This prospective case series is designed to evaluate the effect of autologous bone marrow aspirate concentrate applied around zygomatic implants placed via the intrasinus approach. The study will include adult patients with severe maxillary atrophy requiring zygomatic implant rehabilitation. BMAC will be prepared from iliac crest aspirate and loaded on gelatin sponge at the implant site. Peri-implant bone density will be assessed using CBCT at baseline and 6 months postoperatively. Secondary implant stability will be measured using resonance frequency analysis. (Recruitment has not started yet)

Zygomatic implants provide a viable option for rehabilitation of the severely atrophic maxilla. However, achieving optimal osseointegration remains a challenge due to poor bone quality in the posterior maxilla. Bone marrow aspirate concentrate contains mesenchymal stem cells and growth factors that may enhance local bone formation.

Knowledge Gap:

BMAC has been investigated with conventional dental implants, but its use with zygomatic implants placed via the intrasinus approach is limited to isolated case reports. A systematic evaluation of its effect on peri-implant bone density and stability in this specific context is lacking. This case series addresses that gap.

Study Design and Setting:

This is a single-center, prospective case series planned at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Cairo University. The primary hypothesis is that BMAC application will improve bone density and secondary stability of zygomatic implants at 6 months. (Recruitment has not commenced.)

Surgical Procedure:

Under general anaesthesia, approximately 30 ml of bone marrow will be aspirated from the anterior iliac crest. The aspirate will be processed using a double centrifugation protocol to obtain the buffy coat layer, which will then be loaded onto a gelatine sponge. Zygomatic implants will be placed through a lateral sinus window using the intrasinus trajectory. The BMAC-loaded sponge will be applied around the implant prior to closure. Conventional implants will be placed in the anterior maxilla to support the planned full-arch prosthesis.

Follow-up Protocol:

Patients will be reviewed weekly during the first month, then monthly for 6 months. Cone beam computed tomography will be performed immediately postoperatively and at 6 months to assess changes in bone density in Hounsfield Units. Resonance frequency analysis will be performed at 6 months to evaluate secondary implant stability. Adverse events will be recorded throughout the follow-up period.

Ethical Considerations:

The study protocol has been submitted to the Ethics Committee of Scientific Research, Faculty of Dentistry, Cairo University and is currently pending approval. A written informed consent will be obtained from all participants in Arabic prior to enrollment. Patient data will be coded and stored in a secure, password-protected database accessible only to the research team. The study is self-funded with no conflicts of interest declared.

Outcomes:

The primary outcome is the change in peri-implant bone density at 6 months. Secondary outcome includes secondary stability of the implants . Data will be summarized descriptively given the case series design.

Inclusion Criteria:

• Patients over 18 years old.
• Patients requiring rehabilitation with zygomatic implants in the posterior maxilla.
• Patients who are willing to participate and able to provide informed consent.

Exclusion Criteria:

• Pregnant women.
• Individuals with history of radiation therapy or other contraindications for surgery.
• Patients with bone marrow diseases.
• Patients with local infections at intraoral surgical site or bone marrow aspiration site.
• Patients unwilling to sign the written informed consent.
• Heavy smokers >20 cigarettes per day.
• Patients taking contraindicated drugs such as bisphosphonates.
• Patients with sinus pathology or acute sinusitis.
• Patients with malignancy or pathology of maxilla.

Individual participant data will not be shared due to ethical restrictions and patient privacy regulations.

IPD will be shared after publication.

No masking is used. Both the surgeon and participant are aware of the intervention.