Boundaries:

• Midline line of the neck anteriorly
• Sternomastoid posteriorly
• Body of the mandible superiorly

Four subtriangles of the anterior triangle:

• The muscular triangle, bounded by the midline of the neck, omohyoid, and sternomastoid.
• The carotid triangle, bounded by the omohyoid, posterior digastric, and sternomastoid.
• The submandibular triangle, bounded by the posterior digastric, anterior digastric, and inferior margin of the body of mandible.
• The submental triangle, bounded by the anterior digastric, hyoid bone, and the midline of the neck.

Figure 8-2
Subdivisions and structures of the anterior triangle.

The superior and anterior portions of the anterior triangle (submandibular and muscular triangles) contain the anterior and posterior digastric and omohyoid muscles that aid in swallowing and speech. These muscles attach to the hyoid bone, the mastoid process of the temporal bone and mandible. (Figure 8-2)