Infratemporal Fossa PDF

Field of Medicine Infra-Temporal Fossa Prof. Dr. Ahmed Samir Date : 7/ 11 /2023 Ass. Prof of Anatomy-KSIU  INTENDED LEARNING OBJECTIVES (ILO) By the end of this section the student will be able to: List contents of Infra-temporal fossa Describe begin, course, parts & bra...

Field of Medicine Infra-Temporal Fossa Prof. Dr. Ahmed Samir Date : 7/ 11 /2023 Ass. Prof of Anatomy-KSIU  INTENDED LEARNING OBJECTIVES (ILO) By the end of this section the student will be able to: List contents of Infra-temporal fossa Describe begin, course, parts & branches of maxillary artery Describe site, tributaries of pterygoid venous plexus List branches of origin & branches of trigeminal nerve Describe course & branches of Maxillary nerve Describe course & branches of Mandibular nerve  Infratemporal fossa The space below temporal fossa Boundaries: Ant: posterior surface of the maxilla Post: styloid process Lat: ramus of the mandible Med: lateral pterygoid plate Roof: infratemporal surface of the greater Pterygomaxillary fissure wing of sphenoid Zygomatic arch Communications : With the: Lat pterygoid a.Temporal fossa: deep to the zygomatic arch plate b.Pterygopalatine fossa: through Styloid pterygomaxillary fissure c.Orbital cavity: through the inferior orbital fissure Infratemporal fossa  Contents of infratemporal fossa Superficial Lateral & medial pterygoid ms. Lateral pterygoid Mandibular nerve branches Maxillary artery Maxillary artery Pterygoid venous plexus ECA Medial pterygoid Deep Tensor palati ms. Mandibular nerve trunk & Otic ganglion Chorda tympani (from facial N) Trigeminal ganglion Middle & accessory meningeal arteries Mandibular n. Maxillary n.  Maxillary Artery Maxillary Origin: artery One of the 2 terminal branches of ECA behind neck of mandible inside parotid gland Lateral pterygoid Course: m 1st part: runs deep to the neck of the mandible 2nd part: runs superficial or deep to lateral 3 pterygoid 2 1 ECA 3rd part: pass between 2 heads of lateral pterygoid, then via pterygomaxillary fissure to end in pterygoplatine fossa  Branches of Maxillary Artery 1st part: 2nd part: (Ms. branches) 1.Deep auricular Masseteric 2.Anterior tympanic Deep Temporal Middle & Accessory meningeal a. 3.Middle meningeal Pterygoid (Med & Lat) Deep auricular & 4.Accessory meningeal Buccal anterior tympanic a. 5.Inferior alveolar Middle meningeal artery Enters the cranial cavity via foramen spinosum Its rupture lead to extradural Hemorrhage that compress motor area (contralat. Hemiplegia) For decompression, the burr-hole (trephining) is made over the pterion (4 cm above midpoint of zygomatic arch). Maxillary a. Accessory meningeal artery Inferior alveolar a. Enters cranial cavity via foramen ovale ECA Inf alveolar artery Passes with its nerve via mandibular foramen, runs in mandibular canal & exits from mental foramen  Branches of Maxillary Artery 3rd part: (terminal branches) Infraorbital a. Greater & lesser palatine Sphenopalatine a. Spheno-palatine Posterior superior Pharyngeal branch alveolar a. Pharyngeal a. Artery of pterygoid canal & artery of pterygoid canal Infraorbital artery gives ant sup alveolar Posterior sup alveolar Lesser Greater palatine a. palatine a.  Pterygoid Venous Plexus - Surround lat pterygoid muscle - Receives veins corresponding to branches of Cavernous sinus maxillary artery Pterygoid plexus - Form maxillary vein which joins superficial of veins temporal vein inside parotid gland to form retromandibular vein Communications: Maxillary vein The pterygoid plexus of veins communicates with: Cavernous sinus: through emissary veins Facial vein: through the deep facial vein  Trigeminal Nerve - The largest cranial nerve (Mixed nerve) - Has Motor & sensory nuclei in pons - Has trigeminal ganglion which has central process (sensory root of trigeminal) and peripheral process (3 branches of trigeminal) 5 - Has 3 branches: Ophthalmic, Maxillary & Mandibular  Ophthalmic Nerve Supra-orbital nerve A pure sensory nerve Lacrimal nerve Has 3 branches: Lacrimal, Frontal & Nasociliary Supra-trochlear nerve Frontal nerve  Maxillary Nerve A pure sensory nerve Course: Leaves cranial cavity via foramen rotundum to pterygopalatine fossa Continue as infraorbital nerve Infraorbital nerve passes through infraorbital groove, canal & foramen to terminate in the face Ophthalmic n. Trigeminal ganglion Maxillary nerve Mandibular n.  Maxillary Nerve Branches From the maxillary nerve: Meningeal branch: arises in cranial cavity Two roots to the pterygopalatine ganglion Zygomatic nerve: to orbit Posterior superior alveolar nerve: passes Zygomatic n. through posterior surface of maxilla, and Terminal supplies upper molar teeth branches in face Meningeal branch From the infraorbital nerve: Middle superior alveolar: supplies upper premolar teeth Anterior superior alveolar: pterygopalatine supplies upper canine and ganglion incisors Posterior superior alveolar n. Terminal branches in the face: Middle & anterior palpebral, nasal, labial superior alveolar n.  Mandibular Nerve largest division of trigeminal nerve (mixed nerve) leave cranial cavity via Foramen Ovale It has a trunk which divides into ant. & post. divisions Tensor tympani Nervus spinosus Branches: From trunk: Nervus spinosus (sensory): Passes through Foramen spinosum into the cranial cavity Otic ganglion Tensor palati Nerve to medial pterygoid (motor): gives branch runs through otic ganlion without relay & supply the tensor palati & tensor tympani ms. Medial pterygoid  Mandibular Nerve From anterior division (Mainly Deep temporal Motor): nerves (3 motor branches + 1 sensory branch) Deep temporal nerves (temporalis ms) Nerve to masseter Nerve to lateral pterygoid Buccal nerve (sensory): supplies skin over the buccinator From posterior division (Mainly Sensory): Auriculotemporal nerve (3 sensory branches + 1 motor branch) Inferior alveolar nerve 1. Auriculotemporal nerve Lingual nerve arises by 2 roots (around middle meningeal artery) Buccal nerve carries sensory & parasympathetic fibers from the otic ganglion to the parotid gland  Mandibular Nerve 2. Lingual nerve Joined by the chorda tympani Enters the floor of the mouth medial to the 3rd molar tooth (dangerous position) Carries general sensations from the anterior 2/3 of the tongue The chorda tympani carries taste sensations from the anterior 2/3 of the tongue and parasympathetic fibres to the submandibular and sublingual glands Inferior alveolar Lingual nerve nerve Mylohoid nerve & vessels Mylohoid m.  Mandibular Nerve 3. Inferior alveolar nerve Runs post to the lingual nerve to reach mandibular foramen Before it passes through the mandibular foramen it gives the N. to mylohyoid (motor) supplies mylohyoid & anterior belly of digastric The inferior alveolar nerve continues through mandibular canal and comes out of the mental foramen as mental nerve to supply skin of the chin Inferior alveolar Lingual nerve nerve Mylohoid nerve & vessels Mylohoid m.  Which of the following nerves carry parasympathetic supply to parotid gland? a) Lingual nerve b) Auriculotemporal nerve c) Inf alveolar nerve d) Buccal nerve