Bone Augmentation Techniques in the Mandible Posterior Region

Comparison of Bone Augmentation Techniques in the Mandibular Posterior Region: A Randomized Clinical Trial

This study will compare three methods to rebuild lost bone in the back part of the lower jaw (posterior mandible) before dental implant placement. Seventy-eight adults will be randomly assigned to receive one of three "cortical shell" techniques using either the patient's own bone (autogenous) or prefabricated bone plates from animal (xenogeneic) or human donors (allogeneic). In all groups, the space inside the shell will be filled with a mixture of small bone chips and bone substitute material. The main outcome is the increase in jawbone width measured on 3D cone-beam CT scans at 6 months after surgery. Additional scans and clinical assessments up to 12 months will evaluate healing, bone stability, and postoperative recovery.

Study Overview

• Status: Not yet recruiting
• Conditions: Alveolar Bone Grafting; Bone Substitutes
• Intervention / Treatment: Procedure: Cortical Shell Bone Grafting

• Study Type: Interventional
• Enrollment (Estimated): 78
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Antonio G Lanata-Flores; Phone Number: +593983820084; Email: alanataf@uees.edu.ec

Study Locations

• Ecuador
  • Guayas
    • Samborondón, Guayas, Ecuador, 092301
      • Universidad Espiritu Santo
      • Contact: Antonio Gabriel Lanata-Flores, Phd; Phone Number: +593(04)5000950; Email: alanataf@uees.edu.ec
      • Contact: Estefania Ayala, Phd; Email: payalaa@uees.edu.ec
      • Principal Investigator: Antonio Lanata-Flores, Phd

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Posterior mandibular edentulism requiring horizontal ridge augmentation (Cawood & Howell Classes IV-VI).

One or two eligible posterior mandibular sites suitable for cortical shell augmentation.

Adequate residual bone height to allow safe fixation above the mandibular canal.

Good general health (ASA I or II). Plaque index < 20% and absence of active periodontal infection. Ability and willingness to attend scheduled follow-up visits (up to 12 months). Written informed consent provided prior to any study-related procedure.

Exclusion Criteria:

Uncontrolled systemic diseases affecting bone healing (e.g., uncontrolled diabetes mellitus, immunosuppressive disorders).

Current heavy smoking (>5 cigarettes/day). Pregnancy or lactation. Current use of medications known to affect bone metabolism or healing (e.g., bisphosphonates, long-term corticosteroids, anticoagulants).

Active periodontal disease or untreated oral infection. History of chemotherapy or radiotherapy to the head and neck region.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Autogenous Cortical Shell Graft; Thin cortical bone plates harvested from the mandibular ramus will be fixed to the recipient ridge with titanium microscrews to form a cortical shell. The internal space will be filled with a 1:1 mixture of autogenous bone chips and xenogeneic particulate graft. This conventional technique represents the control group for comparison with xenogeneic and allogeneic materials.	Procedure: Cortical Shell Bone Grafting; Surgical reconstruction of atrophic posterior mandibular ridges using thin cortical plates fixed with titanium microscrews to form a biologic shell. The inner space is filled with a 1:1 mixture of autogenous bone chips and biomaterial. Depending on the study group, the cortical plates are autogenous (from the mandibular ramus), xenogeneic (bovine origin), or allogeneic (human donor).; Other Names: Shell technique; 3D Onlay bone graft
Experimental: Xenogeneic Cortical Shell Graft; Prefabricated bovine cortical laminae will be rehydrated, trimmed to contour, and fixed with titanium microscrews to the mandibular ridge. The enclosed space will be filled with a 1:1 mixture of autogenous bone chips and xenogeneic particulate graft to promote bone regeneration.	Procedure: Cortical Shell Bone Grafting; Surgical reconstruction of atrophic posterior mandibular ridges using thin cortical plates fixed with titanium microscrews to form a biologic shell. The inner space is filled with a 1:1 mixture of autogenous bone chips and biomaterial. Depending on the study group, the cortical plates are autogenous (from the mandibular ramus), xenogeneic (bovine origin), or allogeneic (human donor).; Other Names: Shell technique; 3D Onlay bone graft
Experimental: Allogenic Onlay bone graft; A allogenic onlay cortical sheets will be adapted to the defect site, and fixed with titanium microscrews. The internal space will be filled with a 1:1 mixture of autogenous bone chips and xenogeneic particulate graft, following the same standardized protocol as the other groups.	Procedure: Cortical Shell Bone Grafting; Surgical reconstruction of atrophic posterior mandibular ridges using thin cortical plates fixed with titanium microscrews to form a biologic shell. The inner space is filled with a 1:1 mixture of autogenous bone chips and biomaterial. Depending on the study group, the cortical plates are autogenous (from the mandibular ramus), xenogeneic (bovine origin), or allogeneic (human donor).; Other Names: Shell technique; 3D Onlay bone graft

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Horizontal Bone Gain (mm) Measured by CBCT	Linear horizontal bone gain at the grafted posterior mandibular ridge, measured on cone-beam computed tomography (CBCT) scans using standardized reference points. Measurements will be performed at 3, 6, and 12 months post-surgery by two calibrated, blinded examiners. Mean values per site will be compared among the three groups (autogenous, xenogeneic, allogeneic).	3, 6, and 12 months after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Surgical Duration (minutes)	Total surgical time for each bone augmentation procedure, measured from the first anesthetic injection to the final suture. Timing will be recorded using a standardized chronometer to compare operative efficiency across autogenous, xenogeneic, and allogeneic cortical shell techniques.	Day 0 (intraoperative measurement)
Bone Density (Hounsfield Units) on CBCT	Bone density within the grafted area will be measured using cone-beam computed tomography (CBCT) gray-scale analysis (Hounsfield unit equivalents). Segmentation and density quantification will be performed at standardized points within the augmented region by two blinded examiners.	3, 6, and 12 months after surgery
Postoperative Inflammation (mm Facial Measurement)	Postoperative swelling will be assessed by measuring the linear distance from the lip commissure to the tragus with a flexible tape. Measurements will be taken bilaterally under standardized conditions by the same examiner to evaluate differences among groups.	Preoperative, immediate postoperative, days 3, 7, and 14
Volumetric Bone Gain (mm³)	Three-dimensional volumetric changes of the augmented area will be calculated by superimposing pre- and postoperative CBCT-derived meshes using surface registration software. The difference in total reconstructed volume (ΔVolume) will quantify the amount of new bone formation across techniques.	3, 6, and 12 months after surgery
Morphometric Surface Deviation (mm)	Surface deviation between pre- and postoperative 3D models will be analyzed using color-coded distance maps and point-to-surface metrics (mean absolute distance, RMS error, and 95th-percentile distance). This quantifies contour stability and remodeling patterns for each graft material.	3, 6, and 12 months after surgery

Collaborators and Investigators

• Sponsor: Universidad de Especialidades Espiritu Santo

Publications and helpful links

General Publications

• Khoury F, Hanser T. Three-Dimensional Vertical Alveolar Ridge Augmentation in the Posterior Maxilla: A 10-year Clinical Study. Int J Oral Maxillofac Implants. 2019 Mar/Apr;34(2):471-480. doi: 10.11607/jomi.6869.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: September 2, 2024
• First Submitted That Met QC Criteria: October 25, 2024
• First Posted (Actual): October 28, 2024

Study Record Updates

• Last Update Posted (Actual): February 20, 2026
• Last Update Submitted That Met QC Criteria: February 18, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Bone Substitutes; Bone Resorption; Alveolar Bone Atrophy
• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Periodontal Atrophy; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Alveolar Bone Loss; Bone Resorption
• Other Study ID Numbers: 2024-ODONT-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Yes, De-identified participant data and analysis code will be available upon reasonable request to the corresponding author after publication, following UEES data-sharing policies.
• IPD Sharing Time Frame: De-identified individual participant data (IPD) and supporting documents will be available beginning 6 months after publication of the main results and will remain accessible for 5 years thereafter through the institutional repository of Universidad de Especialidades Espíritu Santo (UEES).
• IPD Sharing Access Criteria: Qualified researchers may request access to the anonymized dataset, protocol, statistical analysis plan, informed consent form, and analytic code by contacting the corresponding author at alanataf@uees.edu.ec. Requests will be reviewed by the study team and the UEES Ethics Committee to ensure compliance with ethical and privacy regulations. Approved users will receive controlled access to the data for non-commercial research purposes only.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

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