third molars 2

Question 1

what is included in history

Answer 1

general appearance of pt
presenting complaint = swelling/difficulty speaking/pericoronitis
history of presenting complaint = how long, episodes, how often, severity, requirement for ABX
medical history
dental history
social history

Question 2

what pain can be mistaken for M3M pain

Answer 2

TMJ pain
very similar pain
if there is no communication to the 7’s, the it is unlikely that the pain is coming from the M3M and more likely from the TMJ

Question 3

when doing I/o exam what do you want to look at regarding M2M

Answer 3

look at the distance between the M2M and the ascending ramus = known as your working space to get the M3M out

Question 4

when do you carry out radiographic assessment for M3M

Answer 4

only if surgical intervention is being considered

Question 5

what is an OPT taken for

Answer 5

presence or absence of disease
anatomy of 3M
depth of impaction
orientation of impaction
working distance
follicular width
periodontal status
relationship of upper 3M to sinus and lower 3M to ID canal

Question 6

how is the depth of impaction assessed

Answer 6

superficially impacted = crown of 8 sitting at same height as crown of adjacent 7
moderate impacted = between superficial and deep, crown of 8 associated with crown and root of 7
deep = crown of 8 same level as root of 7

Question 7

if M3M is impacted what can you see around the crown

Answer 7

radiolucency
usually have a follicle around tooth as it pushes into the oral cavity which disappears when erupts but if tooth is impacted then get a radiolucency when follicle disappears

Question 8

what size of follicle is concerning

Answer 8

> 2.5-3mm
can present as a cyst as it gets bigger

Question 9

how do you know if M3M is close to the ID canal

Answer 9

• interruption of white lines/tram lines/lamina dura of the canal = high risk
• darkening of the root where it is crossed by the canal = high risk
• diversion/deflection of the ID canal = high risk
• deflection of root
• narrowing of ID canal
• narrowing of root
• dark and bifid root
• juxta-apical area

Question 10

what is a juxta-apical area

Answer 10

well defined area around the root
not just at the tip of the apex, around the whole root
lamina dura around the root is still intact and appearance is not pathological

Question 11

why would you take a CBCT

Answer 11

where conventional imaging has shown a close relationship between M3M and the ID canal, CBCT may be of benefit

Question 12

how are CBCT better at identifying relationship between M3M and ID canal

Answer 12

3D images and can assess the exact relationship between the tooth and canal = can show if there is any bone between tooth and canal or if tooth is compressing canal

Question 13

what are the occurrences of angulation of M3M

Answer 13

vertical = 30-38%
mesial = 40%
distal = 6-15%
horizontal = 3-15%
transverse or aberrant

Question 14

what is a transverse angulation of M3M

Answer 14

crown is buccal placed and roots lingually placed, or vice versa

Question 15

what is a aberrant angulation go M3M

Answer 15

tooth positioned in an odd place - somewhere you wouldn’t expect to find it

Question 16

how is angulation of M3M identified

Answer 16

measured against the curve of Speed and the long axis of the adjacent 7 compared to the long axis of the 3rd molar

Question 17

what can distal impaction often be mistaken for

Answer 17

vertical impaction

Question 18

why can distal impaction be hard to extract

Answer 18

because of the roots of the 8 can be very close to the roots of the 7 so it can be difficult to get an application point and not damage the 7 int eh process of removing the 8

Question 19

what does the depth of impaction give an indication of

Answer 19

gives an indication of the amount of bone removal required