Comparative analysis of the frequency and nature of prosthetic and surgical complications associated with zygomatic, pterygomaxillary (pterygoid), and conventional dental implants: a systematic review

BACKGROUND: Rehabilitation of patients with severe maxillary atrophy can be performed using conventional implants (CI), zygomatic implants (ZI), and pterygomaxillary (pterygoid) implants (PI); these strategies differ in biomechanics and complication profiles. AIM: To compare the frequency and nature of surgical, biological, and prosthetic complications associated with ZI, PI, and CI, and to summarize data on survival and success, and marginal bone loss. METHODS: A PRISMA 2020–compliant systematic review was conducted. Searches were performed in MEDLINE and the Russian Science Citation Index up to November 1, 2025. Inclusion criteria were adults undergoing implant placement in the maxilla; outcomes included implant or prosthesis survival, complications, and bone loss. The study designs included randomized controlled trials, prospective and retrospective cohort studies, and case series. Risk of bias was assessed using RoB 2.0, Newcastle–Ottawa Scale, and the National Institutes of Health tool. Due to substantial heterogeneity, a narrative synthesis was performed. RESULTS: Nineteen studies were included. For CI, 5-year survival in randomized controlled trials ranged from 99% to 100% (4 vs 6 supports; no differences in bone loss), whereas at 10–20 years, survival decreased to 93% and 87%, respectively; short and ultrashort implants were not inferior to sinus augmentation protocols regarding survival and were less invasive. Technical complications were more frequent with four supports, particularly in patients with bruxism. For ZI, mid- and long-term survival ranged from 94% to 98%; the complication profile was shifted toward sinus-related and soft-tissue events, and chronic sinusitis occurred less often with extra- and extramaxillary trajectories than with an intrasinus approach. For PI, 1-year survival and success ranged from 88% to 98% depending on the criteria used; key risks included nerve injury, rare implant fractures, and prosthetic failures; first-year marginal bone loss served as an indicator of an unfavorable course; better stability was observed in D2 bone and with bicortical fixation. CONCLUSION: ZI, PI, and CI are complementary strategies with different complication profiles; method selection should consider anatomy, anticipated loading, and adherence to supportive care. Heterogeneity in outcome definitions and units of analysis limits meta-analysis; future studies require standardized criteria for success, peri-implantitis, mucositis, and reporting at the implant, patient, and prosthesis levels.