Zygomatic Bone-to-Implant Contact in 77 Patients With Partially or Completely Edentulous Maxillas

Purpose: Specifically with zygomatic implants, the bone-to-implant contact (BIC) at the zygomatic bone correlates with the survival of the implant because there is little anchorage at the alveolus. The purpose of this retrospective study was to view and measure the BIC of zygomatic implants in the zygomatic bone. Materials and Methods: The patients in this study received zygomatic implants at a single private dental implant center. All patients were treated with the same immediate-loading protocol followed by postoperative cone beam computed tomography. The scans were exported to a computer-aided design system, where the BICs could be measured digitally. The BIC was analyzed by gender, and any statistical difference was determined by analysis of variance. Results: The study sample was composed of 77 patients (62.3% women) receiving 173 zygomatic implants. The mean age of the sample was 59 +/- 8.7 years. The mean BIC was 15.3 +/- 5.6 mm (range, 4.9 to 32.9 mm) in the zygomatic bone. On average, 35.9% +/- 11.7% (range, 12.2% to 67.3%) of the implant came into contact with the zygomatic bone. The average BIC in men was 16.5 +/- 6.0 mm, and the average BIC in women was 14.7 +/- 5.4 mm, a statistically significant difference by analysis of variance (P < .05). Conclusions: Evidence from this report indicates the zygomatic BIC varies greatly from patient to patient. These data show that the typical male patient has a greater zygomatic BIC than the typical female patient; however, these data do not support the hypothesis that the zygomatic BIC influences the zygomatic implant survival rate. (C) 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70:2065-2069, 2012