Introduction To Perio Lect 1 1/4

Front 1

What is periodontum/periodontal attachment? Name the components

Back 1

4 main tissues plus the associated neurovascular supply.

1. alveolar bone - hard connective tissue
2. cementum - hard CT
3. PDL - soft connective tissue
4. gingiva

Front 2

What are the epithelial gingiva components and connective tissue components in gingiva?

Back 2

Gingiva eptihelium
Oral, sulcular, junctional

CT: soft connective tissue, superficial "instructive", deep "permissive"

Front 3

What are the main histological features of bone?
2. Main cell types of bone?

Back 3

1. Cortical and cancellous bone (w/ osteons)
2. osteoblast - alkaline phosphatease; collagens, others
osteoclast - H+, acid phosphatase
osteocyte - no alkaline phosphatase
pleuripotent stem cell - not well understood

Front 4

What are the main histological features of cementum? Main cell types?

Back 4

1. Acellular and cellular cementum (w/o osteons)
2. Cementoblast - alkaline phosphatase; collagens; others

Front 5

What are the main histological features of PDL? Cell types?

Back 5

1. fibers
2. fibroblast - collagens, fibronectin; others
pluripotent stem cell - not well understood

Front 6

What are the components of gingiva (corium)?

Back 6

1. fibers
2. firboblast - collagens, fibronectin, others

Front 7

What are the components of gingival epithelium?

Back 7

1. stratified squamous epthelium, and membrane coating and kertohyalin granules
2. keratinocyte- basement membrane, cell-cell adhesions, keratinized outer layer

Front 8

What are the 4 components of alveolar bone?

Back 8

Bone crest, inner cortical plate, outer cortical plate, marrow bone

Front 9

What is the composition of alveolar bone?

Back 9

~67% Inorganic Mineral [ranges 50-70%, depending on source]
Composed of Hydroxyapatite/Hydroxylapatite [i.e., HAP]: the classic molecular formula is Ca10(PO4)6(OH)2

~33% Organic Matrix (and associated cells)
~85% Collagen Fiber Components (i.e., ~28% of total)
Type I Collagen (~98%) [i.e., FIBERS]

Front 10

How is bone controlled?

Back 10

Systemic through hormones
Local via GFs, cytokines, prostaglandins, mechanical forces, etc.

Front 11

Describe 3 types of developmental patterns in bone formation

Back 11

Endochondral Bone Formation (primarily in the long bones)
Intramembranous Bone Formation (primarily in the flat bones)
Sutural Bone Growth (primarily in the flat bones)

Front 12

Describe lamellar bone

Back 12

Peripheral surface sheets (called cortical plates; either outer or inner) [generally referred to as "compact" bone]

Internal supporting struts (called trabeculae) [generally referred to as "trabecular" bone; also known as "cancellous" bone and "spongy" bone]

Front 13

Describe marrow spaces

Back 13

called central medullary cavity.

[generally referred to as "marrow" bone or "medullary" bone; also known as "cancellous" bone and "spongy" bone] [NB: not empty spaces]

Red Marrow (is primarily vascular)
Yellow Marrow (is primarily fatty)

Front 14

1. circumferential lamellae
2. concentric lamellae
3. interstitial lamellae

Back 14

1. form the outer perimeter that encloses the bone (are relatively thin and avascular)
2. form the bulk of the lamellar bone; composed of Osteons, which are the basic metabolic unit of bone (are consequently relatively thick and vascular)
3. fill in the spaces between adjacent concentric lamellae; actually are residual fragments of pre- existing concentric lamellae that have undergone dynamic remodeling (are consequently of many different shapes & sizes)

Front 15

What is the periosteum?

Back 15

is a 2-layered connective tissue membrane surrounding the external surface of compact bone


Inner Cellular Layer
Bone Cells
Bone Cell Precursors
Rich Microvasculature

Outer Fibrous Layer (includes "Sharpey's Fibers")

2. Endosteum- is a 1-layered structure covering the internal surface of compact bone & all the trabecular bone

Cellular Layer only
Bone Cells
Bone Cell Precursors
Rich Microvasculature

Front 16

1. What is the primary structural and functional unit of bone?
2. What does the mineralization/homeostasis of bone require?

Back 16

1. Osteon
2. requires blood supply, bone forming cells, and minerals.
so, capillary is the central feature of each osteon

Front 17

What is the single central vascular canal, oriented parallel to the long axis of the bone called?
2. What's it lined by?

Back 17

-Haversian Canal.
2. lined by endosteum, this surrounds one capillary

Front 18

1. What are multiple lateral vascular canals called (non-mineralized) generally oriented perpendicular to long axis of bone?
2. What are they lined by?
3. Each surrounded by what..?

Back 18

1. Volkmann Canals
2. lined by endosteum
3. surrounds one capillary. interconnects adjacent haversian canals, resulting in a vascular 3D network.

Front 19

1. Multiple concentric bone cell spaces (non-mineralized areas), generally oriented circularly around the central capillary called?
2. What is bone cell that resides within the lacuna?

Back 19

1. Lacunae - surrounds the bone cell body
2. osteocyte

Front 20

1. What are multiple concentric bone cell canals called?

Back 20

Called Canaliculi
Surround the cell processes of the osteocyte
Functional Syncytium [Clinical Relevance: orthodontics]

Front 21

Where does the alveolar bone get its arterial supply from?

Back 21

-superior and inferior alvelolar arteries.

Well vascularized osteon-associated capillary network often referred to as the "Haversian System"
Allows continuous turnover of cellular & extracellular constituents
Numerous "perforating" lateral arterial branches also pass through cribriform plate to supply the PDL

Front 22

Venous, lymphatic, and nerve supply for alveolar bone?

Back 22

Venous Drainage
achieved by post-capillary venules
Lymphatic Drainage
tends to follow the venous drainage
Nerve Supply
derived from respective branches of Fifth Cranial Nerve

Front 23

1. Where do osteoblasts come from?
2. Morphology?
3. active function?

Back 23

1. from pluripotential mesenchymal cells
2. uninucleated; generally characteristic of secretory cells
3. synthesize osteoid; communicate via gap junctions

Course-fibered "Woven" Bone- is embryonic bone and adult repair bone
Fine-fibered Lamellar Bone- is mature bone

Front 24

1. Osteocytes result from?
2. morphology of osteocytes?
3. Inactive function?

Back 24

Life Cycle- result from entrapped osteoblasts within the osteocytic lacunae
Morphology- characteristic of resting cells
Lacunae- size & number are related to the state of bone development and the speed of bone formation & cell entrapment
Inactive Function- primarily for the control of mineral homeostasis & bone cell vitality
"Lining Cells" & "Osteocytes"

Front 25

1. Osteoclast come from?
2. Morphology?

Back 25

Life Cycle- from pluripotential hematopoietic stem cell
Morphology- multinucleated; characteristic of scavenger giant cells ("multinucleated giant cells")

Ruffled Border or Brush Border
Ruffled/Brush border edges are "sealed"
Adjacent cytoplasm is called the Clear Zone

Front 26

Name the steps of osteoclast function

Back 26

a. Recruited & activated for bone resorption
b. Attachment of osteoclasts to the mineralized bone surface
c. Formation of a sealed acidic environment or compartment
d. Concurrent action of a membrane proton pump, to pump hydrogen ions into the sealed compartment
e. Results in demineralization (first) which exposes the organic matrix


f. Synthesis/Release of tartrate-resistant acid phosphatase (TRAP) & other proteolytic enzymes (ex. Cathepsin B)
g. Degradation of exposed organic matrix (second)
h. Concurrent intracellular uptake of minerals & amino acids
i. Resorption & migration occurs concurrently during active bone resorption
j. Therefore, this leads to hollowed out depressions or troughs called Howship's Lacunae

Front 27

1. Where is alkaline phosphatase?
2. Where does it cleave?

Back 27

Bound on the outer surface of the plasma membranes of osteoblasts

Cleaves organically-bound phosphate, which is necessary for the initiation & progression of bone mineral crystal growth

Also used diagnostically or experimentally

Front 28

1. Where is acid phosphatase?
2. What is it necessary for?

Back 28

Located intracellularly within cytoplasmic granules/vesicles and vacuoles

Necessary for resorption

Also used diagnostically or experimentally

Front 29

What are bone forming cells considered in origin? Bone resorbing cells in origin?

Back 29

1. mesenchymal in origin
2. hematopoietic in origin

Front 30

1. What is the leading edge of bone resorption called?
2. Cross section of bone shows a scalloped area called..?
3. Residual old osteons become?

Back 30

1. Cutting cone
2. Howship's lacunae
3. interstitial lamellae

Front 31

1. Area of active formation is called?
2. Formation of new bone against old bone is characterized by the ?

Back 31

1. filling cone
2. cement line or reversal line (due to staining pattern of adhesive phospho-proteins)

Front 32

1. Inner cortical plate is also called the bundle bone.. why?
2. same for cribiform plate?
3. and lamina dura?

Back 32

Called Bundle Bone because it provides attachment for PDL fiber bundles
Also called the Cribriform Plate because it is perforated by many foramina through which neurovascular structures pass
Also called the Lamina Dura because it appears as a "dense layer" on dental radiographs

Front 33

1. Where is the inner cortical plate derived from embryollically?
2. What is it an important component for?
3. Why is it a dynamic structure?

Back 33

1. from dental follicle/sac
2. imp. for tooth support (via collagen fibers)
3. functional plasticity

Front 34

1. Where is the alveolar crest located in reference to the CEJ?
2. What is the alvelolar crest also called?

Back 34

1. Normally 1-2 mm apical to CEJ
2. Also called crestal lamina dura (a radiographic feature having clinical relevance during periodontal examinations of patients)