"Computer-Guided vs Freehand Zygomatic Implant Placement

Not Applicable

Completed

• Conditions: Dental Implants; Maxillary Diseases

• Registration Number: NCT06925438
• Lead Sponsor: Al-Azhar University

Brief Summary

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.

Detailed 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).

Study Timeline

• Study Start: 2023-01-10
• Primary Completion: 2025-01-15
• Study Completion: 2025-03-12
• Status Verified: 2025-04
• Study First Submitted: 2025-04-06
• Study First Submitted QC: 2025-04-06
• Last Update Submitted: 2025-04-11
• Study First Posted: 2025-04-13
• Last Update Posted: 2025-04-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 8

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)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Angular deviation of zygomatic implants	Measured immediately post-operatively (Day 0)	Difference in degrees between planned (virtual) and actual post-operative implant position, measured at the apical point using superimposed CT scans
Apical linear deviation of zygomatic implants	Measured immediately post-operatively (Day 0)	Difference in millimeters between planned (virtual) and actual post-operative implant position at the apical point, measured using superimposed CT scans along three planes midsagittal plane (MSP) - Frankfort horizontal plane (FHP) - coronal plane (CP)
Coronal linear deviation of zygomatic implants	Measured immediately post-operatively (Day 0)	Difference in millimeters between planned and actual implant position at the coronal point (implant neck), measured using superimposed CT scans along three planes midsagittal plane (MSP) - Frankfort horizontal plane (FHP) - coronal plane (CP)

Secondary Outcome Measures

Name	Time	Method
Implant stability quotient (ISQ)	Immediately post-op and at 6 months	Primary and secondary stability measured using Osstell Mentor device at implant placement and 6-month follow-up"
Postoperative complication rates	Assessed at 1 week, 1 month, 3 months, and 6 months post-op	Incidence of sinusitis, infection, soft tissue dehiscence, and oroantral communication assessed clinically

Trial Locations

Locations (2)

Faculty of Dental Medicine - Boys, Al-Azhar University; 🇪🇬 Cairo, Cairo Governorate, Egypt

Oral and Maxillofacial Surgery Department, Faculty of Dental Medicine - Boys, Al-Azhar University; 🇪🇬 Cairo, Cairo Governorate, Egypt