（The first diagnosis is pediatric myotonic squint. (1) A cartilage-like mass on one side of the sternocleidomastoid muscle is found after birth, and the muscle becomes shorter and loses elasticity; (2) The head is skewed to the affected side, and the lower jaw points to the healthy side; (3) In severe cases, the facial development is asymmetric, and the affected side and skull are smaller than the healthy side, and the level of bilateral eye fissures is asymmetric. (4) Color ultrasound examination: color ultrasound image of the affected side of the sternocleidomastoid muscle thickening, thickening, or detectable muscle mass, echogenicity increased or decreased. (5) Except for other disorders caused by oblique neck. For example: congenital malformation of cervical spine (hemivertebrae, congenital short neck), cervical spine injury (fracture or rotational subluxation), clavicle birth injury fracture, inflammatory lesions (tonsillitis, cervical lymph gland tuberculosis, cervical spine tuberculosis) causing sternocleidomastoid muscle spasm, spontaneous cervical subluxation, visual impairment causing head tilt, etc. (6) If necessary, cervical spine X-ray should be taken to clarify the diagnosis. The mass is located in the middle and lower part of the sternocleidomastoid muscle and is oval or cord-shaped with a hard texture. (2) Non-mass type: a No history of obstructed labor, the mass is not touched on the surface of the sternocleidomastoid muscle, and it shows diffuse increased tension, which can also develop from mass type. b Postural, also called habitual oblique neck: due to improper postpartum health care measures, prolonged bed rest and lack of turning.