Evaluation of 31 zygomatic implants and 74 regular dental implants used in 16 patients for prosthetic reconstruction of the atrophic maxilla with cross-arch fixed bridges

Background: The use of a specially designed implant to be anchored in the zygomatic body has been proposed as an alternative to bone grafting in the prosthetic rehabilitation of the severely resorbed maxilla. However, few studies have evaluated the long-term stability and soft tissue conditions of zygomatic implants. Purpose: The aim of this retrospective study was to evaluate the clinical performance of zygomatic implants when used for prosthetic reconstruction of atrophic maxillae. Materials and Methods: Sixteen patients consecutively treated with 31 zygomatic implants and 74 additional dental implants from 1998 to 2002 were retrospectively evaluated and prospectively followed using a standardized clinical and radiographic study design. Data were collected from the time of implant treatment until the last follow-up. Results: The follow-up period ranged from 9 to 69 months from the day of implant treatment, with a mean of 46.4 months (3 years, 10 months). Three (9.7%) of the 31 zygomatic implants were surgically removed because of recurrent sinusitis. Three (4.1%) of the 71 additional dental implants failed to integrate. Poor oral hygiene and gingivitis were seen at most zygomatic implant sites (10/16). Local infections were observed in 9 of 16 patients. Sinusitis occurred in 6 patients. All patients (16/16) eventually received fixed bridges, which were stable throughout the observation period. Conclusions: The results showed an acceptable outcome with regard to implant and prosthetic survival rates. However, postoperative complications not related to implant and prosthesis stability were frequent. Further investigations of the long-term performance of zygomatic implants and with a focus on soft tissue and maxillary sinus health are needed.