Guided Pterygoid Implant

Comparing Accuracy of Pterygoid Implants Placement Using Computer-guided Surgical Templates Versus Free Hand Technique

Introduction & Background Alveolar ridge resorption after tooth extraction leads to significant bone loss, complicating prosthetic rehabilitation. Traditional bone grafting methods, though effective, involve long healing times and risks. Pterygoid implants offer a graft-free alternative by engaging dense bone structures like the pterygoid process. However, their placement is technically challenging due to limited visibility and proximity to critical structures. Computer-guided surgery may improve accuracy and reduce complications compared to freehand techniques.

Research Question Does computer-guided surgery enhance the accuracy of pterygoid implant placement in atrophic maxillae compared to freehand techniques? Aim To compare the accuracy of computer-generated 3D surgical guides versus freehand placement of pterygoid implants.

Hypothesis

• H0: No difference in accuracy between techniques.
• Hₐ: there is difference between two techniques Study Design A prospective randomized controlled trial (1:1 allocation) with 12 implants (6 per group(.

Patient Selection Inclusion Criteria: Severe posterior maxillary atrophy (Cawood & Howell V-VI), residual bone height <4mm, age 21-75.

Exclusion Criteria: Contraindications for surgery, uncontrolled systemic diseases, or acute sinus infections.

Methods

• Group A: Implants placed using CBCT-based 3D surgical guides.
• Group B: Freehand placement based on anatomical landmarks.
• Primary Outcome: Implant position accuracy (postoperative CBCT vs. virtual plan(.
• Secondary Outcomes: Surgical time, complications, and stability. Surgical Procedure
• Osteotomy: Angled drilling (45-60°) into the pterygoid process.
• Implant Placement: Torque ≥30 Ncm for primary stability.
• Postoperative Care: Antibiotics, analgesics, and follow-up CBCT at one week. Statistical Analysis Data analyzed using SPSS, with G*Power determining sample size (85% power, α = 0.05(.

Ethical Considerations Approved by institutional review boards, with informed consent and confidentiality maintained.

Inclusion Criteria:

1. Patients with severe posterior maxillary atrophy (Class V-VI Cawood & Howell classification) requiring pterygoid implant placement.
2. Patients with severe alveolar bone atrophy in posterior maxilla (Residual alveolar bone height <4mm in posterior maxilla precluding conventional implant placement).
3. Adequate interarch space ≥7mm for prosthetic rehabilitation.
4. Presence of pneumatized maxillary sinus with insufficient bone for sinus augmentation.
5. Patients aged 21-75 years with completed craniofacial growth.

Exclusion Criteria:

1. Patients with systemic conditions contra-indicating general anesthesia.

2. Patients with conditions contraindicating implant placement (e.g.:

   radiation to the head and neck, intra-venous bisphosphonates, uncontrolled Diabetes mellitus).

3. Patients with acute maxillary sinus infection or maxillary sinus cyst.

4. Restricted mouth opening (less than 3cm inter-arch distance anteriorly).