The goal of this prospective study is to assess short term (12-months) clinical outcomes of NobelZygoma TiUltra implants and Multi-unit Abutment Xeal in the rehabilitation of participants with severely atrophic maxilla treated with zygomatic dental implant procedure. The main goal is to assess the sinusitis occurrence at 12-months after implant insertion. Other objectives are to assess: soft tissue health; biological and technical complication; patient's experience, outcomes (sinonasal symptoms and oral health-related quality of life) and satisfaction; clinician's experience with handling of device and satisfaction; implant, abutment and prosthetic survival and adverse events.

Participants will be asked to complete questionnaires at pretreatment visit, postoperative visit, and after 6-months and 12-months of implant insertion. At 12-months a radiological exam (CBCT) will be asked for the participant for the evaluation of the radiological condition of the maxillary sinus.

This is a prospective, interventional, multicenter study that is planned to include 9 sites and 85 participants with severely atrophic maxilla (characterized by class V-VI according to the Cawood and Howell's classification). Participants will be consecutively enrolled upon providing informed consent and meeting all of the inclusion and none of the exclusion criteria (details in eligibility section). Zygomatic implant procedure will be performed as per clinician standard of care and participant's anatomy. Both hybrid and quad zygoma techniques, as well as any implant trajectory can be used in the study (e.g. intra-sinus; extra-sinus; sinus slot). Enrolled participants will be treated with NobelZygoma TiUltra implants and respective abutments in accordance with the IFU. All zygomatic implants will be immediately loaded.

The study is designed to describe and quantify the occurrence of maxillary sinusitis in participants treated with NobelZygoma TiUltra implants and Multi-unit Abutments Xeal Zygoma.

The working assumption is that the incidence of sinusitis can be reliably measured at 12 months using standardized clinical (SNOT-22) and radiological (Lund-Mackay) criteria in participants rehabilitated with this treatment approach The primary endpoint of this clinical investigation is the specificity of diagnosis of maxillary sinusitis at 12-months post-implant placement using a combination of clinical and radiological evaluation, using SNOT-22 questionnaire and LM (Lund-Mackay) scoring system for the clinical and CBCT analysis respectively. Other endpoint and parameters will be described in Outcome measures section.

All included participants will be followed for 12-months post-implant placement to assess the safety, performance, and clinical benefits of TiUltra-surfaced zygomatic implants and Mulit-unit Abutment Xeal Zygoma. Possible dropouts and withdrawals, as well as possible adverse events, will be monitored during the entire investigation period.

Each participant will be assigned a participant ID to maintain the confidentiality of the collected data, which will be recorded in the dedicated eCRF. The eCRF system meets EU GDPR requirements for safe data handling. The data will be processed by the eCRF provider for storage purposes and further processed and analyzed by the sponsor.

Inclusion Criteria:

• Participant has signed the informed consent form (ICF).
• Participant aged ≥ 18 years at the time of treatment.
• Medical and anatomical conditions are in accordance with the applicable IFU.
• Participant with a severely atrophic maxilla classified as Cawood and Howell class V or VI
• Suitable for immediate loading.

Exclusion Criteria:

• Presence of acute or chronic maxillary sinusitis.
• Zygomatic bone pathologies including tumors, infections, or congenital abnormalities
• History of recurrent sinusitis (≥ 4 occurrences/year)
• Pre-operative LM score of ≥ 1
• Uncontrolled systemic disorders including poorly controlled hypertension, uncontrolled diabetes, cardiovascular disease.
• Active malignancy or currently undergoing oncological treatment.
• History of severe maxillary jaw injury or maxillofacial trauma.
• Moderate and heavy smokers (defined as > 5 cigarettes a day).
• Severe bruxism or dysfunctional tendencies
• Previous oro-maxillofacial radiotherapy.
• Use of bisphosphonates.
• Pregnant or lactating women
• Implant loaded > 1 week of zygomatic implant placement

Individual participant data will not be shared. As per data protection regulation in EU participant's identity should be kept confidential. As per informed consent and GDPR consent, participant is informed that their data will be securely stored in EDC system in EU and analyzed in Switzerland by the sponsor. As per EU and Switzerland data protection regulations, access to participant's data should only be given for the sponsor, regulatory authorities and ethic committee members. Study results will be disseminated through peer-reviewed publications and/or conference presentations. Summary results will be shared (e.g. via publication or posting results in ClinicalTrials.gov)