Trigeminal nerve 2 Flashcards
What are the 3 branches of the trigeminal nerve?
- Ophthalmic
- Maxillary
- Mandibular
What is the most important branch of the trigeminal nerve for dentists?
- The mandibular
- Involved in dental blocks in the lower teeth
Where does CN V3 pass through to go into the infratemporal fossa?
- Goes through the foramen ovale
Which one of the 3 openings coming from Meckel’s cave can you see on the base of the external skull?
The foramen ovale
Which of the cranial fossa is the foramen ovale found?
- The middle cranial fossa
The mandibular division of the trigeminal nerve exits into the infratemporal fossa - there is no bone around it so it is not protected. What is an advantage and disadvantage of this?
Advantage: You can target the nerve more easily
Disadvantage: Can be more vulnerable to injury
What is the lateral boundary of the infratemporal fossa?
Ramus of the mandible
What is the medial boundary of the infratemporal fossa?
Lateral pterygoid plate of sphenoid bone
What is the anterior boundary of the infratemporal fossa?
- Posterior aspect of the maxilla
What is the posterior boundary of the infratemporal fossa?
- Tympanic plate, mastoid & styloid process
What is the superior boundary of the infratemporal fossa?
Infratemporal crest of the sphenoid bone
What is the inferior boundary of the infratemporal fossa?
- Angle of the mandible
What are the 3 main sensory branches of CN V3?
- Auriculotemporal
- Buccal
- Mental
The skin over the angle of the mandible is not supplied by CN V, what is it supplied by?
- The cervical plexus with the great auricular nerve (C2,3)
What are the 5 main branches of the mandibular division of the trigeminal nerve?
- Auriculotemporal
- Buccal
- Mental
- Lingual
- Muscular
- Inferior alveolar nerve
Where does the sensory component of CN V3 predominantly supply to? (3 points)
- Temporal, jaw and part of chin
Where does the motor component of CN V3 predominantly supply to?
- The muscles of mastication and a few additional muscles
What are the names of the branches coming from the main branch of CN V3? (4 points)
- Meningeal branch
- Branch of the tensor tympani
- Branch to tensor veli palatini
- Nerve to medial pterygoid
Are the branches coming off of the main trunk of CN V3 sensory or motor?
All motor apart from the meningeal nerve that is sensory to the dura mater
What will the meningeal branch supply?
- Sensory information to the dura mater
What will the branch to the tensor tympani supply?
In the ear have 3 little bones that help with hearing - 2 muscles that will attach to different parts of the bones - these muscles control the vibration of the ear bones - to control how fast the vibrations happen in controlled by the tensor tympani - the nerve that innervates this comes from the main trunk of CN V3
What will the branch to the tensor veli palatini supply?
- Muscle we will find on the soft palate which elevates the soft palate - innervated from the main branch
What will the nerve to medial pterygoid supply?
- Muscle of mastication - nerve supply coming from the main trunk
What are the branches of the anterior trunk of CN V3? (4 points)
- Deep temporal nerves
- Nerve to lateral pterygoid
- Buccal nerve
- Masseteric nerve
Are the branches from the anterior trunk of CN V3 sensory or motor?
- All motor apart from the buccal nerve that is sensory (NOT to be confused with the buccal branch of the facial cranial nerve)
What do the deep temporal nerves supply?
- The temporalis muscle
What does the nerve to the lateral pterygoid supply?
- The lateral pterygoid muscle
What does the nerve to the masseteric branch supply?
- The masseter muscle
What are the 3 branches of the posterior trunk of CN V3?
- Auriculotemporal nerve
- Lingual nerve
- Inferior alveolar nerve
Are the branches coming from the posterior trunk of CN V3 sensory or motor?
- All sensory apart from the inferior alveolar nerve that is mixed (sensory and motor)
Why is the inferior alveolar nerve both sensory and motor?
- Mixed nerve supply
- As goes more inferiorly splits into 2 branches
- Mylohyoid and also goes into jaw and different things happen
- As you go down past mylohyoid the nerve is completely sensory
- The motor part goes to the mylohyoid
- Depends where you look at the nerve
What kind of sensation does the mandibular division of CN V supply to the tongue?
- General sensation to the anterior 2/3 of the tongue (general somatic afferent) via the lingual nerve
What is the name of the nerve that the lingual nerve carries which is a branch of CN VII?
Chorda tympani
Where does CN V3 supply general sensation to (apart from the tongue)? (3 points)
- The floor of the mouth along with the lower teeth and the gums
What is trigeminal neuralgia?
- Terrible pain usually in CN V3 & in CN V2 distribution
Where does the buccal nerve supply?
To cheek & lateral gum
Where does the inferior alveolar nerve & its branch, the incisive nerve supply?
- The lower teeth
Where does the inferior alveolar nerve supply?
To the skin of the chin & lower lip (both skin and mucous membranes) as the mental nerve
Once the inferior alveolar nerve enters the mandibular foramen it splits into 2 nerves. What are the names of these and where do they supply?
- Incisive nerve: supplies the teeth
- Mental nerve: supplies general sensation to the chin, and mucous membranes
- Both of these are sensory
Where foes the inferior alveolar nerve supply before it enters the mandibular foramen? (2 points)
- Supplies the mylohyoid & anterior belly of the digastric
Where does the inferior alveolar nerve loose its motor component to?
- Looses motor component to the mylohyoid
Which nerve supplies sensation to the posterior lower teeth?
- Main trunk of the inferior alveolar nerve (from V3)
Which nerve supplies sensation to the anterior lower teeth?
- Incisive branch of the inferior alveolar nerve (from V3)
Which nerve supplies sensation to the lingual mucosa on the lower jaw?
- The lingual nerve
Which nerve supplies sensation to the posterior buccal mucosa on the lower jaw?
The buccal nerve (from V3)
Which nerve supplies sensation to the anterior buccal mucosa on the lower jaw?
The mental nerve from the inferior alveolar nerve (from V3)
What are the teeth general sensory supply? (5 points)
- Anterior superior alveolar nerve (CN V2)
- Middle superior alveolar nerve (CN V2)
- Posterior superior alveolar nerve (CN V2)
- Inferior alveolar nerve in mandibular canal (CN V3)
- Incisive nerve (CN V3)
What is the general sensation to the tongue? (3 points)
- Pressure, temperature, pain
What is the special sensation to the tongue?
Taste
Which nerve does the anterior 2/3 of the tongue get general sensation from?
- Via the mandibular division of the trigeminal nerve via the lingual nerve
Which nerve does the anterior 2/3 of the tongue get special sensation (taste) from?
Via the facual nerve (CN VII)
The third division of the trigeminal nerve supplies sensation to the muscles of mastication, what other smaller muscles does it supply? (4 points)
- Tensor tympani muscle in middle ear
- Tensor palati (the latter via the branch to the medial pterygoid)
- Mylohyoid
- Anterior belly of the digastric (via in ferior alveolar branch)
Which muscles of mastication elevate the mouth? (3 points)
- Temporalis
- Masseter
- Medial pterygoid
Which muscle of mastication depresses the mouth?
- The lateral pterygoid
Which virus found on the trigeminal ganglion causes shingles?
- The Varicella zoster virus
- (cutaneous involvement in the distribution of CN V1)
What are common signs and symptoms of shingles? (4 points)
- Erythematous
- Vesicular
- Crusting rash
- Burning sensation
What is the Hutchinson’s sign of shingles?
- Cutaneous involvement of the tip of the nose (external nasal branch of nasociliary nerve)
- A positive Hutchinson’s sign increases the likelihood of ocular complications (nasociliary nerve)
What are common ocular complications of shingles? (3 points)
- Conjunctivitis
- Keratitis (cornea)
- Uveitis (anterior chamber of globe)
What are the 3 anatomical features that can be damaged when trying to give an ID block to the trigeminal nerve?
- Medial pterygoid muscle (if damaged patient can get trismus)
- Parotid gland (if hit this patient will be in a lot of pain)
- Facial nerve (if hit this may get facial paralysis but this is not perma nent)
What does the facial nerve supply?
- All the muscles of facial expression