Recent advances in molecular genetics have led to a better understanding of the role of specific genes such as fibroblast growth factor receptor (FGFR) and Twist in cranial bone formation. Specifically, the analysis of osteoblast abnormalities induced by FGFR2 and Twist genetic mutations inducing craniosynostosis in humans has provided some insights into the role of these genes in the premature cranial suture formation in syndromic craniosynostosis. This also led to a better understanding of the cellular and molecular mechanisms that control osteoblast biology and pathology in humans. In this review paper, we summarize the effects of FGFR2 and Twist genetic mutations resulting in altered osteoblast phenotype and premature cranial fusion based on our analysis in human syndromic craniosynostosis.