Head anatomy

• Cranium


  Has joints called sutura cranii and synchondroses cranii, as well as diarthrosis (art. synovialis) type joints
• Art. Fibrosa


  The joint faces fit together completely, between the bones there is connective tissue and hyaline cartilage, solidity is important and movement is not observed
• Types of joints in the head

  • Sutura
  • Gomphosis
  • Syndesmosis
• Sutura


  Found only between flat skull bones, the articulating bone ends are toothed and interlock with each other

  
• Gomphosis


  A type of joint formed by the insertion of a cone into a cavity, found only between tooth roots and the alveoli in the arcus alveolaris

  
• Articulatio Cartilaginea


  The joint surfaces are covered with cartilage and are less mobile joints, synchondrosis joint type is seen between the os sphenoidale and os occipitale until the age of 1-2, and between the pars petrosa of the os temporale and the proc jugularis of the os occipitale
• Articulatio Synovialis (Diarthrosis)


  Synovial joints are functionally important joints that make up a large portion of the joints in the body, they have a joint cavity filled with synovial fluid and articular cartilage covering the joint surfaces
• Structures of a synovial joint


  • Cavitas articularis (Joint cavity)
  • Cartilago articularis (Articular cartilage)
  • Capsula articularis (Joint capsule)
  • Joint Fluid
  • Ligamenta articularis (joint ligaments)
• Temporomandibular Joint (TMJ)


  The body's most complex joint, it is a 'bicondylar' joint that forms between the processus condylaris and the mandibular fossa of the os temporale, with an articular disc (discus articularis) between the two bones
• TMJ


  Included in the "compound" joint class, consisting of three bones (temporal bone, articular disc, and processus condylaris), it is also a synovial joint with the joint surfaces covered in fibrocartilage and the joint cavity filled with synovial fluid
• Discus Articularis


  The articular disc located between the condyle head and fossa mandibularis, consists of dense fibrous connective tissue, divided into three parts in the sagittal plane with the middle zone being the thinnest
• Ligaments of the TMJ

  • Lig. collateral
  • Lig. capsularia
  • Lig. temporomandibulare
  • Lig. sphenomandibulare
  • Lig. stylomandibulare
• Lig. collaterale


  Connects the medial and lateral edges of the articular disc to the condyle head, ensures the articular disc rests passively on the condyle head and moves with it during jaw movements

  
• Lig. Capsularia (Capsula Articularis)


  Surrounds the TMJ, retains synovial fluid and resists forces that separate the articular surfaces
• Lig. Temporomandibulare

  Strengthens the lateral part of the capsular ligament, limits the sliding (backward) movement of the mandible to prevent the condyle from damaging the retrodiscal tissue
• Lig. Sphenomandibulare

  Starts from the spina sphenoidalis, extends downward and forward to the lingula mandibula, rotates the mandible during some movements
• Lig. Stylomandibulare


  Starts from the styloid process, extends downward and forward to the posterior border of the ramus mandible and the angulus mandible, limits excessive protrusive movements of the mandible
• Chewing Movements


  1. Protraction-retraction (sliding movements of the mandibular head forward and backward without rotation)

  2. Depression (corpus moves mandibula downwards to open mouth)

  3. Elevation (mandibular head moves backwards and disc slides backwards)
• Temporal fossa


  A shallow depression on the temporal region of the skull located between the superior temporal line and the zygomatic arch

  
• Infratemporal fossa


  An irregular space at the lateral aspect of the skull, just inferior to the temporal fossa and deep to the ramus of the mandible, communicates with the pterygopalatine fossa

  
• Pterygopalatine fossa


  An inverted pyramidal-shaped, fat-filled space located on the lateral side of the skull, between the infratemporal fossa and the nasopharynx, a major neurovascular crossroad

  
• Articulationes Cranii-Sutura


  • Sutura frontonasalis- between the frontal bone and the nasal bone

  • Sutura frontozygomatica- between the frontal bone and zygomaticbone

  • Sutura zygomaticomaxillaris- between the zygomatic bone and the

  maxillary bone

  • Sutura intermaxillaris- between maxillary bones

  • Sutura metopica- between the frontal bones (in children)

  • Sutura sagittalis- betweenparietal bones

  • Sutura lambdoidea- between parietal bone and occipital bone
• Articulationes Cranii-Synchondrosis

  •Synchondrosis spheno-occipitalis-between sphenoid bone and occipital bone

  • Synchondrosis sphenopetrosa- between the sphenoid bone and temporal

  bone

  • Synchondrosis petro-occipitalis- between temporal bone and occipital bone

  • Synchondrosis intraoccipitalis posterior - between the posterior and lateral

  ossification centers in the occipital bone

  • Synchondrosis intraoccipitalis anterior - between the frontal and lateral

  ossification centers in the occipital bone
• Articulatio Synovialis-(Diarthrosis)


  Cavitas articularis (Joint cavity): It is the

  space between the cartilage-covered

  surfaces and the inner surface of the joint

  capsule. It is filled withsynovial fluid secreted

  from the synovial membrane.
• Cartilago articularis (Articular

  cartilage):


  It is the hyaline cartilage

  that coversthe articular surfaces

  (facies articularis) of the bones that

  form the joint. Their surfaces are

  polished and slippery. It acts as a

  buffer. It reduces the reflection of

  impacts to the bone. Articular

  cartilage has no nerves or blood

  vessels. They are fed from blood vessels

  in the bone marrow and by synovial

  diffusion.
• Capsula articularis (Joint capsule)


  Made

  of collagen fibers. It completelysurrounds

  the joint surfaces and joint cavity. It has two

  layers in terms of structure and function.

  There is membrane fibrosa on the outside

  and membrane synovialis on the inside.
• Joint Fluid:


  By reducing the friction

  between the joint surfaces, it prevents

  firiction. In addition; supplies articular

  cartilage, meniscus and discus
• • Ligamenta articularis (joint ligaments):


  The bones that form the joint are

  connected to each other with

  articular ligaments. The joint capsule

  can also be considered a joint

  ligament. The ligaments formed by the

  thickening of the fibrous membrane of

  the capsule (ligaments formed within

  the structure of the capsule) are

  called ligamenta capsularia. Capsule

  ligaments are present in the hip and

  shoulder joints.