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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.
"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).
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Computer-Guided Zygomatic Implants | Active Comparator | Zygomatic implants placed using 3D-printed bone-supported surgical guides created from preoperative CT scans. |
|
| Free-Hand Zygomatic Implants | Placebo Comparator | Zygomatic implants placed using anatomical landmarks (ZAGA classification) without surgical guides. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Computer-guided zygomatic implant system | Procedure | Preoperative digital planning (DICOM data) to fabricate guides with metal sleeves for drill alignment |
|
| 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) |
| 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 |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| 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 | Study Director |
| Abdelfattah Moawad, BDS, MSc | Al-Azhar University, faculty of dentistry, Oral & Maxillofacial Surgery Dept | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Faculty of Dental Medicine - Boys, Al-Azhar University | Cairo | Cairo Governorate | 11651 | Egypt | ||
| Oral and Maxillofacial Surgery Department, Faculty of Dental Medicine - Boys, Al-Azhar University |
Data is available with corresponding offer on reasonable request
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| ID | Term |
|---|---|
| D008439 | Maxillary Diseases |
| ID | Term |
|---|---|
| D007571 | Jaw Diseases |
| D009140 | Musculoskeletal Diseases |
| D009057 | Stomatognathic Diseases |
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"The participants, care providers, and outcomes assessors were blinded to the method of implant placement (computer-guided or freehand) to minimize bias."
| free-hand zygomatic implant placement | Procedure | Standard placement using sequential drills (2.8-3.6mm) under saline irrigation |
|
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 |
| Cairo |
| Cairo Governorate |
| 11651 |
| Egypt |