Background: Prosthetic rehabilitation with implant-supported prostheses in the atrophic edentulous maxilla often requires a bone augmentation procedure to enable implant placement and integration. However, a rigid anchorage can also be achieved by using so-called zygomatic implants placed in the zygomatic arch in combination with regular implants placed in residual bone.
Purpose: The aim of the present study was to report on the clinical outcome of using zygomatic and regular implants for prosthetic rehabilitation of the severely atrophic edentulous maxilla.
Materials and methods: Sixty-nine consecutive patients with severe maxillary atrophy were, during a 5-year period, treated with a total of 69 fixed full-arch prostheses anchored on 435 implants. Of these, 131 were zygomatic implants and 304 were regular implants. Fifty-seven bridges were screw-retained and 12 were cemented. The screw-retained bridges were removed at the examination appointments and each implant was tested for mobility. In addition, the zygomatic implants were subjected to Periotest (Siemens AG, Bensheim, Germany) measurements. The patients had at the time of this report been followed for at least 6 months up to 5 years in loading.
Results: Two regular implants failed during the study period giving a cumulative survival rate of 99.0%. None of the zygomatic implants was removed. All patients received and maintained a fixed full-arch bridge during the study. Periotest measurements of zygomatic implants showed a decreased Periotest values value with time, indicating an increased stability. Three patients presented with sinusitis 14-27 months postoperatively, which could be resolved with antibiotics. Loosening of the zygomatic implant gold screws was recorded in nine patients. Fracture of one gold screw as well as the prosthesis occurred twice in one patient. Fracture of anterior prosthetic teeth was experienced in four patients.
Conclusions: The results from the present study show that the use of zygomatic and regular implants represents a predictable alternative to bone grafting in the rehabilitation of the atrophic edentulous maxilla.