Evaluation of the zygomatic bone prior to the quad zygoma surgery: Virtual implant placement study on cone beam computed tomography

Abstract

Purpose Quad zygoma surgery is challenging procedure that requires an accurate prosthetic and implant planning. The objective of our study was to evaluate zygomatic implants placed according to quad zygoma protocol in the severely absorbed maxilla on cone beam computed tomography (CBCT) scans using an virtual implant placement program and to compare the variables according to gender. Methods 56 zygomatic bones from 28 patients were examined using CBCT scans. A total of 112 zygomatic implants were evaluated to zygomatic bone-implant contact (BIC) lenght, the relationship zygomatic implants between the maxillary sinus and zygomaticofacial foramen were compared and analyzed by gender on the virtually placed anterior and posterior implants on the three-dimensional reconstruction images. Results The average zygomatic BICs length in males was found to be 11.77 ± 3.47 mm, in females 11.23 ± 2.61 mm. Among the anterior and posterior exit profile according to zygoma anatomy-guided approach (ZAGA) classification, respectively, 1.7% and 7.2% were classified as ZAGA 0, 7.2% and 7.2% as ZAGA 1, 16.1% and 21.4% as ZAGA 2, 55.3% and 14.2% as ZAGA 3, 19.7% and 50.0% as ZAGA 4. No statistically significance found between gender-related parameters that were investigated. However, it was found that the contact to zygomaticofacial foramen was significantly higher in implants with an anterior exit profile compared to implants placed posteriorly (p < 0.05). Conclusion Examining the anatomy of the region with three-dimensional imaging techniques before quad zygoma surgery and conducting surgical rehearsals with programs that allow virtual surgery are crucial to prevent potential complications.