Alveolar Bone Flashcards
Periodontium
tissues around tooth used for structural attachment and maintenance
Periodontal disease
chronic gingival inflammation with varied periodontal attachment loss
- Plaque induced
- Host mediated - increases immune response + failure to turn off inflame
- Env modified - e.g. smoking, diabetes,
- Site -specific - not all teeth destroyed the same and not all parts of tooth have equal disease
(SHE P)
Bone
Cortical and cancellous bone
Has osteons
Cell types in BONE
- Osteoblast: alkaline phosphatase, Collage 1, 3, 5 MMPs
- OsteoCLAST: acid phosphatase, H+ pump, TRAP
- Osteocyte
- Pluripotent SC
Cementum
Acellular and cellular cementum
NO osteons
Cell: cementoblast
Collagen I, 3, 5, alkaline phosphatase
PDL
Type 1 collagen fibers
Fibroblast : Collagen 1, 3, 5 fibronectin, lysyl oxidase
Pluripotent SC
Components of Periodontium
Alveolar bone, PDL, Cementum, Gingiva
Gingiva
two parts: Corium and Epithelium
Corium : type I collagen fibers, fibroblast, Collagen I, 3, 5 fibronectin lysyl oxidase
Gingiva E
Epithelium:
stratified squamous epithelium, membrane coating keratohyaline granules
Cell: keratinocyte
BM: Type 4 collagen, integrin, laminin
Cell-cell adhesions: cadherin, CAMs, keratin
Keratinized outer layer: flaggrin/loricrin, keratin
Alveolar crest
coronal junction of outer/inner cortical plates
- Crestal, supporting bone, crystal lamina dura
- Healthy=1-2 mm apical from CEJ
Inner cortical plate
- Bundle - attachment for PDL fiber bundles
- Supporting Bone
- Cribriform plate - perforated by foramina for neurovasculature structures to pass
- Alveolar Bone Proper
- Lamina Dura - “dense layer” derived from dental follicle/sac
BS CAL
Outer Cortical Plate
- Cortical
- Lamellar
- Compact
- Non-supporting bone
Marrow Bone
- Cancellous, trabeclar, spongy, medullary, non-supporting, central sponges?
Alveolar bone
Formed by INTRAMEMBRANOUS mechanism
- thickened ridge of bone circumscribing and forming tooth sockets
- well vascularized, highly inn/mineralized
- Type I collagen fibers
Alveolar Bone FXNS
- Attachment/support
- Protection
- Mineral reservoir
Supplied by: superior and inferior alveolar artieres + Haversian system, CN-V
Endochondral bone formation
cartilage skeleton
LONG bones
Intramembranous bone formation
No cartilaginous precursor
FLAT bones (skull)
bone directly from MESENCHYME
Sutural bone growth
form of intramembraneous bone formation
fusion of flat bone sutures (skull)
Bone Turnover
Replacement of old with ne, rate of turnover slows with inc age
- Formation/resorption coupled
- Regulated via hormones (PTH, VitD, calcitonin, estrogen), GFs, cytokines, prostaglandins
Turnover, CUTTING CONE
leading edge of reposition
occurs in migrating groups
residual osteons become interstitial lamellae
FILLING CONE, turnover
active formation area
- bone formation also occurs in migrating groups
Reversal lines
formation of new bone against old bone - staining pattern of adhesive phosphoproteins
- occurs b/c of H&E stain. Scalloped interface (seam) between old bone and new matrix
Bone formation
- Course fibered woven bone - embryonic bone
- Immature bone - neonatal
- Lamellar - adult
Lamellar bone
Outside of bone Dense Well organized osteons Thicker when more force/stress Cortical, compact, dense, periosteum-associated