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Page 2 of 5 Muñoz-Jimenez et al. Plast Aesthet Res 2018;5:14 I http://dx.doi.org/10.20517/2347-9264.2018.04

INTRODUCTION
The infrahyoid muscles are a group of paired strap-like muscles that include the thyrohyoid, sternothyroid,
sternohyoid and the omohyoid. The omohyoid muscle is a digastric structure with an inferior belly originated
in the scapula, a central tendon and a superior belly that inserts in the inferior border of the hyoid bone.
Previous authors have described the gross and microsurgical anatomy of the infrahyoid muscles at length,
however, the inferior belly of the omohyoid has remained largely ignored .
[1-8]
The infrahyoid muscles´ blood supply has been found to arise from the superior and inferior thyroid
arteries, and the sternal branch of the internal thoracic artery; nevertheless, most authors have limited
their investigations to the omohyoid´s superior belly . The ansa cervicalis has been found to present many
[1-3]
variants in the terminal branches that innervate the strap muscles, but as of today there is no description on
the branches directed to the inferior belly of the omohyoid muscle .
[4]
Several descriptions on the use of the infrahyoid muscles for reconstruction of the tongue, larynx, esophagus
and the vocal cords have been published, however it should be noted that most surgeons avoid the inclusion of
the inferior belly of the omohyoid muscle in their flaps due to its distance from the site to be reconstructed [5-10] .

The inferior belly of the omohyoid muscle possesses appealing characteristics that may allow it to serve
as a specialized functional flap, such as serving a noncritical function (easily performed by the rest of the
infrahyoid muscles), and possessing small dimensions that allow for functional reconstruction in small
areas; however, its potential use as a free flap has never been studied.

The objective of this work is to describe the surgical morphology of the inferior belly of the omohyoid muscle.

METHODS
Fresh human cadavers were used for this study; standardized dissections were conducted to establish the
anatomical characteristics of the inferior belly of the omohyoid muscle.

Approval by the institutional ethics board was received. Data recorded included patients’ demographic
characteristics; history for trauma, or surgical procedures on the neck; muscle belly dimensions from its
origin in the scapula to the central tendon; length of the vascular and nerve pedicle from its proximal
dissection to the point of its emergence in the muscle fibers.

Statistical analysis
Descriptive analyses of patient demographic and clinical characteristics were performed. Continuous
variables are expressed in central tendency measures, categorical values are presented as percentages.

Cadaveric dissection
A supraclavicular incision was performed following the contour of the sternocleidomastoid muscle.
Subplatysmal flaps were elevated to expose the strap muscles and the sternocleidomastoid muscle. The
sternocleidomastoid muscle is retracted laterally to expose of the omohyoid muscle.

The ansa cervicalis and the vascular pedicles were identified and dissected from their origin to the point of
entry of the muscle belly; finally, the inferior muscle belly was extracted by disinserting it from the scapular
surface and transecting the central tendon.

RESULTS
Five male anatomic models were studied (range 18 to 65 years), 2 muscles were discarded due to previous