The focus on nonsyndromic craniosynostosis, the most common type of isolated craniosynostosis, is sagittal, followed by unilateral coronal, bilateral coronal, metopic, and lambdoid, in order of decreasing frequency. Certain forms of craniosynostosis display a sex predilection. For example, boys outnumber girls in a 4:1 ratio in sagittal synostosis, but girls outnumber boys in a 3:2 ratio in unilateral coronal synostosis. Other forms, such as metopic, lambdoid, and bilateral coronal synostosis, demonstrate no sex dominances tract.