Fig. 6.5 Cartilaginous structures of the nose

Nasion

Rhinion

Nasal bones

Septal cartilage

Nasal dome

Medial crus

Lateral crus

Infratrochlear N.

Infratrochlear/ dorsal nasal A.

External nasal artery and nerve

Angular A.

Lateral nasal A.

Infraorbital artery and nerve

Transverse facial A.

Superior labial A.

Frontal process of maxila

Upper lateral cartilage

Accessory alar

(sesamoid) cartilage

Lesser alar cartilage

Lower lateral cartilage

Alar fibrofatty tissue

Septal cartilage

6.3.1.2 Nerves

The zygomatic and buccal branches of the facial nerve (CN VII) provide motor innervation to the procerus muscle at the nasal root, depressor septi nasi, and nasalis muscles (Fig. 6.6). The ophthalmic and maxillary divisions of the trigeminal nerve provide sensory innervations to the nose. The infratrochlear and external nasal branches of the ophthalmic division (CN V1) and the infraorbital branch of the maxillary division (CN V2) are the primary sources of sensory innervations for this subunit.

6.3.1.3 Lymphatic Drainage

Lymphatic drainage from the nose is collected primarily by the submandibular lymph nodes (Fig. 6.3).

Facial A.

Fig. 6.6 Nasal vasculature and sensory nerves

of the internal carotid, supply the dorsal nose (Fig. 6.6). Vascular supply to the nasal sidewalls, columella, and nasal alae is provided by the angular artery, a branch of the facial artery that originates off of the external carotid (Fig. 6.6).

6.3.2Perioral

The surface anatomy of the lip is divided into the lateral cutaneous upper lip, philtrum, lower lip, and the vermillion border which demarcates the red and white portion of the lips (Fig. 6.7a) [4]. The underlying musculature includes orbicularis oris, zygomaticus major and minor, levator anguli oris, depressor anguli oris, levator labii superioris, depressor labii inferioris, risorius, mentalis, and the buccinator muscles (Fig. 6.7b).

The cutaneous insertion of lip elevator musculature forms the nasolabial crease.

6.3.2.1 Vasculature

Vascular supply to the lips is provided by labial branches of the facial artery. The labial arteries are frequently resected during Mohs micrographic surgery of the perioral region. Ligation or electrosurgery of these vessels is usually sufficient to prevent excessive bleeding.

6.3.2.2 Nerves

Motor innervation to the perioral musculature is carried by the zygomatic, buccal, marginal mandibular, and cervical branches of the facial nerve (CN VII) (Fig. 6.8). The maxillary division (CN V2) provides sensory innervations to the upper perioral region via the infraorbital nerve. The mandibular division (CN V3) contributes to the sensory nerve supply of the lower lip via the mental nerve.