Temporal, infratemporal & pterygoplatine fossae and TMJ.pptx

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1. Temporal Region By: Dr. Tajdar Ahmad

2. Temporal Fossa The temporal fossa lies on the side of the skull and is bounded by: Anteriorly: Frontal and zygomatic bones Posteriorly: Inferior temporal line and supra-mastoid crest Superiorly: Superior temporal line Laterally: Zygomatic arch Inferiorly: Infratemporal crest Floor is formed by parts of four bones that form pterion: frontal, parietal, temporal and greater wing of sphenoid.

3. Contents of Temporal Fossa Following are the contents of temporal fossa: Temporalis muscle Middle temporal artery (branch of superficial temporal artery) Zygomaticotemporal nerve and artery Deep temporal nerves for supplying temporalis muscle Deep temporal artery, branch of maxillary artery

4. Infra-temporal Fossa The infra-temporal fossa is an irregularly shaped space deep and inferior to zygomatic arch, deep to the ramus of mandible, and posterior to the maxilla. The boundaries of infratemporal fossa are as follows: Laterally: The ramus of mandible Medially: The lateral pterygoid plate Anteriorly: The posterior aspect of the maxilla Posteriorly: The tympanic plate and the mastoid and styloid processes of temporal bone Superiorly: The inferior surface of greater wing of sphenoid Inferiorly: Where the medial pterygoid muscle attaches to the mandible near its angle

5. Contents of Infra-temporal Fossa The infratemporal fossa contains the Inferior part of the temporalis muscle Lateral and medial pterygoid muscles Maxillary artery Pterygoid venous plexus Mandibular, inferior alveolar, lingual, buccal, and chorda tympani nerves Otic ganglion

6. Temporomandibular Joint

7. Articular Surfaces TMJ is a modified hinge type of synovial joint. The bony articular surfaces involved are: Mandibular Fossa Articular tubercle of the temporal bone superiorly Head of the mandible inferiorly The two bony articular surfaces are completely separated by intervening fibrocartilage, the articular disc of TMJ, attached at its periphery to the internal aspect of joint capsule. This creates separate superior and inferior articular cavities or compartments, lined by separate superior and inferior synovial membranes.

8. Ligaments A thickened part of joint capsule forms the intrinsic lateral ligament of TMJ , which strengthens the joint laterally and with the post-glenoid tubercle acts to prevent posterior dislocation of joint. The stylomandibular ligament , which is actually a thickening of the fibrous capsule of parotid gland, runs from styloid process to the angle of the mandible. It does not contribute significantly to the strength of the joint .

9. Contd. The sphenomandibular ligament runs from the spine of the sphenoid to the lingula of the mandible. It is the primary passive support of the mandible ,although the tonus of muscles of mastication bears the mandible’s weight. However, the sphenomandibular ligaments serve as a “swinging hinge’’ for the mandible, serving both as a fulcrum and a check ligament for the movements of mandible at the TMJs.

10. Movements of Temporomandibular Joint Movements of Mandible Muscles involved Elevation (close mouth) Temporalis, masseter and medial pterygoid Depression (open mouth) Lateral pterygoid, suprahyoid, and infrahyoid Protrusion (protrude chin) Lateral pterygoid, masseter, and medial pterygoid Retrusion (retrude chin) Temporalis (posterior oblique and near horizontal fibers) and masseter Lateral movements (grinding and chewing) Temporalis of same side, pterygoids of opposite side, and masseter

11. Movements of Temporomandibular Joint

12. Pterygopalatine Fossa

13. Pterygopalatine fossa It is a small pyramidal space inferior to the apex of orbit. Boundaries: Anteriorly: Posterior surface of maxilla Posteriorly: Pterygoid process of the sphenoid Medially: Perpendicular plate of palatine bone Laterally: Infratemporal fossa Floor: Pyramidal process of palatine bone Roof: Medial continuation of infratemporal surface of greater wing of sphenoid

14. Communications Antero-superiorly: Into orbit through the inferior orbital fissure Posteriorly: Middle cranial fossa through foramen rotundum Foramen lacerum through pterygoid canal Pharynx through palatinovaginal canal Laterally: With infratemporal fossa through the pterygomaxillary fissure Inferiorly: With the oral cavity through the greater and lesser palatine canals

15. Contents Terminal (pterygopalatine or third) part of maxillary artery , and the initial parts of its branches, and accompanying veins ( tributaries of pterygoid venous plexus ). Maxillary nerve (CN-V2 ), with which the pterygopalatine ganglion is associated. Branches arising from ganglion within the fossa are considered to be branches of maxillary nerve Neurovascular sheaths of the vessels and nerves and a fatty matrix occupy all remaining space.

16. Maxillary Artery The pterygopalatine part of the maxillary artery , its third part (i.e., the part located anterior to the lateral pterygoid), passes medially through the pterygomaxillary fissure and enters the pterygopalatine fossa. The artery lies anterior to the pterygopalatine ganglion and gives rise to branches that accompany all nerves entering and exiting the fossa, sharing the same names with many.

17. Maxillary Nerve It runs anteriorly through the foramen rotundum, which enters posterior wall of fossa. Within the pterygopalatine fossa, maxillary nerve gives off the zygomatic nerve , which in turn divides into zygomaticofacial and zygomaticotemporal nerves. While in the pterygopalatine fossa, the maxillary nerve also gives off the two ganglionic branches to the pterygopalatine ganglion, that suspend the parasympathetic pterygopalatine ganglion in the superior part of pterygopalatine fossa.

18. Pterygopalatine Ganglion The parasympathetic fibers to the pterygopalatine ganglion come from facial nerve by way of its branch, the greater petrosal nerve . This nerve joins the deep petrosal nerve as it passes though the foramen lacerum to form the nerve of pterygoid canal, which passes anteriorly through this canal to the pterygopalatine fossa. The parasympathetic fibres of the greater petrosal nerve synapse in the pterygopalatine ganglion. Postganglionic fibres arise in the ganglion to supply secretomotor fibres to the lacrimal gland and to the mucous glands of the nose, the paranasal sinuses, the palate and the nasopharynx. The sympathetic root is also derived from the nerve of the pterygoid canal. It contains postganglionic fibres arising from the superior cervical sympathetic ganglion which pass through the internal carotid plexus, the deep petrosal nerve and the nerve of pterygoid canal to reach the ganglion. The fibres do not synapse in the ganglion but pass directly though it into branches which supply mucous glands of the nose, the paranasal sinuses, the palate and the nasopharynx.

19. Pterygopalatine Ganglion

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