"Computer-Guided vs Freehand Zygomatic Implant Placement

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

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.

Study Overview

• Status: Completed
• Conditions: Dental Implants; Maxillary Diseases
• Intervention / Treatment: Procedure: Computer-guided zygomatic implant system; Procedure: free-hand zygomatic implant placement

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 Type: Interventional
• Enrollment (Actual): 8
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo Governorate
    • Cairo, Cairo Governorate, Egypt, 11651
      • Faculty of Dental Medicine - Boys, Al-Azhar University
    • Cairo, Cairo Governorate, Egypt, 11651
      • Oral and Maxillofacial Surgery Department, Faculty of Dental Medicine - Boys, Al-Azhar University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Computer-Guided Zygomatic Implants; Zygomatic implants placed using 3D-printed bone-supported surgical guides created from preoperative CT scans.	Procedure: Computer-guided zygomatic implant system; Preoperative digital planning (DICOM data) to fabricate guides with metal sleeves for drill alignment
Placebo Comparator: Free-Hand Zygomatic Implants; Zygomatic implants placed using anatomical landmarks (ZAGA classification) without surgical guides.	Procedure: free-hand zygomatic implant placement; Standard placement using sequential drills (2.8-3.6mm) under saline irrigation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Angular deviation of zygomatic implants	Difference in degrees between planned (virtual) and actual post-operative implant position, measured at the apical point using superimposed CT scans	Measured immediately post-operatively (Day 0)
Apical linear deviation of zygomatic implants	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)	Measured immediately post-operatively (Day 0)
Coronal linear deviation of zygomatic implants	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)	Measured immediately post-operatively (Day 0)

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Al-Azhar University
• Investigators: Study Director: Bahaa El-Din Abd Raboo, phd, Al-Azhar University, faculty of dentistry ,Oral & Maxillofacial Surgery Dept; Study Director: Mohamed Abdel Akhar, PhD, Al-Azhar University, faculty of dentistry, Oral & Maxillofacial Surgery Dept; Principal Investigator: Abdelfattah Moawad, BDS, MSc, Al-Azhar University, faculty of dentistry, Oral & Maxillofacial Surgery Dept

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2023
• Primary Completion (Actual): January 15, 2025
• Study Completion (Actual): March 12, 2025

Study Registration Dates

• First Submitted: April 6, 2025
• First Submitted That Met QC Criteria: April 6, 2025
• First Posted (Actual): April 13, 2025

Study Record Updates

• Last Update Posted (Actual): April 16, 2025
• Last Update Submitted That Met QC Criteria: April 11, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: "Zygomatic implants"; "Atrophic maxilla rehabilitation"; "Guided implant surgery"; "Free-hand dental implantation"; "3D-printed surgical guides"
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Stomatognathic Diseases; Jaw Diseases; Maxillary Diseases
• Other Study ID Numbers: ZygomaticRCT880/62

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data is available with corresponding offer on reasonable request

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No