IndicationsConsensus statement 1

Zygomatic implants are indicated in cases with maxillary bone atrophy or deficiency (118 patients), unsuccessful previous treatments with grafts and/or implants (34 patients), avoidance of staged bone graft procedures (29 patients) and conditions that may complicate traditional bone grafting procedures, such as benign cysts and trauma (5 patients).

This statement is supported by 10 publications reporting on 209 patients and 622 implants.

It is based on the systematic review by Polido et al. [1].

Consensus statement 2

Zygomatic implants are an alternative when the maxillary bone is completely or partially absent, secondary to resection, trauma, or congenital defects.

This statement has a moderate level of evidence, it is supported by 3 papers (23 patients) reporting on the use of zygomatic implants in these situations.

It is based on the systematic review by Polido et al. [1].

Consensus statement 3

Zygomatic implants are an alternative when the maxillary bone is completely or partially absent, secondary to failure of previously placed implants and/or bone grafts.

This statement is supported by six articles reporting on 34 patients utilized as a rescue alternative in cases of failure of bone grafts and previous implants, and expert opinion.

It is based on the systematic review by Polido et al. [1].

SurvivalConsensus statement 4

This statement is based on 24 studies reporting treating 918 patients survival rates of ZI ranged between 90.3% and 100% after a follow-up of 6 months. There are many factors potentially altering the final outcomes.

It is based on the systematic review by Kämmerer et al. [2].

Consensus statement 5

Zygomatic implants are an evidence-based alternative to support fixed or removable prostheses to restore partially or completely edentulous maxillae, allowing high survival rates when splinted to other implants.

This statement is based on data collected from the papers included in this review, that showed a mean survival rate of 97% (89–100%) in a mean follow-up period of 28.5 months (range 12–162 months).

It is based on the systematic review by Polido et al. [1].

Consensus statement 6

The mean zygomatic implant survival was 96.2% [95% CI 93.8; 97.7] over a mean follow-up of 75.4 months (6.3 years) with a follow-up range of 36–141.6 months (3–11.8 years).

This statement is based on a meta-analysis of 18 case series reports, which included a total of 1349 ZIs placed in 623 patients.

It is based on the systematic review by Brennand Roper et al. [4].

Quad zygomaConsensus statement 7

The quad zygomatic implant approach (two zygomatic implants bilaterally placed) can be indicated as an alternative when conventional implants cannot be placed in the posterior and anterior maxillary regions, and grafting alternatives are not feasible, predictable, or preferred by patients. In this situation all implants should be splinted.

This statement is supported by 7 publications reporting on 107 patients with quad zygoma approach.

It is based on the systematic review by Polido et al. [1].

Loading protocolConsensus statement 8

ZI survival for immediate Loading protocols were 98.1% [95% CI 96.2; 99.0] over a mean of 73.6 months follow-up.

This statement is based on a meta-analysis of 7 case series reports, which included 458 ZIs.

It is based on the systematic review by Brennand Roper et al. [4].

Consensus statement 9

Mean survival prevalence for delayed load protocols was 95% [95% CI 91.7; 97.1] over a mean of 69.3 months follow-up.

This statement is based on a meta-analysis of 7 case series reports, which included 535 ZIs.

It is based on the systematic review by Brennand Roper et al. [4].

Surgical risksConsensus statement 10

Fifteen citations report transient infraorbital nerve (V2) paresthesia, 15 studies report oro-antral communications, and 16 report peri-abutment soft tissue recession and/or hyperplasia. In six cases, a fractured ZI was described. Failure is mostly seen within the first 6 months.

This statement is based on the systematic review by Kämmerer et al. [2].

Consensus statement 11

Intraoperative-specific complications of ZI malposition, orbital cavity penetration (reported in four cases in three studies; in one case with lateral rectus muscle damage), and subcutaneous peri-malar emphysema are reported.

This statement is based on the systematic review by Kämmerer et al. [2].

FailuresConsensus statement 12

A higher failure incidence may occur within the first year (2%) compared to that of subsequent years (0.5%/year).

This statement is based on a meta-analysis of 17 case series reports, which included a total of 1247 ZIs.

It is based on the systematic review from by Brennand Roper et al. [4].

Consensus statement 13

The overall annual failure incidence of ZIs was 0.7%, with follow-up times ranging from 36 to 141.6 months.

This statement is based on a meta-analysis of 18 case series reports, which included a total of 1349 ZIs placed in 623 patients.

It is based on the systematic review by Brennand Roper et al. [4].

Consensus statement 14

Reasons for failure within the first year were related to a failure to integrate or subsequent loss of integration/stability. Failure within the subsequent years was related to loss caused by biological or mechanical complications.

This statement is based on a meta-analysis of 18 case series reports, which included a total of 1349 ZIs placed in 623 patients.

It is based on the systematic review by Brennand Roper et al. [4].

SinusitisConsensus statement 15

Sinusitis is the most commonly reported biological complication related to ZI therapy. Sinusitis is reported to be the most common complication which may lead to ZI implant loss. There is no clear relationship between sinusitis and ZI survival.

Sinusitis presented with a total prevalence of 14.2% [95% CI 8.8; 22.0] over a mean of 65.4 months follow-up. The prevalence of sinusitis ranged from 2.8% [95% CI 0.1; 14.5] to 36.4% [95% CI 20.4; 54.9] from 36 to 141.6 months of mean follow-up.

Disease was diagnosed clinically, radiographically, using patient-reported questionnaires, or via combined methods.

This statement is based on descriptive data from 11 case series reports in 409 patients.

It is based on the systematic review by Brennand Roper et al. [4].

Consensus statement 16

Maxillary sinusitis was the most reported complication. Pooled incidence rates for sinusitis in the original surgical technique (OST) were 9.5% (0–37.5%), and in Anatomy-Guided were 4.4% (0–11.8%). In most cases, sinusitis was reported by the literature without differentiation between symptomatic and asymptomatic cases.

This statement is based on descriptive data of 864 patients.

It is based on the systematic review by Kämmerer et al. [2].

Consensus statement 17

Sinusitis may be successfully treated. When sinusitis was diagnosed, successful treatment with antibiotics and/or via a surgical meatotomy was reported with no further consequences.

This statement is based on descriptive data from 7 case series reports in 22 patients.

It is based on the systematic review from Brennand Roper et al. [4].

Biological complicationsConsensus statement 18

10 of 18 studies reported factors related to the biological complications of ZI therapy.

Among them, one study, investigating two groups of 10 patients (20 in total), reported a prevalence of peri-implant ZI mucositis at 13.1% (3.7–41%) within an atrophic group and 39.7% (9.7–91.7%) in an oncologic group over a group mean follow-up of 39.9 months (± 19.5).

One study reported recession exposing 2–3 threads in 14% of ZI implants (n = 6 of 43) in 25 patients over 72 months of mean follow-up (48–72).

One study reported infective soft tissue dehiscences affecting 6 of 67 ZI (9%) in 33 patients with a mean follow-up of 141.6 months (range 109–198).

This statement is based on the systematic review by Brennand Roper et al. [4].

Technical complicationsConsensus statement 19

Technical complications for ZI supported reconstructions include fracture of the metal substructure, chipping or loss of the veneering material (ceramic or acrylic), and abutment or screw fracture and/or loosening.

3 metal framework fractures occurred in 43 prostheses. 77 episodes of veneering acrylic loss occurred in 228 prostheses. 28 episodes of veneering ceramic loss occurred in 141 prostheses. 8 episodes of prosthetic tooth loss occurred in 116 prostheses. 29 episodes of screw or abutment loosening occurred in 323 prostheses. 15 episodes of screw or abutment fracture occurred in 136 prostheses.

This statement is based on descriptive data from 10 case series reports including 400 prostheses with a mean follow-up ranging from 36 to 120 months.

It is based on the systematic review by Brennand Roper et al. [4].

Consensus statement 20

The mean prosthesis survival supported by ZIs was 94% [95% CI 88.6; 96.9] at 76.0 months of mean follow-up. Prostheses constituted fixed and removable designs, with materials including resin and ceramic superstructures on metal substructures.

This statement is based on a meta-analysis of 9 case series reports, which included 304 ZI supported prostheses.

It is based on the systematic review by Brennand Roper et al. [4].

Patient-reported outcome measuresConsensus statement 21

Patients reported an increase in satisfaction using a range of patient-reported outcome measures (PROMs) when rehabilitated with ZI supported reconstructions.

This statement is based on descriptive data from 7 case series reports in 266 patients using OHIP14, OHIP EDENT, Likert, and subjective questioning assessment tools.

It is based on systematic review by Brennand Roper et al. [4].