Trigeminal Nerve Worksheet #1 Distribution by Nerve Dr. Darren Hoffmann Dental Gross Anatomy, Spring 2013 We have drawn out each of the branches of CN V in lecture and you have an idea now for their basic pathways. The next step is to incorporate the details of the distribution of those nerves sensory territories into the framework of the pathway. This worksheet is written as an incomplete outline. The pathway components we ve already discussed are provided and the distribution for each nerve is left blank. Your textbook (Liebgott Anatomical Basis of Dentistry) has exactly the right level of detail for each of the nerve branches, so you can use the textbook to fill in each of these blanks. Page numbers in the third edition and second edition are provided for each nerve in parentheses (3 rd ed., 2 nd ed.). To get you started, here is a condensed outline of the branches of CN V. V1 (Ophthalmic n.) 1. Frontal n. Supraorbital n. Supratrochlear n. 2. Lacrimal n. 3. Nasociliary n. Short and long ciliary nn. Posterior ethmoidal n. Anterior ethmoidal n. External nasal n. Infratrochlear n. V2 (Maxillary n.) 1. Zygomatic n. Zygomaticofacial n. Zygomaticotemporal n. 2. Infraorbital n. Middle superior alveolar n. Anterior superior alveolar n. Inferior palpebral n. Lateral nasal n. Superior labial n. 3. Posterior superior alveolar n. 4. Nasopalatine n. 5. Posterolateral nasal nn. 6. Pharyngeal n. 7. Greater palatine n. 8. Lesser palatine n. V3 (Mandibular n.) 1. Buccal n. 2. Lingual n. 3. Inferior alveolar n. Nerve to mylohyoid n. (motor) Mental n. 4. Auriculotemporal n. Articular branch to TMJ 5. Nervus spinosus Other motor branches N. to masseter N. to temporalis N. to medial pterygoid N. to lateral pterygoid N. to tensor tympani N. to tensor veli palatini Trigeminal Nerve Worksheets, Distributions Page 1
V1 (Opthalmic nerve) Modality: Enters orbit through Superior orbital fissure of Sphenoid bone 1. Frontal nerve Runs along roof of orbit (frontal bone) Supraorbital n. (p. 259 3 rd ed. Liebgott, pp. 282-283 2 nd ed. Liebgott) Passes through supraorbital foramen/notch Supratrochlear n. Exits orbit medial to supraorbital nerve (not through supraorbital foramen), superior to the trochlea 2. Lacrimal nerve (p. 259, p. 283) Runs along lateral orbit to Lacrimal gland 3. Nasociliary nerve Crosses superior to optic nerve to run along medial orbit 3a. Short ciliary and long ciliary nerves (p. 260-261, p. 283) Long ciliary branch from nasociliary and pass directly to eyeball Short ciliary branch from ciliary ganglion to eyeball (also carry parasympathetics from CN IIII and sympathetics from Superior cervical ganglion) Both supply: 3b. Posterior ethmoidal nerve (p. 260, p. 283) Pass through posterior ethmoidal foramen and enter ethmoid bone 3c. Anterior ethmoidal nerve (p. 260, p. 283) Pass through anterior ethmoidal foramen, then continues to enter nasal cavity Runs along roof of nasal cavity *External nasal nerve (p. 260, p. 283) Termination of Anterior ethmoidal nerve, exits the nasal cavity onto median strip of nose 3d. Infratrochlear nerve (p. 260, p. 283) Termination of Nasociliary nerve, exits orbit inferior to trochlea Trigeminal Nerve Worksheets, Distributions Page 2
V2 (Maxillary nerve) Modality: All branches of V2 also carry parasympathetics from CN VII (Greater petrosal n.) V2 passes through Foramen rotundum to enter Pterygopalatine fossa (PPF) 1. Zygomatic nerve Enters orbit through Inferior Orbital Fissure Runs along lateral wall of orbit, sends communicating branch up to Lacrimal n. of V1 Passes through Zygomatic bone (Zygomatic canal) Canal diverges into two foramina: Zygomaticofacial foramen, Zygomaticotemporal foramen 1a. Zygomaticofacial nerve (p. 293, p. 318) 1b. Zygomaticotemporal nerve (p. 293, p. 318) 2. Infraorbital nerve Enters orbit through Inferior Orbital Fissure Runs along the floor of the orbit, runs in Infraorbital groove Passes into Infraorbital canal of Maxilla and drops off two branches within the bone: 2a. Middle superior alveolar nerve (p. 293-4, p. 319) 2b. Anterior superior alveolar nerve (p. 294, p. 319) Nasal branches: Exits maxilla through Infraorbital foramen, splits into three terminal branches: 2c. Inferior palpebral nerve (p. 294, p. 319) 2d. Lateral nasal nerve (p. 294, p. 319) 2e. Superior labial nerve (p. 294, p. 319) Trigeminal Nerve Worksheets, Distributions Page 3
3. Posterior Superior Alveolar nerve (p. 293, p. 318) Enters maxilla through Posterior superior alveolar foramen 4. Nasopalatine nerve (p. 294, p. 322) Exits PPF medially through Sphenopalatine foramen which takes it into the nasal cavity Runs anterior-inferiorly along nasal septum Passes through incisive foramen of maxilla to reach anterior hard palate 5. Posterolateral nasal nerves (p. 295, p. 322) Exit PPF medially through Sphenopalatine foramen which takes them to nasal cavity 6. Pharyngeal branches (p. 295, p. 322) Exits PPF medially through Sphenopalatine foramen which takes it into the nasal cavity 7. Greater palatine nerve (p. 294, p. 320) Exits PPF inferiorly through palatine canal, passes through Greater palatine foramen to reach hard palate 8. Lesser palatine nerve (p. 294, p. 320-322) Exits PPF inferiorly through palatine canal, passes through Lesser palatine foramen to reach soft palate Trigeminal Nerve Worksheets, Distributions Page 4
V3 (Mandibular nerve) Modalities: Passes through Foramen ovale to enter Infratemporal fossa 1. Buccal n. (p. 286, p. 309) Passes anteriorly between heads of lateral pterygoid m. to cheek region 2. Lingual n. (p. 286, p. 311) Passes between medial and lateral pterygoid mm. Also receives fibers from Chorda tympani (CN VII) Enters floor of the mouth 3. Inferior Alveolar n. (p. 287, p. 311) Passes between medial and lateral pterygoid mm. Drops off one branch before entering mandible: 3a. Nerve to mylohyoid (motor) (p. 287, p. 311) Enters mandible through Mandibular foramen Exits mandible through Mental foramen to become: 3b. Mental nerve (p. 287, p. 312) 4. Auriculotemporal n. (p. 286, p. 309) Passes laterally, posterior to TMJ, then on side of face, just anterior to ear Carries post-ganglionic parasympathetics from CN IX to Parotid gland 5. Nervus spinosus (p. 286, p. 309) Passes through foramen spinosum to re-enter skull Other motor branches: (pp. 285-286, p. 309) Nerve to Masseter Nerve to Temporalis Nerve to Medial pterygoid Nerve to Lateral pterygoid Nerve to Tensor Tympani Nerve to Tensor Veli Palatini Trigeminal Nerve Worksheets, Distributions Page 5