A Retrospective Service Evaluation of Biological and Prosthodontic Complications Associated with Zygomatic Implants Placed in a UK Dental Hospital

Objectives: The study assessed the incidence of complications [biological, mechanical and prosthodontic] associated with zygomatic implants placed at a UK dental hospital. The patient cohort consisted of those with challenging denture bearing areas, who have undergone advanced levels of bone resorption following tooth loss or have bony defects following surgical procedures, i.e. oncology patients. In these cases, traditional treatment modalities such as removable dentures can prove unsuccessful and there may be insufficient bone for conventional dental implants.

Methods: A retrospective study assessed all patients that had been treated with zygomatic implants over a 15-year period. Patients were identified from a pool of over 3500 patients that had received dental implants. Once patients had been identified data was captured from electronic and paper notes and analysed.

Results: 26 patients had zygomatic implants placed between 2000 and 2015. 2 patients had to be excluded from the study due to data corruption in electronic storage. The remaining 24 patients had a total of 48 implants placed. Restorative treatment involved either a fixed implant supported bridge or removable implant supported overdenture. There was a 96% survival rate for the implants placed, however 87% of patients experienced complications. A variety of complications were reported ranging in severity from fractured denture teeth to permanent diplopia. 2 patients had implants removed due to infection and failed osseointegration. 35% of patients had problems relating to the implants, 50% had prosthodontic complications and 1 patient had permanent diplopia. The patients with complications attended 226 outpatient appointments in relation to the complications.

Conclusion: This study has found that while zygomatic implants can be an effective treatment, they can be associated with multiple post-operative complications and can involve significant time and resource commitments for the patient and clinician.