Supernumerary insertions of the sternocleidomastoid muscle: a rare anatomical variation with clinical significance

Morphological variations of the sternocleidomastoid muscle are relevant for clinical, surgical and radiological approaches of the neck. To our knowledge, the present case is the second reported insertional variation of the sternocleidomastoid muscle with supernumerary tendons. Its potential role in the treatment of facial palsy as a split muscle flap is also discussed and confirmation in the setting of a clinical scenario is encouraged.