Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Stage 2 Cheat sheets > CTB > Flashcards

CTB Flashcards

1
Q

Concresence

A

Fusion of teeth after eruption due to fusion of their cementum surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Causes of concrescence?

A

Crowding or trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Dilacerated root?

Cause

A

Curved or bent roots

Developmental trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cause of multiple (lateral) roots?

A

Abnormal folding of HERS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

IF cleft palate fuses with premaxilla what teeth are likely to not develop?

A

Lateral incisors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Process of tooth development with signalling molecules involved in enamel knot formation

A

Initiation stage - overlapping gradients of signalling molecules (BMP and FGF) cause transcriptional response in dental mesenchyme (PAX9 and MSX1). Determines tooth position
Bud stage - mesenchyme secretes FGF and BMP and induces formation of enamel knot in dental epithelium
Cap stage - enamel knot secretes signalling molecules, BMP induces cell cycle arrest in enamel knot cells, FGF induces cell proliferation in surrounding cells. determines tooth shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2 processes the mandible undergoes during growth in adult displacement and relocation?

A 
Adult growth = bone remodelling
Bone formation (osteoblasts)
Bone resorption (by osteoclasts)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Rotations within the mandible, causes and results?

A

Forward rotation, due to excessive growth in posterior face height = deep bite
Backward rotation, due to excessive growth in anterior face height = open bite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does anterior and posterior face height increase?

A

Growth at cervical region of vertebrae displace head from shoulder girdle
This causes stretch of muscles from mandible to skull base, from mandible to hyoid and from hyoid to should girdle
This causes descent of mandibular symphysis and hyoid bone resulting in increased anterior face height
Growth of condyle = increased posterior face height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does craniosynostosis change head shape?

A

Premature fusing of sutures of the skull
So brain expansion causes excess bone growth in the parallel direction to ensure intracranial pressure does not increase
Saggital craniosynostosis = long
Coronal = wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is cementum thicker at apical and interradicular regions?

A

This is where cellular cementum is deposited as we age due to masticatory forces to ensure tooth stays in occlusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Histological difference between cervical loop and HERS?

A

Cervical loop = IEE, OEE, SI, SR

HERS = IEE and OEE only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Formation of enamel pearls

A

Epithelial rests of mallassez formed when HERS stretches and degenerates but leaves remnants
Epithelial rests can form enamel pearls
Due to localised attachment of rests to predestine due to lack of cementum. Signs from pre-dentine could cause HERS cells to differentiate into ameloblasts (Stem cells) or if remnants of SI, SR stuck in HERS, they can then signal ameloblast differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the cerivical loop and what is its role?

A

Growing end of the enamel organ (IEE, SR, SI, OEE), involved in cell interactions and root formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is cervical loop involved in crown formation?

A

IEE of the cervical loop separated from dental papilla by a cell free zone
IEE elongate into pre-ameloblasts and release signals for differentiation of odontoblasts from dental papilla cells
Odontoblasts align and produce pre-dentine
Signals from odontoblasts in pre-dentien induce differentiation of pre-ameloblasts into ameloblasts and produce pre-enamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is cervical loop involved in root formation?

A

IEE and OEE of the cervical loop proliferate down after crown formation and form a double layer of epithelial cells = HERS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A child presents with opacities on the occlusal side of the incisors and all four first molars. You ask if she used to swallow toothpaste as a baby and when learning to first brush teeth or whether she is from a foreign country. What problem are you trying to eliminate?

A

Dental fluorosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do cephalometric line show?

A

Angles

Determine skeletal pattern and anteroposterior position of dentition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

2 classes of skeletal relationship according to angles and what do both show?

A

Class II = retrognathic = mandible posteriorly displaced
More acute angle associated with taller head (docicephalic)
Div I = U1 proclined = larger overjet
Div II = U1 retroclined = normal overjet

Class III = prognathic = mandible more anteriorly displaced = more obtuse angle
associated with wider head (brachycephalic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Compensation of mandibular rotation

A

Skeletal compensation - open bite (backward rotation)
Growth of wider ramps will more mandible forward
Dento-alveolar compensation - open bite means mandibular incisors grow up and maxillary incisor grow down to reach occlusion = curve in occlussion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Width of mantle dentine?

A

20-150 micrometres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is mantle dentine framed and what are its properties?

A

Formed from newly differentiated odontoblasts (first to be formed), lacks phosphoprotein, highly acidic and attracts calcium = reduced demineralisation
Loosely packed collagen fibrils and strongly branched tubules = prevent cracks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Width of dentine in root corresponding to mantle?

A

Hyaline = 20 micrometres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Size of PDL

A 
0.15-0.38mm - thinnest in the middle
PDL thickness decreases with age
11-16 = 0.21 mm
35-53 = 0.18mm
53-67 = 0.15 mm
Mastication increases PDL remodelling = increased width in areas of tension not compression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Disease affecting all enamel in teeth?

A

Amelogenesis imperfecta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What fails to fuse in bilateral and unilateral cleft palate?

A 
Bilateral = failure of both maxillary processes to fuse with medial nasal process
Uni = on one side so only one maxillary process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the structure of the Trabecular bone, what does it contain, and why is it a structural component of the bone given that the compact bone is harder?

A

Trabecular bone contains many cavities filled with bone marrow interrupted by a network of bone plates
Compact bone is harder and forms the outer layer but it is very dense, trabecular bone allows the bone to be light and moveable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Osteocytes - how are they connected what is the purpose of this?

A

Osteoblasts that have become trapped in matrix

Linked by cannaliculi - exchange nutrient and mechanical sensors to maintain bone integrity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Direction of cannaliculi of cementocytes? why?

A

Towards the PDL

Connects cells to PDL to provide nutrients to cementocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

REE

Function

A

Remnants of enamel organs and flattened ameloblasts

Surrounds the erupting tooth and prevents enamel from being resorbed by osteoclasts. Forms the JE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Function of layers of the enamel organ

A 
OEE = cuboidal =  exchanges substances with DF (nutrients and waste) via capillaries 
DF = condensed mesenchymal cells surround the enamel organ = form the periodontium. Provide nutrients to OEE. Some capillary links with ameloblasts (when enamel and dentine form links with DP destroyed)
DP = condensed mesenchyme cells beneath the EO = form odontoblasts and fibroblasts of the pulp
SR = star shaped cells operated with GAGs between = protects the developing tooth and maintaining shape (cushioning)
SI = flat epithelial cells = ameloblast supporting function and produce alkaline phosphatase which aids mineralisation
IEE = form ameloblasts which form enamel (pre-ameloblasts signal fro odontoblast differentiation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the embryological origins of the olfactory sensory epithelium?

A

Olfactory placodes and neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Hypertolerism

A

Large distance between eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does HERS form?

A

Epithelial rests of Malassez which allow dental follicle cells to enter and differentiate into cementoblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Give an example of a hyperplasia that causes problems during extraction? Why?

A

Hyperplasia = over secretion/formation
Hypercementosis = abnormally high cementum deposition
May result in attachment to surrounding alveolar bone or other teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Problems associated with HERS

A

Abnormal folding can cause the formation of lateral roots

It can form epithelial rest of Malassez which can from periodontal cysts and enamel pearls in cementum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Embryological origin of HERS?

A

Proliferation of IEE and OEE from cervical loop after crown completion
IEE and OEE = epithelium = ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Structural difference between primary and secondary dentine

A

Visible change in tubule direction between the 2
Secondary dentine at the pulp border has fewer tubules and is unevenly distributed around the pulp chamber
Primary has more tubules (more odontoblasts when they were formed), the tubules are straighter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is growth through primary and secondary displacement?

A

Primary displacement - growth in one one location causes the bone to be pushed away from other structures
Secondary displacement - Bone displaced as a result of growth of another bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Example of primary and secondary displacement in nasomaxillary complex

A

Primary - growth at sutures causes forward and downward displacement e.g. growth at zygomaticomaxillary suture = maxilla down and forward
Secondary - growth of the middle cranial fossa displaces the nasomaxillary complex forward and down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Example of primary and secondary displacement in mandible?

A

Primary - condylar growth = forward and downward displacement
Secondary - growth of cranial base moves mandible forward and down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Reversible pulpitis

A

Short duration of pain that disappears when stimulus is removed (thermal and sweet)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Irreversible pulpitis

A

Long duration of pain that doesn’t disappear when stimulus is removed.
Cold can make pain better by reducing pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Management of reversible vs irreversible pulpits?

A 
Reversible = remove irritant and restore, preserving pulp
Irreversible = pulpotomy, pulpectomy or extraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Identifying feature of apical periodontitis

A

Symptomatic = tenderness to pressure and widening of apical PDL
Symptomatic and non-symptomatic = apical radiolucency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Identifying feature of apical accesses

A

Tenderness to pressure
Radiolucency
Swelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is condensing osteitis? Identifiable feature?

A

Inflammatory disease after dental infection causing bone formation
Radiopaque

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Alveolar osteitis?

A

after tooth extraction the socket fills with blood and forms a clot
Detachment of the clot can cause bone inflammation - bad odour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Identifiable feature of cracked cusp syndrome?

A

Small crack hard to see
Sharp pain on mastication
Pain goes when biting released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Identifiable features of pulp necrosis

A

Tooth much darker in colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Identifiable feature of ankylosis

A

Tinny on percussion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is ankylosis? - consequence

A

Fusion of tooth to bone - infraocclusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Calcium hydroxyapatite formula

A

Ca10(PO4)6(OH)2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Solution of pH 9 on tooth

A

Critical pH 5.5, below this is rapid demineralisation
Normal pH of mouth 6.2-6.5
Above this the equilibrium moves to left and remineralisation occurs = bond making = exothermic reaction = temperature rise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Mechanism of F- action that contribute to caries resistance?

A

When bacteria produce acid hydroxyapatite dissociates

Can then bind to fluoride which has a reduced solubility product = more resistant to acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Why not give tetracylines to children?

A

High affinity for calcium, during development it would be incorporated into tooth structure and result in dark brown spots in enamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Signalling molecule determining tooth shape?

A

BMP, FGF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Function of osteocytes

A

Presence of canaliculi allows recruitment of osteoblasts and osteoclasts to maintain bone homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

When do paired primary cartilages develop?

A

6 weeks i.u

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

When do secondary cartilages develop?

A

10 weeks i.u

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Name 3 secondary cartilages?

A

Condyle, coronoid and sympyseal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

4 bone remodelling stages

A
  1. Resorption - active osteoclasts = bone resorption
  2. Reversal - disappearance of osteoclasts (apoptosis or migration)
  3. Formation - activation of osteoblasts
  4. Resting - cessation of been formation - surface covered in flat bone lining cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Male vs female skull

A 
Female = flatter and more delicate, zygomatic bone more prominent
Male = bulky, wide long nose, large overhang of supraorbital ridges
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Dentine that forms too quickly?

A

Interglobular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Difference between pre-enamel and pre-dentine?

A

Pre-enamel is already partially mineralised (30%)

Pre-dentine is completely unmineralised = 100% protein matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

3 risks of orthodontic treatment

A 
Root resorption (especially if history of trauma) 
Decalcification 
Relapse (PDL)
Transient inflammatory response in pulp
PD due to difficulty cleaning
67
Q

Component of Tomes processes

A

Distal portion = prismatic (rod) enamel

Proximal portion = inter prismatic (inter-rod) enamel

68
Q

Advantages of prism decussation

A

Prevent propagation of cracks

69
Q

Function of MSX1

A

Transcriptional response in dental mesenchyme to allow determination of tooth position - causing formation of enamel knot
Determines tooth identity (incisors)

70
Q

Histological features present at late bell stage

A 
Pre-dentine
Pre-enamel
SR
Cervical loop
Dental lamina breaks down
71
Q

A patient comes into clinic with sensitivity to hot and cold drinks, he has sharp pains but no carious lesion present. What is this and how would you treat it?

A

Pulpitis
Pain isn’t relieved by cold so probably reversible pulpitis
Remove irritant and restore, preserving the pulp.
Irreversible = pulpotomy, pulpectomy or extraction

72
Q

What is a risk faced in the 3-8 week period of craniofacial development and what is the reason?

A

Weeks 3-8 = embryonic period (craniofacial development)
High susceptibility to teratogens
Failure of neural tube to close - anacephaly

73
Q

Incomplete removal of dental lamina result in:

A

Eruption cysts
Supernumary teeth
Odontomes

74
Q

Why does sclerotic dentine and dead tracts form, how does it differ in the root and crown, and why does it appear transparent?

A

Sclerotic = continues peritubular dentine formation to occlude tubules = transparent due to increased mineralisation
Dead tracts = recession of odontoblast processes in tubules = air filled

May be that root = due to ageing and mastication
Crown due to caries

75
Q

Result of PAX9 and MSX1 mutation?

Characteristics?

A

Hypodontia
PAX9 = missing molars
MSX1 = missing pre-molars

76
Q

Role of submucosa

A

Loose connective tissue containing BV, N glands

Mobility and cushioning

77
Q

Phases of tooth development?

A

Initiation, morphogenesis, histogenesis

78
Q

Problems in children with posterior cleft palate?

A

Cannot eat and breathe = problems breastfeeding

Speech difficulties

79
Q

3 functions of HERS

A

Extends around the pulp and defines future root shape
IEE of HERS induce odontoblast differentiation = root dentine
Curved end = epithelial diaphragm = primary apical fo.
Disintegration of HERS causes differentiation of odontoblasts, cementocytes and fibroblasts from DF

80
Q

Bone holding anterior teeth structures?

A

Pre-maxilla

81
Q

4 functions of REE

A

Fuse with OE to form a continuum so no bleeding on eruption
Protects the erupting crown from resorption by osteoclasts
Form JE
Forms Nasmyths membrane

82
Q

Cephalometry

a) Sella
b) Nasion
c) Orbitale
d) A
e) ANS
f) PNS
g) B
h) Menton
i) Gonion

A

a) centre of sells turcica
b) point when frontal and nasal bones meet
c) base orbit
d) Deepest concavity on anterior maxilla
e) anterior nasal spine = tip of anterior maxilla
f) posterior nasal spine = posterior tip of maxilla
g) deepest concavity on anterior mandible
h) lowermost point of mandibular symphysis
i) most posterior-inferior point on angle of mandible

83
Q

Cartilages giving rise to

a) lesser and greater wing of sphenoid
b) body of sphenoid
c) temporal
d) nasal cartilage

A

a) ala orbitali and ala temporalis
b) hypophyseal and trabecular
c) optic capsule and parachordal
d) paired nasal and prechordal

84
Q

Most common cause of white patches in mouth?

A

Candida albicans

85
Q

Most abundant type fo collagen in PDL?

A

Type 1 = fibrillar

type 3 = reticular

86
Q

Why are BV near PDL fenestrated?

A

To allow passage of nutrients to other cells e.g. cementocytes

87
Q

What type of bone is made in response to fracture?

A

woven

88
Q

What type of bone attached bone to PDL?

A

Bundle bone

89
Q

Which movement requires a low orthodontic force?

A

Intrusion (15-25g)

90
Q

How much force does tipping require?

A

50-75g

91
Q

How much force does rotation and extrusion require?

A

50-100g

92
Q

How much force does translation require?

A

100-150g

93
Q

How does enamel repair?

A

Physicochemical processes

Remineralisation

94
Q

What fibre resists tooth extraction and intrusion

A 
Extraction = oblique
Intrusion = alveolar crest, apical and interradicular
95
Q

Name long period phasic lines in

a) enamel
b) dentine

A

a) Striae of Retzius

b) Andresen lines

96
Q

Name short period lines in

a) enamel
b) dentine

A

a) cross-striations

b) Von-Ebner lines

97
Q

What cell has tight junctions distally?

A

Ruffle-ended ameloblasts

98
Q

Functions of ruffle ended ameloblasts

A

Increase mineral content of enamel

99
Q

Function of smooth-ended ameloblasts

A

Decrease organic content of enamel

100
Q

What cell has tight junctions proximally?

A

Smooth-ended

101
Q

Describe the cranial base angle of retrognathic profile

A

Cranial base angle more obtuse = backward rotation of the mandible

102
Q

Describe the cranial base angle of prognathic profile

A

Cranial base angle more acute = forward rotation of mandible

103
Q

What head form, occlusion and mandible type would a small cranial base flexion person have?

A

Class III
Brachycephalic head
Prognathic jaw
Forward rotated mandible

104
Q

What occurs during gastrulation?

A

Formation of ectoderm, mesoderm and endoderm, they fold

105
Q

Derivatives of ectoderm?

A

Epithelium, CNS, neural rest cells

106
Q

Muscular and skeletal derivatives of pharyngeal arches

A 
I = trigeminal = muscles of mastication, mylohyoid. Malleus, incus, meckels cartilage
II = facial = muscles of facial expression, stapediua, stylohyoid. Stapes, styloid process, lesser horn of hyoid
III = glossopharyngeal = stylophayrngus. Greater horn of hyoid
IIII = Vagus = pahyengeal and laryngeal muscles. Laryngeal cartilages
107
Q

How are neural crest cells specified?

A

By opposing gradients of signalling molecules at the border between neuroectoderm and epidermis

108
Q

Fate of neural crest cells

A

Migrate to pharyngeal arches (due to signalling molecules)

109
Q

Formation fo primary palate?

A

Merged medial nasal processes that continue inwards towards oral cavity

110
Q

Persistence of oronasal membrane?

A

Choanal atresia = narrowing or blockage of basal airway by tissue

111
Q

Formation of secondary palate?

A 
Lateral outgrowths of maxillary processes (palatal shelves) grow downwards (7 weeks)
Shelves elevate (8 weeks)
Shelf fusion (9weeks)
112
Q

Incomplete removal of medial epithelial seam?

A

Palatal cyst

113
Q

Torus palatinus?

A

Benign overgrowth in midline of hard palate

114
Q

Enchondondral ossification?

Example?

A

Bone made from cartilage model (produced by chondrocytes and replaced by osteoid)
Condyle of mandible
Base of skull (synchondroses)

115
Q

Intramembranous ossification?

Example?

A

Bones made of osteoclasts differentiated from mesenchymal stem cells
Mandible
Maxilla

116
Q

Sutural ossification?

Example

A

Bones made from osteoblasts from mesenchyme but sutures proved fibrous connection =stability
Post-natal growth of skull

117
Q

Perichondrium

Formation

A

Source of cells that make chondrocytes

Formed from chondrocytes derived from condensed mesenchymal cells

118
Q

Structure of epiphyseal growth plate

A

Resting chondrocytes = reservoir to replenish chondrocytes being made into osteoblasts)
Proliferation chondrocytes = growth in one direction
Prehypterophic chondrocytes = swollen, increased cartilage matriculates
Hypertrophic chondrocytes = very large and swollen = fully matured
Calcification zone = cartilage being replaces by osteoblasts

119
Q

Synchondroses

Growth?

A

Cartilaginous jointed of cranial base

Mirror image of 2 epiphyseal growth plates allows growth in both directions

120
Q

Epiphyseal cartilage vs condylar cartilage

A 
Epiphyseal = growth of endochondral bones (cartilage formed from chondrocyte proliferation, maturation and hypertrophy)
Condylar = mediates growth of intramembranous bone = mesenchymal cells respond to functional loading and differentiate into chondrocytes. random alignment = multi-directional growth
121
Q

Suture

Growth?

A

Fibrous joints between skull

Skull bone growth in response to brain growth, respond to mechanical stress

122
Q

Neurocranium

A

Cranial vault and cranial base = encloses the brain

123
Q

Viscocranium

A

Facial skeleton = surrounds oral cavity, pharynx

124
Q

Simple bone

A

Formed by ossification fo a single element e.g. endochondral or intramembranous

125
Q

Compound bone

A

Formed by fusion of 2 or more ossifying elements e.g. maxilla = 2 intramembranous
Sphenoid = endochondral and intramembranous

126
Q

When is Meckels cartilage formed?

A

6 weeks i.u.

127
Q

Synovial joint

A

2 bones each covered with particular surface (hyaline cartilage) surrounded by fibrous capsule that creates a joint cavity filled with synovial fluid

128
Q

TMJ movements

A

Rotation (horizontal) and translation (forward and backwards)

129
Q

Fibrous layer covering the condyle contains …

A

Progenitor cells that form chondrocytes that undergo endochondral ossification

130
Q

How does cranial base grow?

A

Remodelling and synchondroses

131
Q

Growth of what influences the angle of the cranial base?

A

Spheno-occipital synchondroses

132
Q

How does cranial vault grow?

A

Remodelling and sutures

133
Q

How does maxilla grow in height?

A

Bone deposition at symptomatic and frontal sutures
vertical drift of alveolar process
Deposition on inferior surface of palate and resorption on superior

134
Q

Growth of maxilla in width?

A

Growth at mid palatal suture

135
Q

Growth of maxilla in length?

A

Posterior surface of maxillary tuberosity

136
Q

Forward and downward displacement of mandible results in…

A

Growth of condylar cartilage

Bone remodelling of ramus

137
Q

Early enamel formation?

A

Starts by secretion of enamel proteins, immediately partially mineralised
First layer is a prismatic and formed against mantle dentine. Tomes processes form - proximal = interprismatic, distal = prismatic

138
Q

Function of amelogenins?

A

Form nano spheres which surround crystals and prevent them from fusing
Regulates growth and thickness of enamel crystals

139
Q

Function of non-amelogenins?

A

Form enamel sheath
Enamelin = promotes and guides formation of enamel crystals
Amelobastin = adhesion of ameloblasts to enamel surfaces

140
Q

What process can epithelial rest of malassez under go?

A

Epithelial-mesenchymal transition

141
Q

How far do odontoblast processes extend in the tubules?

A

Normally to the EDJ
Increased age/attrition can cause retraction of processes (peritubular, dead tracts)
Some times can overshoot = enamel spindles

142
Q

Main nerves in the pulp?

A

Mainly unmyelinated C fibres
Major = afferent (terminate at odontoblasts layers and transmit pain to CNS)
Minor = efferent (cause vasodilation/constriciton of capillaries)
Some myelinated afferent fibres

143
Q

Equivalent to Contour lines of Owen in enamel?

A

Wilson lines

144
Q

What does gnarled enamel look like and how is it caused?

A

Very angular prism decussation
Ameloblasts adapting to rapidly expanding enamel layer
Cohorts of ameloblasts are displaced apically by their own enamel production

145
Q

Granular layer of Tomes
Where?
How?
Mineralisation?

A

Peripheral root dentine, beneath hyaline dentine
Extensive branching and backwards looping of odontoblast processes or incomplete fusion of calcospherites
Hypomineralised

146
Q

Prism direction in primary and permanent teeth?

A 
Primary = inclined occlusally
Permanent = inclined apically
147
Q

Enamel tuft

A

Hypomineralised voids from EDJ extending a short distance into enamel following prism decussation, they contain residual enamel proteins

148
Q

Enamel lamellae

A

Tufts passing through the full thickness of enamel containing organic material

149
Q

Keratinisation status of gingival epithelium?

A

Parakeratinised plus some orthokeratinisation in areas of higher abrasive forces

150
Q

Keratinisation of sulcular epithelium

A

Non-keratinised = binds gingival sulcus and may act as epithelial barrier

151
Q

How is correct depth of sulcular epithelium determined?

A

Masticatory forces

152
Q

What is Nasmyths membrane?

A

Primary enamel cuticle and remnants of REE

153
Q

What is primary enamel cuticle?

A

Internal basal lamina produced by cells of REE, attached to enamel

154
Q

How does junctional epithelium attach to enamel?

A

Via enamel cuticle and hemidesmosomes

155
Q

How does structure of JE change in the deepest part compared to upper part?

A

Deepest part = REE cells (2-3 layers of cuboidal/flat epithelial cells)
Upper part = gingival epithelium cells (multiple layers of cells with epithelial ridges)

156
Q

Consequence of inflammation on the sulcular epithelium?

A

Causes the epithelium to form long, irregular rate pegs that project into the lamina proprietary = epithelium hyperplasia . This is to compensate for collagen loss due to chronic inflammation

157
Q

Why are monkeys gingival and palatal epithelium more orthokeratinxied than human?

A

Functional adaption - eat tougher food

158
Q

What is submucosa made of?

A

Loose connective tissue (Fb), adipose tissue, minor salivary glands, BV and N

159
Q

Where on the hard palate is submucosa found?

A

Lateral and posterior regions

160
Q

Functional significance of epithelial-connective tissue interface?

A

Interdigitation of rete pegs and papillae of lamina proprietary increase SA and stability of epithelial-mesenchyme surface

161
Q

Type of collagen in gingiva and palatal mucosa and why

A

Type 1 = fibrillar = high tensile strength and can resist shearing

162
Q

When does condyle stop growing? What happens to the condyle cartilage?

A

16-20
Progenitor cells of proliferative zone stop dividing but cells persist through life. Endochondral ossification stops and condyle cartilage converted to fibrocartilage and highly calcified cartilage

163
Q

Effect of bite jumping device on condyle

A

Pulls mandible froward inducing condylar growth
Chondroblasts of proliferative zone reactivated by mechanical stress, differentiate into chondroblasts = endochondral ossficiation

Stage 2 Cheat sheets (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions