Oral Biology Midterm Prep

Front 1

Neural crest cells separate from lateral aspect of neural tube during the 3rd week of development and give rise to?

Back 1

1. dental pulp, dorsal root ganglion, and facial skeleton

Front 2

What occurs in meisos I but not in mitosis?

Back 2

Synapsis (pairing of homologous chromosomes)

Front 3

Skeletal contribution of the ____ pharyngeal arch gives rise to mandibular.
The development of body of mandible involves ______

Back 3

1. first arch
2. intramembranous bone development

Front 4

Maxillary prominence fo the 1st arch gives rise to..

Back 4

secondary palate

Front 5

1. Length of attachment apparatus in health is the distance between CEJ and alveolar bone crest. T/F?

Back 5

T

Front 6

What should bleeding gums cause you consider as a diagnosis?

Back 6

Leukemia, gingivitis, scurvy, and periodontitis

Front 7

What does the nasolacrimal groove separate?

Back 7

The maxillary prominence from the lateral nasal prominence

Front 8

1. Where do the muscles of facial expression develop from?
2. CN IX is the nerve of what arch?

Back 8

1. 2nd arch
2. 3rd pharyngeal arch

Front 9

When does dental caries incidence decrease with respect to fluoride concentration?

Back 9

When fluoride concentration in drinking water is increased up to 1 ppm.

High concentration of fluoride in surface enamel reduces caries incidence
both systemic and topical fluoride applications reduce dental caries

Front 10

Where is cementum the thickest?

Back 10

Apical portion of root

Front 11

How often does overlap of cementum occur?

Butt joint?

Gap?

Back 11

Overlap of cementum over enamel (occurs ~60% of the time; consists of acellular afibrillar cementum)

Butt joint between cementum & enamel (occurs ~30% of time; based on classic studies)
Gap of exposed root dentin between cementum & enamel (occurs ~10% of the time; may lead to root sensitivity)
Considerable variability circumferentially around tooth
Clinical Relevance: Clinical Attachment Level (CAL)

Front 12

What is a synctiotrophoblast?
Zona pellucida?

Back 12

1) breaks down endometrial wall to faciliate blastocyst implanation that beings one week after fertilization.

Zona pellucida - glycoprotein sturcture surrounding paslma of an oocyte that degenerates to allow for rapid growth of blastocyst implantation

Front 13

What process results in formation of 3 germ layers?

Back 13

gastrulation

Front 14

Why is bone considered to be "coupled"?

Back 14

since its a dynamic, mineralized tissue w/ concurrent formation and resorption.

Front 15

What is aggressive periodontitis an example of in periodontology?

Back 15

Site specificity

Front 16

1. What's the primary struct. and functional unit of cellular cementum that's characterized by a central blood vessel?

Back 16

1. nooo osteons or "cementeons" its avascular!

Front 17

What is an adult remnant of the pharyngeal membranes?

Back 17

tympanic membrane

Front 18

Name the collagen fiber groups found within the PDL

Back 18

alveolar, horizontal, apical, oblique, interradicular

Front 19

1. Why does the intermaxillary segment form?

Back 19

1. Due to fusion of medial nasal prominences. This includes the philtrum of the upper lip

Front 20

What does plaque fluid contain?

Back 20

1. Inorganic ions like Ca and P
2. organic acids produced by plaque bacteria
3. its effected by exposure of dental plaque to carbs
4. has low levels of fluoride

Front 21

Name the 2 main types of cementum

Back 21

Acellular and cellular cementum

Front 22

What is the prognosis of gingival recession primarily based on?

Back 22

based on extent of available vascularity at the site of recession

Front 23

What are the components the stratum granulosum of keratinized gingival epithelium?

Back 23

1. keratohyalin granules
2. membrane coating granules
3. intracellular thickening
4. involucrin
5. filaggrin
6. loricrin

Front 24

How can fluoride be incorporated into the enamel mineral structure?

Back 24

substitute for hydroxyl

Front 25

Where does PDL derive from?

Back 25

The dental sac or follicle

Front 26

Primary Acellular Intrinsic Fiber Cementum

Back 26

Recently identified
Collagen fibers are synthesized by cementoblasts before the formation of the PDL
These form an ~15-20 µm thick "fibrous fringe" to which PDL collagen fibers eventually connect (via lysyl oxidase/Cu2+ crosslinking)
No surface cementoid is present
Minimal function in tooth attachment

Front 27

Primary Acellular Extrinsic Fiber Cementum

Back 27

Constitutes the bulk of the Primary Cementum type
Collagen fibers are synthesized by PDL fibroblasts
Extends from CEJ towards the apex of the root, covering ~2/3 of the coronal portion of the root
Extends all the way to apical foramina of incisors & canines
The average/mean thickness increases apically
Relatively structureless (i.e., amorphous)

Front 28

What's the main tissue for attachment function?

Back 28

primary acellular extrinsic fiber cementum


Cementoblasts migrate toward the PDL and ultimately reside on the periphery, facing the PDL
No surface cementoid is present
Main tissue for attachment function
Likely represents the progressive mineralization of PDL at the root surface

Front 29

During the 4th week of development the first branchial arch divides to form..

Back 29

maxillary process and mandibular process

Front 30

Where does Hertwig's epithelial root sheath first form?

Back 30

in region of future CEJ

Front 31

What are the layers of the enamel organ in the bell stage?

Back 31

inner enamel epithelium
stratum intermedium
stellate reticulum
outer enamel epithelium

Front 32

1. Where in the oral cavity can you find Type 1 collagen?
2. Type 2 collagen?
3. What type of collagen does PDL have?
4. How about gingiva?

Back 32

1. Alveolar bone
2. Cementum
3. Type 1 and 3
4. 1,2,3, 5, 8

Front 33

Alveolar crest is 1-2 mm apical to the?

Back 33

CEJ

Front 34

1. What is the ruffled border associated with?
2. Where can you find osteoclasts?

Back 34

1. w/ osteoclasts
2. within hollowed out depressions called Howship's lacunae

Front 35

1. What percent of alveolar bone is ground substance?
2. Where can you find ground substance in the gingiva?
3. What percentage of cementum is ground substance?
4. What ground substance materials can you find in PDL?

Back 35

1. 5% total composition. BMPs, BSPs, noncollagen substance
2. In the lamina propria (ECM of connective tissue)
3. 4-8% similar components to bone
4. GAGs, GP, GL. major substance of PDL to withstand tension

Front 36

Why does the solubility of enamel mineral through incorporation of fluoride reduced?

Back 36

since fluoride stabilizesthe crystal structure of ename mineral in part through formation of H bonds

Front 37

What's the difference between gingival sulcus and gingival pocket?

Back 37

The “free gingiva” or “marginal gingiva” or “papillary gingiva” or rarely the “nonattached gingiva”

Is measured from gingival crest to base of the sulcus
Forms a space around the tooth referred to clinically as the gingival sulcus/crevice (in health) or pocket (in disease)
Sometimes a clinical feature called "free gingival groove" can be seen that corresponds ~ to the sulcus base or CEJ


note: part of keratinized gingiva

Front 38

1. When is a solution supersaturated?
2. Saturated?
3. Undersaturated?
4. How does degree of saturation change with pH?

Back 38

1. DS > 1
2. DS =1
3. DS<1
4. DS decreases with increasing pH

Front 39

What are epithelial invaginations that correspond to the future of deciduous teeth called?

Back 39

dental lamina

Front 40

What is periosteum?

Back 40

Periosteum- 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")

Front 41

What is endosteum?

Back 41

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 42

With respect to tooth enamel, what is saliva in terms of saturation?

Back 42

its supersaturated

Front 43

How can the salivary pellicle absorbed onto the tooth surfaces reduce the rate of enamel demineralization?

Back 43

reduces the rate of transport of mineral ions out of enamel surface

Front 44

What is the bone lining the alveolus to which PDL fibers are attached to called?

Back 44

Bone directly lining the alveolus (i.e., directly adjacent to PDL)

Bundle bone; Cribriform plate; Alveolar bone proper; Inner cortical plate; Lamina dura; "Supporting" bone; "Alveolar" bone

Front 45

Describe the molecular structure of type I collagen.

Back 45

repeating tripeptide seq of Gly-X-Y.
more Pro than others found in anture
alpha chains
hydroxylated proline and lysine residues

Front 46

What are the multiple interconnective lateral vascular canals of the osteon called?

Back 46

volkmann's canals

Front 47

When is the caries process initiated?

Back 47

when the plaque fluid becomes undersaturated with respect to enamel mineral

Front 48

What cell type in the gingival epitehlium is a dendritic cell component important for immune defense?

Back 48

Langheran's cells

Front 49

What is secreted by osteoclasts?

Back 49

acid phosphatase

Front 50

What parts make up the alveolar process?

Back 50

Inner and outer cortical plates, alveolar crest, central marrow space

Front 51

What skeletal components come from the 1st pharyngeal arch?

Back 51

mandible, maxilla, zygomatic bone, and portion of temporal bone

Front 52

What type of cementum forms on enamel?

Back 52

acellular afibrillar cementum

Front 53

Secondary Cellular Intrinsic Fiber Cementum

Back 53

Is a minor component of the Secondary Cementum type
Variable presence, found usually only on posterior teeth
Located on the apical 1/3 of the root, when present, and also in the interradicular area of multirooted teeth
Surface cementoid is present
Minimal function in tooth attachment

Front 54

Secondary Cellular Mixed Fiber Cementum

Back 54

Formerly called Secondary Cellular Extrinsic Fiber Cementum
Constitutes bulk of the Secondary Cementum type
Located on the apical 1/3 of the root
Microscopic features include:
Cementocyte cell bodies trapped within lacunae
Cementocyte cell processes enclosed within canaliculae which are directed toward the PDL space (i.e., nutritional/vascular supply)
Lamellar/Laminated structure
Surface cementoid is present
No osteons
No syncytium formed by the cell processes

Front 55

Mixed Stratified Cementum

Back 55

Consists of alternating layers of acellular extrinsic & cellular intrinsic cementum
Located at apex of tooth
Functions in response to adaptive needs of the tooth

Front 56

Intermediate Cementum

Back 56

Incorrectly used sometimes as a synonym for the Hyaline Layer of Hopewell-Smith
Is a form of Secondary Cellular Intrinsic Fiber Cementum
Location is restricted to the apex of the tooth
Contains entrapped residual cell debris from either the Hertwigs Epithelial Root Sheath (HERS) or the odontoblast (i.e., dentin-forming) cell layer
No function in tooth attachment (or tooth adaptation (?) )

Front 57

Acellular Afibrillar Cementum

Back 57

Is a developmental anomaly when found in humans
Located on the enamel (instead of dentin) surface, near CEJ
Occurs as isolated spurs or patches extending onto enamel
No function in tooth attachment
Results from local foci of breakdown of the Reduced Enamel Epithelium (REE), allowing cells of the Dental Follicle to contact the enamel (normally no contact)
Demonstrates the significance of different biochemical signals from different calcified matrices (i.e., this type of cementum is afibrillar as well as acellular)

Front 58

Layers of Cementum/"Cementing" Cross-sectional View (tooth root-through the PDL-to the external surface)

Back 58

Mantle Dentin
Granular Layer of Tomes (not always present) [Note: do not confuse with Tomes Process of ameloblasts]
Hyaline Layer of Hopewell-Smith (~10 µm wide)
Formerly called "hyalin dentin" (or "predentin," sometimes)
Incorrectly called "intermediate cementum"
More appropriately considered as "enameloid"
Primary Cementum (i.e., acellular fibrillar)
Secondary Cementum (i.e., cellular fibrillar)- when it is present

Front 59

From DCJ, what does internal half of PDL have?

Back 59

Contains HERS remnants; called epithelial cell rests of Malassez
Provides nutrients/vascularity for cementocytes & cementoblasts
Cementum cells face towards this aspect of PDL

Front 60

From DCJ, what does external half of PDL have?

Back 60

Bundle Bone (also called cribriform plate or inner cortical plate)
Cancellous Bone (endosteal spaces contain progenitor cells for the cellular cementum)
Outer Cortical Plate
Investing Gingiva

Front 61

What is a white spot lesion characterized as?

Back 61

highly mineralized layer of enamel overlying a zone of demineralized enamel

Front 62

What does the use of high concentration of topical fluoride result in significant cariostatic effect by?

Back 62

it forms a layer of CaF on the tooth surface that inhibits bacterial acid production

Front 63

What layer of cells forms the enamel organ, but doesn't actually secrete enamel?

Back 63

stratum intermedium

Front 64

1. What are bone resorbing cells in origin?
2. What are bone forming cells in origin?

Back 64

1. hematopoietic
2. mesenchymal

Front 65

Name and describe the 3 types of lamellar bone

Back 65

1. Circumferential Lamellae
form the outer perimeter that encloses the bone (are relatively thin and avascular)

2. Concentric Lamellae
form the bulk of the lamellar bone; composed of Osteons, which are the basic metabolic unit of bone (are consequently relatively thick and vascular)

Front 66

1) Mantle dentin of crown requires?
2) Mantle dentin of root requires?

Back 66

Mantle Dentin of Crown requires Reduced Enamel Epithelium (REE)
Mantle Dentin of Root requires Hertwigs Epithelial Root Sheath (HERS)

Front 67

1. What does lysyl hydroxylase require as a cofactor?
2. What does lysyl oxidase require as a cofactor?

Back 67

1. Requires Fe as a cofactor
2. requires copper as a cofactor

Front 68

What's the embryonic precursor of dentin?

Back 68

dental papilla

Front 69

1) What type of intermediate filament found in the cytoskeleton of epi cells?
2) type of intermediate filament found in the cytoskeleton of fibroblasts?

Back 69

1) keratin
2) vimentin

Front 70

1) DGJ of tooth is composed of what?
2) biological width refers to what?

Back 70

1) epithelial attachment and the connective tissue attachment, comprise attachment apparatus.

2) refers to avg dimensions of attachment apparatus plus corresponding gingival sulcus. all together should be less than 3 mm.

Front 71

What is cold sensitivity most associated with for an organized nerve ending?

Back 71

Krause's bulbs

Front 72

What are the tissues of the periodontum

Back 72

Consists of alveolar bone, cementum, periodontal ligament, and gingiva, but not enamel.

Front 73

What is the mucogingival junction?

Back 73

The attachment between the keratinized gingiva and non-keratinized alveolar mucosa

Front 74

1. what types of collagen group fibers has the most coronal attachment to the root?

Back 74

1. dentogingival collagen fiber - they are the first ones destroyed during periodontal disease that allows the jucnal epithelium to migrate in an apical direction

Front 75

What is the usual form of kertainization of gingival epithelium?

Back 75

Orthokeratinized

Front 76

1. what is considered to be responsible for the attachment function of PDL?
2. What is considered to be responsible for the adaptation function of PDL?

Back 76

1. collagen
2. elastin, ground substance, tissue fluid, and microvasculature

Front 77

What tissue has the highest capacity for regeneration?

Back 77

PDL

Front 78

Where is filaggrin found?

Back 78

found within keratohyalin granules in the granular cell layer of epithelium

Front 79

1. What is keratinized gingival epitehliu characterized by?

Back 79

1. a basement membrane taht has multiple interdigitations of epithelail rete pegs and connective tissue papillae.

can see this as "stippling" of healthy gingiva

Front 80

What attaches to the tooth by hemidesmosome basement membrane?

Back 80

junctional epithelium

Front 81

1. In what direction does mandible form by intramembranous ossification with respect to Mecke's cartilage?

Back 81

1. lateral to

Front 82

What cell type found in the gingival epthelium has a function that's similar to the Schwann cell in the gingival connective tissue?

Back 82

Merkel's cell

Front 83

What is the name of the line that forms when new bone forms against old bone?

Back 83

Cement or Reversal Line

Front 84

What is the collagen fiber group that is found specifically within the gingiva?

Back 84

transseptal group

Front 85

What are 3 properties of the cellular form of cementum?

Back 85

1. contains entrapped cementocytes
2. considered to be bone like
3. fcns in dynamic adaptation to various tooth related stresses

Front 86

What is the name of the family of proteins found in the ground substance of bone?

Back 86

Bone morphogenetic Protein (BMP)

Front 87

How are DSEn and calcium related?

Back 87

Degree of saturation of a soln with respect to enamel increases with increasing calcium

Front 88

When does plaque fluid become understaurated with respect to enamel mineral?

Back 88

When its exposed to carbohydrate. otherwise, its usually supersaturated with respect to enamel mineral.

Front 89

What is characteristic of osteoblasts?

Back 89

alkaline phosphatase

Front 90

What term is synonymous with keratin filaments?

Back 90

tonofilaments

Front 91

In the lamina reticularis of basement membrane, anchoring fibrils are mainly associated with what type of collagen?

Back 91

Type I collagen

Front 92

What type of cementum is formed mostly before tooth eruption, exhibits few entrapped cementocytes, and is phenotypically unlike bone?

Back 92

Acellular cementum

Front 93

What is the embryonic precursor of cementoblasts?

Back 93

dental sac/dental follicle.

Note: wiki says dental follicle

Front 94

What 2 things occurs during the histodifferentiation stage of tooth development?

Back 94

1) tooth germ is at bell stage
2) stratum intermedium layer characterized by actively secretes alkaline phosphatase

Front 95

What must cells respond to in order to be considered competent?

Back 95

must respond to the inducer

Front 96

What 3 things do the mesenchymal cels that surround the epithelial tooth bud function in?

Back 96

1. condense and form the dental papilla
2. interact with epitheliam
3. limited by the dental follicle

Front 97

How is the inner enamel epithelium involved in the differentiation of ameloblasts and enamel formation?

Back 97

interacts with stratum intermedium through signaling.

Front 98

What is the cap stage of tooth development characterized by?

Back 98

1. increased cellular density in mesenchyme
2. presence of enamel knot

Front 99

1) what is the dentin matrix formed by?
2) At what stage does the dentin matrix start to be deposited?

Back 99

1. formed by odontoblasts
2. at crown stage

Front 100

During amelogensis, what contributes to the nutritive supply of the ameloblasts?

Back 100

The stellate reticulum

Front 101

Developmental mechanisms in the dental lamina stage of tooth development include what 2 things?

Back 101

1) neural crest migration
2) epithelial-mesenchymal interactions

Front 102

Where do ameloblasts derive from?

Back 102

Dental epithelium

Front 103

1) Hunter -Shreger bands
2) Lines of Retzius
3) Perikymata

Back 103

1) strengthen the enamel and prevent cracks from propagating through the tooth

2) incremental growth lines seen in enamel and are the result of enamel development.
3) pits around the long prisms of tooth enamel.

Front 104

1) Lines of Owen
2) Lines of von Ebner

Back 104

1) Accentuated incremental line's in the dentin thought to be due to disturbances in the mineralization process.
2) Incremental line's in the dentin of the tooth that reflect variations in mineralization during dentin formation; the distance between the line's corresponds to the daily rate of dentin formation.

Front 105

What is the difference between rod and interrod enamel?

Back 105

There's more enamel matrix in the interrod enamel

Front 106

Cooperative effects are vital in immune response. What are 3 immune cell types that are invovled in cooperation?

Back 106

Macrophages, T cells, and B cells

Front 107

What does the secretory components (polymeric immunoglobulin receptor) play a role in?

Back 107

cellular transport of dimeric IgA

Front 108

The major types of cells derived from the gingival crevice are?

Back 108

Neutrophils

Front 109

During acid etching of enamel..what happens?

Back 109

crystals perpendicular to the tooth surface are preferentially etched

Front 110

What is interrod enamel a result of?

Back 110

Cooperative secretory activity of many ameloblasts

Front 111

The base of the histological sulcus is at the..

Back 111

top of the junctional epithelium

Front 112

In absolute gingival health, what is the lenght of the junctional epithelium?

Back 112

1 mm

Front 113

In gingival health, what is the dimension of the connetive tissue attachment (w/ supracrestal collagen fiber bundles)

Back 113

1 mm

Front 114

The base of the junctional epithelium is located at the..

Back 114

CEJ

Front 115

What does reparative dentin not contain?

Back 115

peritubular dentin

Front 116

What do odontoblasts stop producing when the tooth erupts?

Back 116

Stop producing matrix proteins when the tooth erupts

Front 117

What disintegrates during root formation?

Back 117

Hertwig's Root Sheath