Branches of two cranial nerves join branches of the mandibular nerve [V3] in the infratemporal fossa (Fig. 8.150). These are the chorda tympani branch of the facial nerve [VII] and the lesser petrosal nerve, a branch of the tympanic plexus in the middle ear, which had its origin from a branch of the glossopharyngeal nerve [IX] (see Fig. 8.125, p. 953).