Comparative Analysis of a Novel Rat Bone Augmentation Model for Guided Bone Regeneration With Barrier Membranes.

OBJECTIVE

This study aimed to establish and validate a standardized, minimally invasive rat mandibular vertical bone augmentation model for evaluating the performance of digitally fabricated space-maintaining barrier membranes in guided bone regeneration (GBR).

METHODS

Public single-cell RNA sequencing datasets were analyzed to compare the cellular microenvironment between the cranium and mandible. Three experimental models were established: cranial augmentation group (Crania group), mandibular augmentation group (Mandible group), and mandibular augmentation group with nutrient foramen preparation (Mandible +NF group). A circular retention form was prepared to fix hemispherical barrier membranes without screw fixation. Outcomes were assessed at 8 weeks via stereomicroscopy, micro-CT, and histology. Both intention-to-treat (ITT) and per-protocol (PP) analyses were performed to evaluate vertical bone augmentation, bone quality, survival rate, success rate (membrane retention), and body weight.

RESULTS

The mandible presented a higher abundance of mesenchymal stem cells (MSCs) and osteoblasts than the cranium. ITT and PP analyses revealed that the Mandible group and Mandible + NF group achieved significantly higher vertical bone gain, bone volume to total volume ratio (BV/TV), and bone mineral density (BMD) than the Crania group, while additional NF preparation showed no enhanced osteogenic benefit. The Mandible group achieved the highest ITT survival rate (86.7%) and success rate (83.3%), whereas NF preparation increased surgical trauma and mortality. Mechanical analysis confirmed that circular retention alone ensured sufficient membrane stability in the mandibular model.

CONCLUSION

A novel, minimally invasive, and highly reliable rat mandibular vertical bone augmentation model was successfully established. This model recapitulates the biological principles of clinical vertical GBR, presents favorable translational relevance, and serves as a low-cost, high-efficiency platform for the preclinical evaluation of GBR barrier membranes.