Alveolar Bone Flashcards
% of organic composition of alveolar bone?
Collagen %?
Noncollagenous %?
33%
28%
5%
% of inorganic composition of alveolar bone?
67% hydroxyapatite
Forces alveolar bone can best resist? (2)
- Compressive forces
- Forces directed along the long axis of the tooth
Forces alveolar bone can least resist? (2)
- Tensile forces
- Slicing forces
Functions of alveolar bone? (4)
- Support and protection
- Attachment of muscles
- Reservoir of minerals
- Hemopoiesis
Part of maxilla and mandible with the teeth and alveolar sockets?
Alveolar process
It is where the alveolar process rests.
Basal bone
True or false. Proper development of tooth depends on the alveolar process?
False.
Proper development of alveolar process is dependent on tooth eruption
True or false. Alveolar process may be found in newborns?
False. No teeth, no alveolar process
True or false. If bone is lost, remodeling occurs and alveolar process is restored
False. No more alveolar process after bone remodeling
It is what occurs after remodeling of alveolar bone.
Residual ridge
Compose of outer and inner cortical plate of bone that encloses the spongiosa?
Alveolar process
Other terms for spongy bone?
Trabecular or cancellous bone
Lines the alveolus contained within the alveolar process?
Alveolar bone proper
Perforations of the alveolar bone?
Cribriform plate
It is formed by the coronal rim of the alveolar bone.
Alveolar crest
Alveolar bone parallels the CEJ at a distance of ____ apical to it.
1-2mm
True or false. Alveolar bone proper may be fused with the cortical plate of the alveolar process?
True
Radiographic term for alveolar bone proper?
Lamina dura
Cell responsible for mineralization of bone?
Osteoblast
Osteoblasts synthesize what? (2)
- Type I and IV collagen
- Cytokines
Osteoblasts are derived from what cells?
Mesenchymal stem cells (BM-MSC and liver; CB-MSC)
When bone formation stops, osteoblasts become inactive and termed as?
Bone lining cells
True or false. The faster bone formation, the more osteocytes trapped.
True
Cells responsible for osteolysis and osteoplasia?
Osteocytes
Cells that prevent hypermineralization of bone by pumping Ca back to the blood stream?
Osteocytes
True or false. After bone formation, osteocytes lose the ability to form matrix and becomes smaller?
True
Limited resorption of bone in lacunae and canals?
Osteolysis
Secondary rebuilding of perilacunar bone mineral?
Osteoplasia
Osteoclasts are located on?
Howship’s lacunae
Organelle-poor brush like cytoplasmic border of osteoclasts which demarcates the bone of resorption?
Ruffled border
Ruffled border of osteoclast release what? (2)
- Acids
- Proteolytic enzymes
Part of osteoclasts attached to bone during resorption?
Sealing zone
Sequence of resorptive events (4)
- osteoclast attach to bone
- creates sealed environment
- releases acid to demineralize hard tissues
- secretes proteolytic enzymes to degrade organic matrix
Encloses the entire bone forming outer and inner perimeter?
Circumferential lamellae
Makes up the bulk of compact bone?
Concentric lamellae
Fragments of preexisting concentric lamellae from osteons created during remodeling?
Interstitial lamellae
Fibrous membrane that surrounds the compact bone?
Periosteum
Periosteum that contains bone cells and precursors?
Inner layer
Periosteum which is more fibrous and gives rise to Sharpey’s fibers?
Outer layer
It separates the bone surface from the bone marrow?
Endosteum
Lamellae of bone that are arranged in flattened spicules?
Spongy bone
3 structures of the alveolar bone?
- Cortical plate
- Alveolar bone proper
- Spongiosa
Cortical plate is continuous with the alveolar bone proper at the?
Alveolar crest
Cortical plate is thicker in the mandible or maxilla?
Mandible
Cortical plate is greater on labial or lingual side?
Lingual
Bone found in areas of recent apposition penetrated by the Sharpey’s fiber?
Bundle bone
2 locations of hematopoietic marrow?
- Maxillary tuberosity
- Angle of mandible
Spongiosa is more in maxilla or in mandible?
Maxilla
3 mechanisms of bone formation/ossification?
- Endochondral/intracartilaganious
- Intramembranous
- Sutural bone growth
True or false. In endochondral ossification, cartilage develops and becomes the bone.
False. Cartilage is replaced/substituted by bone
Endochondral ossification occurs where?
In the condyles
Type of ossification in which bone develops directly from fibrous tissue?
Intramembranous ossification
Intramembranous ossification is found where? (3)
- Maxilla
- Body of mandible
- Cranial vault
Cartilage of the first branchial arch?
Meckel’s cartilage
Meckel’s cartilage is found on mesial or distal side of mandible?
Mesial
When does intramembranous ossification of mandible begins?
At the 7th week
When is rudimentary mandible formed?
At the 10th week
Fates of Meckel’s cartilage. (4)
- Incus
- Malleus
- Sphenomandibular ligament
- Sphenomalleolar ligament
Cartilages of the mandible. (3)
- Condylar cartilage (12th week)
- Coronoid cartilage (4th month)
- Symphysis cartilage (obliterated w/in the 1st yr)
Only cartilage that remains in the mandible?
Condylar cartilage
Incremental lines of alveolar bone?
Cementing lines
Alveolar line formed by new bone layer and resorption?
Reversal line
Line found on the surface of inactive bone?
Aplastic line
Line formed by new bone layer from inactive old bone
Resting line
True or false. Thicker trabeculae and smaller marrow spaces indicates increased function?
True
True or false. Thin trabeculae with wider marrow spaces indicates decreased function?
True
Pressure to bone results to _____?
Tension to bone results to ______?
Resorption
Deposition
It depends on the functional and nutritional demands of bone.
Bone remodeling
An important diagnostic landmark of alveolar bone?
Lamina dura
Window-like defect in which the bone resorb locally and cause the root to be seen?
Fenestration
Occurs when the rim of the bone between the fenestration and the alveolar crest disappeared together?
Dehiscence
Hyperfunction of the pituitary gland which causes overgrowth of bone?
Acromegaly
