Intrasinus versus extrasinus zygomatic implant placement: A 5-year retrospective observational analysis of survival and complications

BACKGROUND: Edentulism, a common condition, may be congenital or acquired later in life as a result of dental caries, periodontitis, aging, craniofacial trauma, or tumor resection. The rehabilitation of missing teeth can be achieved with dental implants. In cases of insufficient alveolar bone, several treatment options have been described in the literature, including maxillary sinus augmentation with bone grafting, the Le Fort I osteotomy, the angulated placement of conventional implants, and the use of specialized implants, such as zygomatic implants, which are anchored in the zygomatic bone. OBJECTIVES: The aim of this retrospective study was to compare 2 surgical approaches - intrasinus and extrasinus - for the placement of zygomatic implants in patients with severe maxillary atrophy. MATERIAL AND METHODS: The study was based on the medical records of patients who underwent zygomatic implant treatment conducted by the same surgeon at 2 dental facilities in Poland between 2004 and 2021. A total of 190 zygomatic implants placed in 69 patients of varying age and sex were included in the analysis. The follow-up period was 5 years. Two surgical approaches for zygomatic implant placement - intrasinus and extrasinus - were evaluated. Statistical analysis was performed using a significance level of 0.05. Differences between the groups were assessed using the χ2 test or Fisher's exact test, as appropriate. RESULTS: The zygomatic implants placed using the intrasinus approach demonstrated a 100% survival rate. In the extrasinus group, the osseointegration rate was 94.27%, with implant loss occurring in 7 patients. Maxillary sinusitis was observed in 7 patients. Soft-tissue atrophy occurred in 4 patients (8.33%) and involved 14 zygomatic implants placed using the extrasinus technique. Cutaneous fistulas developed in 2 patients treated with the extrasinus approach. One case of zygomatic bone fracture was reported in the extrasinus group. CONCLUSIONS: No statistically significant differences in the complication rates were observed between the intrasinus and extrasinus techniques for zygomatic implant placement. Both approaches appear to be equally effective for the rehabilitation of patients with severe maxillary atrophy.