Bone Augmentation Techniques in the Mandible Posterior Region

N/ANot Yet RecruitingNCT06661447

Universidad de Especialidades Espiritu Santo78 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Bone Substitutes Alveolar Bone Grafting

Interventions

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).

Eligibility

Sex: ALLMin age: 18 YearsMax age: 64 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Horizontal Bone Gain (mm) Measured by CBCT

Participant-level horizontal bone gain at 6 months after surgery, measured on cone-beam computed tomography (CBCT) scans using standardized reference points. When two eligible posterior mandibular sites are treated in the same participant, the participant-level mean will be used for the primary analysis.

Time frame: 6 after surgery

Secondary Outcomes

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.

Time frame: Day 0 (intraoperative measurement)

Relative Radiographic Density Using CBCT Gray Value Units

Relative radiographic density within the grafted area will be assessed using device-specific CBCT gray value measurements under standardized acquisition parameters. These values will not be interpreted as calibrated Hounsfield Units. Measurements will be performed by calibrated examiners.

Time frame: 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.

Time frame: 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.

Time frame: 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.

Time frame: 3, 6, and 12 months after surgery

Secondary Horizontal Bone Gain at 3 and 12 Months

Horizontal bone gain measured on CBCT scans at 3 and 12 months after surgery will be analyzed as a secondary longitudinal outcome.

Time frame: 3 and 12 months after surgery

Bone Augmentation Techniques in the Mandible Posterior Region

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts