This morning, a mother brought her one-year-old boy to the specialist’s clinic, saying anxiously that her baby’s neck was crooked to one side and he could not turn his head to the right, and that the left side of his face had become smaller and his eyes were slightly slanted. After examination, it was found that the baby had congenital myotonic neck, which is commonly known as “crooked neck”. Congenital myotonic squint is caused by fibrosis of the sternocleidomastoid muscle, and the lump is found within the first two weeks after birth. It is more common on the right side than on the left side, and the lesion can involve all the muscles, but more often the lesion involves only the sternocleidomastoid muscle near the clavicle attachment point. The masses are largest in the first two months of life and then remain the same or decrease slightly in size, usually becoming smaller or disappearing within six months, with permanent fibrosis and contracture of the muscle, resulting in a “crooked neck”. The deformity mostly appears 2 to 3 weeks after birth. At the beginning of the disease, the head movement is slightly restricted, but there is no obvious slanting neck. On palpation, a hard and painless pike shaped swelling can be found, which is in the same direction as the sternocleidomastoid muscle. Some patients do not remain oblique neck; in most patients, if untreated, the muscle gradually fibrosis and contracture harden, forming a hard bundle-like strip next to the neck, the head is pulled by the contracted muscle and oblique neck deformity occurs, and the face on the shortened side of the muscle is also deformed. If the deformity is not corrected in time, the face is also gradually deformed, the eyes also appear strabismus, and finally the skull develops asymmetrically, and the cervical vertebrae and even the upper thoracic vertebrae develop scoliosis deformity. The direct cause of this disease is the contracture and shortening of the sternocleidomastoid muscle due to fibrosis, but the real cause of this muscle fibrosis is not well understood. However, regardless of the cause, the early detection of congenital myotonic neck, the early or late treatment, and the correct approach will result in a different outcome of “crooked neck”. Our research proves that early detection and proper treatment can not only prevent secondary pathologies such as facial asymmetry and cervical scoliosis deformity, but also reduce the difficulty of treatment, and in some cases, surgery can even be avoided.