Zygoma implant-supported midfacial prosthetic rehabilitation: a 4-year follow-up study including assessment of quality of life

Abstract

Objective: Successful prosthetic rehabilitation is crucial for quality of life in cases of large maxillary defects when surgical reconstruction is not advisable because of general health or patient refusal. For this purpose, the extended indications for Zygomaticus fixtures in different defect types were evaluated.

Patients and methods: Twelve patients received 28 zygoma implants and 23 dental implants (if a segment of alveolar process was available) and were followed-up 14-53 months. Zygoma implants were positioned classically in the maxillary molar region and to reduce leverage, a premolar and a canine position was developed. The quality of life was assessed by a validated questionnaire after complete rehabilitation.

Results: Cumulative zygoma implant survival was 82%. Three losses occurred because of persistent infection and gradual loosening. Lost implants were immediately replaced in adjacent bone. Insufficient implant length within soft tissue reconstructions was prone to chronic infection by pocketing and recurrent overgrowth of granulating tissue. Longer implants were free of soft tissue inhibition, yet prone to overloading and high leverage in cases when no anterior alveolar process and dental implants were present. Zygoma implant success was therefore 71%, including the new premolar and canine Zygomaticus fixture-position. Periotest values increased from 0 to +7 to the fourth year, peri-implant bleeding and plaque index were decreasing from 56% to 0% and 33% to 0%, respectively, and good general quality of life with the priorities on chewing and activity was noted.

Conclusion: Zygoma implants can reliably anchor the midfacial maxillary prostheses and enable a quality of life comparable with autologous maxillary reconstruction. They can be replaced immediately if local infection or loosening should occur. A premolar and canine position reduce leverage when no anterior alveolar process is present. The patient can alternatively be provided with dental implants.