OBJECTIVE: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction.
METHODS: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned.
RESULTS: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement.
CONCLUSIONS: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

BACKGROUND: Studies on different surgical approaches have been published with excellent success rates for zygomatic implants. The same publications offer different results regarding the complications associated with the use of such implants. A consensus protocol on zygomatic implant interventions has yet to be documented.
OBJECTIVE: To seek to establish a consensus at each step of treatment consisting of oral rehabilitation using zygomatic implant-anchored restorations, and to share the outcome of the process to serve as a basis for practitioners and researchers.
METHODS: A wide variety of protocols were identified based on the results of a literature review conducted previously. All participants received the results of the systematic literature search. A modified Delphi process was used to establish a consensus protocol. Six sections were defined: Diagnosis and indications, Planning, Medication, Surgery, Prosthesis, and Follow-up. The first round of 17 open-ended questions was shared with 63 participants, all of whom were experts in zygomatic implant rehabilitation and part of the ZAGA Centers network. A total of 77 follow-up questions were then generated after analysis of the responses to the first 17 questions.
RESULTS: Of the 63 experts enrolled, 48 responded to both rounds of questions. Consensus was determined based on the percentage of agreement: < 70% was considered \"no consensus\" and ≥ 70% was considered \"consensus\". A high level of consensus was reached. The sections with the lowest percentage of agreement were Medication and Surgery, where a consensus was reached for 67% of the questions. Of the questions included in the Follow-up section in both rounds, a consensus was reached for 80%. Overall, agreement was obtained on 71% of the topics.
CONCLUSIONS: Use of the modified Delphi process led to the creation of the first consensus protocol for oral restorations anchored to zygomatic implants.

The aim of the ITI Consensus Workshop on zygomatic implants was to provide Consensus Statements and Clinical Recommendations for the use of zygomatic implants.
Three systematic reviews and one narrative review were written to address focused questions on (1) the indications for the use of zygomatic implants; (2) the survival rates and complications associated with surgery in zygomatic implant placement; (3) long-term survival rates of zygomatic implants and (4) the biomechanical principles involved when zygoma implants are placed under functional loads. Based on the reviews, three working groups then developed Consensus Statements and Clinical Recommendations. These were discussed in a plenary and finalized in Delphi rounds.
A total of 21 Consensus Statements were developed from the systematic reviews. Additionally, the group developed 17 Clinical Recommendations based on the Consensus Statements and the combined expertise of the participants.
Zygomatic implants are mainly indicated in cases with maxillary bone atrophy or deficiency. Long-term 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). Immediate loading showed a statistically significant increase in survival over delayed loading. Sinusitis presented with a total prevalence of 14.2% [95% CI 8.8; 22.0] over a mean 65.4 months follow-up, representing the most common complication which may lead to zygomatic implant loss. The international experts suggested clinical recommendations regarding planning, surgery, restoration, outcomes, and the patient\'s perspective.