Isolated brachycephaly is a relatively frequent nonsyndromic craniosynostosis consisting of premature fusion of both coronal sutures leading to skull deformity with a broad flat forehead and palpable coronal ridges.

Fusion involving two or more metacarpal bones (A synostosis of the first metacarpal and the proximal phalanx of the thumb can also be observed, note that the first metacarpal bone corresponds to a proximal phalanx).