Radioanatomical characteristics of zygoma for planning of quad zygoma implants: a cross sectional study.

PURPOSE: To evaluate the radioanatomical measurements of the zygoma as a guide for treatment planning of quad zygomatic implant placement. METHODS: This cross sectional study was carried on 17 patients of 34 zygomatic regions reported with atrophic maxilla for placement of zygomatic implants. The zygomatic implants were placed virtually in a quad approach using "Real Guide" version 3.0" and, the following parameters were assessed at 20 points in antero- superior, antero-inferior, postero-superior and postero-inferior regions. The thickness of zygomatic bone, Installation angle of zygomatic implants, Length of the installed zygomatic implants and Distance between the zygomatic implants on each side were measured using Cone Beam Computed Tomography (CBCT) on a virtual planning software "Materialise Mimics" version 15. RESULTS: The mesial implant can be emerged in antero-superior region and the distal implant can be emerged in antero-inferior region on the right side zygoma since the maximum thickness of zygomatic bone was seen in D2, A1, A3 and D4 directions. Similarly in the left side of zygoma, the mesial implant can emerge in postero-superior region and distal implant can be emerge in postero-inferior region since the maximum thickness was seen in D2 and A3 directions (P > 0.05). The installation angle for mesial implant in right and left side was 45(0) and the distal implant angle for right and left side was 45(0) and 46(0) (P < 0.05). The mesial zygomatic implant length for right and left side was 55.88 mm and 56.18 mm while, the distal zygomatic implant length for right and left side was 44.56 mm and 45.59 mm (P > 0.05). The distance between the two zygomatic implants in right and left side was 5.06 mm and 4.54 mm (P > 0.05). CONCLUSION: Virtual planning for placement of implants in quad zygoma approach would be a feasible requirement as it eases out the surgeon's practice and prevents the possibilities of causing intrusion complications intraoperatively. Hence, quad zygoma implants remains a promising viable option for patients presenting with severe atrophic maxilla. CLINICAL TRIAL NUMBER: Not Applicable.