Nerves - Oral Cavity Flashcards
Cranial Nerve V:
Trigeminal nerve
Cranial Nerve VII:
Facial nerve
Cranial Nerve IX:
Glossopharyngeal nerve
Cranial Nerve XII:
Hypoglossal nerve
Trigeminal Nerve
Fifth Cranial Nerve
Afferent (sensory = “I feel, taste”) • Efferent (motor; make it “move”) • Secretory (to glands: salivary)
• Proprioceptive receptors provide sense of position as in periodontal ligaments and TMJ
Originates in the Trigeminal ganglion
• Three divisions:
3 Divisions of trigeminal nerve
Division I = ophthalmic (not to mouth)
– Division II = maxillary (to all maxillary teeth)
– Division III = mandibular (to all mandibular teeth and muscles of mastication)
Sense of position or proprioception
Proprioceptive receptors in muscles and ligaments (including the periodontal ligament) provide the brain info of position of teeth and mandible at all times) Division I and II
Trigeminal Nerve (CN V): Division I (Ophthalmic Nerve)
Exitscraniumvia superior orbital fissure (sphenoid) to upper third of face, eye ball, superior eyelid, nose, maxillary sinus forehead, and scalp
Trigeminal Nerve (CN V): Division II (Maxillary Nerve)
Exitscraniumviaforamenrotundum (sphenoid) into the pterygopalatine space
First Branch: Pterygopalatine Branch
b. Second Branch: Posterior Superior Alveolar (PSA) Nerve
c. ThirdBranch:Infraorbital Nerve
d. Fourth Branch: Zygomatic Nerve
Maxillary Division II: Pterygopalatine Branches
Descending palatine- Greater palatine branch goes to mucosa of posterior two-thirds of hard palate and gingiva
• Nasopalatinebranch goes to anterior one- third of hard palate
• Middle and Posterior or Lesser palatine branch goes to tonsils and soft palate
Greaterpalatine
enters palate through greater palatine foramen
Nasopalatinebranch
enters palate through incisive foramen
MiddleandPosterior palatine
enters through lesser palatine foramina
Posterior Superior Alveolar PSA nerve
PSAseparatesfromthe maxillary nerve before its entry into the infraorbital fissure. Enters the maxillae behind and above third molars through alveolar canals
• Goestomaxillary molars: pulps, ligaments, alveolar bone, facial gingiva
• Passagewayseen behind maxillae
Infraorbital Branch
While in infraorbital canal, gives off MSA (middle superior alveolar) branches to premolar
pulps and mesiobuccal root max 1 molar as well as facial gingiva, bone and ligament and ASA (anterior superior alveolar) branches to anterior teeth, facial gingiva, part of sinus etc.
Goesthrough infraorbital canal (roof of maxillary sinus) giving off ASA, MSA
• Terminal branches out of infraorbital foramen to upper lip, nose etc.
Zygomatic Branch
Supplies skin of temporal and orbit region (not to mouth)
Trigeminal Nerve (CN V): Division III (Mandibular Nerve)
Branches
a. Auriculotemporal Nerve
b. Buccal (or Long Buccal or Buccinator) Nerve c. Lingual Nerve
d. Inferior Alveolar Nerve
Exitscraniumvia foramen ovale
Auriculotemporal Branch mand div 3
- Provides sensation to outer ear and skin of the face anterior to the ear
- ProvidesproprioceptiontoTMJ
Buccal Nerve Branch Mand div 3
Goesthrough infratemporal space (between heads of lateral pterygoid muscles) to buccal gingiva of molars and premolars (and buccal mucosa and skin of cheeks up to corner of mouth (commissure )
Goes lateral to ramus, to cheek and mucosa/gingiva next to molars
Mandibular Division II: Lingual Nerve Branch
Passesmedialtoramus but lateral to medial pterygoid muscles
• Generalsensationto anterior two-thirds of tongue and lingual gingiva in mandible
Passesmedialtoramus but lateral to medial pterygoid muscles
Inferior Alveolar Nerve: Terminal Branches
Mental branch, incisive branch
Mental branch
exits mandible via mental foramen; goes to lower lip, anterior facial gingiva
Incisive branch
is continuation of inferior alveolar within mandible to anterior pulps
d. Mandibular Division III: Inferior Alveolar nerve
Before entering the mandible gives the mylohyoid branch (to mylohyoid and anterior belly)
• Entersmandibularforamen
• While in the canal provides for to mandibular premolars and molars pulps, ligaments, surrounding alveolar bone
Mandibular Division II: Motor Branches Go to Muscles of Mastication
• Branchestomusclesof mastication:
– Masseteric (Masseter +TMJ)
– Posterior and anterior temporal
– Medial pterygoid – Lateral pterygoid
Facial Nerve (Seventh Cranial Nerve)
Mix nerve (efferent and afferent branches).• Exit brain case via internal acoustic meatus into petrous part of temporal bone
Branches exit temporal bone:
– Via petrotympanic fissure becoming chorda tympani (taste) joining lingual branch of CN V to anterior two- thirds of tongue
– Via stylomastoid foramen for efferent fibers
Efferentfibersgoto many muscles of facial expression posterior belly, stylohyoid and platysma
• Secretoryfibersgoto submandibular and sublingual salivary glands
Glossopharyngeal Nerve (Ninth Cranial Nerve)
• Exitscraniumvia jugular foramen
Via jugular foramen
– Afferent fibers to posterior one-third of tongue for general sensation and taste also pharynx, and tonsils
– Secretory fibers to parotid gland
– Efferent fibers to muscles of the pharynx
Hypoglossal Nerve (12th Cranial Nerve)
• Exitscraniumvia hypoglossal canal (on walls of foramen magnum)
Efferentfibersgoto the muscles that move the tongue
Afferent fibers to the tongue
– CN V: anterior two-thirds general sensation
– CN VII: anterior two-thirds taste
– CN IX: posterior two-thirds general sensation and taste
Efferent fibers to the tongue
– CN XII: tongue muscles
Palatoglossus(tonguemuscle)isinnervatedby
CNX.
Secretory fibers to salivary glands:
– CN VII: to submandibular and sublingual glands
– CN IX: to parotid glands
Arteries That Supply Blood to the Oral Cavity
Blood to mouth comes via left ventricle of heart to aorta, then to external carotid, which has the important maxillary artery with branches to all upper and lower teeth
• Many arteries from the heart join with nerves from the brain (in the area medial to the ramus) and have the same name as the nerve to that location
Branches of the external carotid
Lingual to tongue, floor of the mouth, sublingual gland and adjacent gingiva
– Facial to soft palate, tonsils, pharynx, chin, floor of the mouth, lips, and nose
– Maxillary to all maxillary and mandibular teeth and muscles of mastication
Lingual
l to tongue, floor of the mouth, sublingual gland and adjacent gingiva
Facial
to soft palate, tonsils, pharynx, chin, floor of the mouth, lips, and nose
Maxillary
to all maxillary and mandibular teeth and muscles of mastication
Maxillary Artery Branches (in Three Groups)
Arteries to mandible:
Arteries to muscles
Arteries to maxillae
Arteries to maxillae
– Pterygopalatine part : PSA (molars) , infraorbital branches ASA, MSA (premolars and anterior teeth) ; descending palatine ( nasal cavity, palate and lingual gingiva
Arteries to muscle
Pterygoid part ( muscles of mastication and buccinator muscle)
Arteries to mandible:
Mandibular part : Inferior alveolar (molars and premolars), mental (chin , lower lip), and incisive (anterior teeth)
Common facial vein
• Veins drain blood from the face into the common facial vein
pterygoid plexus
• Blood from the upper part of the face, including maxillary teeth is collected by the pterygoid plexus
The pterygoid plexus empties into the maxillary vein and into the Retromandibular vein
The inferior alveolar v.
The inferior alveolar v. drains the mandible and lower teeth into the pterygoid plexus
The facial v.
runs parallel to the facial artey collect from the superior , inferior labial v. and muscles of mastication, nose and eyes. Blood from tongue is collected by the Lingual vein
Lingual vein
Collects blood from tongue
All orofacial veins drain via the common facial vein into internal jugular vein - superior vena cava - heart
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Lymph nodes Drain Fluids of the Face and Neck
Parotid
Submental
Submandibular
All drain to cervical nodes
Parotid nodes
nodes drain cheek, ear and eyelids
Submental nodes
nodes drain tip of tongue, anterior part of lower lip, anterior part of floor of mouth and mandibular incisors
Submandibular nodes
Submandibular nodes (drain other maxillary and mandibular teeth as well as posterior floor, tongue upper lip and part of lower lip )
