Temporal & Infratemporal Fossae Anatomy 2024-2025 PDF

TEMPORAL AND INFRATEMPORAL FOSSAE Prof Dr. Mona Zoair- Prof. Dr. Doaa Haiba 27-31/10/2024  Objectives of the lecture 1. Define temporal fossa, its boundaries and list its contents. 2. Define infratemporal fossa, its boundaries and list its contents. 3. Identify origin, insertion, ner...

TEMPORAL AND INFRATEMPORAL FOSSAE Prof Dr. Mona Zoair- Prof. Dr. Doaa Haiba 27-31/10/2024  Objectives of the lecture 1. Define temporal fossa, its boundaries and list its contents. 2. Define infratemporal fossa, its boundaries and list its contents. 3. Identify origin, insertion, nerve supply and action of the muscles of mastication. 4. Define origin, course, parts and branches of the maxillary artery. 5. Define pterygoid venous plexus, its end and list its communications. 6. Define maxillary vein and its end  Temporal Fossa Definition: Temporal fossa is an oval area on the lateral surface of the skull. Boundaries: 1. Anteriorly: frontal process of zygomatic bone. 2. Superiorly and posteriorly: superior and inferior temporal lines 3. Inferiorly: Supramastoid crest and zygomatic arch 4. Laterally: zygomatic arch  Temporal Fossa Contents: 1. Temporalis muscle and temporal fascia. 2. Deep temporal nerves and vessels 3. Superficial temporal vessels Auriculotemporal nerve 4. Zygomatico- temporal nerve 5. Auriculotemporal nerve  Infratemporal Fossa Ramus of mandible Pharynx Zygomatic arch Definition: It is wedge- shaped area inferior to zygomatic arch and between ramus of mandible laterally and wall of the pharynx medially.  Infratemporal Fossa Boundaries: 1. Above: Infratemporal surface of the greater wing of sphenoid and infratemporal crest. 2. Anteriorly: Back of maxilla. 3. Medially : Lateral pterygoid plate.  Infratemporal Fossa Boundaries: Zygomatic arch 4. Laterally: zygomatic arch, coronoid process and ramus of mandible. Coronoid process 5. Below and posteriorly: the fossa is free Ramus of mandible  Contents of Infratemporal Fossa 1. Muscles& ligaments: Lateral pterygoid muscle Maxillary n. Medial pterygoid muscle Sphenomandibular ligament Mandibular n. 2. Nerves: Mandibular nerve Maxillary nerve Chorda tympani nerve Otic ganglion  Contents of Infratemporal Fossa 3. Vessels: Maxillary artery Pterygoid venous plexus TMJ 4. Joints: Pterygoid venous plexus Temporomandibular joint (TMJ)  Muscles of Mastication Lateral pterygoid They are 4 muscles: Temporalis , Medial Temporalis pterygoid masseter , medial & lateral pterygoids. They arise from the bones of the Masseter skull and are inserted into the ramus of the mandible. They are supplied by the mandibular nerve through their deep surface.  Temporalis Origin: From the floor of the temporal fossa From the deep surface of the temporal fascia. Insertion: into coronoid process of mandible.  Temporalis Nerve supply: Deep temporal branches of anterior division of mandibular nerve.  Temporalis Action 1. Anterior fibers elevate the mandible 2. Posterior fibers retract the mandible  Masseter Origin: The muscle arises by 2 heads: ▪ Superficial head : Arises from the lower border of the zygomatic arch. ▪ Deep head : Arises from the deep surface of the zygomatic arch. Insertion: Into the lateral surface of the ramus of mandible. Nerve supply: masseteric branch of anterior division of mandibular nerve. Action: elevates the mandible to occlude the teeth  Lateral pterygoid Origin : By two heads: ▪ Upper head: From the infratemporal crest and infratemporal surface of the greater wing of the sphenoid ▪ Lower head: From the lateral surface of the lateral pterygoid plate.  Lateral pterygoid Insertion: The two heads converge as they pass backward and are inserted into : The pterygoid fovea on the front of the neck of mandible The articular disc of temporomandibular joint. The capsule of temporomandibular joint. Nerve supply: from anterior division of Lateral pterygoid mandibular nerve. Action: protraction (forward pull or protrusion), depression and side to side movements of mandible.  Medial pterygoid Origin: By two heads which clasp the lower head of the lateral pterygoid: Superficial head: Arises from the tuberosity of the maxilla. Deep head: Arises from the medial surface of the lateral pterygoid plate and pterygoid fossa.  Medial pterygoid ▪ Insertion: − The fibers run downward, backward, and laterally − It is inserted into the medial surface of the angle of the mandible below the mandibular foramen and behind the mylohyoid groove. ▪ Nerve supply: By a branch from the trunk of mandibular nerve ▪ Action: Elevation, protrusion and side to side movements of mandible  Maxillary artery Origin: It is the larger of the 2 terminal branches of the external carotid artery. It arises behind the neck of the mandible in the parotid gland.  Maxillary artery Course: It is divided into 3 parts 1st part Runs horizontally medial to the neck of mandible along the lower border of the lateral pterygoid muscle. 2nd part Passes upward and forward, either superficial or deep to the lower head of the lateral pterygoid. 3rd part Leaves the infratemporal fossa by passing between the two head of lateral pterygoid muscle to enter the pterygo-palatine fossa  Branches of Maxillary Artery Branches of 1st part: 1. Deep auricular artery: it supplies external acoustic meatus. 2. Anterior tympanic artery: it supplies middle ear cavity. 3. Middle meningeal artery: It enters cranial cavity through foramen spinosum to supply dura of anterior and middle cranial fossae. 4. Accessory meningeal artery: it enters cranial cavity through foramen ovale to supply meninges of middle cranial fossae and trigeminal ganglion. 5. Inferior alveolar artery: it gives mylohyoid branch then enters mandibular foramen to supply teeth of lower jaw, then divides into incisors for incisor teeth and mental for chin.  Branches of Maxillary Artery Branches of 2nd part: 1. Deep temporal arteries supplies temporalis muscle. 2. Lateral and medial pterygoid arteries supply lateral and medial pterygoid muscles. 3. Masseteric artery supplies masseter muscle. 4. Buccal artery supplies external surface of buccinator muscle.  Branches of Maxillary Artery Branches of 3rd part: 1. Posterior superior alveolar artery supplies molars, premolars and maxillary sinus. 2. Infraorbital artery gives: Orbital branches Anterior superior alveolar artery supplies canine& incisors 3. Greater palatine artery: passes through greater palatine canal to supply the hard palate, then enters nasal cavity through lateral incisive foramina. It gives 2 or 3 lesser palatine arteries to supply soft palate. 4. Pharyngeal artery passes through palato-vaginal canal to supply roof of nasal cavity, sphenoid sinus and auditory tube. 5. Artery of pterygoid canal passes through the canal to supply mucosa of nasopharynx. 6. Sphenopalatine artery passes through its foramen to nasal cavity to supply its lateral and medial walls.  Veins of infratemporal fossa Pterygoid venous plexus It is a plexus of veins situated in the infratemporal region around the lateral pterygoid muscle. The posterior end of the plexus is drained Pterygoid through a short maxillary vein. venous plexus It communicates with: 1. Anterior facial vein through the deep facial vein. 2. Cavernous sinus by emissary veins which pass through foramen oval, foramen lacerum and emissary sphenoidal foramen. 3. Pharyngeal plexus. 4. Inferior ophthalmic vein through the inferior orbital fissure Maxillary vein: A short vein joins superficial temporal vein within parotid gland to form retromandibular vein IN CLASS EXERCISE Which of the following structures lies in the infratemporal fossa? A. Maxillary nerve B. Superficial temporal vessels C. Masseter muscle D. Zygomaticotemporal nerve Which of the following muscles of mastication depresses the mandible? A. Lateral pterygoid B. Masseter C. Medial pterygoid D. Temporalis Nerve supply of medial pterygoid muscle is from ………………… IN CLASS EXERCISE Pterygoid venous plexus is present around which of the following muscles of mastication? A. Medial pterygoid B. Lateral pterygoid C. Masseter D. Temporalis Which of the following branches of 1st part of maxillary artery is labeled by black arrow? A. Deep auricular B. Anterior tympanic C. Middle meningeal D. Inferior alveolar  SOURCES& REFERENCES Books Videos Temporal& infratemporal fossae https://www.youtube.com/watch?v= 6h8GW386e14 Infratemporal fossa https://www.youtube.com/watch?v=j LrkUTIqsAM Chapter : Head& Neck Chapter : Head& Neck Muscles of mastication Pages:1002-1011& 1018- :1508-1509 1020 Lecture Notes PDF Temporal& infratemporal fossae: 1602-1607 Thank You [email protected]