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 A1 (8.01 ± 2.10 mm), Point B1 (7.02 ± 1.73 mm), and Point C0 (6.65 ± 1.66 mm), respectively. The virtually placed implants at Point A3 (16.70 ± 4.18 mm) and Point B1 (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 A3 ) and the center of zygoma (Point B1 ) were the optimal places for the placement of quad zygomatic implants.