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NCT Number: NCT06925438

"Computer-Guided vs Freehand Zygomatic Implant Placement

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.

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Key information

Conditions

Dental Implants Jaw Diseases Maxillary Diseases Musculoskeletal Diseases Stomatognathic Diseases

Age range

40 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

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

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About this study

"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).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

Computer-guided zygomatic implant system

Procedure

Preoperative digital planning (DICOM data) to fabricate guides with metal sleeves for drill alignment

free-hand zygomatic implant placement

Procedure

Standard placement using sequential drills (2.8-3.6mm) under saline irrigation

Primary outcomes

  1. Angular deviation of zygomatic implants

    Time frame: 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

  2. Apical linear deviation of zygomatic implants

    Time frame: 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)

  3. Coronal linear deviation of zygomatic implants

    Time frame: 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 outcomes

  1. Implant stability quotient (ISQ)

    Time frame: Immediately post-op and at 6 months

    Primary and secondary stability measured using Osstell Mentor device at implant placement and 6-month follow-up"

  2. Postoperative complication rates

    Time frame: 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

Sponsors and collaborators

Lead sponsor

Al-Azhar University

Other

Registry information

Official study title

Comparison Between Computer Guided and Free Hand Placement of Zygomatic Implants (Clinical and Radiographic Evaluation)

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Apr 13, 2025
Registry last updated
Apr 16, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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