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Oral Histology > Midterms - Development and Growth of Teeth, Enamel, Dentin > Flashcards

Midterms - Development and Growth of Teeth, Enamel, Dentin Flashcards

1
Q

Which of the following statement is correct?
A. Enamel cannot form in absence of dentin
B. The formation of enamel and dentin are independent of each other
C. Enamel formation can occur in absence of dentin
D. None of the above

A

A. Enamel cannot form in absence of dentin

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2
Q

Dental lamina is active up to_______________?
A. 1 year
B. 2 years
C. 3 years
D. 4 years

A

D. 4 years

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3
Q

Ectodermal cells in tooth bud are responsible for_______________?
A. Determination of shape of crown and root
B. Formation of periodontal ligament
C. Formation of cementum
D. Formation of pulp

A

A. Determination of shape of crown and root

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4
Q

In considering the process of eruption, the pre-functional eruptive stage of a tooth begins when the_____________?
A. Bud stage begins
B. Cap stage begins
C. Bell stage begins
D. Dental lamina begins forming

A

D. Dental lamina begins forming

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5
Q

Hertwig’s epithelial root sheath is made up of_______________?
A. Outer and inner enamel epithelium
B. Stratum intermedium
C. Stellate reticulum
D. Hyaline layer of Hopewell-smill

A

A. Outer and inner enamel epithelium

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6
Q

Following is derivative of dental lamina____________?
A. Epithelial rests of Malassez
B. Enamel pearls
C. Rests of serres
D. All of the above

A

C. Rests of serres

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7
Q

Accessory canals result from____________?
A. Defects in cementogenesis
B. Dividing epithelial bridges
C. Break in Hertwig’s root sheath
D. Adherent epithelial rests

A

C. Break in Hertwig’s root sheath

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8
Q

A supernumerary tooth results from a deviation during_____________?
A. Initiation
B. Differentiation
C. Apposition
D. Calcification

A

A. Initiation

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9
Q

Blood supply of ameloblast for most of its life cycle comes form_______________?
A. Dental papilla
B. Reduced enamel organ
C. Dental Sac
D. Dental pulp

A

C. Dental Sac

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10
Q

The successors of deciduous teeth develops form_______________?
A. Successional lamina
B. Dental lamina
C. Stellate reticulum
D. Neutral ectodermal cells

A

A. Successional lamina

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11
Q

Outer and inner enamel epithelium first seen in____________?
A. Bud stage
B. Advanced bell stage
C. Cap stage
D. Bell stage

A

C. Cap stage

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12
Q

High levels of albumin is present in____________?
A. Inner enamel epithelium
B. Outer enamel epithelium
C. Stellate reticulum
D. Stratum intermedium

A

C. Stellate reticulum

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13
Q

Membrana performative is seen in_________________?
A. Bell stage
B. Cap stage
C. Bud stage
D. Advanced bell stage

A

A. Bell stage

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14
Q

Any insult to cells in apposition stage result in______________?
A. Hutchinson’s incisor
B. Osteodentin formation
C. Enamel hypoplasia
D. Anodontia

A

C. Enamel hypoplasia

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15
Q

Cementum formation is seen_______________?
A. After dentin formation
B. Before dentin formation
C. Both are formed at same time
D. None of the above

A

A. After dentin formation

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16
Q

Morphological stages of tooth development are explained based on_____________?
A. Shape of enamel organ
B. Shape of tooth germ
C. Function of enamel organ
D. Shape of dental papilla

A

A. Shape of enamel organ

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17
Q

Tooth develops from_______________?
A. Ectoderm, mosoderm
B. Ectoderm
C. Mesoderm
D. Ectoderm and endoderm

A

A. Ectoderm, mosoderm

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18
Q

The relationship between the pulpal and periodontal tissue complex begins during dental development at_____________?
A. Adolescent stage
B. 5-10 years
C. Embryonic stage
D. None of the above

A

C. Embryonic stage

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19
Q

The cells of the enamel organ which differentiate into future ameloblasts are_____________?
A. Cells of inner enamel epithelium
B. Cells of outer enamel epithelium
C. Cells of stellate reticulum
D. Cells of stratum intermedium

A

A. Cells of inner enamel epithelium

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20
Q

The cap stage in tooth development is characterized by_____________?
A. Morphodifferentiation
B. Reversal of functional polarity
C. Formation of hammock ligament
D. Increased mitotic activity

A

D. Increased mitotic activity

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21
Q

In cap stage, regulating factor for cusp shape formation is present in____________?
A. Dental papilla
B. Dental follicle
C. Inner enamel epithelium
D. Enamel Knot

A

D. Enamel Knot

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22
Q

Which of the following is not an ecto-mesenchymal derivative?
A. Dentin
B. Cementum
C. Pulp
D. Enamel

A

D. Enamel

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23
Q

The disturbances occurred during calcification stage of tooth development is seen in_____________?
A. Peg laterals
B. Microdontia
C. Supernumerary tooth
D. Interglobular dentin

A

D. Interglobular dentin

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24
Q

Stellate reticulum is seen in______________?
A. Dental lamina
B. Enamel organ
C. Hertwig’s root sheath
D. All of the above

A

B. Enamel organ

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25
Q

Order of development of tooth germ is____________?
A. Bell-bud-cap
B. Cap-bell-bud
C. Bud-cap-bell
D. Bell-cap-bud

A

C. Bud-cap-bell

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26
Q

Atypical or osteodentin is formed due to disturbance during____________?
A. Morphodifferentiation
B. Histodifferentiation
C. Apposition
D. Initiation

A

B. Histodifferentiation

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27
Q

Enamel pearls are found in_____________?
A. Occlusal surface of premolars
B. Furcation areas of permanent molars
C. On the incisal edges of incisors
D. None of the above

A

B. Furcation areas of permanent molars

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28
Q

Nutrition for ameloblasts after 1st layer of enamel is laid is______________?
A. Dental sac
B. Odontoblastic process
C. Reduced enamel epithelium
D. Dental Papilla

A

A. Dental sac

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29
Q

Temporary structures in enamel organ are (before enamel formation)?
A. Enamel knot
B. Enamel cord
C. Both A and B
D. Enamel Cuticle

A

C. Both A and B

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30
Q

Lip furrow band is______________?
A. Vestibular lamina
B. Successional lamina
C. Dental lamina
D. Basal lamina

A

A. Vestibular lamina

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31
Q

Which of the following anomalies occur during the initiation and proliferation of tooth development ?
A. Amelogenisis imperfecta
B. Dentinogenesis imperfecta
C. Enamel hypoplasia
D. Oligodontia

A

D. Oligodontia

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32
Q

The hertwig’s epithelial root shealth is essential to development of the root because it_______________?
A. Gives rise to cementoblasts that produce cementum of the root
B. Moulds the shape of roots and stimulates differentiation of odontoblasts
C. Given rise to odontoblasts that lay down dentin of the root
D. Remains as an essential constituents of the periodontal ligament

A

B. Moulds the shape of roots and stimulates differentiation of odontoblasts

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33
Q

The formation of the dental lamina is initiated by______________?
A. Forebrain
B. Rathke’s pouch
C. Neural crest cells
D. Odontoblasts

A

C. Neural crest cells

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34
Q

In multirooted teeth, formation of multiple roots is due to presence of_____________?
A. Epithelial diaphragm
B. Cell rests of Malassez
C. Toot bud division or bell stage
D. None of the above

A

A. Epithelial diaphragm

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35
Q

First appearance of tooth formation occurs in____________?
A. 6th week IU
B. 2nd week IU
C. 9th week IU
D. 4th week IU

A

A. 6th week IU

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36
Q

Disturbance during the morphodifferentition stage of tooth development will result in______________?
A. Change in number of teeth
B. Ameloblastoma
C. Change in form and shape of the teeth
D. Hypoplasia

A

C. Change in form and shape of the teeth

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37
Q

Dental papilla gives rise to_____________?
A. Pulp only
B. Pulp & Dentin
C. Pulp & Periodontal ligament
D. All of the above

A

B. Pulp & Dentin

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38
Q

The bud, cap and bell stage of the developing tooth are based, on growth of the______________?
A. Stellate reticulum
B. Dental papilla
C. Enamel organ
D. Dental sac

A

C. Enamel organ

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39
Q

The transitory structures that may be seen during early tooth development are:
A. Enamel Knot
B. Enamel Navel
C. Enamel Cord
D. All of the above

A

D. All of the above

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40
Q

During cap stage, signalling in odontogenic epithelium is done by:
A. Dental follicle
B. Enamel knot
C. Dental papilla
D. Inner enamel epithelium

A

B. Enamel knot

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41
Q

Which of the following is correct?
A. Each rod is formed by 4 ameloblasts
B. Each ameloblast contributes to 4 different rods
C. Head of the rod is formed by one ameloblasts, and tail is formed by three other ameloblasts
D. All of the above

A

A. Each rod is formed by 4 ameloblasts

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42
Q

Enamel can act in a sense like a_______________?
A. Permeable membrane
B. Impermeable membrane
C. Semipermeable membrane
D. Infrapermeable membrane

A

C. Semipermeable membrane

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43
Q

Dark bands that are present in enamel rods at intervals of 4 μms are______________?
A. Neonantal bands
B. Cross striations
C. Striae of Retzius
D. Hunter-Schregar bands

A

B. Cross striations

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44
Q

The average width of enamel rods is______________?
A. 10mm
B. 5mm
C. 2mm
D. 0.5mm

A

B. 5mm

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45
Q

The shallow furrows on the enamel surface, where stria of Retzius end are known as _______________ ?
A. Cracks
B. Pellicle
C. Perikymata
D. Enamel lamellae

A

C. Perikymata

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46
Q

The key hole, pattern appearance in the cross section is feature of______________?
A. Aprismatic enamel
B. Prismatic enamel
C. Intertubular dentin
D. Intratubular dentin

A

B. Prismatic enamel

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47
Q

The class of low molecular weight calcium binding proteins seen predominantly in developing enamel are_____________?
A. Enamelin
B. Amelogenin
C. Tuftelin
D. Ameloplakin

A

B. Amelogenin

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48
Q

Metalloprotienases are used in which stage of the amelogenesis_____________?
A. Organising
B. Formative/ Secretory
C. Protective
D. Desmolytic

A

B. Formative/ Secretory

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49
Q

Nutritional supply of the ameloblasts during most of their life cycle is from the_____________?
A. Dental pulp
B. Odontoblastic processes
C. Dental sac
D. Reduced dental organ

A

C. Dental sac

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50
Q

Neonatal line is also referred to as______________?
A. Retzius line
B. Line of cross striations
C. Incremental lines
D. Line of enamel tufts

A

C. Incremental lines

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51
Q

Among the following the structure that is most calcified is_______________?
A. Enamel lamella
B. Enamel rod
C. Enamel spindle
D. Enamel tuft

A

B. Enamel rod

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52
Q

Synthesis of enamel matrix proteins occurs in the________________?
A. Outer enamel epithelium
B. Ameloblast
C. Stratum intermedium
D. Stratum granulosum

A

B. Ameloblast

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53
Q

Enamel is laid down______________?
A. Mainly by odontoblasts
B. Mainly by ameloblasts
C. Only on odontoblasts
D. Only by ameloblasts

A

D. Only by ameloblasts

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54
Q

The striking difference between enamel and other mineralized tissues is______________?
A. Presence of high percentage of organic matrix
B. Presence of incremental lines
C. Enamel has high reparative capacity
D. Most of organic component is lost during mineralization

A

D. Most of organic component is lost during mineralization

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55
Q

Formation of dentin by odontoblasts begins in_______________?
A. Morphogenic stage
B. Organizing stage
C. Desmolytic stage
D. Formative stage

A

B. Organizing stage

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56
Q

Chronological hypoplasia is_____________?
A. Hypoplasia of local origin
B. Hypoplasia of systemic origin
C. Hypoplasia of hereditary origin
D. None of the above

A

B. Hypoplasia of systemic origin

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57
Q

Dentino enamel junction is_________________?
A. Non-scalloped
B. Straight
C. Scalloped and the convexities are directed towards dentin
D. Scalloped and the convexities are directed towards enamel

A

C. Scalloped and the convexities are directed towards dentin

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58
Q

True about direction of enamel rods______________?
A. They originate at right angle to dentin surface
B. They are almost vertical near the incisal edge (or) cusp tip areas
C. In the cervical third of deciduous crowns they are almost horizontal in direction
D. In cervical region of permanent teeth, they deviate in apical direction
E. All of the above

A

E. All of the above

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59
Q

The diameter of the rod is______________?
A. 4 μ m
B. 9 μ m
C. 7 μ m
D. 2 μ m

A

A. 4 μ m

60
Q

Inorganic content of enamel is about______________?
A. 35%
B. 50%
C. 4%
D. 96%

A

D. 96%

61
Q

Calcification in enamel starts at____________?
A. Enamel matrix
B. Root
C. CEJ
D. DEJ

A

D. DEJ

62
Q

The enamel has no capacity of self repair because______________?
A. It has only a small percent of organic content
B. Its formative cells are lost once it is completely formed
C. It is essentially a keratin tissue and has no blood vessels
D. It has no direct connection with the active cells of the dental pulp

A

B. Its formative cells are lost once it is completely formed

63
Q

The formative cells of which of the following dental tissues disappear once tissue is formed___________?
A. Enamel
B. Dentin
C. Periodontal ligament
D. Cementum

A

A. Enamel

64
Q

On microscopic examination enamel rods have___________?
A. Key hole appearance in cross section
B. Paddle appearance in cross section
C. Lanullate appearance in cross-section
D. None of the above

A

A. Key hole appearance in cross section

65
Q

All are true about the striae of retzius except___________?
A. Constitute the rest lines with in the enamel rods
B. Have high inorganic content
C. They are areas of increased porosity
D. Allow the movement of water and small ions

A

B. Have high inorganic content

66
Q

Ionic exchange between enamel surface and environment______________?
A. Does not take place once enamel surface and invironment
B. Stops after 2 years of eruption
C. Continues till adult life
D. Continues through out life

A

D. Continues through out life

67
Q

Incremental lines of retzius are seen in______________?
A. Enamel
B. Dentin
C. Cementum
D. Pulp

A

A. Enamel

68
Q

Blunt cell processes seen on the developing ameloblasts are celled as________________?
A. Tomes’ fibers
B. Tomes’ layer
C. Tomes’ processes
D. Odontoblastic processes

A

C. Tomes’ processes

69
Q

Following is not an external manifestation of enamel________________?
A. Enamel tufts
B. Enamel lamella
C. Incremental lines of enamel
D. Enamel cuticle

A

A. Enamel tufts

70
Q

Hunter Schreger band are____________?
A. Dark and light bands of enamel seen in longitudinal ground section
B. Dark and light bands of enamel seen in horizontal ground section
C. Dark and light brands of dentin seen in longitudinal section
D. Dark and light bands of dentin seen in horizontal

A

A. Dark and light bands of enamel seen in longitudinal ground section

71
Q

The percentage of inorganic matter in fully developed enamel is about____________?
A. 66%
B. 76%
C. 86%
D. 96%

A

D. 96%

72
Q

Non acidic, nonionic protein which helps in enamel mineralization _______________?
A. Tuftelin
B. Sheathlin
C. Enamelin
D. Amelogenin

A

D. Amelogenin

73
Q

Which of the following is correct about enamel crystals ?
A. Same as dentin crystals
B. Contains organic portion in the center
C. Roughly hexagonal in shape
D. Their diameter is about 5 microns in size

A

C. Roughly hexagonal in shape

74
Q

Maximum amount of phosphate is seen in_______________?
A. Bone
B. Enamel
C. Gingiva
D. Dentin

A

B. Enamel

75
Q

Neonatal lines are seen in_______________?
A. Enamel of deciduous incisiors
B. Enamel of permanent incisors
C. Enamel of premolars
D. Dentin of all teeth, as if is formed first

A

A. Enamel of deciduous incisiors

76
Q

Gnarled enamel is seen in_____________?
A. Proximal surface of tooth
B. Cervical region of tooth
C. Cusp tips of tooth
D. All of the above

A

C. Cusp tips of tooth

77
Q

The thickness of prismless enamel in deciduous teeth is______________?
A. 25 μm
B. 50 μm
C. 75 μm
D. 100 μm

A

A. 25 μm

78
Q

Enamel rods at the cervical area at the occlusal edge and incisal lip in permanent teeth are______________?
A. Straight
B. Shallow
C. Bent
D. Curved

A

C. Bent

79
Q

Incremental lines of Retzius appear_____________?
A. As lines in the enamel running at right angles to the enamel surface
B. As lines in the dentin running at right angles to the dentino-enamel junction
C. In enamel and follow the apposition pattern
D. In dentin and follow the appositional pattern

A

C. In enamel and follow the apposition pattern

80
Q

Enamel spindles are formed by______________?
A. Cracks
B. Ameloblasts
C. Odontoblasts
D. Hypocalcified rods

A

C. Odontoblasts

81
Q

The small ridges, perikymata, seen on facial surfaces of canines are the result of_____________?
A. Hyperplasia
B. Hypoplacification
C. Normal development
D. Interstitial development

A

C. Normal development

82
Q

Ameloblasts is______________?
A. A cell from which tooth enamel is formed
B. A tissue from which tooth erupts
C. A tumour of the jaw
D. Pertaining to dentin

A

A. A cell from which tooth enamel is formed

83
Q

Shape of enamel rod is______________?
A. Key hole or paddle shaped
B. Square
C. Round
D. None of the above

A

A. Key hole or paddle shaped

84
Q

Moth eaten appearance of of enamel is seen in____________?
A. Odontodysplasia
B. Amelogenisis stage
C. Desmolytic stage
D. Mottled enamel

A

A. Odontodysplasia

85
Q

Hertwig’s root sheath is formed from______________?
A. Stratum inter medium
B. Stellate reticulum
C. Outer enamel epithelium
D. Cervical loop

A

D. Cervical loop

86
Q

Thin leaf like structures that extend from enamel surface in to DEJ are____________?
A. Enamel spindles
B. Enamel lamella
C. Enamel tufts
D. Perikymata

A

B. Enamel lamella

87
Q

Which of the following statement is correct_________________?
A. In cross sections enamel rods appear hexagonal and resembles fish scales
B. The bodies of rods are near occlusal and incisal surfaces, where as the tails point cervically
C. The apatite crystals are parallel to bodies and deviate 65° from the tails
D. All of the above

A

D. All of the above

88
Q

Length of enamel rods is_____________?
A. Greater than the thickness of enamel
B. Less than the thickness of enamel
C. Equal to the thickness of enimal
D. None of the above

A

A. Greater than the thickness of enamel

89
Q

Specific gravity of enamel is_____________?
A. 2.8
B. 3.8
C. 4.8
D. 2.3

A

A. 2.8

90
Q

The type of fibrous element in enamel is_____________?
A. Tono filament
B. Keratin like fiber
C. Collagen fiber
D. Vimentin filament

A

B. Keratin like fiber

91
Q

Which of the following tissues have no reparative capacity______________?
A. Enamel
B. Dentin
C. Cementum
D. Periodontal ligament

A

A. Enamel

92
Q

Which of the following structures is not of ectodermal origin_______________?
A. Hunter-Schreger bands
B. Enamel spindles
C. Enamel tufts
D. Enamel lamellae

A

B. Enamel spindles

93
Q

Neonatal lines are found in all of the following except____________?
A. Enamel of primary incisors
B. Enamel of permanent canines
C. Enamel and dentin of permanent first molars
D. Dentin of permanent mandibular incisors

A

B. Enamel of permanent canines

94
Q

Approximately how many enamel rods will be present in a maxillary molar ?
A. 5 million
B. 7 million
C. 9 million
D. 12 million

A

D. 12 million

95
Q

All are true regarding the enamel spindles except____________?
A. Produced by ameloblasts
B. Found in the region of cusps
C. Surrounded by inter prismatic enamel
D. Terminate as rounded process

A

A. Produced by ameloblasts

96
Q

Interwining of the enamel rods at the cusp timps and the incisal edges of a tooth is called______________?
A. Enamel spindles
B. Gnarled enamel
C. Incremental lies of woven
D. Incremental lines of retzius

A

B. Gnarled enamel

97
Q

Ratio of diameter of enamel rods in the DEJ to the enamel surface is______________?
A. 1:4
B. 1:1
C. 1:2
D. 2:1

A

C. 1:2

98
Q

Enamel tufts are_______________?
A. Thin tuft like structure extending from enamel surface of dentin enamel junction
B. Tuft like structure arising from dentin-enamel junction towards enamel surface
C. Odontoblastic processes extending into enamel
D. None of the above

A

B. Tuft like structure arising from dentin-enamel junction towards enamel surface

99
Q

The enamel of the posterior teeth is thickest at____________?
A. Cervical third of buccal surface
B. Middle third of buccal surface
C. Middle third of lingual surface
D. Occlusal surface

A

D. Occlusal surface

100
Q

Perikymata are the external surface manifestations of_____________?
A. Enamel rods
B. Incremental lines of retzius
C. Nasmyth’s membrane
D. Pellicle

A

B. Incremental lines of retzius

101
Q

Water content in enamel by volume is :
A. 2-3 %
B. 6-7 %
C. 20- 25 %
D. 10-12 %

A

B. 6-7 %

102
Q

Which of the following is correct?
A. Reparative dentin is characterized by having fewer and more twisted tubules than normal dentin and may include odontoblasts
B. Dead tracts appear black in transmitted and white in reflected ligth
C. Sclerotic transparent dentin appears transparent or light in transmitted light and dark in reflected light
D. All of the above

A

D. All of the above

103
Q

Matrix vesicles_______________?
A. Are found in mantle dentin
B. Contain collagen
C. Produce alkaline phosphatase
D. Inhibit mineralization

A

A. Are found in mantle dentin

104
Q

1st formed dental tissue______________?
A. Enamel
B. Dentin
C. Cementum
D. Bone

A

B. Dentin

105
Q

Excess deposition of calcium in the dentinal tubules is referred to as______________?
A. Sclerotic dentin
B. Mantle dentin
C. Interglobular dentin
D. Intertubular dentin

A

A. Sclerotic dentin

106
Q

Regarding teeth which statement is wrong ?
A. Enamel is harder than dentine
B. Enamel has no cells
C. Ameloblast secrete enamel and dentin
D. Odontoblast produce dentin

A

C. Ameloblast secrete enamel and dentin

107
Q

The formation of which of the following does not represent normal physiological process of dentin formation_______________?
0
A. Primary and secondary dentin
B. Secondary dentin and circumpulpal dentin
C. Tertiary dentin and sclerotic dentin
D. All of the above

A

C. Tertiary dentin and sclerotic dentin

108
Q

Fluid flow, in or out of the dentinal tubules is proportional to the tuble diameter by______________?
A. Third power of the diameter
B. Sixth power of the diameter
C. Square of the diameter
D. Fourth power of the diameter

A

D. Fourth power of the diameter

109
Q

In adult teeth, the type of dentin present underlying dentin-enamel junction is_______________?
A. Predentin
B. Mantle dentin
C. Interglobular dentin
D. Tertiary dentin

A

B. Mantle dentin

110
Q

The most accepted theory for dentin sensitivity is:
A. Transduction theory
B. Direct neural stimulation
C. Hydrodynamic theory
D. Hydrostatic theory

A

C. Hydrodynamic theory

111
Q

One of the following statement is unique about circumpulpal dentin______________?
A. Collagen fibers are oriented perpendicular to DEJ
B. Vonkorff fibers are present
C. Contain phosphophoryn
D. Requires matrix vesicle for mineralization

A

C. Contain phosphophoryn

112
Q

The pain transmission through dentin is______________?
A. Direct neural stimulation
B. Fluid or hydrodynamic theory
C. Transduction theory
D. All of the above

A

D. All of the above

113
Q

The type of dentin that is formed prior to root completion______________?
A. Inter tubular dentin
B. Peritubular dentin
C. Circumpulpal dentin
D. Secondary dentin

A

C. Circumpulpal dentin

114
Q

Organic portion can be separated from the mineral by_____________?
A. Incineration/organic chelation
B. Decalcification
C. Devitrification
D. Combustion

A

A. Incineration/organic chelation

115
Q

Shape of crown and the size of the roots is determined by______________?
A. Pulp
B. Dentin
C. Enamel
D. Cementum

A

B. Dentin

116
Q

Sclerotic dentin has following features_____________?
A. Caries susceptible
B. Insensitive
C. Hypersensitive
D. Resistant to caries

A

D. Resistant to caries

117
Q

Inter globular dentin results due to_____________?
A. Failure of coalescence of calcospherities
B. Fracture of the dentin
C. Artifact in light microscopy
D. Disturbance in dentinal tubules

A

A. Failure of coalescence of calcospherities

118
Q

The main bulk of dentin is formed by______________?
A. Peritubular dentin
B. Mantle dentin
C. Intertubular dentin
D. Predentin

A

C. Intertubular dentin

119
Q

Tomes’ fibers are____________?
A. With out but not with in the dentin
B. Odontoblastic processes in dental tubules
C. Type of sharpey’s fibres
D. Originate from tome’s granular layer

A

B. Odontoblastic processes in dental tubules

120
Q

Korff’s fibers are seen in______________?
A. Mantle dentin
B. Secondary dentin
C. Reactionary dentin
D. Indeed dermal tubules

A

A. Mantle dentin

121
Q

The type of tertiary dentin which contains cellular inclusions is found in_____________?
A. Sclerotic dentin
B. Mantle dentin
C. Predentin
D. Osteodentin

A

D. Osteodentin

122
Q

The organic lining of the calcified dentinal tubules is known as_______________?
A. Lamina propria
B. Lamina lucida
C. Lamina limitans
D. Lamina densa

A

C. Lamina limitans

123
Q

The cells that form secondary dentin are_______________?
A. Cementoblasts
B. Fibroblasts
C. Odontoblasts
D. Osteoblasts

A

C. Odontoblasts

124
Q

Which of the areas of the tooth is most sensitive during cavity preparation ?
A. Enamel (anterior teeth)
B. Enamel (posterior teeth)
C. Dentin
D. Dentinoenamel junction

A

D. Dentinoenamel junction

125
Q

Transmission of stimulus across dentin is______________?
A. Direct activation of nerve endings
B. Correlated with the innervation density of the dentin
C. Stimulus induced fluid flow
D. There is no transmission of stimulus across dentin

A

C. Stimulus induced fluid flow

126
Q

During the formation of primary teeth_______________?
A. Enamel forms more cervically than dentin
B. Enamel forms faster than dentin
C. Dentin forms faster than enamel
D. Processes of their cells remain in content with each other

A

C. Dentin forms faster than enamel

127
Q

Compared to the inter tubular dentin, peritubular dentin is characterized by which of the following?
A. Greater stainability
B. Lesser content of inorganic salts
C. Greater content of inorganic salts
D. Greater content of large collagen fibers

A

C. Greater content of inorganic salts

128
Q

All factors covering dentine permeability EXCEPT_______________?
A. Smear layer
B. Fluid convection
C. Length of dentinal tubules
D. Diffusion coefficient

A

B. Fluid convection

129
Q

The average diameter of coronal dentinal tubules near the pulp is____________?
A. 0.2-0.5 microns
B. 2-3 microns
C. 0.2-0.3 microns
D. 7 microns

A

B. 2-3 microns

130
Q

All of the following is true about dentinal tubules except______________?
A. Inner pulpal layer contains more dentinal tubules than outer dentin layer
B. The diameter of dentin tubules ranges from 5 to 7μm
C. The diameter of dentinal tubule is more at pulpal layer than outer layer
D. The bonding is more on the inner layer of dentin compared to outer surface

A

B. The diameter of dentin tubules ranges from 5 to 7μm

131
Q

S-shape of dentinal tubules is due to______________?
A. Incremental deposition
B. Peritubular dentin
C. Crowding of odontoblasts
D. Due to excess amount of organic component

A

C. Crowding of odontoblasts

132
Q

Dentin formed through out the life is______________?
A. Sclerotic dentin
B. Secondary dentin
C. Reparative dentin
D. All of the above

A

B. Secondary dentin

133
Q

Dentinal tubules are calcified in_______________?
A. Sclerotic dentin
B. Primary dentin
C. Secondary dentin
D. Interglobular dentin

A

A. Sclerotic dentin

134
Q

Accentuated incremental lines in dentin due to disturbances in matrix and mineralization process is_____________?
A. Incremental lines of Retzius
B. Incremental lines of Von Ebner
C. Contour lines of Owen
D. None of the above

A

C. Contour lines of Owen

135
Q

Formula of hydroxyapatite crystal is____________?
A. Ca3 (Po4)2 CaCo3
B. 3Ca3(Po4)2. Ca(OH)2
C. CaPo4 Ca(OH)2
D. None of the above

A

B. 3Ca3(Po4)2. Ca(OH)2

136
Q

Physically and chemically, the dentin is closely related to______________?
A. Bone
B. Acellular cementum
C. Enamel
D. None of the above

A

A. Bone

137
Q

The microhardness of dentin is about____________?
A. 1/2 that of enamel
B. 1/7 that of enamel
C. 1/4 that of enamel
D. 1/5 that of enamel

A

D. 1/5 that of enamel

138
Q

Migration of odontoblasts into dentinal tubules occurs during ________________?
A. Cavity preparation
B. Dehydration
C. Water irrigation
D. None of the above

A

A. Cavity preparation

139
Q

The dentin receptors are unique because_____________?
A. They elicit pain to hot and cold
B. They elicit pain to touch and pressure
C. They elicit pain to chemicals
D. Elicit only pain as a response

A

D. Elicit only pain as a response

140
Q

The zone of dentin most recently formed and uncalcified is known as____________?
A. Mantle dentin
B. Circumpulpal dentin
C. Predentin
D. Secondary dentin

A

C. Predentin

141
Q

Dentinogenesis by odontoblasts first begins at_____________?
A. Pulpal end
B. Cusp tip
C. Tooth bud stage
D. Cervical area

A

B. Cusp tip

142
Q

Dentinal tubules are______________?
A. Concave
B. Straight
C. S-shaped
D. None of the above

A

C. S-shaped

143
Q

Dead tracts in ground section appears as_____________?
A. Dentinal tubules
B. Coarse fibril bundles arranged at right angle to the dentinal surface
C. Black in transmitted light and white in reflected light
D. White in transmitted light and dark in reflected light

A

C. Black in transmitted light and white in reflected light

144
Q

Which of the following dentinal layers is more mineralized______________?
A. Peritubular dentin
B. Inter tubular dentin
C. Dentinal tubules
D. Circum pulpal dentin

A

A. Peritubular dentin

145
Q

The dentin adjacent to the dentinoenamel junction is called the______________?
A. Mantle dentin
B. Circumpulpal dentin
C. Predentin
D. Secondary dentin

A

A. Mantle dentin

146
Q

During hydrodynamic theory movement of fluids in dentinal tubules cause:
A. Movement of odontoblasts
B. Touch the nerves of the pulp to cause pain
C. Minimum effect on odontoblast
D. Stimulation of odontoblastic process

A

B. Touch the nerves of the pulp to cause pain

147
Q

False statement regarding interglobular dentin is :
A. The term interglobular dentin refers to organic matrix that remains unmineralized because the mineralising globules fail to coalesce
B. This occurs most often in the circumpulpal dentin just below the mantle dentin
C. Where the pattern of mineralization is likely to be appositional than globular
D. Large areas of interglobular dentin is a characteristic feature of childhood hypophosphatasia

A

C. Where the pattern of mineralization is likely to be appositional than globular

Oral Histology (8 decks)

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