Alveolar Bone Flashcards
What type of tissue is the Alveolar Bone?
Mineralised connective tissue.
Where is cancellous bone found?
-fills in spaces
-interdental
-interradicualar spaces
Where is compact bone found?
-lining of tooth socket
-provides attachment to PDL fibres
What’s the name of unmineralised organic bone matrix?
Osteoid
Name the cells present in the Alveolar Bone. (3)
Osteocytes
Osteoclasts
Osteoblasts
What’s the function of osteoblasts?
Bone forming cells
- secrete organic bone matrix (collagen I)
What’s the function of osteoclasts?
Break down bone
- bone resorbing cells
What’s the function of osteocytes?
Mature bone cells
What’re the components of the Alveolar Bone?
- hydroxyapatite crystals
- organic matrix (collagen I, produced by osteoblasts)
Which is more dense, cancellous or compact bone?
Compact bone
What’re the main processes in the bone remodelling cycle?
- Osteocytes ‘sense’ need for remodelling and are attracted to site
- Osteoclasts begin resorption + form cavity
- Mesenchymal stem cells appear along the cavity
- Stem cells proliferate + differentiate = osteoblasts
- Osteoblasts release Osteoid
How are incremental lines formed in the Alveolar Bone?
SMOOTH REGULAR LINE
- laid down gradually due to rate of bone deposition
REVERSAL LINE
- irregular ‘scalloped’ line
- marks where resorption has occurred
What’s the structure of the Alveolar Bone-PDL interface?
CEJ (Cemento-enamel junction)
- where enamel meets cementum
- at gingival line
What are the components of the ground substance in Alveolar Bone?
-GAGs
-proteoglycans & glycoproteins
-Osteoid (specifically in bone)
What does Osteoid consist of?
- collogen I
- proteoglycans & glycoproteins
How is Osteoid mineralised?
Deposition of hydroxyapatite crystals in Osteoid matrix
What’s the meaning of woven bone & its appearance?
Newly formed bone
Miss-matched appearance
What’s the meaning of lamellar bone & its appearance?
Bone that replaces woven bone
More structured appearance.
Are Sharpey’s fibres intrinsic or extrinsic?
Extrinsic
Describe in more detail the structure of compact bone.
- Circumferential lamellae
- parallel layers enclosing bone - Haversian system + rings around them
-Haversian canals surrounded by Haversian lamellae - Interstitial lamelle
-area between Haversian lamellae
Describe in more detail the structure of cancellous bone.
- arranged in layers
- specifically along lines of stress
- withstand masticatory forces
How quickly is Osteoid mineralised?
Theres a lag phase before the mineralisation
