Four Heads of Sternocleidomastoid: A Case Report.

During the routine cadaveric dissection, the presence of accessory heads of Sternocleidomastoid was observed on right side. i.e., additional bellies from sternal and clavicle were observed on the right side. These additional slips were innervated by the spinal accessory nerve. These additional slips could have been formed due to unusual splitting in the mesoderm of post-sixth branchial arch during organogenesis. The awareness of variations of sternocleidomastoid muscle is important for Anaesthetists, Plastic surgeons, Orthopaedicians and Dental surgeons while taking muscle flap in reconstructive surgeries and is also important for radiologists while interpreting MR images of this region.