Alveolar Bone Flashcards
(64 cards)
1
Q
Specialized mineralized CT. Composed of intercellular substance and osteocytes
A
Alveolar bone
2
Q
67%
A
Inorganic; hydroxyapatite
3
Q
33%
A
Organic
4
Q
28%
A
Collagenous
5
Q
5%
A
Non collagenous
6
Q
Alveolar bone can best resist
A
- Compressive forces
2. Forces directed along long axis of the tooth
7
Q
Alveolar bone can least resist
A
- Tensile strength
2. Shear stresses
8
Q
Function of alveolar bone
A
- Support and protection
- Attachment of muscles
- Reservoir of minerals
- Hemopoiesis- formation of blood cells
9
Q
- Portion of jaw bone that contains the teeth
A
Alveolar process
10
Q
- Rest on basal bone
A
Alveolar process
11
Q
- Proper development of alveolar process is dependent on tooth eruption and its maintenance of tooth retention(residual ridge- no teeth process)
A
Alveolar process
12
Q
Composed of an outer and inner cortical plate of compact bone that enclose the spongiosa-
compartment of spongy bone also called as TRABECULAR or CANCELLOUS BONE
A
Alveolar process
13
Q
- Lines the alveolus
- Thin plate of cortical bone with perforations (cribriform plate)
A
Alveolar bone proper
14
Q
- Surrounds each tooth as continuous thin plate of compact bone
- Becomes fused with indistinguishable from the cortical plate of the Alveolar process in
some areas
A
Alveolar bone proper
15
Q
- The coronal rim of the alveolar bone
- parallel to CEJ at a distance of 1-2mm apical to it
A
Alveolar crest
16
Q
- corresponds to alveolar bone proper
- thin white line that is parallel to the outline of the roots of the teeth - radiographic representation of alveolar bone proper
A
Lamina dura
17
Q
- Active mononucleated nucleus
- Function: formation of cells
- Derived from mesenchymal stem cells
A
Osteoblast
18
Q
Osteoblast synthesize what
A
a. Type I and IV collagen
b. Cytokines and growth factors – BMP “bone morphogenic factor”
19
Q
- Entrapped osteoblast in the lacunae
- Number varies depending on the capacity of bone formation - Active in bone remodeling
- Found within matrix of bone
- Surviving cells and functional
- Function: to prevent hyper mineralization of bone
A
Osteocytes
20
Q
limited resorption in lacuna and canals
A
Osteolysis
21
Q
secondary rebuilding of perilacunar bone mineral
** after bone formation: it loses its ability to form matrix and becomes smaller
** occupies osteocytic lacuna and 2 canaliculi- maintain contact with adjacent osteocytes
and osteoblast/ lining cells
** nutrition is not a problem
A
Osteoplasia
22
Q
Big multinucleated cells found inside the howships lacuna
- Migration to PDL is not normal
A
Osteoclast
23
Q
- Can be seen at the surface attached to bone
- where acid and proteolytic enzymes( acids destroy inorganic component) exit
- Organelle- poor brush-like cytoplastic border w/c demarcates the zone of resorption
A
Ruffled border
24
Q
Sequence of resorption events
A
- Attachment of osteoclast to bone
- Create sealed environment
- Releases acids to demineralized the hard tissue
- Organic matrix is degradated by secretion of proteolytic enzymes
25
Dense outer sheet of bone with closely packed layers
Compact bone
26
Encloses the entire bone forming its outer and inner perimeter
Circumferential lamellae
27
Makes up the bulk of compact bone
| - Form the basic metabolic unit of bone – osteon
Concentric lamellae
28
wide haversian canals, relatively young
Osteon HS1
29
small haversian canal, more mature
| ** more mature, becomes smaller
Osteon HS2
30
Between concentric lamellae
- Fragments of pre-existing concentric lamel-
lae from osteons mature during remodeling
Interstital lamellae
31
connective membrane sur- rounding compact bone
Periosteon
32
next to the bone surface, w/ bone cells and precursors
Inner layer
33
more fibrous, gives rise to sharpey’s fiber
Outer layer
34
covers the internal surface of compact and
spongy bone.
- Not well demarcated
- Loose CT with osteogenic cells
- Physically separates the bone surface from
the marrow w/n
Endosteon
35
3 spongy bone
1. Trabecular- cancellous bone
2. Lamellae of bone arranged in flattened PAPILLA
3. Surrounds narrow spaces containing bone marrow- fat cells, RBC
36
- Outside wall of mandibular and maxillary
- Continuous with alveolar bone proper at alveolar crest
- More pronounced, thicker in areas of mandible than maxilla
- Generally greater on lingual
Cortical plate
37
- contains osteons and interstitial lamellae
- with bundle bone ➡ with several layers of bone parallel to the surface of the bone penetrated by
sharpey's fibers
- found in areas of recent bone apposition - with lines of rest
Alveolar bone
38
spongy bone between : 2 bony plates
- alveolar bone proper of adjacent teeth/roots
- more in maxillary than mandible
- trajectories represents planes or lines of stress
Spongiosa
39
maxilllary tuberosity - angle of mandible **thick lingual surface
Hematopietic marrow
40
3 mechanism of bine formation
1. Endochondral/Intracartilaginous bone formation
2. Intramembranous bone formation
3. Sutural bone growth
41
cartilage formation➡ cartilage removed➡ substituted by bone
Occurs by substitution rather than transformation (resorption of cartilage than bone deposition)
Occurs in the condyle
Endochondral bone formation
42
bone develops directly from fibrous tissue
Mesenchymal cells differentiates into osteoblasts
Maxilla, body of mandible and cranium
Intramembranous ossification
43
Function of sutures: accommodates growth of organs such as brain and eyes
Structural bone growth
44
- cartilage of the first branchial arch
- Supports the developing mandible but does not con-
tribute to it
- 2 bilateral cartilages from the otic capsule to midline
but do not meet (mesial to developing mandible -
rod)
- (Area of canine)
Meckel’s cartilage
45
intramembranous ossification begins here, form- ing the first bone of the mandible (embryonic period)
7th week
46
rudimentary mandible is formed by in- tramembranous ossification
10th week
47
Fate of meckel’s cartilage
1. Incus of inner ear
2. Malleus of inner ear
3. Sphenomalleolar ligament
4. Sphenomandibular ligament
48
12th week
Condylar cartilage
49
- 4th month; transient
Coronoid cartilage
50
between meckel's cartilage; obliterated within 1st year after birth
Symphysial cartilage
51
incremental lines (parallel)
Cementing lines
52
new bone layer and resorption (scalloped)
Reversal line
53
basophilic substance on surface of inactive bone.
Aplastic line
54
bone layer from inactive old bone
Resting line
55
thicker trabeculae, smaller marrow spaces.
Increased function
56
thin trabeculae, wider marrow spaces.
Decreased function
57
Tooth movement
1. Pressure side -
| 2. Tension side -
58
resorption of bone
Pressure side
59
deposition of bone
Tension side
60
After tooth extraction, embryonic bone forms within the socket.
Residual ridge
61
important diagnostic landmark
| - Radiographic presentation
Lamina dura
62
bone resorbs locally, creating a window through which the root can be seen.
Fenestration (hole)
63
- the rim of bone between the fenestration and the alveolar crest disappears altogether.
Dehiscence
64
Hyperfunction of the pituitary gland.
| Disturbance in condylar growth
Acromegaly
