IA
|
Symphysis of mandible
|
Body of hyoid
|
Anterior belly of contralateral digastric muscle
|
Anterior belly of ipsilateral digastric muscle
|
IB
|
Body of mandible
|
Posterior belly of diagastric muscle
|
Anterior belly of digastric muscle
|
Stylohyoid muscle
|
IIA
|
Skull base
|
Horizontal plane defined by the inferior border of the hyoid bone
|
The stylohyoid muscle
|
Vertical plane defined by the spinal accessory nerve
|
IIB
|
Skull base
|
Horizontal plane defined by the inferior body of the hyoid bone
|
Vertical plane defined by the spinal accessory nerve
|
Lateral border of the sternocleidomastoid muscle
|
III
|
Horizontal plane defined by the inferior body of hyoid
|
Horizontal plane defined by the inferior border of the cricoid cartilage
|
Lateral border of the sternohyoid muscle
|
Lateral border of the sternocleidomastoid or sensory branches of cervical plexus
|
IV
|
Horizontal plane defined by the inferior border of the cricoid cartilage
|
Clavicle
|
Lateral border of the sternohyoid muscle
|
Lateral border of the sternocleidomastoid or sensory branches of cervical plexus
|
VA
|
Apex of the convergence of the sternocleidomastoid and trapezius muscles
|
Horizontal plane defined by the lower border of the cricoid cartilage
|
Posterior border of the sternocleidomastoid muscle or sensory branches of cervical plexus
|
Anterior border of the trapezius muscle
|
VB
|
Horizontal plane defined by the lower border of the cricoids cartilage
|
Clavicle
|
Posterior border of the sternocleidomastoid muscle
|
Anterior border of the trapezius muscle
|
VI
|
Hyoid bone
|
Suprasternal notch
|
Common carotid artery
|
Common carotid artery
|
VII
|
Suprasternal notch
|
Innominate artery
|
Sternum
|
Trachea, esophagus, and prevertebral fascia
|