Congenital Muscular Torticollis
Congenital muscular torticollis (CMT) refers to unilateral contracture of the sternocleidomastoid (SCM) muscle that restricts the infant's range of motion at the neck, with the head tilted toward the shortened SCM and the chin rotated to point away from the affected side. Although a mass often is palpable in the inferior part of the affected SCM, in many cases this is not appreciated in the immediate newborn period; the condition may be recognized only as the infant develops better head control over the first few weeks of life, making the head tilt more obvious. Potential complications of CMT include facial asymmetry and plagiocephaly from the uneven tension produced by the contracted SCM as well as cervical scoliosis, with a compensatory thoracic scoliosis.