Vessels and nerves of the deep facial region

Maxillary artery (a. maxillaris)

The artery branches off from the external carotid artery within the thickness of the parotid gland. It loops around the neck of the mandibular condyle and runs transversely across the outer surface of the lateral pterygoid muscle (m. pterygoideus lateralis). Topographically, the vessel is divided into three parts:

1. First part (maxillary): located between the neck of the articular process and the stylomandibular ligament. Here, the inferior alveolar artery (a. alveolaris inferior), passing downwards into the mandibular canal, and the middle meningeal artery (a. meningea media), ascending into the foramen spinosum of the skull, originate.
2. Second part (pterygoid part): supplies the masticatory muscles. It gives off the buccal artery (a. buccalis), masseteric artery (a. masseterica, passing through the mandibular notch), deep temporal branches (aa. temporales profundae anterior et posterior), and pterygoid branches (rr. pterygoidei).
3. Third part (pterygopalatine part): located in the pterygopalatine fossa. This gives rise to the infraorbital artery (a. infraorbitalis), posterior superior alveolar arteries (aa. alveolares superiores posteriores), descending palatine artery (a. palatina descendens), artery of the pterygoid canal, and sphenopalatine artery (a. sphenopalatina), which enters the nasal cavity.

Mandibular nerve (n. mandibularis)

The branches of this nerve run within the interpterygoid space. The nerve trunk itself is short (not exceeding 0.5 cm), and its initial segments, along with the medial pterygoid muscle, are enclosed in the interpterygoid fascia. To visualize the deep branches, the lateral pterygoid muscle must be dissected.

Main branches:

• Masseteric nerve (n. massetericus).
• Deep temporal nerves (nn. temporales profundi): curve superior to the lateral pterygoid muscle; the anterior branch goes to the masseter muscle, and the posterior ascends into the temporal region.
• Buccal nerve (n. buccalis): passes between the heads of the m. pterygoideus lateralis, pierces the buccinator muscle, and innervates the buccal mucosa.
• Auriculotemporal nerve (n. auriculotemporalis).
• Inferior alveolar nerve (n. alveolaris inferior): runs within the interpterygoid fascia beneath the lateral pterygoid muscle and enters the mandibular canal. Before entry, it gives off the mylohyoid nerve (n. mylohyoideus).
• Lingual nerve (n. lingualis): located between the buccal and inferior alveolar nerves, running inferiorly and medially.

Autonomic ganglia and parasympathetic innervation

Otic ganglion (ganglion oticum) is located on the external skull base in the region of the foramen ovale. It lies adjacent to the posteromedial surface of the mandibular nerve. The parasympathetic root of the ganglion is the lesser petrosal nerve (n. petrosus minor), which carries fibers from the glossopharyngeal nerve (CN IX). In the ganglion, these fibers synapse and travel to the parotid gland.

An important role is also played by the chorda tympani (chorda tympani), which joins the lingual nerve from above and laterally, 1.5–2.0 cm inferior to the foramen ovale, being covered by the inferior alveolar nerve.

Pterygopalatine fossa and its contents

The deep facial region anatomically transitions into the pterygopalatine fossa. Its boundaries are:

• Posterior: pterygoid process of the sphenoid bone.
• Anterior: maxilla (maxillary tuber).
• Medial: perpendicular plate of the palatine bone.
• Inferior: narrows and continues into the greater palatine canal.

Through the foramen rotundum (foramen rotundum), the maxillary nerve (n. maxillaris) enters the fossa, giving off the zygomatic, pterygopalatine, infraorbital, and superior alveolar nerves here.

The pterygopalatine ganglion (ganglion pterygopalatinum) is also located here. Its parasympathetic root is the greater petrosal nerve (n. petrosus major), which provides secretory innervation to the lacrimal gland, nasal glands, and palatine glands. The sympathetic root is the deep petrosal nerve (n. petrosus profundus). Combining in the pterygoid canal, they form the nerve of the pterygoid canal / Vidian nerve (n. canalis pterygoidei).

Posterior parapharyngeal space

Behind the "styloid diaphragm" lies the posterior parapharyngeal space. It contains major blood vessels: the internal carotid artery (a. carotis interna) lies medially, and the internal jugular vein (v. jugularis interna), along which the deep cervical lymph nodes extend, lies laterally.

Four pairs of cranial nerves also pass here:

1. Glossopharyngeal nerve (n. glossopharyngeus, CN IX).
2. Vagus nerve (n. vagus, CN X).
3. Accessory nerve (n. accessorius, CN XI).
4. Hypoglossal nerve (n. hypoglossus, CN XII).

Within the fascia separating the posterior parapharyngeal and retropharyngeal spaces lies the superior cervical sympathetic ganglion (ganglion cervicale superius).

Class and exam questions

What else to study on this topic

• Boundaries and walls of the pterygopalatine fossa in 3D
• Fasciae and fascial spaces of the deep facial region
• Anatomy of the interpterygoid fascia and its clinical significance
• Topography of cranial nerves in the posterior parapharyngeal space

Other topics in the section "Topographic Anatomy of the Head"

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