Step 5 Dissection to the Pterygomasseteric Muscular Sling

Dissection through the superficial layer of deep cervical fascia is the step that requires the most care because of the anatomic structures with which it is associated. The facial vein and artery are usually encountered when approaching the area of the premasseteric notch of the mandible, as may the marginal mandibular branch of the facial nerve (Fig. 9-6). The facial vessels can be isolated, clamped, and ligated if they are in the way of the area of interest. When approaching the mandible posterior to the premasseteric notch, these vascular structures generally are not encountered; if they are easily retracted anteriorly. The marginal mandibular branch, however, occasionally is inferior to the mandible posterior to the premasseteric notch, so care must be taken.

Eric Temporal Nerve
Figure 9- 6 Relationship of the facial artery and vein, the marginal mandibular branch of the facial nerve, and the submandibular (premasseteric) lymph node to the inferior border of the mandible and masseter muscle.

Dissection through the superficial layer of deep cervical fascia is accomplished by nicking it with a scalpel and bluntly undermining with a hemostat or Metzenbaum scissors. The level of the incision and undermining of the fascia should be at least 1,5 cm inferior to the mandible to help protect the marginal mandibular branch of the facial nerve. Thus, dissection through the fascia at the level of the initial skin incision is performed, followed by dissection superiorly to the level of the periosteum of the mandible. The capsule of the submandibular salivary gland if often entered during this dissection, and the gland is retracted inferiorly (Fig. 9-7). A consistent submandibular lymph node (node of Stahr) is usually encountered in the area of the premasseteric notch and can be retracted superiorly or inferiorly. Its presence should alert the surgeon to the facial artery just anterior to the node, deep to the superficial layer of the deep cervical fascia. The marginal mandibular branch of the facial nerve may be located close by, within or just deep to the superficial layer of deep cervical fascia, passing superficial to the facial vein and artery. An electrical nerve stimulator can be used to identify the nerve so that it can be retracted superiorly. In many instances, however, this facial nerve branch is superior to the area of dissection and is not encountered.

Dissection continues until the only tissue remaining on the inferior border of the mandible is the periosteum (anterior to the premasseteric notch) or the pterygomasseteric sling (posterior to the premasseteric notch).

Platysma Submandibular Gland

Figure 9- 7 Coronal illustration of the path of dissection. The initial dissection is through the platysma muscle (PM) to the superficial layer of deep cervical

(Mand), which is incised at the inferior border. FA= facial artery; MM =

Figure 9- 7 Coronal illustration of the path of dissection. The initial dissection is through the platysma muscle (PM) to the superficial layer of deep cervical fascia (SLDCF), then through it in the area of the submandibular gland (SG) to the periosteum (P) of the mandible masseter muscle; ZA = zygomatic arch; VII = marginal mandibular branch of the facial nerve.

Was this article helpful?

0 0
How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

Get My Free Ebook


Post a comment