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BDS stage 2 > Theme 8- Radiology > Flashcards

Theme 8- Radiology Flashcards

1
Q

How does radiographic imaging work using the principles of shadowing ?

A

x-ray passes through objects
the film is originally white
objects that stop the x-ray appear white on x-ray and are radiopaque
objects that are black on the film have let the x-ray pass though and are radiolucent
objects that are grey stop the x-ray partially

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2
Q

What are the factors affecting radiographs ?

A

type and density of material
thickness of material
intensity of the beam- the higher the beam the more penetrating power

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3
Q

What is the lamina dura >?

A

radiographic appearance of the alveolar bone

specifically is the cortical bone of the socket

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4
Q

What is also visible besides the lamina dura ?

A

PDL

trabecular bone

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5
Q

What are the limitations of radiographs ?

A

superimposition- shadows on top of each other

might have to view the radiograph from different angles

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6
Q

What does the quality of a radiographic image depend on ?

A

contrast- difference between black, grey and white areas
the positioning of the image receptor, beam and object
image resolution

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7
Q

What is the ideal positioning of the image receptor, x-ray beam and object ?

A

the object and image receptor should be in contact
object and image receptor should be parallel
x-ray beam positioned so beam meets object/receptor at right angles

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8
Q

What is the effect of the image receptor not being not being parallel to the object ?

A

image is elongated

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9
Q

What is the effect of the object not being parallel to the image ?

A

foreshortened image

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10
Q

What is the effect of the x-ray beams not being perpendicular ?

A

distorted image

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11
Q

What are the 2 categories of dental radiographs ?

A

intraoral- image receptor in persons mouth

extraoral - image receptor outside the patients mouth

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12
Q

What are the types of intraoral radiographs ?

A

bitewings
periapical
occlusal

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13
Q

What are the types of extraoral radiographs ?

A

oblique lateral radiographs
lateral skull radiographs
panoramic radiographs

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14
Q

What does the x-ray tube do ?

A

the x-ray tube is within the tubehead

it produces high speed electrons that bombard tungsten targets and are bought to rest

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15
Q

What are the components of the x-ray tube ?

A

cathode- a tungesten filament that is a source of electrons (-)
anode- a tungsten target within a copper block (+)

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16
Q

What is the role of the copper block ?

A

remove heat

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17
Q

What is the role of a focusing device ?

A

aims the stream of electrons on the tungsten target

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18
Q

What is the kilovoltage ?

A

connected between the cathode and anode

it accelerates the electrons from the cathode to the anode

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19
Q

How are x-rays produced ?

A
  1. filament is heated and produces a cloud of electrons
  2. high kilovoltage accelerates electrons from cathode to anode
  3. focusing device aims the electrons at the tungsten target
  4. Electrons bombard target and are bought to rest
  5. Energy is lost as either heat or x-ray
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20
Q

What are the 2 types of interactions at the atomic level ?

A

x-ray producing collisions

heat producing collisions

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21
Q

What happens during a heat producing collision ?

A

incoming electrons bombard with outer shell electrons of a tungsten atom
leads to either
excitation- electron is displaced to higher outer shell
ionisation- electron is displaced from atom

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22
Q

What happens during x-ray producing collisions ?

A

incoming electrons are deflected as they pass close to the nucleus
incoming electron leads to excitation or ionisation

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23
Q

What does an x-ray consist of ?

A

a single beam consists of photons of different energies

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24
Q

What is the beam quantity of an x-ray ?

A

the number of photons in a stream

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25
Q

What is the beam quality ?

A

the penetrating power

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26
Q

How do x-rays behave in free space ?

A

travel in straight lines in free space

obey the inverse square lar

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27
Q

What is the inverse square law and what does it mean ?

A

intensity= 1/d2

doubling the distance from the beam reduces intensity by 1/4

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28
Q

Why are x-rays known as ionising radiation ?

A

they are capable of producing ionisation in biological tissues

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29
Q

What are the types of x-ray interaction with matter ?

A

scattering
attenuation
absorption
ionisation

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30
Q

What is scattering ?

A

change in direction with loss of energy or no loss of energy

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31
Q

What is absorption ?

A

loss of energy as the x-ray is absorbed and the energy is deposited

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32
Q

What is attenuation ?

A

combo of scattering and absorption

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33
Q

What is ionisation ?

A

removal of electron from the tungsten target electron shells

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34
Q

What are the 2 types of interaction of x-rays at the atomic level ?

A

photoelectric effect - pure absorption with low energy photons
compton effect - mixture of absorption and scattering with high energy photons

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35
Q

What happens in the photoelectric effect ?

A
  1. photons interact with inner shell electrons - electron is ejected as a result of energy deposition
  2. energy deposition- absorption
  3. leaves unstable vacancy
  4. vacancy is filled with outer shell electron which jumps down
  5. Jump from outer to inner shells emits a photon
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36
Q

What is the relationship between atomic number and photoelectric effect ?

A

higher atomic number- more inner shell electrons- more deposition and absorption of energy- the electron is emitted and another one will replace from periphery leading to photon emitting

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37
Q

Why is lead used in radiation protection ?

A

has a high atomic number- so has a high chance of photoelectric effect - absorption

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38
Q

What is the probability of photoelectric interactions occurring proportional to ?

A

1/kv3 hence

the lower the KV the better the radiation dose and better good contrast

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39
Q

Where is the comptom effect the predominant process ?

A

air
water
soft tissue

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40
Q

What happens in the compton effect ?

A
  1. incoming photon interacts with free or loosely bound electron
  2. some energy is absorbed and the electron is lost
  3. remainder of the energy is scattered
  4. scattered photo can go onto -
    Compton or photoelectric interactions
    escape from tissues as scatter radiation
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41
Q

What increases the compton effect ?

A

increasing the Kv increases the compton effect

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42
Q

What is the controlled area ?

A

based on the inverse square law
the controlled area is anywhere within 1.5m from the beam
only the patient is allowed in this area

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43
Q

What is periapical radiography ?

A

intraoral imaging of 2-4 teeth and the apicla tissues

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44
Q

What are the main indications for periapical radiography ?

A 
infection of the apical tissues 
trauma to teeth/alveoalr bone 
endodontics
root morphology 
position of impacted/unerupted teeth
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45
Q

When carrying out radiography how should the image film be placed in relation to incisors, canines and molars and premolars ?

A

for incisors and canines- long axis of film vertical to tooth
for molars and premolars- long axis horizontal to the tooth

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46
Q

What is problematic about needing the image receptor and x-ray beam to be parallel ?

A

anatomy of the arches and the palate means the film and x-ray tube are not able to be parallel
to overcome this the film is held apart from the tooth
but this increases magnification
so the source is held further away from object to reduce beam divergence

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47
Q

What is the relationship between object and film distance and magnification ?

A

the greater the object film distance the greater the magnification

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48
Q

What are the 2 theories of image taking ?

A

paralleling technique

bisecting angle technique

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49
Q

What is the paralleling technique ?

A

the image receptor and the object are in contact and are parallel (might not always be possible due to the anatomy of the palate- so hold the image receptor away and increase the source object distance)

x-ray beam aimed at right angles to the object

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50
Q

What is the theory behind the bisecting angle technique ?

A

the image receptor and the object placed as close as possible without bending
angle between the object and film mentally bisected
x-ray beam aimed at 90 to the bisected angle line
aimed through the tooth apex

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51
Q

Which technique is the technique of choice ?

A

paralleling

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52
Q

Where should the occlusal plane be located when taking images ?

A

occlusal plane should be parallel to the floor and horizontal

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53
Q

What are the advantages of paralleling technique ?

A

reprodcucible
easier to carry out

however might be difficult if shallow palate or floor of mouth

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54
Q

What are advantages of the bisected angle technique ?

A

easier positioning of the receptor- only has to be as close as possible

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55
Q

What do bitewings show ?

A

crowns of molars and premolars on one side of the jaws

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56
Q

What are the indications for bitewings ?

A

detection and progression of carious lesions

looking at existing restorations

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57
Q

How do you take bitewings ?

A

image receptor placed according to tooth
image receptor and tooth are in contact
beam meets receptor at right angles
beam MUST pass through interproximal area

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58
Q

WHy must the beam go through interproximal areas for bitewings ?

A

to prevent overlapping

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59
Q

What is occlusal radiography ?

A

intraoral technique where the image receptor is placed in the occlusal plane

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60
Q

What are the types of maxillary occlusal radiographs ?

A

upper standard occlisal
upper oblique occlusal
vertex occlusal - no longer used

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61
Q

What are mandibualr occlusal projections ?

A

lower 90 true occlusal
lower 45 degree occlusal- standard
lower oblique occlusal

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62
Q

What does the upper standard occlusal show ?

A

view of the anterior maxilla and anterior maxillary teeth

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63
Q

What are the indications for an upper standard occlusal ?

A

periapicla assessment of upper anterior teeth
detection of unerupted canines/supernumeraries
cyst detection in the anterior maxilla

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64
Q

What is the technique for an upper standard occlusal ?

A

image receptor placed in occlusal plane
long axis AP for children and Crossway for adults

x-ray beam aimed through bridge of nose at 65 degree angle to the occlusal plane

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65
Q

What does an upper oblique occlusal show ?

A

posterior maxilla

upper posterior teeth on onse side

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66
Q

What are the indications for upper oblique occlusal ?

A

determination of the position of the upper posterior teeth roots to the maxillary sinus

periapicla assessment of upper posterior teeth
lesion, cyst and tumour detection in the posterior maxilla

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67
Q

What is the technique for the upper oblique occlusal ?

A

long axis of the film placed AP

x-ray tubehead focused through cheek at 65-70 degrees to the occlusal plane

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68
Q

What does a lower 90 true occlusal show ?

A

plan view of the tooth bearing part of the mandible

also floor of mouth

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69
Q

What are the indications for a lower true 90 occlusal ?

A

detection of radiopaque submandibular calculi
assessment of unerupted teeth - their bucco-lingual position
Body of the mandible cysts/tumours

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70
Q

What is the technique for a lower 90 occlusal ?

A

tilt head backwards
film placed crossways
tubehead palced below chin and aimed 90 degrees to an imaginary line joining the 6s

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71
Q

What doe the lower 45 standard occlusal show ?

A

anterior mandible and anterior mandibualr teeth

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72
Q

What are the indications for a standard lower occlusal ?

A

periapical and cyst assessment of the anterior mandible

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73
Q

How do you carry out a lower standard occlusal ?

A

head is not tilted back

x-ray tube aimed at 45 degrees to image receptor

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74
Q

What is a lower oblique occlusal ?

A

shows the submandibular gland

as oblique the other structures will be distorted

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75
Q

What are indications for a lower oblique occlusal ?

A

detection of radiopaque submandibular calculi
assessment of B/L position of unerupted 8s
cysts tumour detection in angle of mandible

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76
Q

What is the technique for a lower oblique occlusal ?

A

image receptor placed A-P long axis
patient rotates head away from side being imagef
beam placed below and behind angle of mandible

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77
Q

What is cephalometric radiography used for ?

A

relationship between teeth and jaws and the jaws to the rest of the facial skeleton

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78
Q

What are the main projections used in cephalometry ?

A

true cephalometric lateral skull

cephalometric postoanterior of jaws

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79
Q

Where does the anterior cranial base run from ?

A

nasion to the sella turcica

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80
Q

Where is the nasion ?

A

frontonasal suture

where the frontal bone and nasal bones meet

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81
Q

What does the frankfurt plane join ?

A

orbitale to porion

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82
Q

What does the maxillary plane join ?

A

the ANS and the PNS

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83
Q

What does the mandibular plane join ?

A

menton and the gonion

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84
Q

What is the A point ?

A

the most concave point on the anterior maxilla

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85
Q

What is the B point ?

A

the moist concave point on the anterior mandible

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86
Q

What is a normal ANB ?

A

ANB is the differnece in the SNA and SNB

it is usually 3 degrees

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87
Q

How can you classify a patients skeletal relationship ?

A 
class I-  2-4 
class II- 4+ as the SNA will be huge 
class III - less than 2 as SNB will be pushed in
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88
Q

What does DPT depict ?

A

curved slice through the dental arches

shows teeth and supporting structures

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89
Q

What are the principles of DPT imaging ?

A

the x-ray tubehead moves in one direction and the film in another direction
many images are taken and compiled together

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90
Q

Which age range are DPTs no suitable for ?

A

under 6 years

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91
Q

What are the types of shadows ?

A

real/actual shadows

ghost/artefact shadows

92
Q

What are real/actual shaodws ?

A

they are shadows of structures in the focal trough that you want to view

93
Q

What are ghost shadows ?

A

shadows of structures not in the focal trough- you don’t want to view them
usually structures from the opposite side you are viewing

94
Q

What are the disadvantages of DPTs ?

A

Ghost shadows - superimposition
structures might be outside the focal trough and not visible
Earrings/piercings

95
Q

What is cone beam computed tomography ?

A

equipment orbits the patient and takes multiple images to reconstruct a cross sectional image
can be formatted into 3D constructions

96
Q

What are the categories that determine the detail of an image ?

A

contrast
resolution
sharpness
geometry

97
Q

What are the types of contrast ?

A

subject contrast, film contrast, fog and scatter

98
Q

What is subject contrast ?

A

there are differences in contrast within subjects as
tissue thickness varies
tissue density varies
atomic number varies - proportional to photoelectric effect
Kv- penetrating power

99
Q

What is the relationship between contrast and Kv ?

A

as the KV increases the contrast decreases

100
Q

What is fog and scatter ?

A

radiation in the form of scatter (from the Compton effect)

can reach the film and blacken it reducing contrast

101
Q

What are the types of unsharpness ?

A

geometric unsharpness
absorption unshaprness
motion unsharpness

102
Q

WHat is geometric unsharpness ?

A

the penumbra effect

103
Q

What is the penumbra effect ?

A

the penumbra is the zone of unsharpness around an actual shadow (the umbra)
the larger the penumbra the more unsharp the umbra will be

104
Q

How does the penumbra form ?

A

beams pass through extremes and point in between

105
Q

What is a motion unsharpness ?

A

patient moved during the exposure

106
Q

What is absorption unsharpness ?

A

cervical burnout at the neck of the tooth

107
Q

Which walls of the maxillary antrum are only visible on the DPT ?

A

posterior
medial
floor

108
Q

What is primary caries ?

A

caries on unrestored surfaces

109
Q

What is secondary caries ?

A

caries adjacent to restorations

110
Q

What is residual caries ?

A

demineralised tissue left behind before filling the tooth

111
Q

What is rampant caries ?

A

multiple active lesions in the same patient

112
Q

What is misleading about looking at caries radiographically ?

A

caries is always deeper clinically than it appears radiographically

113
Q

What can we use to aid caries detection and diagnosis ?

A 
probing
transillumination 
fluoresence 
bitewings
clinical visualisation
114
Q

What is problematic regarding approximal lesions and radiographs ?

A

approximal lesions are only visible radiogrpahically when 30-40% of demienralisation has occured
this means that approximate caries might be present in a patient even though not seen radiographically

115
Q

What is the bitewings frequency according to caries risk ?

A

low risk- every 2 years
moderate risk- every 12 months
high risk- every 6 months

116
Q

How does residual caries appear in a radiograph ?

A

radiolucency below a restoration

117
Q

What can be easily misidentified on a radiograph ?

A

dentine bonding agents and GIC as they are not fully opaque and have the same contrast as dentin

118
Q

What is cervical burn out ?

A

radiolucent shadows on the cervical neck of the tooth

119
Q

Why does cervical burnout occur ?

A

there is less tissue in the cervical areas (dentine only)

less tissue means less attenuation so the area appears radiolucent

120
Q

What are the differences in the radiographic appearances between cervical burnout and root caries ?

A

cervical burnout is usually triangular whilst caries is saucer shaped
cervical burnout will usually effect all the teeth in the radiograph - especially the 4 and 5

121
Q

How does the PDL appear radiogrpahically ?

A

as a thin black line around the roots

122
Q

How does the lamina dura appear radiographically ?

A

radioopaque line

white line adjacent to PDL line

123
Q

What might you observe in the periapical region for a deciduous tooth ?

A

successor tooth germ

root resorption prior to exfoliation

124
Q

How does a developing tooth germ root appear ?

A

open funnel shaped - not closed yet

125
Q

What are the inflammatory changes that can occur in the periapical region ?

A 
swelling 
redness
pain
heat
loss of fucntion
126
Q

How does acute apical periodontitis appear radiographically ?

A

widened PDL space

127
Q

What might you observe radiographically for a periapical abscess ?

A

apical radiolucency
root resorption
bone resorption

128
Q

What might you observe radiographically for a deciduous tooth with a periapical abscess ?

A

furcation radiolucency

129
Q

What might you use radiographs for in the treatment of periodontitis?

A

assess bone levels
assess furcation involvement
assess plaque retentive factors like restorations
assess root length/morphology

130
Q

What is the relationship between crestal bone level and the CEJ in a healthy patient ?

A

crestal bone margins within 2-3mm of the CEJ

131
Q

Are radiographs useful for gingivitis ?

A

no as radiogrpahs dont show soft tisues

132
Q

What is chronic periodontitis ?

A

slow rate of bone destruction and pocketing that happens over time

133
Q

What is the opposite of chornic periodontitis ?

A

aggressive periodontitis

134
Q

What are the forms of bone loss in periodontitis ?

A

horizontal
vertical
furcation

135
Q

What is furcation involvement a sign of

A

advanced disease

136
Q

In which teeth are furcations easier to see ?

A

mandibular molars

in maxilalry molars you can get superimposition of the palatal root

137
Q

What might also be destroyed in periodontitis ?

A

PDL

138
Q

What are the limitations of periodontal radiographs ?

A

difficult to differnetiate between lingual and buccal bone levels
furcations hard to see in maxillary molars

139
Q

What are the reasons for missing teeth ?

A

localised anodontia/hpodontia - effects 8s/2s/5s

syndromic and associated with systemic disease- downs syndrome and ectodermal dysplasia

140
Q

What are the types of additional teeth ?

A

supernumerary teeth
supplemental teeth- duplication
syndromic hyperdontia

141
Q

What are the forms of ameloegenesis imperfecta ?

A

hypomaturation
hypoplasia
hypomineralisation

142
Q

What is regional odontodysplasia ?

A

in a certain region of the mouth
enamel. dentine and pulp are effected
they all appear radiolucent and are known as ghost teeth
developmental disorder

143
Q

What is dentine dysplasia ?

A

rare genetic condition
affects dentine production and can lead to root malformation and sometimes rootless teeth
clinically the crowns appear normal

144
Q

How does fluorosis present ?

A

mottling

faint white opacities

145
Q

What is a potential cause of tooth discoluration ?

A

tetracycline staining

146
Q

What is tooth fusion ?

A

fusion of teeth due to fusion of 2 adjcanet tooth germs

147
Q

What is germination ?

A

1 teeth joined together that ahe origianted for a single tooth germ

148
Q

What is concrescense ?

A

Teeth joined together at the cementum surfaces

149
Q

What is dens in dente ?

A

Folding of an outer surface of the tooth into the interior

eg. at cingulum pit of upper 2s

150
Q

Which crown abnormalities present in congenital ? symphylis

A

Hutchinson’s incisors- barrel shaped

mulbery incisors- dome shaped

151
Q

What are the presentations of teeth in ectodermal dysplasia ?

A

pointed tapered incisors

152
Q

What are some manifestations in additional roots ?

A

2 roots in 1/2
3 roots in 4/5
4 roots in molars

153
Q

What are some morphological root abnormalities ?

A

dilaceration
bifid roots
enamel pearls

154
Q

What is taurodontism ?

A

enlarged pulp chamber and body of tooth ar the expense of the roots as the pulp chamber takes up more of the body

155
Q

What are the local causes of delayed eruption ?

A 
loss of space 
abnormal cyst position 
overcrowding and additional tooth 
eruption cysts 
retention of the primary predecessor
loss of space due to drifting of teeth
156
Q

What are potential systemic cases of delayed eruption ?

A

rickets- metabolic disorder

developmental disorder- cleidocranial dysplasia

157
Q

What is tooth transposition ?

A

2 teeth occupying swapped positions

158
Q

What are wandering teeth ?

A

movement of unerupted teeth in bone

159
Q

What is infraocclusion ?

A

ankylosis leads to fusion of tooth and bone so the tooth is infraoccluded as the bone continues to grow around it

160
Q

Which teeth are frequently infraoccluded ?

A

primary molars

problematic as 5s wont erupt

161
Q

What is micrognathia ?

A

small mandible

162
Q

What are potential causes of micrognathia ?

A

ankylosis

hypoplasia

163
Q

What is macrognathia ?

A

large mandible

164
Q

What are the causes and complications of macrognathia ?

A

causes- acromegaly

complications- prognathism

165
Q

What is torus platinus ?

A

benign overgrowth of palatal bone

166
Q

What can be in close proximity to the ID canal ?

A

roots of the 8

167
Q

Why might the ID canal and 8 be closely related ?

A

they might just be superimposed in the image but they can actually be intimately related

168
Q

What is cleidocranial dysplasia ?

A 
delayed eruption of teeth
affects clavicles
affects skull- widened 
supernumerary teeth 
delayed ossification of the fontanelles
169
Q

What is osteopetrosis ?

A

sclerosis of the skeleton
appear as marble bones
loss of normal skull markings

170
Q

What are potential dental manifestations of osteopetrorosis ?

A

thickening of lamina dura

thickening of trabeculae

171
Q

What is osteomyelitis ?

A

spreading inflammation of the medullary bone can spread to the outer cortical bone
leads to destruction of bone
exacerbated with periapical infection, pericoronitis, acute periodontal lesions

172
Q

How does osteomyelitis appear radiographically ?

A

moth eaten patchy areas of radiolucency

173
Q

What is osteoradionecrosis ?

A

high doses of radiation reduce vascualrity and reparative mechanisms
subsequent trauma or infection leas to bone death

174
Q

What do bisphosphanates do ?

A

reduce the loss in bone density

used to treat osteoporosis

175
Q

What is BRONJ ?

A

bisphosphonate related osteonecrosis of the jaw

necrosis of the jaw in a patient recently on bisphosphanates

176
Q

How to identify BRONJ ?

A

area of uncovered bone that does not heal 8 weeks after identification
no previous radiotherapy and is on BPT

177
Q

What does PTH do ?

A

increases plasma calcium

through effects on bone, intestine and kidney

178
Q

What happens in hyperparathyroidism ?

A

excess PTH is releease

179
Q

What is primary hyperparathyroidism ?

A

hyperplasia
adenoma of parathyroid glands
leads to excess PTH release

180
Q

What is secondary hyperparathyroidism ?

A

Seen in patients with chronic kidney failure

181
Q

What can hyperparathyroisims lead to ?

A

generalised skeletal bone resorption
osteopenia (reduction in bone dnesity)
high plasma calcium
brown tumours

182
Q

What are brown tumours ?

A

lesions relating to excess osteoclast activity in hyperparathyroidism
common in mandible

183
Q

How might hyperparathyroidism manifest dentally ?

A

osteopenia- fine trabecular pattern
loss of lamina dura
thinning of the lower border of the body of mandible

184
Q

What causes acromegaly ?

A

adenoma in pitutary gland- releases excess GH

185
Q

What are the manifestations of acromegaly ?

A

enlarged cranial vault skull bones
enlarged ramus of mandible leading to prognathism
enlarged ID canal
enlarged alveoalr bone- teeth spread out - leads to open bite

186
Q

What is sickle cell anaemia ?

A

abnromal levels of Hb
leads to fragile erythrocytes that are sickle shaped in hypoxia
they have a decreased oxygen capacity so are destroyed leading to anaemia

187
Q

How do homozygotes respond to anaemia ?

A

increased RBCs- due to hyperplasia of bone marrow

bony infarcts

188
Q

How can sickle cell anaemia present radiogrpahically ?

A

coarse trabecular pattern
stepladder trabeculae inbetween roots
enalrged maxilla- class II and separation of anterior teeth and overjet

189
Q

What are alpha and beta thalassemia ?

A

alpha thalassemia- reduced or absent synthesis of alpha globin chains
beta thalassemia- reduced or absent synthesis of beta globin chains

190
Q

What are the dental complications of thalassemia ?

A

large trabecular pattern and marrow pattern

encroachment of maxillary antrum

191
Q

What is a tooth concussion ?

A

injury to the tooth supporting structures without tooth displacement but TTP is present

192
Q

How do fractures of the mandible ususlly present ?

A

they are usually bilaterla

193
Q

What are common places for a mandibular fracture ?

A 
condylar neck 
ramus 
angle 
body 
symphysis 
canine region
194
Q

What are the le fort fracture lines ?

A

le fort 1- speak - lower maxilla
le fort 2- floating maxilla - see
le fort 3- hear extends to ear

195
Q

What are the 2 types of movements the TMJ can mediate ?

A

rotational- rotation of the condyle within the glenoid fossa for the initial opening

translational- movement of the condyle downwards along the AE moves the disc forwards

196
Q

What is TMJ pain dysfunction syndrome ?

A

clicking and stiffness
spontaneous pain in the joint and muscles of mastication and jaw function related pain
possible displacement of the condylar head anteriorly or posteriorly when the mouth is in occlusion

197
Q

How does osteoarthritis affect the TMJ ?

A

pain in stress bearing joints
trismus and clicking
might observe osteophytes on the articular surface of the condyle ( bony fragments on te surface of the condyle)

198
Q

How does rheumatoid arthritis effect the TMJ ?

A

flattening of the condyle head seen radiographically
destruction of the condyle head leading to irregular outline
limited range of movements

199
Q

What is juvenile rheumatoid arthritis known as ?

A

still disease

200
Q

What are the signs of juvenile rheuamtoid arthritis in the TMJ ?

A

flattening and destruction of the condyle

possible interference with condyle growth- ankylosis and micrognathia

201
Q

What are the signs TMJ ankylosis ?

A

ankylosis is the fusion of the bony elements of the TMJ
no obvious joint space in radiograph and loss of normal anatomical outlines
problems opening mouth
if ankylosis precedes completion of condylar growth can lead to micrognathia

202
Q

What are the possible causes of TMJ ankylosis ?

A

stills disease
trauma
infection

203
Q

Where can tumours develop in the TMJ ?

A

in the condyle head

seen radiographically as a radiolucency

204
Q

When is a fracture of the condylar neck common ?

A

after a blow to the chin

205
Q

What are some developmental anomalies that can lead to problems with the condyle ?

A

condylar hyperplasia/hypoplasia
bifid condyle
first arch syndrome - treacher collins and pierre robin syndrome

206
Q

What is first arch syndrome ?

A

failure of CNCs to migrate into the first pharyngeal arch

leads to congenital anomalies in mandible, palate, ears etc-

207
Q

What are the 2 manifestations of first arch syndrome ?

A

pierre robin syndrome

treacher collins syndrome

208
Q

What is the maxillary sinus ?

A

one of the 4 paranasal sinuses
in close proximity to the orbit and maxillary teeth
lined with mucoperosteum
central air filled cavity

209
Q

What are the walls of the maxillary sinus ?

A

roof- floor of orbit
medial wall- bounded by nasal cavuty
posterior wall- pterygopalatine fossa
lateral wall- zygoma

210
Q

What is the floor of maxillary sinus associated with ?

A

maxillary posterior teeth

211
Q

How does the maxillary sinus appear radiographically ?

A

as a radiolucency with radioapque walls

only the medial, roof and posterior wall seen radiogrpahically

212
Q

What is infection/inflammation of the maxillary sinus known as ?

A

sinusitis- it is an upper respiratory tract infection acute- secretions and pus
chronic- polyps, pus and shrinkage

213
Q

What can trauma do to the maxillary sinus ?

A

form a-
oro-antral communication
fracture of skeleton
foreign bodies in the antrum

214
Q

What are some radiological changes in sinus disease ?

A

obliteration/partial opacity
alteration in wall integrity due to tumour or fracture
foreign body

215
Q

What are radiographic changes in chronic sinusitis ?

A

mucosal thickening
fluid level
polyps

216
Q

What are the consequences for upper posterior teeth extraction due to the close proximity to the antrum ?

A

extraction can remove parr of the antral floor
root can be displaced into antrum
obvious radiographically
may lead to ingress of bacteria - sinusitis

217
Q

What are the possible foreign bodies in the maxillary antrum ?

A

displaced root fragments and teeth
excess root canal material forced through apex
antrolith

218
Q

What might cause acute intermittent generalised swelling of the salivary glands ?

A

stricture (restriction)
stenosis (narrowing) of ducts secondary to surgery, stones or infection
sialolithiasis

219
Q

What might cause acute generalised swelling o salivary glands ?

A

viral infection like mumps or EBV

220
Q

What can cause chronic generalised swelling of the salivary glands ?

A 
sjogrens syndrome- autoimmune disease
sialolosis
HIV
cystic fibrosis
granulomas
221
Q

What is sialolosis ?

A

bilateral noninflammatory swelling of glands

222
Q

What might cause discrete swellings of lymph nodes ?

A

intrinisic/extrinsic tumours

223
Q

What might be the causes of dry mouth ?

A 
sjogrens syndrome 
xerostomia
post radiation damage 
mouth breathing 
dehydration 
drugs and polypharamcy- like TCAs
chronic anxiety states
224
Q

What is the most common disorder of the major salivary glands ?

A

obstruction by calcification
structure of the ducts
seen radiopaque on radiograph

225
Q

Where does the submandibular gland open ?

A

at the sublingual papilla (base of lingual frenulum)

226
Q

Where does the sublingual gland open ?

A

sublingual folds at the base of tongue

BDS stage 2 (28 decks)

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