So far, the cause of the disease is unknown and there is no satisfactory explanation. Some scholars have found that the disease is familial, so it is believed that the disease is related to heredity. The lesions are mostly concentrated in the coronal suture or multiple bone suture ossification. Some scholars refer to the ossification of the cranial sutures that exists at birth for unknown reasons as primary stenosis, while early ossification of the cranial sutures secondary to other diseases in the body is referred to as secondary stenosis, such as early ossification of the cranial sutures in patients with cretinism accompanied by excessive use of thyroid hormone replacement therapy. The cranium consists of multiple cranial bones, including the frontal, parietal, temporal, and pterygoid bones, each of which is separate at birth, with fibers connecting the bones to each other, called the cranial sutures. During normal development, the cranial bones are both fused together and grow gradually. The two develop in a harmonious balance until puberty when the volume of the cranial cavity is basically fixed, and then the cranial bones ossify together, and the cranial suture is completely ossified after the age of 30. If a certain factor affects the ossification of the cranial suture, a lesion can occur. Premature ossification of a cranial suture or multiple cranial sutures affects the development of the cranial cavity, while the brain tissue continues to develop and grow, resulting in compensatory enlargement of the cranium and the formation of a variety of craniofacial deformities.