Infratemporal Fossa Animation

Overview of the Temporal and Infratemporal Fossa

Introduction to Key Structures

• This video covers essential anatomical features including bony landmarks, muscles of mastication, the maxillary artery and its branches, as well as the mandibular division of the trigeminal nerve. It also discusses the facial nerve's relationship with the infratemporal fossa.

Anatomy of the Temporal Fossa

• The temporal fossa is a shallow depression on the lateral side of the skull, formed by several bones: frontal, parietal, temporal, and sphenoid. Its boundaries are defined by superior and inferior temporal lines and the zygomatic arch.

Anatomy of the Infratemporal Fossa

• The infratemporal fossa is an irregularly shaped cavity located below the temporal fossa and medial to the mandible. Its boundaries include:

• Posterior surface of maxilla

• Lateral pterygoid plate of sphenoid

• External acoustic meatus

• Undersurface of greater wing of sphenoid

Muscles of Mastication

Major Muscles Involved

• The primary muscles responsible for mastication include:

• Masseter: Originates from zygomatic arch; inserts onto angle of mandible.

• Temporalis: Originates from entire temporal fossa; inserts onto coronoid process.

• Medial Pterygoid: Has two heads originating from maxillary tuberosity and medial surface of lateral pterygoid plate; both insert onto medial surface of mandible.

• Lateral Pterygoid: Also has two heads; one originates on lateral surface of lateral pterygoid plate while another originates on infra-temporal crest. Both insert near temporomandibular joint capsule.

Maxillary Artery in Infratemporal Fossa

Overview and Branches

• The maxillary artery arises within the parotid gland, visible superficial to or deep to lateral pterygoid muscle depending on individual anatomy. It is categorized into three parts:

• Mandibular Part: Includes branches such as deep anterior tympanic, middle meningeal, accessory meningeal, inferior alveolar, mylohyoid.

• Pterygoid Part: Contains masseteric branch, deep temporal branch, pterygoid branch, buccal branch.

• Third Part (Teral Palatine): Comprises sphenoid palatine artery, infraorbital artery, posterior alveolar branches along with descending palatine artery.

Nerves Associated with Infratemporal Fossa

Mandibular Division (V3) Insights

• The largest division (V3) exits through foramen ovale after giving rise to meningeal and medial pterygoid branches before splitting into anterior and posterior divisions:

• Meningeal branch travels back into skull via foramen spinosum.

• Anterior division includes masseteric nerve among others which innervate muscles involved in mastication.