A unique muscle bridge between sternohyoid and sternothyroid muscles

Abstract

During cadaveric dissection, a unique muscle bridge on the left anterior cervical region of male cadaver was detected and

morphometric measurements were performed. The unique muscle bridge was between the sternohyoid and sternothyroid

muscles. Ipsilateral sternohyoid muscle started from the lower back surface of the sternal extremity of the clavicula and from

costoclavicular ligament, but it had no fibers starting from the sternum. Three nerve branches were observed separating from

ansa cervicalis on the lateral of that muscle bridge; the top and the lowest nerve branches went to the sternothyroid muscle,

the median branch innerved the muscle bridge. As a result of the thorough literature review made, no case similar to

the variation detected in this study was encountered. During the surgical interventions such as tracheostomy, thyroidectomy

and trachea resections, knowing the presence of this muscle bridge can reduce the iatrogenic injuries to this structure.

Keywords

• infrahyoid; muscle bridge; muscle variation; sternohyoid; sternothyroid

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