Lateral Mandibular ramus and zygomatic archInferior No borderPosterior No border
Contents of the Infratemporal Fossa1. The mandibular division of the trigeminal nerve,2. Contains pterygoid plexus and the pterygoid muscles,3. Maxillary artery and its branches, middle meningeal artery,4. Inferior alveolar artery,5. Posterior alveolar artery.
THE PTERYGOPALATINE FOSSA
A cone-shaped depression, deep into the infratemporal fossa.
It is located between the pterygoid process and the maxillary tuberosity near the apex of the orbit.
BOUNDARIES OF THEPTERYGOPALATINE FOSSA
Boundaries StructureSuperior Inferior surface of the body of the sphenoidAnterior Maxillary tuberosityMedial Vertical plate of the palatine bone
Boundaries StructureLateral Pterygomaxillary fissureInferior Pterygopalatine canalPosterior Pterygoid process of the sphenoid bone
Contents of the Pterygopalatine Fossa1. Maxillary artery and its branches,2. Pterygopalatine ganglion,3. Maxillary nerve.
The Temporomandibular Joint
- is a complex articulation of the movable mandible and the base of the skull.Articulation takes place in two areas:1. Between maxillary and mandibular teeth ( interjaw dental occlusion ), and2. Between the mandibular condyle and the temporal bone.
Bones Involved in the TMJ1. Condylar process or condyle of the mandible2. Mandibular fossa3. Articular emminence of the temporal bone
COMPONENTS OF THE TMJ
1. Articular or Fibrous Capsule2. Temporo- mandibular (lateral) Ligament
3. Articular Disc4. Joint Cavities
1. ARTICULAR OR FIBROUS CAPSULE
- encloses the jointsurfaces like a sleevethat runs from thetemporal bonesuperiorly, to thecondyle of themandible inferiorly.The enclosed spacebetween the articularsurfaces is the jointcavity
Superior attachment : area surrounding the mandibular fossa and articular eminence of the temporal bone. Inferior attachment: periphery of the mandibular condyle.
2. TEMPOROMANDIBULAR (LATERAL)LIGAMENT
- is a lateral thickening of the joint capsule and is similar to the collateral ligaments of other joints.- It prevents posterior and inferior displacement of the condyle but allows limited anterior movements of the condyle.
3. ARTICULAR DISC
- it is composed of dense fibrous tissues and lies within the jointcapsule, intervening between the condyle and the mandibular fossa.- It is a biconcave disc that serves to provide reciprocal articularsurfaces between its inferior surface and the condyle, and its superiorsurface and the mandibular fossa and eminence.
Three zones of the articular disc:1. Posterior thickening – sits atop the condyle and fills the mandibular fossa above when the mandible is at rest.2. Anterior thickening - lies just below the posterior slope of the articular eminence.3. Intermediate zone - lies between the two previous zones.
4. JOINT CAVITIES
The disc effectively divides the joint cavity into two distinct upper andlower compartment that allow two types of joint movements. These cavities are also filled with synovial fluid which nourishes thearticular disc.
Two accessory ligaments span the joint but do not significantly limit mandibular movements:1. Sphenomandibular ligament - it runs from the spine of the sphenoid bone to the lingula of the mandible.2. Stylomandibular ligament - it runs from the styloid process of the temporal bone to the angle of the mandible.
THE SYNOVIAL MEMBRANE
A layer of synovium lines the inner aspects of thejoint capsule. This relatively dense membrane does notline the actual articular surfaces of the joints becausesynovial joints are generally weight-bearing joints. The pressure in the TMJ is provided by the occludedmaxillary and mandibular teeth. Synovium secretes synovial fluids for lubricationand nourishment of the opposing articular surfaces.
Two Layers of the Synovial Membrane1. An intimal cellular layer - contains type A cells which are phagocytic, and type B cells which synthesize hyaluronate found in synovial fluid.2. A vascular subintimal layer - Contains blood vessels, and lymphatics within the loose connective tissue matrix.
NERVE SUPPLY OF THE TMJ
1. Branches of the temporalis N.2. Branches of the auriculotemporal N.3. Branches of the masseteric N.
BLOOD SUPPLY OF THE TMJ
1. Superficial temporal artery2. Muscular branches of the maxillary artery