Finite element analysis of three zygomatic implant techniques for the severely atrophic edentulous maxilla.

STATEMENT OF PROBLEM

A variety of zygomatic implantation techniques currently exist; however, a consensus regarding the most suitable method has not yet been reached.

PURPOSE

The purpose of this study was to evaluate and compare 3 zygomatic implantation techniques and to clarify the optimal number and position of zygomatic and dental implants for the reconstruction of the severely atrophied edentulous maxilla.

MATERIAL AND METHODS

A 3-dimensional finite element analysis craniofacial model was constructed from the computed tomography data of a selected patient with a severely atrophic edentulous maxilla. Modeled zygomatic implants were inserted into the craniofacial model with 3 surgical techniques (classic Brånemark, exteriorized, and extramaxillary), and with 3 model variations that involved the number and position of zygomatic and dental implants. The zygomatic implants were loaded with a vertical force of 150 N and a lateral force of 50 N. The stresses on and deformations of the bones and implants were then observed and compared.

RESULTS

No obvious differences in the amount and distribution of stress on the external craniofacial bones were detected in the models. The lowest stresses on the zygomatic implants were observed in the exteriorized technique group. The lowest deformations of the bone that surrounds zygomatic implants and dental implants were observed in the exteriorized technique and classic Brånemark technique groups. For the exteriorized technique group, the model with 1 dental implant in the site of the maxillary lateral incisor exhibited the lowest stress on the zygomatic implants and the least deformation of the bone surrounding the zygomatic and dental implants.

CONCLUSIONS

All 3 zygomatic implant techniques resulted in more or less homogeneous transference of force and thus could reconstruct the edentulous maxilla; however, the exteriorized technique with 1 dental implant in the lateral incisor appeared to be the most appropriate reconstruction method for the severely atrophied edentulous maxilla.