Some patients lose a large amount of bone in the upper jaw. When this happens, it can be difficult to place regular dental implants. In these cases, special implants called zygomatic implants can be used. These implants are longer than normal implants and are fixed in the cheekbone, which usually has enough bone to support them. They can help support fixed teeth for patients with severe bone loss in the upper jaw.

Placing zygomatic implants requires careful planning and high accuracy. To help guide the surgeon during the operation, a surgical guide can be used. A surgical guide is a custom-made device that helps the surgeon place the implant in the planned position.

Surgical guides can be made from different materials. The most common type is made from resin (a strong plastic material) using 3D printing. Recently, fully metallic surgical guides have been developed. These metal guides may be stronger and more stable during surgery, but it is not yet clear if they improve the accuracy of implant placement.

The purpose of this study is to compare the accuracy of metal surgical guides and resin surgical guides when placing zygomatic implants in patients with severe bone loss in the upper jaw.

Patients included in the study will undergo a clinical examination and a CT scan before surgery to plan the implant positions. During the surgery, each patient will receive zygomatic implants on both sides of the upper jaw. On one side, the implants will be placed using a metal surgical guide, and on the other side, they will be placed using a resin surgical guide. This allows the two types of guides to be compared in the same patient.

After the surgery, another CT scan will be taken to check the final position of the implants. The planned implant position will be compared with the actual position after surgery to measure the accuracy of placement.

The results of this study will help determine whether metallic surgical guides or resin surgical guides provide better accuracy when placing zygomatic implants.

Participation in this study is voluntary. All patients will receive full information about the study and will sign a consent form before participating.

Inclusion Criteria:

• Patients ≥18 years with severely atrophic maxilla.
• Acquired maxillary defects resulting from trauma, pathology, or previous surgical resection.
• Indicated for zygomatic implant-supported fixed prosthesis.
• Sufficient mouth opening for zygomatic implants placement.
• Patients willing to sign informed consent and attend follow-ups.

Exclusion Criteria:

• Uncontrolled systemic disease affecting healing (e.g., uncontrolled diabetes, etc).
• Heavy smokers
• Previous radiotherapy or bisphosphonate therapy.
• Active sinus or nasal infection.
• Severe parafunctional habits (e.g., bruxism).
• Pregnant or lactating women.
• Patients with psychiatric disorders affecting compliance.