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.

An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width.