The lingual nerve lies anterior to the inferior alveolar nerve and first descends deep to the lateral pterygoid muscle and superficial to the medial pterygoid muscle. From the lower border of the lateral pterygoid muscle, the nerve passes obliquely forward between the medial pterygoid muscle and the ascending ramus's inner aspect until it reaches the bottom fold of the pterygomandibular space. At the posterior mylohyoid line-height, it exits the space and curves anteriorly to take a longitudinal direction. For a short distance, it lies close to the lingual cortex of the inner mandibular angle (temporal crest), the retromolar trigone, and the third molar region. Towards the oral cavity, it is covered by the mucous membrane and the posterior tail of the submandibular gland so that it can often be visualized as a pale shade by tightening the soft tissues of the posterior glossoalveolar sulcus. On its course to the dorsum and the tongue's tip, it turns medially and crosses the lateral side of the superior pharyngeal constrictor, styloglossus, and hyoglossus muscles to split into its terminal branches.
Exiting from the petrotympanic fissure, the chorda tympani joins the lingual nerve's back at an acute angle at the lateral pterygoid muscle level.
The lingual nerve provides pain, temperature, and touch sensation to the anterior two-thirds of the tongue, the glossoalveolar sulcus, and the lingual gingiva of the entire lower quadrant. Taste mediating fibers from the anterior two-thirds of the tongue are conveyed centrally via the chorda tympani. The chorda tympani also contains visceral efferent fibers traveling to the sublingual and submandibular glands.
The lingual nerve is prone to injury during intraoral approaches exposing the medial side of the retromolar trigone and the ascending ramus's inner aspect. Sometimes the nerve is damaged during drilling or transverse screw insertion along the upper border (oblique line) of the inner bony angle. The chorda tympani itself is out of reach during fracture repair procedures, but its fascicles inside the lingual nerve can be affected.