This is the rarest form of non-syndromic craniosynostosis. This can be confused with positional plagiocephaly, as both can cause uneven flattening of the back of the head. Patients with lambdoid suture craniosynostosis have flatness of the back of the head and a downward bulging of the skull behind the ear on the side of the closed suture. The affects on the appearance of the face can range from no affects to significant asymmetry. The ears on the side of closed suture may be uneven in their position on the head compared with the other ear.