Reabilitação oral com implantes zigomáticos comparados a implantes instalados em maxilas atróficas: uma análise de custo-efetividade para o serviço público de saúde no Brasil

Abstract

Objective: An economic cost-effectiveness evaluation was carried out for prosthetic rehabilitation of maxillary edentulism using zygomatic implants, compared with prostheses on implants placed only in the maxilla, within the context of Brazil’s Unified Health System (SUS). Methods: A cost-effectiveness analysis was conducted from the perspective of the federal SUS manager, using a hypothetical cohort of 1,000 patients (55 years old), completely edentulous in the maxilla and eligible for surgery. Four strategies were compared: RC I (6 implants with autogenous bone graft), RC II (6 implants plus sinus lift with xenogeneic graft), RZ I (4 zygomatic implants), and RZ II (2 zygomatic implants plus 2 conventional implants). A Markov model with four states (rehabilitated; repairable damage; failure; unrelated death) was used, with a twenty-year time horizon and a five percent annual discount rate for costs and effects. Costs (BRL, Feb/2025) came from official databases, an expert panel, and market prices. Effectiveness was measured in QALY (Quality-Adjusted Prosthesis Year), obtained via linear transformation of OHIP-14 scores. Transition probabilities were drawn from clinical studies and the national life table. A probabilistic sensitivity analysis was performed (1,000 Monte Carlo simulations; beta distributions for probabilities/utilities and gamma for costs). The adopted threshold was R$ 40.000 per QALY. Results: RC II was dominated by RC I (higher cost and lower effectiveness). Relative to RC I, RZ I yielded a gain of +1.761,17 QALY at an incremental cost of R$ 24.989.713,60 (ICER = R$ 14.189,26 per QALY); RZ II yielded +1.026,34 QALY with an incremental cost of R$ 14.499.559,64 (ICER = R$ 14.127,48 per QALY). Both results were substantially below the national threshold. The CEACs indicated RC I was more likely to be cost-effective only below R$ 15.000 per QALY; above this, RZ I and RZ II became preferable, approaching a decision probability near one hundred percent above R$ 25.000 per QALY. The cost-effectiveness plane showed scatter in the quadrant of higher cost and higher effectiveness, mostly below the decision line of R$ 40.000 per QALY. Conclusion: Strategies using zygomatic implants (RZ I and RZ II) were cost-effective compared with RC I in the SUS, whereas RC II was dominated. The findings supported considering zygomatic implants for clinically eligible atrophic maxillae, contingent on installed capacity, standardized protocols, and post-implementation monitoring.