"Computer-Guided vs Freehand Zygomatic Implant Placement

Al-Azhar University

Status: Completed

Conditions: Maxillary Diseases; Dental Implants

Treatments: Procedure: Computer-guided zygomatic implant system; Procedure: free-hand zygomatic implant placement

Study type: Interventional

Funder types: Other

Identifiers

NCT06925438

ZygomaticRCT880/62

Details and patient eligibility

About

This randomized trial compares computer-guided versus free-hand zygomatic implant placement in patients with atrophic maxillae or maxillary defects. Participants receive either 3D-navigated implants (using stereolithographic guides) or conventional free-hand placement. Primary outcomes measure accuracy through apical angular deviation (°), apical/coronal linear deviations (mm) relative to MSP/FHP/CP planes (CT-based), while secondary outcomes assess implant stability (ISQ) and complications (sinusitis/infection) over 6 months. The study evaluates whether guided surgery improves precision in complex maxillary rehabilitation.

Full description

"This study was retrospectively registered due to initial lack of awareness of prospective registration requirements. All procedures followed ethical guidelines (Approval #880/62), and results are reported transparently."

Study Design

A single-center, randomized controlled trial conducted at Al-Azhar University, comparing computer-guided versus free-hand zygomatic implant placement. Participants are allocated 1:1 to:

Group A (Free-hand): Implants placed using ZAGA classification with conventional surgical techniques.

Group B (Guided): Implants placed via 3D-printed bone-supported surgical templates (DICOM-based planning).

Interventions

Both Groups:

Pre-op: CT scans for zygomatic bone assessment.

Anesthesia: General anesthesia with local infiltration for hemostasis.

Surgical Protocol: Full-thickness flap, implant placement , two-stage healing.

Group B-Specific Steps:

Digital implant path planning (entrance/exit points).

Stereolithographic guide fabrication with metal sleeves.

Guide fixation with monocortical screws during surgery.

Rationale Zygomatic implants require high precision due to anatomical complexity. While free-hand placement depends on surgeon skill, computer guidance may reduce errors. This trial evaluates whether guided surgery improves accuracy (angular deviation) and reduces complications (sinusitis, infection).

Methodological Rigor Randomization: Block randomization via SPSS.

Blinding: Radiographic assessors blinded to group allocation.

Sample Size: 16 implants (8/group), powered to detect 3.73° mean angular deviation difference (α=0.05, β=0.10; based on Grecchi et al. 2022).

Ethical Compliance Approved by Al-Azhar University (Ref: 880/62).

Consent forms documented risks/benefits (e.g., sinus perforation, infection).

Enrollment: 8 patients

Sex: All

Ages: 40+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients aged ≥40 years
• Atrophic maxillary ridge (Cawood & Howell Class IV-VI)
• Maxillary defects due to trauma, tumor resection, or congenital conditions

Exclusion criteria

• Acute maxillary sinusitis
• Uncontrolled systemic diseases affecting osseointegration
• Pathological lesions in maxilla/zygoma
• Heavy smoking (>20 cigarettes/day)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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8 participants in 2 patient groups, including a placebo group

Computer-Guided Zygomatic Implants

Active Comparator group

Description:

Zygomatic implants placed using 3D-printed bone-supported surgical guides created from preoperative CT scans.

Treatment:

Procedure: Computer-guided zygomatic implant system

Free-Hand Zygomatic Implants

Placebo Comparator group

Description:

Zygomatic implants placed using anatomical landmarks (ZAGA classification) without surgical guides.

Treatment:

Procedure: free-hand zygomatic implant placement