Interventions for replacing missing teeth: zygomatic implants for the rehabilitation of the severely atrophic edentulous maxilla

Rationale Dental implants are widely used to replace missing teeth but require sufficient bone for support. In people with severe maxillary (i.e. upper jaw) bone loss, zygomatic implants provide an alternative to bone augmentation by anchoring in the cheekbone instead of the upper jaw. Potential advantages include avoiding bone grafting and enabling immediate or early placement of a fixed prosthesis. However, the procedure is technically demanding and may be associated with serious complications. Objectives To assess the effects of zygomatic implants for the rehabilitation of people with severely atrophic maxillae requiring implant‐supported prostheses by comparing: (1) zygomatic implants with or without bone augmentation procedures versus conventional dental implants in augmented bone; (2) zygomatic implants with or without conventional implants versus subperiosteal implants; (3) one type of zygomatic implant or technique versus another type or technique. Search methods We used CENTRAL, MEDLINE, Embase, and two trial registers, together with reference checking and contact with study authors to identify the studies included in the review. We conducted searches in November 2025. Eligibility criteria We included randomised controlled trials (RCTs), with either a parallel‐group or split‐mouth design, involving at least 10 participants per arm, with at least one year of follow‐up. Participants had severely resorbed maxillae and could not receive conventional dental implants. Outcomes Our outcomes were prosthesis and implant failures, complications, patient satisfaction or preference, and cost‐effectiveness, assessed as time required to rehabilitate the patient. Risk of bias We used Cochrane's RoB 2 tool to assess bias in the RCTs. Synthesis methods We did not synthesise data because we included only one study each for two comparisons. We used GRADE to assess the certainty of the evidence. Included studies We included two RCTs, each with a three‐year follow‐up. One parallel‐group RCT included 71 participants and compared zygomatic implants—used either alone or in combination with conventional implants and immediately loaded—with delayed placement of conventional implants in bone augmented with bone substitutes (comparison 1). The other split‐mouth RCT included 20 participants and compared the placement of zygomatic implants using conventional rotary drills with piezoelectric preparation on the contralateral side (comparison 3). Synthesis of results Comparison 1: zygomatic implants with and without bone augmenting procedures versus conventional dental implants in augmented bone After three years, zygomatic implants may reduce prosthetic failures compared with conventional dental implants placed in grafted bone (odds ratio (OR) 0.29, 95% confidence interval (CI) 0.05 to 1.56; 66 participants; low‐certainty evidence). Zygomatic implants probably reduce implant failures compared with conventional implants (OR 0.23, 95% CI 0.06 to 0.96; 61 participants; moderate‐certainty evidence). Zygomatic implants probably increase complications (OR 4.53, 95% CI 1.47 to 13.98; 66 participants; moderate‐certainty evidence). Zygomatic implants may have little to no effect on patient satisfaction compared with conventional implants in grafted bone (MD 0.40, 95% CI −3.05 to 3.85; 60 participants; low‐certainty evidence). As a measure of cost‐effectiveness, time to rehabilitation is probably shorter with zygomatic implants compared with conventional implants in grafted bone (MD −442.98 days, 95% CI −518.64 to −367.32; 64 participants; moderate‐certainty evidence), corresponding to approximately one day (1.3 days) with zygomatic implants versus more than one year (444 days) with bone grafting. Comparison 3: