Snapshot A 2-day-old boy is evaluated in the newborn nursery for a neck deformity. He was born at 39 weeks gestation and was noted at birth to have bilateral clubfeet. On exam, the top of his head is tilted to the left and his chin is rotated to the right. An ultrasound of his neck demonstrates no masses or cysts. His left sternocleidomastoid muscle is dystonically contracted. Introduction Clinical definition "packaging deformity" caused by a contracture of the sternocleidomastoid (SCM) muscle login to view 1 more bullet Epidemiology demographics login to view 2 more bullets risk factors login to view 1 more bullet Etiology unknown etiology but may be due to login to view 2 more bullets Pathoanatomy normal anatomy login to view 9 more bullets aberrant anatomy login to view 1 more bullet Associated conditions other packaging disorders login to view 4 more bullets Presentation Symptoms head tilt and rotation noticed by parents the condition is typically not painful login to view 1 more bullet Physical exam child's head is tilted to the affected side and the chin is rotated to the unaffected side palpable contracted SCM muscle login to view 1 more bullet Imaging Ultrasound indication login to view 1 more bullet findings login to view 2 more bullets Differential Congenital neck mass cysts and tumors can be distinguished from a contracted SCM by ultrasound login to view 3 more bullets Atlantoaxial rotatory subluxation neck pain is common SCM spasm may occur on the same side as the chin in contrast to congenital torticollis in which the chin will be rotated away from the affected side Treatment Conservative physical therapy to stretch affected SCM muscle indication login to view 1 more bullet Medical botulinum toxin injection login to view 2 more bullets Complications Permanent rotational deformity Positional plagiocephaly asymmetric flattening of the skull due to an imbalanced positioning of the skull while the infant is supine Facial asymmetry