This is a formal translation of the ITI Consensus Workshop summary regarding zygomatic implants. I have maintained a professional, clinical tone suitable for a medical report or academic sharing.

ITI Consensus Workshop: First Consensus Guidelines for Zygomatic Implants
Introduction
Zygomatic implants (ZIs) are primarily indicated for cases with severe maxillary atrophy or bone deficiency. With an average follow-up of 75.4 months (6.3 years), the long-term survival rate of ZIs is 96.2% (range: 36–141.6 months).

Compared to delayed loading, immediate loading showed a statistically significant increase in survival rates. At a mean follow-up of 65.4 months, the incidence of sinusitis was 14.2%, identifying it as the most common complication leading to zygomatic implant failure.

This ITI Consensus Workshop established guidelines and clinical recommendations regarding planning, surgery, prosthetic reconstruction, outcomes, and patient perspectives.

Below is a summary of the expert consensus guidelines.

I. Indications
Dr. Lee’s Summary: Zygomatic implants are indicated for:

Cases with severe maxillary atrophy or deficiency.

Failed previous bone grafting or implant procedures.

Patients wishing to avoid multiple bone grafting surgeries.

Patients who have undergone complex maxillary resections (e.g., benign cysts, trauma).

Alternative treatment for congenital maxillary defects, trauma, and jaw resection.

II. Survival Rates
Mean survival rate: 90.3% – 100% (6-month follow-up).

Mean survival rate: 97% (89–100%) at a mean follow-up of 28.5 months (range 12–162 months).

Mean survival rate: 96.2% [95% CI 93.8; 97.7] at a mean follow-up of 75.4 months (6.3 years).

➤ Dr. Lee’s Summary:
Data from two systematic reviews and one meta-analysis demonstrate that ZIs have a success rate exceeding 90% in mid-to-long-term follow-ups.

III. Quad Zygoma
“Quad Zygoma” involves placing two ZIs on each side of the maxilla, which must be splinted. This approach is used when conventional implants cannot be placed in the anterior or posterior regions and bone grafting prognosis is poor.

IV. Loading protocol
Immediate Loading Protocols: 98.1% [95% CI 96.2; 99.0] (mean 73.6 months follow-up).

Delayed Loading Protocols: 95.0% [95% CI 91.7; 97.1] (mean 69.3 months follow-up).

➤ Dr. Lee’s Summary:
While immediate loading has a slightly higher success rate, clinicians must be wary of oro-antral communications (OAC). Dr. Lee recommends delayed loading protocols if a significant OAC occurs during surgery.

V. Surgical Risks
Based on a systematic review:

Transient infraorbital nerve (V2) paresthesia: 15 cases.

Oro-antral communications: 15 cases.

Peri-abutment soft tissue recession/hyperplasia: 16 reports; Fractured ZI: 6 cases.

ZI malposition or orbital cavity penetration: 4 cases.

➤ Dr. Lee’s Summary:
Retract tissues gently to avoid V2 nerve injury. Ensure osteotomy sites are not oversized to prevent OAC. Avoid orbital invasion during placement. Note that the relationship between the implant platform and alveolar bone support significantly impacts mechanical loading and potential soft tissue complications.

VI. Implant Failure
Failure rates may be higher in the first year (2%) compared to subsequent years (0.5%/year).

➤ Dr. Lee’s Summary:
Failures in the first year are usually due to a lack of osseointegration or primary stability. Subsequent failures are typically caused by biological complications or mechanical factors.

VII. Sinusitis
Sinusitis is the most common biological complication and a leading cause of ZI loss. Incidence ranges from 2.8% to 36.4%.

➤ Dr. Lee’s Summary:
Incidence is closely tied to surgical technique: Original Surgical Technique (OST) reported 9.5%, while Anatomy-Guided techniques reported 4.4%. Sinusitis can be successfully managed with antibiotics or surgical meatotomy.

VIII. Biological Complications
Peri-implant mucositis: 13.1% in atrophic groups; 39.7% in oncologic groups.

Recession (exposing 2–3 threads): 14%.

Soft tissue dehiscence: 9%.

➤ Dr. Lee’s Summary:
Poor oral hygiene, implant instability, thin/absent crestal bone, and excessive buccal placement are key risk factors for biological complications.

IX. Mechanical Complications
Mean prosthesis survival rate: 94% [95% CI 88.6; 96.9] (76-month follow-up).

Technical complications include framework fractures, veneer chipping (ceramic/acrylic), and abutment or screw loosening/fracture.

➤ Dr. Lee’s Summary:
Protheses supported by ZIs show high long-term success. Stability is improved and mechanical stress is reduced when there is sufficient alveolar bone support.

Clinical Recommendations (Selected)
Zygomatic implantation is a complex procedure; success depends on the clinician’s expertise and experience.

Diagnostic tools must include 3D CT/CBCT imaging of the midface to evaluate the maxilla, zygomatic bone volume, and sinus health.

Q: At what level of maxillary atrophy are ZIs indicated?
A: The most cited criteria are Cawood and Howell (1988) Classes IV, V, and VI.

Q: Can ZIs be placed immediately into extraction sockets?
A: The risk of complications increases when performing zygomatic implantation in fresh extraction sockets.

Q: What is the role of guided or navigated surgery?
A: Even with surgical guides, direct visualization remains crucial to avoid compromising anatomical structures.

Q: What unique challenges exist for full-arch reconstruction with ZIs?
A: ZI reconstructions require higher maintenance standards (Dr. Lee’s Note: Due to thin/absent buccal bone and proximity to the sinus). There are also limitations regarding occlusal force; patients with heavy bruxism may not be ideal candidates. Patients must also understand that managing subsequent complications is more complex than with standard implants.