown. PURPOSE: To identify the zygomatic regions for placing quad zygomatic implants that obtain the largest BIC. MATERIALS AND METHODS: The zygomatic thicknesses of 300 zygomata were measured at total 12 points on the superior, middle, and inferior areas on the 3-dimensional reconstruction images. In 50 edentulous maxillae, the zygomatic BICs of virtually placed implants were measured and the incidence of the intrusion into the infratemporal fossa calculated at each point. RESULTS: The largest thickness in the superior, middle, and inferior regions were at Point A(1) (8.01 +/- 2.10 mm), Point B(1) (7.02 +/- 1.73 mm), and Point C(0) (6.65 +/- 1.66 mm), respectively. The virtually placed implants at Point A(3) (16.70 +/- 4.18 mm) and Point B(1) (12.07 +/- 3.84 mm) had the highest BICs while retaining the minimum incidence of the intrusion complications. CONCLUSION: To obtain the largest BICs and avoid the intrusion complications, results suggested that the postero-superior region (Point A(3) ) and the center of zygoma (Point B(1) ) were the optimal places for the placement of quad zygomatic implants.