602 Pterygopalatine Fossa

Pterygopalatine Fossae

pyramidal space medial to the infratemporal fossa bwtn the sphenoid, maxilla, & palatine bone
*major distribution site for
-pterygopalatine region of maxillary artery
-maxillary nerve (V2 of CNV)
-pterygopalatine ganglion --> associated w/ autonomics
>greater petrosal nerve (of CNVII)
>deep petrosal nerve (sympathetics from internal carotid plexus)

Branches of Maxillary Nerve (V2 of CNV)

-infraorbital nerve --> somatic sensation to the face
-zygomatic nerve --> somatic sensation to the face
-posterior lateral nasal nerve --> somatic sensation to nasal mucosa
-pharyngeal nerve --> somatic sensation to nasopharynx
-nasopalatine nerve --> somatic sensation to the anterior part of hard palate
-greater palatine nerve --> somatic sensation to the majority of the hard palate
-lesser palatine nerve --> somatic sensation to the soft palate
-superior alveolar nerves --> somatic sensation to maxillary teeth
-meningeal branches --> go thru foramen ovale to innervate dura near the pterion

Boundaries of Pterygopalatine Fossa

-posterior = pterygoid process
-anterior = posterior part of the maxilla
-medial = perpendicular plate of the palatine bone
-superior = greater wing of the sphenoid
-lateral = opening to the infratemporal fossa
-inferior = pyramidal process of the palatine bone

Maxillary Nerve Pathway

Trigmenial Ganglion in middle cranial fossae --> V2 division goes thru foramen rotundum --> enters pterygopalatine fossa --> gives off posterior superior alveolar branch + posterior lateral nasal branch + pharyngeal branch --> enters infraorbital groove --> then V2 becomes infraorbital nerve --> gives off middle/anterior alveolar branches before exiting thru infraorbital foramen --> somatic sensory to face

What connects the infratemporal fossa to the pterygopalatine fossa?

pterygomaxillary fissure

what connects the pterygopalatine fossa to the nasal cavity?

sphenopalatine foramen

what runs through the pterygomaxillary fissure?

3rd part of the maxillary artery (pterygopalatine region)

what runs through the sphenopalatine foramen?

-sphenopalatine artery
-nasopalatine nerve
-posterior lateral nasal nerve

what connects the pterygopalatine fossa to the palate?

palatine canal

what runs through the palatine canal?

-descending palatine artery
-greater palatine nerve
-lesser palatine nerve

what connects the pterygopalatine fossa to the orbit?

infraorbital fissure

what runs through the infraorbital fissure?

-zygomatic nerve
-infraorbital nerve
-infraorbital blood vessels

what connects the pterygopalatine fossa to the pharynx?

pharyngeal canal (palatovaginal canal)

what runs through the pharyngeal canal?

-pharyngeal nerve
-pharyngeal artery

what runs through the pterygoid canal?

-nerve of pterygoid canal (vidian nerve)
-artery of the pterygoid canal

Superior Dental Plexus

posterior, middle, & anterior superior alveolar branches of V2 that innervate the maxillary teeth & maxillary sinuses

anterior superior alveolar nerve

innervates the tooth, pulp, PDL, alveolar process, & vestibular gingiva of #6 - #11

middle superior alveolar nerve

innervates the tooth, pulp, PDL, alveolar process, & vestibular gingiva of #4, #5, #12, #13, & anterior 1/2 of #14

posterior alveolar nerve

innervates the tooth, pulp, PDL, alveolar process, & vestibular gingiva of #1- #3, posterior 1/2 of #14 - #16

What innervates the lingual gingiva of the #1- #5, #12-#16?

greater palatine nerve

what innervates the lingual gingiva of #6 - #11?

nasopalatine nerve

supraperiosteal nerve block

injection at mucobuccal fold superior to the tooth to anesthesize individual maxillary teeth
*blocks V2 in individual teeth

inferior alveolar nerve block

injection approx 1 cm above the tooth line near the notch of the mandible behind the molars
*blocks inferior alveolar nerve of V3

superior alveolar nerve block

injection at muccobuccal fold w/ needle directed posteriorly at 2nd molar (poster sup av), bwtn 1st molar & 2nd premolar (middle sup av), & canine (anterior sup av)
*blocks all branches of superior alveolar nerve in a quadrant

infraorbital nerve block

insertion of needle approx 2cm @ muccobuccal fold directed superiorly at 2nd premolar to anesthesize soft tissues of the face & lip (not just the teeth)

Mental Nerve Block

anesthesizes the lower lip & chin area of the face (not the mandibular teeth)
*needle directed inferiorly at mucobuccal fold at 2nd premolar approx 1 cm & inject

How does postganglionic parasympathetic fibers & sympathetic fibers reach the lacrimal gland in the orbit from the pterygopalatine ganglion in the pterygopalatine fossa?

exits pterygopalatine fossa --> rides w/ zygomatic branch of V2 --> zygomaticotemporal branch --> connecting branch --> lacrimal nerve of V1 --> lacrimal gland

True or False: The infraorbital artery & the ophthalmic artery anastomose

True

Superior Dental Arterial Plexus

anastomosis of superior alveolar arteries that supply the maxillary teeth

True or False: Kiesselbach's Plexus is the most common site for nose bleeds

True ==> anastomosis of several arteries at this area of the nose makes it prone to bleeding (anterior/posterior ethmoidal arteries, sphenopalatine artery, & facial artery)

True or False: The greater palatine artery & sphenopalatine artery anastomose near the incisive canal

True ==> posterior septal branch of sphenopalatine artery anastomoses w/ the greater palatine artery

Why are infections and cancers spread easily from the pterygopalatine fossa?

-pterygoid plexus --> drains multiple veins & other plexuses, & doesn't have valves so infections can spread (& cause cavernous sinus thrombosis)

-pterygopalatine fossa connected to oral cavity, nasal cavity, ear, & middle cranial fossa --> cancer in pterygopalatine fossa can easily spread (ex: malignant perineural invasion that allowed the cancer that started in nasopharynx of a 17 yo to spread thru sphenopalatine foramen to pterygopalatine fossa & then to the entire infratemporal fossa)

True or False: Maxillary Division (V2) of Trigeminal Nerve (CNV) travels through the lateral wall of the cavernous sinus

True

1.) lesser palatine nerve
2.) nerve of pterygoid canal (vidian nerve)
3.) Trigeminal Nerve (CNV)
4.) pituitary gland
5.) pterygopalatine ganglion
6.) descending palatine artery
7.) greater palatine nerve

1.) pterygopalatine fossa
2.) trigeminal ganglion
3.) trigeminal nerve (CNV)
4.) maxillary nerve (V2)
5.) foramen rotundum (w/ V2 running thru it)

1.) infraorbital artery
2.) pterygopalatine region of maxillary artery (3rd region)
3.) posterior superior alveolar artery