A mechanically regulated computational framework for simulating infant cranial growth and craniosynostosis-associated...

In early years of life, the cranium rapidly changes in size and shape to accommodate brain growth, primarily driven by mechanical stress from brain expansion. Developmental disorders such as premature fusion of sutures in craniosynostosis disrupt normal growth process, leading to abnormal cranial shapes. Thus, understanding the interplay between biomechanical forces, soft tissues, and individual bone plates is crucial for understanding their role in shaping infant cranial development. This study develops a mechanically driven growth model to simulate healthy cranial growth in the first year. The algorithm considers simultaneous and coupled growth of brain, cranial bones, sutures, with volumetric brain expansion as the primary driver, with strain-based feedback governing growth in bone and suture tissues. A bulk bone formation approach accounts for evolving mechanical properties, with elastic moduli of bone and sutures increasing monthly. The growth algorithm was applied on an idealised geometry model of a healthy cranium, then on individual fused sutures cases, and dysmorphologies due to craniosynostosis were developed. The results showed good agreement with the typical features of clinical observations. Stress at bone-suture interfaces and elevated contact pressure under fused sutures highlighted biomechanical impacts due to the disorders. Sensitivity analysis explored how material properties and growth rates affect cranial morphology in the absence of longitudinal clinical data. This framework enhances understanding of cranial growth and is potential to be further modified and validated to support treatment planning for craniosynostosis.