quizz questions module 1 Flashcards
1
Q
What is the major inorganic constituent of enamel by weight? and why?
Calcium
Fluoride
Collagen
Phosphate
Carbonate
A
phosphate- because it forms the backbone of the hydroxyapetite crystalline hence there is more of it compared to calcium, Collagen is a major component of dentin, not enamel.
Fluoride can incorporate into hydroxyapatite, forming fluorapatite, which strengthens enamel, but it is not the primary constituent.
Carbonate is present in small amounts as a substitute in the hydroxyapatite crystal structure, but it is not the major component.
2
Q
Which of the followings is secreted at mineralising front with a high affinity for calcium and hydroxyapatite surfaces?
A
dentine phosphoprotein
3
Q
A
4
Q
Which of the followings is secreted at mineralising front with a high affinity for calcium and hydroxyapatite surfaces?
A
dentine phosphoprotein
5
Q
Which one of the following is classified as a biomineral
A
hydroxyapatite
6
Q
Which cell synthesizes enamel
A
ameloblast
7
Q
Which of the following teeth has an almost symmetrical crown?
A
41
8
Q
Tooth structure is formed by both the oral epithelial and underlying mesenchymal cell types. Which of the cell types give rise to the dentine-pulp complex?
A
neural crest cells
9
Q
Which of the following statements is INCORRECT regarding induction mechanisms of human tooth development?
A
Successional tooth bud develops from a division of dental papilla of the correlative primary tooth
10
Q
Amelogenin locus is found in the X chromosome. Amelogenesis imperfect by mutation of this gene can affect both males and females. That means this gene is inherited in which of the following patterns?
A
x linked dominant
11
Q
Mutations in which of the following genes is the most common cause of “Dentinogenesis Imperfecta”
A
DSPP
12
Q
Which of the following is the most accurate definition of a gene or an “Allele”
A
Alleles are different versions of a gene, which vary according to the nucleotide
13
Q
Regarding pre-dentine, which of the flowing statement is CORRECT
A
it is a collagen matrix
14
Q
The major organic component of dentine is
A
collagen
15
Q
The most highly mineralised region of dentine is the
A
intratubular dentine
16
Q
Which statement regarding enamel is INCORRECT
A
Each enamel prism is reinforced with mineralised collagen matrix
17
Q
The hardness of dentine increases with age is mainly due to the increase of
A
peritubular dentine
18
Q
Which of the following statements about enamel is CORRECT
A
Enamel consists of calcium hydroxyapatite and organic matrix
19
Q
What ion is replaced by fluoride in enamel?
A
hydroxyl
20
Q
The functions of maxillary incisors EXCEPT
A
grinding food
21
Q
Which of the following teeth has a cingulum centered mesiodistally?
A
tooth 23
22
Q
The diagram illustrates the late bell stage of tooth development. Which labelled structure is responsible for instructing differentiation of odontoblasts?
A
D
23
Q
The diagram illustrates the late bell stage of tooth development. Which labelled structure is deposited by ameloblasts
A
G
24
Q
All of the following are part of or arise from the dental organ except
A
epithelial root sheath
25
Mutations in which of these genes will NOT cause "Dentinogenesis imperfecta"?
tuftelin
26
Collagen is not part of the organic matrix of:
enamel
27
Which of the following correctly represents the order of increasing inorganic content of a fully erupted tooth?
pulp, cementum, dentine, enamel
28
How many odontoblastic processes occupy each dentinal tubule
one
29
Which of the following list of conditions, best accounts for the scenario provided? A ground section of a molar tooth is provided, in which the only unusual feature comprises a rounded mass of dentine approximately 1mm in extent on the surface of the root. This dentinal mass interrupts coverage by cementum, and is itself covered by regular prismatic enamel.
enamel pearl
30
The main protein in intertubular dentine is
collagen type I
31
Which of the following enamel proteins self-assembles into nanospheres which act as spacers to allow the crystals to grow as enamel matures
amelogenin
32
Tooth formation involves complex differentiation of the cells and substructures. Which structure is NOT involved in formation of the tooth crown or root
Vestibular lamina - HERS functions to organize the shape of the root by inducing adjacent root dental papilla mesenchyme to differentiate into root odontoblasts, which in turn secrete root dentin.
33
The diagram illustrates the late bell stage of tooth development. Which labelled structures are the Cell Rests of Serres?
B
34
Jennifer is a healthy 3-day-old baby. She is brought to your clinic by her mum because of an erupted tooth in her mouth. You explained to her about the tooth. Jennifer's mum wants to know more about the baby teeth. Which of the following statements is INCORRECT regarding to her dentition at this age?
Jennifer does not have any permanent tooth bud in her jaws at this stage
35
Mutations in which of the following genes will NOT cause "Amelogenesis imperfecta"
Dentin sialophosphoprotein
36
The histology of enamel may be best observed using which of the following methods of slide preparation
ground section
37
Disruption of the early bell stage of tooth development is responsible for
Dens invaginatus
38
The correct order of structures, from outermost to innermost, in an unerupted tooth is:
Ameloblasts, Enamel, Dentine, Odontoblast, Pulp
39
Which of the followings helps remove the inhibition of mineral deposition in the maturation phase of amelogenesis
Enamel matrix serine proteinase 1: EMSP-1 is an enzyme which degrades the amelogenin that inhibits mineral deposition
40
Which of the following teeth has a greater mesiodistal width than the labiolingual width?
tooth 21
41
Which biomineral is more compact?
enamel
42
The maxillary permanent central incisors when viewed from the buccal aspect:
Are asymmetrical and have one 90 degree corner at the mesial
43
A 14 year old Anna was diagnosed with dentinogenesis imperfecta. It runs in the family as her father and paternal cousin have the same condition. Which of the following statements is correct regarding this condition?
Dentinogenesis imperfecta can be part of a syndromic osteogenic defect
44
The diagram illustrates the late bell stage of tooth development. Which labelled structure is responsible for instructing the final differentiation of pre-ameloblasts to become ameloblasts secreting enamel?
H
45
The diagram illustrates the late bell stage of tooth development. Which labeled structure is composed of calcium hydroxyapatite embedded in a matrix of collagen fibers?
H
46
Which of the following is commonly associated with "Autosomal dominant" mode of genetic inheritance?
Affected males and females have equal probability of passing the condition to their offspring.
47
Which of the following statements is "INCORRECT" about amelogenesis imperfecta (AI)?
AI is often inherited as an autosomal recessive disease.
48
Regarding to the ectodermal dysplasia, which of the following statement makes the most sense?
Ectodermal dysplasia has a broader impact on the development of epithelial organs such as skin, teeth, and cause hyperhidrosis
49
On a wet weight basis, dentine contains ___organic material and __ water
20%, 10%
50
Which of the following histological terms used to describe the dentine formed after root formation is complete?
secondary dentine
51
A patient gives a history of teeth which appeared chalky on eruption, and which subsequently displayed extensive wear and staining. Which diagnosis is this presentation most consistent with?
Amelogenesis imperfecta
52
Which of the following proteins is most prevalent in enamel?
amelogenin
53
Which of the following histological terms is used to describe the outermost layer of dentine?
mantle dentine
54
The major inorganic constituent of enamel by weight is
phosphate
55
The diagram illustrates the late bell stage of tooth development. Which labelled structure is adjacent to a dense network of blood vessels required for the formation and maturation enamel?
C
56
The correct order of structures, from outermost to innermost, in an erupted tooth is:
Enamel, Dentine, odontoblast, Pulp
57
Which teeth are usually affected with Dens Invaginatus:
Permanent upper lateral incisors
58
Peritubular dentine is comprised primarily of
Calcium phosphates
59
Which of the following terms describes the grooves resulting from incremental lines reaching the surface of enamel?
Perikymata
60
Enamel epithelial cells residuum usually disappear after a period of time. Which of the statements regarding residuum epithelial cells is incorrect?
The secessional laminar is a pathological epithelial residuum that gives rise to cysts in later life
61
The diagram illustrates the late bell stage of tooth development. Which labeled structure provides nutrition for odontoblasts?
E
62
Which of non-collagenous protein (in dentine) is mostly affected in Dentinogenesis imperfecta?
Dentin sialophosphoprotein
63
Which of the following structure may represent odontoblast processes insinuate themselves between the ameloblasts during the enamel development?
enamel spindles
64
Which term can be used to describe the association with or proximity to the cheeks?
buccal
65
Which of the following statements regarding dentin is correct?
Circumpulpal dentine has collagen fibres orientated parallel with the dentino- enamel junction
66
Which of the following dental effect is NOT associated with Regional odontodysplasia?
Obliteration of the pulp
67
Which of the following statements on biomineralization is correct?
Mineralisation of enamel occurs in two stages, being the secretory and maturation stages, with most mineralization occurring during the maturation stage
68
Which statement regarding the structure of enamel is INCORRECT
Enamel has higher force resistance than dentine
69
Which of the following statements about the cemento-enamel junction is false?
The enamel always overlaps the cementum
70
Which of the following statements regarding enamel is INCORRECT?
Each short-term incremental line in enamel corresponds to growth over a period of 7-11 days
71
During odontogenesis, neural crest cells do NOT produce which cell type?
Ameloblasts
72
Tooth formation goes through distinct stages and each stage has it is unique histological presentations. Which structure can be found at the cap stage of tooth development?
stellate reticulum
73
Which of the following terms does NOT refer to a crown line angle?
Mesioincisal
74
Which of the following terms used to describe the enamel regions where there are sudden changes in crystallite orientation?
Prism boundaries
75
Jennifer is a healthy 3-day-old baby. She is brought to your clinic by her mum because of an erupted tooth in her mouth. You explained to her about the tooth. Jennifer's mum wants to know more about the baby teeth. Can you explain to Jennifer's mum about generation of her permanent tooth by pointing to the structure depicted at the arrow which is:
Successional lamina
76
Which of the following statements on histological feature of a mature tooth is correct?
The dentino-enamel junction is scalloped with peaks directed away from the pulp
77
Preparing a tooth for a restoration may stimulate all of the following actions except:
an increase in the number of dentinal tubules
78
Which of the following teeth presents an almost straight continuous crown-root outline on the mesial surface?
tooth 33
79
Which of the following statements is correct in describing the dental follicle?
Dental follicle gives rise to cementum and periodontal ligaments
80
Regarding Hydroxyapatite, which of the following statements is NOT CORRECT?
Cementum contains a higher level of hydroxyapatite than dentin
81
Which of the following morphological structures is not possible to access from the distal view?
Mesial 1/3 of tooth 28
82
To measure the palatal labial dimension, tooth 11 can be orientated in the following aspects EXCEPT?
palatal
83
In response to chronic stimuli such as attrition, odontoblasts produce a less regular form of dentine which is also known as ___
reactionary dentine
84
A 13 year old boy presents with yellow brown discolouration of both upper and lower teeth. The incisiors and first molars show signs of wear as well as enamel chipping in places while radiographs reveal obliteration of the dental pulps. Which of the followings will be the most likely cause of his dental issue?
Dentinogesis Imperfecta
85
A fourteen year old child presents for examination. Little caries is seen and there is no pain, but the teeth are noted to have a chalky white appearance, while the mesial and distal margins of the upper and lower incisors appear chipped in places. Careful examination reveals similar minor chipping in the posterior dentition. There are no clear radiographic abnormalities. What is the most likely diagnosis?
Amelogenesis imperfecta
86
Which of the following statements about permanent maxillary canines is INCORRECT?
The mesial surface of the crown bulges out more prominently than the distal
87
Splitting of a single tooth germ into two separate but incomplete germs to produce a connoted tooth called:
germination
88
Which one of the following statements regarding dentinal tubules is CORRECT?
they radiate from pulp to dentine-enamel junction
89
What is the major matrix protein in dentin
collagen
90
A history of acute infection of a newly erupted permanent lateral incisor tooth is most consistent with a diagnosis of:
dens invaginatus
91
What is the main difference between biominerals and inorganic minerals
Matrix-assisted nature of biomineralisation
92
Which of the following tooth presents with the middle buccal lobe making up the major bulk of the tooth crown?
34
93
A transverse ridge is ___
a combination name for joining buccal and lingual cusp triangular ridges
94
Which tooth surface faces the lips
labial
95
Which of the following histological terms used to describe the outermost layer of dentine
Mantle Dentine
96
Which of the following statements regarding enamel rods is incorrect?
the rod sheath has the highest concentration of hydroxyapatite in the enamel
97
98
stellate reticulum
1. ectodermal derivative of the cap stage:
99
1. The major inorganic constituent of enamel by weight is:
phosphate
100
1. Enamel undergoes a marked physical and chemical transition during
maturation stage
101
1. Most principal fibers of the periodontal ligament insert into
cementum
102
1. Which of the following dental (enamel) organs (teeth) is the first to develop?denbf
decidios central incisor
103
1. Ameloblast differentiation starts at the
incisal region of tooth germ
104
Avitaminaosis (scurvy) results in a loosening of the tooth in the sockets chiefly because ascorbic acid (vitamin C) is needed by
cells to produce collagen
105
histodifferentiation, epithelial cells begin to differentiate. during histodifferentation is the aveolar bone present ?
Aveolar bone ( from cAp stage
106
When a tooth first erupts into the oral cavity, the attached epithelial cells is composed of epithelium derived from
REE reduced enamel epithelium
107
1. The periodontal ligament is composed chiefly of
collagen fibers
108
1. The formation of the bone in the absence of pre existing cartilage framework is called
intramembranous
109
Hypo-mineralized structures which extend from the dentin-enamel junction to the surface of enamel and are aligned with the longitudinal axis of tooth are
enamel tufts
110
1. The cells that form cementum arise from the:
dental sac (follicle)-- also periodontal ligament and aveolar bone ( cap stage)
111
histodifferentiation, epithelial cells begin to differentiate. during histodifferentation is the aveolar bone present ?
NO . Aveolar bone is from cAp stage
112
1. Which is not in the cap stage of tooth development
stratum intermedium- bell stage
113
1. The epithelial (Hertwig's) root sheath is involved in the formation of
root
114
1. Amelioblasts are derived from:
inner dental epithelium
115
1. Which portion of the tooth germ is the primary source of the periodontal ligament?
dental follicle ( sac)
116
Which collagen type is not found in the periodontal ligament:
type 2 , main components are type 1 (70 %) and 3 20%, 4 and 7 associated with BV and epithelial cells
117
1. Which is not in the cap stage of tooth development? is stratum intermedium ?
stratum intermedium- bell stage
118
Periodontal ligament is composed of
collagen fibers
119
sharpys fibers insert into what two tissues
aveolar and cementum
120
tooth germ composed of
dental (enamel ) organ, dental papila and dental follicale
121
which lamina is mane 1st and second
dental lamina first, vestibule lamina second
122
cap stage enamel epitheliu forms
enamel organ
123
inner dental epithelium is made of ___ cells RNA and ___ and is the ____ zone also known as zone of
inner dental epithelium is made of columnar cells RNA and glycogen and is the free cell zone also known as zone of weilf
124
what provides nutrients for ameloblast
stratum intermedium ( made in bell stage) makes enamel
125
junctional epithelium adheres to teeth by
hemidesmosomes
126
cervical loop seen in what stage and gives rise to
bell stage gives rise to root by hertwigs (HERS) after crown formation
127
permanent teeth bud on ____ side
permanent teeth develop on LINGUAL side always of primary tooth
128
epitelial pearls are formed from remanents of
dental lamina
129
REE reduced enamel (dental) epithelium arrises from
combonation of mature ameloblast and the papilllary layer
130
enamel is what percent inorganic material
96% inorganic, 4 percent protein 1 percent water
131
initial secretion of enamel occurs in response to
dentin deposition
132
_______ in a ground section extend from the dentinoenamel junction into the enamel and most frequently are f ound at cusp tips.
Enamel spindles (arrows)
133
where is the rest of molasses found
cementum
134
Primary dentin that forms most of the tooth also called
circumpulpual dentin
135
morphodifferentation stage is also known as the
bell stage ( histo differnetation is late cap stage)
136
first primary attachment to teet site is
cementuum
137
epithelial cells called resdt of malassez are found in what structure
periodontal ligament
138
Tooth 30 has an occlusal cavity and the removalof decay lost to the pulp and needs capping , which of the following develops as a result of the procedure ?? Mantle dentin, secondary dentin, tertiary dentin , or pirmary dentin
TERITIARY DENTIN
139
The nerve fibers approach the developing tooth during which of the following stages?
Bud-cap stage
140
In early ontogeny the histological features of cells In the center of the enamel organ are called?
stellate reticulum
141
A patient comes into a dental office and gives a history of having Osteogensis Imperfecta. Which collagen mutated to cause this disease type 1 collagen
of the following collagen has mutated to cause this disease?
type 1
142
During the complex process of tooth development there are mutiple laminae used to form structures, which lamina is the second to form.
vestibular lamina
143
Cementum has all of the following characterisitics EXCEPT ONE. Which of the following is the EXCEPTION? Choice=Is vascular Choice=Is acellular Choice=Is cellular Choice=Similiar to bone
is vascuar ( cementum is NOT vascular!!!)
144
What material is enamel compared to when relating it to its hardness? Choice=Iron Choice=Diamond Choice=Platinum Choice=Bronze Choice=Steel
steel
145
During the eruption process of human teeth. Which of the follwoing is most plausable in allowing for teeth to erupt?
periodontal ligament ( KNOW THIS)
146
During light microscopy under special stain the structure Plexus of Raschkow is observed. In which of the following areas in the pulp is this structure seen? Choice=Cell free zone Choice=Supraodontoblastic layer Choice=Granular layer of Tomes Choice=Cell rich zone Choice=Odontoblastic layer
cell free zome
147
From which of the following cells is the reduced enamel epithelium established?
ameloblase
