Study Evaluating the Performance and Safety in the Medium and Long Term of Global D ZygoFixU System

Inclusion Criteria: * Adult male or female patient, * Patient whose growth and development of the maxillary bone is complete according to the investigator's judgement, * Partially or completely edentulous patient, * Patient with advanced maxillary atrophy (grades IV, V and VI according to the Cawood and Howell classification if used), * Patient requiring implant treatment with Global D zygomatic implants (placement of two or four implants), * Patient with acceptable oral opening (\>3 cm measured anteriorly), * Patient able to read, understand and answer the quality-of-life questionnaire of the investigation and able to give consent, * Patient agreeing to comply with the protocol design and to send his/her follow-up data, even in the event of a move, * Patient having signed the consent form, * In France, patient affiliated to a social security scheme. Exclusion Criteria: * Patient's state of health at enrolment: * General contraindications to implant surgery * Patient with zygomatic bone disease * Patient with untreated periodontal disease * Patient with acute or chronic infection in the implant placement area, or systemic infection, including acute or chronic maxillary sinusitis * Patient with acute or chronic inflammation in the implant placement area, or systemic inflammation, * Patient with uncontrolled diabetes (unstable blood glucose) * Patient with immunodeficiencies or using immunosuppressants * Patient who received radiation of more than +70 Gy to the head and neck region * Patient using intravenous aminobisphosphonates within 5 years prior to surgery * Patient who are smokers (\>10 cigarettes/day) or with alcohol or drug addiction * Person placed under legal protection (this includes guardianship, curatorship and legal protection). * Pregnant or breastfeeding women