Large defect rehabilitation of upper jaw with zygomatic/oncologic implants. Preliminary results of a prospective study

Background The maxilla reconstruction with bone free flap after a resection for cancer or malformation may be required for a functional rehabilitation of the patient. A secondary dental implant placement into the reconstructed bone may be needed for the restoration of masticatory functions. The implants placed in free flap may have, on a long term, a higher number of perimplatitis and a lower survival rate than those placed in native bone. An alternative method for these rehabilitations could be represented by the employment of zygomatic implants for fixed bridges support. This effectiveness of this technique, already reported in literature and used for severe maxilla atrophy treatment too, has been proved by several long- term clinical studies. The use of three-dimensional diagnostic systems could allow a surgical and prosthetic virtual planning and a guided implant placement through the aid of a navigation system. These devices may help the surgeon with positioning the implant and consequently reduce the working time. Aim/Hypothesis The primary objective of this project is to evaluate the survival rate and the surgical and prosthetic problems of zygomaticoncologic implant placed in upper jaw where this is affected by a large anatomical defect. The secondary aim is to evaluate the quality of life. Material and methods Ten patients with a large anatomic defect due to resection for cancer or malformation were recruited in our protocol starting from September 2013, following the Ethical Committee approval. The patients were scheduled in base of the extent of the resection and the residual bone: (1) Full maxillary resection, treated with four zygomaticoncologic implants. (2) Hemimaxillectomy, treated with two zygomaticoncologic implants on the resected side and on the other side: (A) contralateral side dentate, one zygomaticoncologic implant behind the dental roots; (B) edentulous contralateral side, standard implants; (C) edentulous atrophic contralateral side, two zygomatic implants. In all cases the simultaneous use of standard implants was allowed. Four patients were treated up today: two hemimaxillectomy, one total maxillectomy and one anatomical defect due to palatal cleft. The implant placement was performed in two cases under the navigation guide. Three patients were immediate loaded with a fixed prosthesis and one delayed. Survival rate, early and late surgicalprosthetic complications were reported. Evaluation record of quality of life was filled pre and post surgery and in every follow-up at 3 and 6 months. Results After a follow-up period of 6 months no complications occurred with an implant survival rate of 100%. The quality of life in these patients resulted improved by 40%. Conclusion and clinical implications The results seem to be encouraging but long terms results are needed to confirm the reliability of the technique. This procedure may reduce the extent of intervention and minimize morbidity and procedure cost. Therefore there is a need to investigate the possibility to simplify the rehabilitation procedure using fixed bridges supported by zygomatic implants.