Zygomatic implants in the rehabilitation of severe maxillary atrophy: A retrospective study of 274 zygomatic implants with a mean follow-up period of 7.5 years

Purpose: Zygomatic implants are considered one of the last options for the rehabilitation of severe maxillary atrophy when standard implants cannot be placed. They offer several advantages but can also present complications. This study aimed to investigate the long-term clinical and radiographic outcomes of zygomatic implant placement.
Materials and methods: A retrospective chart review was conducted, and the inclusion criteria consisted of patients previously treated with zygomatic implants who had Class V or VI maxillary bone atrophy according to Cawood and Howell, and with a minimum follow-up period of 2 years after prosthetic loading. Outcome measures included implant and prosthesis survival rate, biological and biomechanical complications, and Lund-Mackay staging score before and after implant placement.
Results: The study included 78 patients who received a total of 274 zygomatic implants. The mean follow-up period was 90.4 ± 26.0 months. Seventeen implant failures occurred, resulting in a survival rate of 93.8%, with a statistically significant negative correlation with smoking habits (P = 0.049), anchorage to the two zygomatic bone cortices (bicorticality) (P 0.001) and soft tissue complications (P 0.001). The prosthetic success rate was 92.3%. A statistically significant increase in maxillary sinus radiopacity was recorded when comparing the situation before and after surgery (P 0.001), and the intrasinus pathway had a statistically significant influence on that increase (P = 0.003).
Conclusions: Zygomatic implants utilised for rehabilitating patients with severe maxillary atrophy have shown favourable outcomes. Nonetheless, owing to potential complications, strict case selection is necessary, combined with regular recall visits and proper oral hygiene maintenance. Furthermore, this type of surgery necessitates specialised training and expertise on the part of the practitioner.