Ten Cate's Oral histology - Development, Structure and function

Question 1

According to Ten Cate’s Oral histology - Development, Structure and function, During which stage of development can the enamel organ be first identified?

Answer 1

Cap Stage

Question 2

According to Ten Cate’s Oral histology - Development, Structure and function, What germ layer is the enamel organ derived from and what structure gives rise to it?

Answer 2

Ectoderm and dental lamina

Question 3

According to Ten Cate’s Oral histology - Development, Structure and function, What is in the centre of the enamel organ?

Answer 3

The center of the enamel organ is termed the stellate reticulum.

Question 4

According to Ten Cate’s Oral histology - Development, Structure and function, What is morphodifferentiation? What phase of development does it occur during?

Answer 4

When the tooth crown assumes its final shape, bell stage

Question 5

According to Ten Cate’s Oral histology - Development, Structure and function, What is the cervical loop?

Answer 5

Location where inner and outer enamel epithelium meet at the reflection of the epithelium

Question 6

According to Ten Cate’s Oral histology - Development, Structure and function, What is the first layer of dentin laid down called?

Answer 6

Mantle dentin

Question 7

According to Ten Cate’s Oral histology - Development, Structure and function, Do ameloblasts make enamel first, or do odontoblasts make dentin first?

Answer 7

Odontoblasts, but ameloblasts secrete protein first, which may be inductive signal to odontoblasts

Question 8

According to Ten Cate’s Oral histology - Development, Structure and function, What are the three components of the tooth germ?

Answer 8

Enamel organ, dental papilla, dental follicle

Question 9

According to Ten Cate’s Oral histology - Development, Structure and function, What will cells of the dental papilla eventually become, and what will they produce?

Answer 9

Eventually will become odontoblasts and cells of the pulp, produce dentin

Question 10

According to Ten Cate’s Oral histology - Development, Structure and function, What will cells of the dental follicle become and what will they produce?

Answer 10

Cementoblasts, produce cementum, and PDL fibroblasts, produce and remodel PDL

Question 11

According to Ten Cate’s Oral histology - Development, Structure and function, What is the purpose of hertwigs epithelial root sheath, what cells does it come from?

Answer 11

Epithelial cells that cause ectomesenchyme of the dental papilla to become root odontoblasts. Proliferation of the cervical loop of the enamel organ in an apical direction,

Question 12

According to Ten Cate’s Oral histology - Development, Structure and function, What is the eventual fate of hertwigs epithelial root sheath?

Answer 12

Most of the root sheath breaks up, but leaves behind cell rests of mallasez

Question 13

According to Ten Cate’s Oral histology - Development, Structure and function, What happens when hertwigs epithelial root sheath breaks up?

Answer 13

Cells of the dental follicle (sac) come into contact with the newly formed root dentin, causes them to differentiate into cementoblasts to begin forming cementum

Question 14

According to Ten Cate’s Oral histology - Development, Structure and function, What is the chemical makeup of bone?

Answer 14

Organic 33% (mostly type I collagen) Inorganic (hydroxyapatite) 67%

Question 15

According to Ten Cate’s Oral histology - Development, Structure and function, In bone homeostasis, what is a cutting cone?

Answer 15

A group of osteoclasts moving through bone and resorbing

Question 16

According to Ten Cate’s Oral histology - Development, Structure and function, In bone homeostasis what is a filling cone?

Answer 16

A group of new osteoblasts and pre-osteoblasts that are generating new bone along behind a group of osteoclasts

Question 17

According to Ten Cate’s Oral histology - Development, Structure and function, What is the composition of enamel?

Answer 17

96% mineral and 4% organic material and water

Question 18

According to Ten Cate’s Oral histology - Development, Structure and function, What are the three phases of enamel production?

Answer 18

Pre-secretory

Secretory

Maturation

Question 19

According to Ten Cate’s Oral histology - Development, Structure and function, What is happening during the presecretory phase?

Answer 19

differentiating ameloblasts acquire their phenotype

change polarity

develop an extensive protein synthetic apparatus

prepare to secrete the organic matrix of enamel

Question 20

According to Ten Cate’s Oral histology - Development, Structure and function, What is happening during the secretory phase?

Answer 20

ameloblasts elaborate and organize the entire enamel thickness, resulting in the formation of a highly ordered, partially mineralized, tissue.

Question 21

According to Ten Cate’s Oral histology - Development, Structure and function, During which stage of tooth development does enamel form?

Answer 21

Bell stage

Question 22

According to Ten Cate’s Oral histology - Development, Structure and function, What is happening during the maturation phase?

Answer 22

ameloblasts “modulate” and transport specific ions required for accretion of mineral

Question 23

According to Ten Cate’s Oral histology - Development, Structure and function, What is different about the first layer of enamel produced?

Answer 23

Does not contain rods

Question 24

According to Ten Cate’s Oral histology - Development, Structure and function, What is the cytoplasmic extension of the ameloblast called?

Answer 24

Tome’s process NB Don’t confuse with Tomes Fibre – the odontoblast process

Question 25

According to Ten Cate's Oral histology - Development, Structure and function, What is the difference between rod and interrod enamel?

Answer 25

Orientation of their crystals – chemically the same

Question 26

According to Ten Cate's Oral histology - Development, Structure and function, Describe the formation of rod and interrod enamel?

Answer 26

Proximal portion of tomes process secretes enamel around the periphery of the process, which creates a pit in which tomes process resides. This creates the interrod enamel, which is continuous with that produced by adjacent ameloblasts. Tomes process elongates as more interrod enamel is laid down, and the distal portion of the process makes enamel with crystals oriented in a different direction. This makes the rod. As the rod grows it squishes the tip of the process out of existence and the thin space where it last was becomes filled with organic material to become the rod sheath. The ameloblast continues retreating as more enamel is laid down.

Question 27

According to Ten Cate's Oral histology - Development, Structure and function, What is different about the last layer of enamel formed?

Answer 27

It has no rods.

Question 28

According to Ten Cate's Oral histology - Development, Structure and function, What parts of enamel are thought to be continuous with one another?

Answer 28

Initial layer, interrod enamel and last layer – all deposited by the same proximal portion of Tomes process

Question 29

According to Ten Cate's Oral histology - Development, Structure and function, When is enamel fully mineralized?

Answer 29

During the maturation phase

Question 30

According to Ten Cate's Oral histology - Development, Structure and function, How much mineral is deposited initially when enamel is being laid down?

Answer 30

Approx 30%

Question 31

According to Ten Cate's Oral histology - Development, Structure and function, When are most of the enamel proteins removed?

Answer 31

During the maturation phase

Question 32

According to Ten Cate's Oral histology - Development, Structure and function, What is the mechanism for removing enamel protein?

Answer 32

Degradation by extracellular proteolytic enzymes and escape through leaky distal junctions of the smooth ended ameloblasts

Question 33

According to Ten Cate's Oral histology - Development, Structure and function, What is modulation with respect to ameloblasts?

Answer 33

During the maturation phase of enamel secretion, they alternate back and forth between ruffle ended and smooth ended

Question 34

According to Ten Cate's Oral histology - Development, Structure and function, What are Striae of Retzius?

Answer 34

Cause unknown, but they are horizontal dark bands in the enamel, usually seen on ground sections

Question 35

According to Ten Cate's Oral histology - Development, Structure and function, What are hunter Schreger bands?

Answer 35

Optical phenomenon resulting in an appearance of alternating light and dark bands in enamel. Caused by different orientation of enamel rods

Question 36

According to Ten Cate's Oral histology - Development, Structure and function, What are enamel tufts, what is their clinical significance?

Answer 36

Branching defects in the enamel beginning at the DEJ and radiating into the enamel, contain greater amount of enamel matrix protein No known clinical significance

Question 37

According to Ten Cate's Oral histology - Development, Structure and function, What are enamel lamellae and how can they be distinguished from fractures?

Answer 37

Linear, longitudinally oriented defects in enamel, extending from the surface to a variable depth. Filled with organic material (this is how they are distinguished from fractures, as a fracture will not contain organic material.

Question 38

According to Ten Cate's Oral histology - Development, Structure and function, What are enamel spindles?

Answer 38

Odontoblast processes that were sticking into the ameloblast layer when enamel formation began. Become trapped and become enamel spindles

Question 39

According to Ten Cate's Oral histology - Development, Structure and function, What is the chemical composition of mature dentin?

Answer 39

Mature dentin is made up of approximately 70% inorganic material, 20% organic material and 10% of water. Most organic is type I collagen

Question 40

According to Ten Cate's Oral histology - Development, Structure and function, During which stage of tooth development is dentin first produced in the crown?

Answer 40

Bell stage

Question 41

According to Ten Cate's Oral histology - Development, Structure and function, Why is dentin production slightly later in the root than the crown?

Answer 41

Requires proliferation of hertwigs epithelial root sheath from the cervical loop first

Question 42

According to Ten Cate's Oral histology - Development, Structure and function, What is predentin?

Answer 42

Dentin matrix which has been secreted but not yet mineralized, mineralization of dentin lags behind secretion of the matrix.

Question 43

According to Ten Cate's Oral histology - Development, Structure and function, What is mantle dentin? What is different about it than primary or secondary dentin?

Answer 43

First dentin laid down by odontoblasts, and it is atubular and usually globular

Question 44

According to Ten Cate's Oral histology - Development, Structure and function, What are Von Korff fibres?

Answer 44

distinct, large-diameter collagen fibrils which are the first sign of dentin formation

Question 45

According to Ten Cate's Oral histology - Development, Structure and function, How does the initial mineralization begin in dentin?

Answer 45

Matrix vesicles are ruptured by growing crystals which fuse with other growing crystals to make the initial layer

Question 46

According to Ten Cate's Oral histology - Development, Structure and function, What is a dead tract?

Answer 46

A dentinal tubule where the odontoblast has died and the process is gone, leaving an empty tunnel

Question 47

According to Ten Cate's Oral histology - Development, Structure and function, What is peritubular dentin, what is different?

Answer 47

The layer of dentin surrounding the tubule space. It is more highly calcified than other types of dentin

Question 48

According to Ten Cate's Oral histology - Development, Structure and function, What is sclerotic dentin?

Answer 48

Dentin where the tubules have become filled with calcified material

Question 49

According to Ten Cate's Oral histology - Development, Structure and function, What is intertubular dentin?

Answer 49

Dentin located between the tubules

Question 50

According to Ten Cate's Oral histology - Development, Structure and function, What is globular dentin?

Answer 50

Dentin that has arisen as a result of calcospheric deposition of dentin, as in the mantle dentin, which forms from matrix vesicles

Question 51

According to Ten Cate's Oral histology - Development, Structure and function, What is the granular layer of Tomes?

Answer 51

A layer that appears between the root dentin and cementum that can only be seen on ground sections under transmitted light. May represent a special arrangement of collagen and non collagen proteins in this area.

Question 52

According to Ten Cate's Oral histology - Development, Structure and function, What is interglobular dentin?

Answer 52

Areas of unmineralized and hypomineralized dentin in between areas of globular dentin. Usually seen in mantle dentin or circumpulpal dentin near the mantle dentin.

Question 53

According to Ten Cate's Oral histology - Development, Structure and function, What are the 4 zones of the pulp?

Answer 53

(1) the odontoblastic zone at the pulp periphery; (2) a cell-free zone of Weil beneath the odontoblasts, which is prominent in the coronal pulp; (3) a cell-rich zone, where density is high, which again is seen easily in coronal pulp adjacent to the cell-free zone; (4) the pulp core, which is characterized by the major vessels and nerves of the pulp

Question 54

According to Ten Cate's Oral histology - Development, Structure and function, Which cells are most numerous in the pulp?

Answer 54

Fibroblasts

Question 55

According to Ten Cate's Oral histology - Development, Structure and function, What is the subodontoblastic plexus of Raschkow?

Answer 55

Extensive plexus of nerves in the cell free zone, composed of sensory fibres

Question 56

According to Ten Cate's Oral histology - Development, Structure and function, What are the major nervous components that enter the apical foramina?

Answer 56

Sympathetic branches from the superior cervical ganglion (provide autonomic control of blood vessels) sensory branches of CN V

Question 57

According to Ten Cate's Oral histology - Development, Structure and function, What are the three theories of dentin sensitivity?

Answer 57

1) The dentin contains nerve endings that respond when it is stimulated, (2) the odontoblasts serve as receptors and are coupled to nerves in the pulp, (3) the tubular nature of dentin permits fluid movement to occur within the tubule when a stimulus is applied, a movement registered by pulpal free nerve endings close to the odontoblast

Question 58

# According to Ten Cate's Oral histology - Development, Structure and function, What is they type of joint that supports the tooth?

Answer 58

Gomphosis

Question 59

# According to Ten Cate's Oral histology - Development, Structure and function, What is the chemical composition of cementum?

Answer 59

45-50% hydroxyapatite, 50-55% organic, (90% Type I collagen)

Question 60

# According to Ten Cate's Oral histology - Development, Structure and function, What is the difference between cellular and acellular cementum? Where is each found?

Answer 60

Acellular cementum has no cementocytes in lacunae, cellular cementum has cementocytes in lacunae, acellular cementum found more coronally and cellular cementum found more apically

Question 61

# According to Ten Cate's Oral histology - Development, Structure and function, What is the difference between intrinsic fibre cementum and extrinsic fibre cementum?

Answer 61

Intrinsic fibre cementum has colalgen produced by cementoblasts arranged parallel to the root surface. Since fibres made by cementoblasts they are 'intrinsic' to the cementum. Extrinsic fibre cementum has no discernable fibres made by cementoblats, only fibres are the PDL fibres entering the cementum made by PDL fibroblasts, or 'extrinsic' to the cementum.

Question 62

# According to Ten Cate's Oral histology - Development, Structure and function, What 3 histological configurations are there for the CEJ?

Answer 62

butt joint where enamel and cementum abut, overlap, where a small amount of acellular afibrillar cementum overlaps the enamel, gap where there is a small amount of exposed dentin because cementum terminates apical to enamel.

Question 63

# According to Ten Cate's Oral histology - Development, Structure and function, What is the alveolar process?

Answer 63

the bone of the jaws that contains the tooth sockets

Question 64

# According to Ten Cate's Oral histology - Development, Structure and function, What is bundle bone?

Answer 64

the inner aspect of the alveolus, where PDL fibres are embedded

Question 65

# According to Ten Cate's Oral histology - Development, Structure and function, What are the predominant collagen types in PDL fibres?

Answer 65

I, III, XII

Question 66

# According to Ten Cate's Oral histology - Development, Structure and function, What are principle fibre bundles?

Answer 66

Spliced ropes of collagen that run from the tooth to the bone

Question 67

# According to Ten Cate's Oral histology - Development, Structure and function, What are the three phases of eruptive movement?

Answer 67

Pre-eruptive, eruptive and post-eruptive

Question 68

# According to Ten Cate's Oral histology - Development, Structure and function, What is the pre-eruptive stage?

Answer 68

Made by the deciduous and permanent tooth germs within tissues of the jaw before they begin to erupt.

Question 69

# According to Ten Cate's Oral histology - Development, Structure and function, What is eruptive tooth movement?

Answer 69

Made by a tooth to move from its position within the bone of the jaw to its functional position in occlusion. This phase sometimes is subdivided into intraosseous and extraosseous components.

Question 70

# According to Ten Cate's Oral histology - Development, Structure and function, What is post-eruptive tooth movement?

Answer 70

Maintaining the position of the erupted tooth in occlusion while the jaws continue to grow and compensate for occlusal and proximal tooth wear.

Question 71

# According to Ten Cate's Oral histology - Development, Structure and function, What is the gubernacular cord?

Answer 71

remnant of the dental lamina that connects the successional tooth to the oral lamina propria

Question 72

# According to Ten Cate's Oral histology - Development, Structure and function, What is undermining resorption in orthodontic movement?

Answer 72

Remodelling of bone from the endosteal surface

Question 73

# According to Ten Cate's Oral histology - Development, Structure and function, What are the rete pegs?

Answer 73

interdigitations between the oral epithelium and the underlying lamina propria. Most pronounced in the attached gingiva

Question 74

# According to Ten Cate's Oral histology - Development, Structure and function, What is the epithelial turnover time in the gingiva? In the cheek?

Answer 74

epithelial turnover time is 41-57 days in the gingiva, 25 days in the cheek

Question 75

# According to Ten Cate's Oral histology - Development, Structure and function, What regions of oral mucosa are keratinized?

Answer 75

Gingiva, hard palate, some parts of the dorsal surface of the tongue

Question 76

# According to Ten Cate's Oral histology - Development, Structure and function, List the epithelial layers in the keratinized oral mucosa from the bottom up?

Answer 76

Basal, prickle/spinosum, granular, keratinized

Question 77

# According to Ten Cate's Oral histology - Development, Structure and function, What is parakeratinization?

Answer 77

When the superficial layer of epithelium maintains pyknotic nuclei

Question 78

# According to Ten Cate's Oral histology - Development, Structure and function, What regions of oral mucosa are non-keratinized?

Answer 78

lining mucosa: lips, buccal mucosa, alveolar mucosa, underside of the tongue and soft palate

Question 79

# According to Ten Cate's Oral histology - Development, Structure and function, Aside from keratinocytes, wht other cells are commonly found in oral epithelium?

Answer 79

pigment-producing cells (melanocytes), Langerhans cells, merkel cells, and inflammatory cells (e.g., lymphocytes), that together make up as much as 10% of the cell population in the oral epithelium

Question 80

# According to Ten Cate's Oral histology - Development, Structure and function, What are langerhans cells?

Answer 80

likely have an immunologic function, processing antigen in the epithelium and presenting it to T lymphocytes

Question 81

# According to Ten Cate's Oral histology - Development, Structure and function, What are Merkel cells?

Answer 81

probably touch receptors in the epithelium, closely associated with nerve fibres

Question 82

# According to Ten Cate's Oral histology - Development, Structure and function, What is the mechanism of gingival overgrowth in response to drugs like cyclosporine and amlodipine?

Answer 82

Fibroblasts of the lamina propria are overactive, and secrete more ground substance than is normal.

Question 83

# According to Ten Cate's Oral histology - Development, Structure and function, What (sensory nerves) innervates the hard palate?

Answer 83

greater, lesser and sphenopalatine nerves

Question 84

# According to Ten Cate's Oral histology - Development, Structure and function, What (Sensory nerves) innervates the soft palate?

Answer 84

lesser palatine nerve, tonsillar branch of glossopharyngeal

Question 85

# According to Ten Cate's Oral histology - Development, Structure and function, What sensory nerves are responsible for taste innervation in the rostral 2/3 of the tongue?

Answer 85

lingual branch of the mandibuar nerve carries fibres, but they originate in the facial nerve and pass via chorda tympani to the lingual nerve

Question 86

# According to Ten Cate's Oral histology - Development, Structure and function, What is responsible for taste and general sensation in the caudal 1/3 of the tongue?

Answer 86

glossopharyngeal nerve

Question 87

# According to Ten Cate's Oral histology - Development, Structure and function, Which tongue papillae contain taste buds?

Answer 87

fungiform, foliate, circumvallate, NOT Filiform

Question 88

# According to Ten Cate's Oral histology - Development, Structure and function, Why do different sections of the tongue have different innervation?

Answer 88

Rostral 2/3 derived from the first pharyngeal arch, caudal third derived from the third pharyngeal arch

Question 89

According to Ten Cate's Oral histology - Development, Structure and function, Name the PDL fibre bundles shown here

Answer 89

Apical group oblique group horizontal group alveolar crest group interradicular group (Transseptal group - doesn't attach to bone, but shown here)

Question 90

According to Ten Cate's Oral histology - Development, Structure and function, Name the gingival fibre bundles shown here:

Answer 90

Dentogingival group dentoperiosteal group alveologingival group circular group (Transseptal not shown)

Question 91

According to Ten Cate's Oral histology - Development, Structure and function, Name the gingival fibres show here, from the vantage between teeth:

Answer 91

Circular fibres, dentogingival, alveologingival Dentoperiosteal (Transeptal not shown)