Related Experiment Video
Updated: May 16, 2026
A 3-D Visualization Technique for Bone Remodeling in a Suture Expansion Mouse Model
Published on: August 18, 2023
Rapid re-synostosis following suturectomy in pediatric mice is age and location dependent
Christopher D Hermann1, Kelsey Lawrence, Rene Olivares-Navarrete
1Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.
Insights
Craniosynostosis treatment can lead to rapid re-fusion. This study used a pediatric mouse model to show that bone regeneration over cranial sutures is age and location dependent, with faster healing in younger mice over sutures.
Area of Science:
- Craniofacial development and regeneration
- Pediatric surgical complications
- Biomaterials and tissue engineering
Background:
- Craniosynostosis, premature cranial suture fusion, can cause deformities and increased intracranial pressure.
- Standard surgical treatment may result in rapid re-synostosis, necessitating further interventions.
- Understanding the mechanisms of bone regeneration is crucial for improving treatment outcomes.
Purpose of the Study:
- To investigate age and location-dependent bone regeneration in a pediatric mouse model of craniosynostosis re-synostosis.
- To characterize the healing process of cranial defects in weanling and adolescent mice.
- To identify factors influencing rapid bone healing in the context of craniosynostosis.
Main Methods:
- Surgical creation of cranial defects in weanling (21 days) and adolescent (50 days) C57Bl/6J mice.
- Micro-computed tomography with advanced image processing to assess bone regeneration.
- Real-time PCR to analyze gene expression related to defect healing.
Main Results:
- Weanling mice exhibited biphasic healing over the posterior frontal suture: bone bridging by post-op day 3 and increased bone volume by day 14.
- Adolescent mice showed delayed bone bridging and no significant increase in bone volume.
- Defects lateral to the suture in both age groups did not bridge within 14 days post-operation.
Conclusions:
- Cranial bone regeneration is significantly influenced by both the age of the subject and the anatomical location of the defect.
- Rapid and robust bone regeneration occurs specifically over cranial sutures in immature weanling mice.
- These findings highlight the importance of developmental stage and anatomical context in craniofacial bone repair.
Abstract:
Craniosynostosis is the premature fusion of the cranial sutures early in development. If left untreated, craniosynostosis can lead to complications resulting from cranial deformities or increased intracranial pressure. The standard treatment involves calvarial reconstruction, which in many cases undergoes rapid re-synostosis. This requires additional surgical intervention that is associated with a high incidence of life threatening complications. To better understand this rapid healing, a pediatric mouse model of re-synostosis was developed and characterized. Defects (1.5mm by 2.5mm) over the posterior frontal suture were created surgically in weanling (21 days post-natal) and adolescent (50 days post-natal) C57Bl/6J mice. In addition, defects were created in the frontal bone lateral to the posterior frontal suture. The regeneration of bone in the defect was assessed using advanced image processing algorithms on micro-computed tomography scans. The genes associated with defect healing were assessed by real-time PCR of mRNA isolated from the tissue present in the defect. The results showed that the weanling mouse healed in a biphasic process with bone bridging the defect by post-operative (post-op) day 3 followed by an increase in the bone volume on day 14. In adolescent mice, there was a delay in bone bridging across the defect, and no subsequent increase in bone volume. No bridging of the defect by 14 days post-op was seen in identically sized defects placed lateral to the suture in both weanling and adolescent animals. This study demonstrates that bone regeneration in the cranium is both age and location dependent. Rapid and robust bone regeneration only occurred when the defect was created over the posterior frontal suture in immature weanling mice.
