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

Abstract

Background: The objectives of our study were to evaluate zygomatic implants placed according to quad zygoma protocol in the severely absorbed maxilla on cone-beam computed tomography (CBCT) scans using virtual implant placement program and to compare the variables according to gender. The secondary objectives were to examine the intra and extra-sinus pathways of anterior and posterior implants. Materials and 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 (zBIC) lenght, the relationship zygomatic implants between the maxillary sinus and zygomaticofacial foramen (ZFF) were compared and analyzed by gender on virtually placed anterior and posterior implants on the three-dimensional reconstruction images. Results: The average zBICs length in males was found to be 11.77 ± 3.47 mm, in females 11.23 ± 2.61 mm. Although the zBIC lenghts of anterior implants were reported to be higher than those of posterior implants, no significant differences were found, respectively (p > 0.05). Among the anterior and posterior zygomatic implants classified according to ZAGA classification, ZAGA 3 (%55,3) and ZAGA 4 (%50) were most common reported, respectively. ZFF contact was significantly higher in implants with an anterior exit profile (p < 0.05). No statistically significant differences were found between gender-related parameters that were investigated (p > 0.05). Conclusion: BIC length was not affected by gender or implant position. Most of the zygomatic implants were placed extrasinus trajectory. Anteriorly placed zygomatic implants presented high risk for ZFF contact. Trial registration: Not applicable.