Brainscape's Knowledge GenomeTM

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


See full index

BDS4 ORAL SURGERY > Third Molars > Flashcards

Third Molars Flashcards

1
Q

Between what ages do third molars usually erupt into the mouth?

A

Between 18-24yrs

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

At what age does crown calcification of upper third molars begin?

A

between 7-9y/o

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

At what age does crown calcification of lower third molars begin?

A

between 8-10y/o

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

If third molars are missing at age 14 on a radiograph, what will likely happen?

A

unlikely to develop

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

What is agenesis in terms of third molars?

A

Failure of an organ to develop eg failure of third molars to develop

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

In which jaw is agenesis of third molars more likely to occur?

A

Maxilla

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

What does an impacted third molar mean?

A

tooth eruption is blocked

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the most common reasons for impacted third molars?

A
  • blocked by adjacent tooth
  • alveolar bone
  • surrounding mucosal soft tissue
  • combination of above
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some potential consequences of impacted third molars?

A
  • caries
  • pericoronitis
  • cyst formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What nerves are at risk during third molar surgery?

A
  • inferior alveolar nerve
  • lingual nerve
  • nerve to mylohyoid
  • long buccal nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why do we almost ALWAYS need an OPT radiograph before third molar surgery on lowers?

A

To see how close third molar lies in relation to the inferior alveolar nerve canal

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

Where does the lingual nerve lie roughly in relation to the mandible?

A

between 0-3.5mm medial to the mandible

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

What guidelines are referred to for third molar surgery?

A
  • NICE = guidance on extraction of wisdom teeth 2000
  • SIGN Publication 43 = management of unerupted and impacted third molar teeth, 2000
  • FDS, RCS 2020 = parameters of Care for patients undergoing mandibular third molar surgery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are therapeutic indications for extractions of third molars?

A
  • infection (caries, pericoronitis, local bone infection)
  • cysts
  • tumours
  • external resorption of 7 or 8
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some other indications for extractions of third molars?

A
  • surgical indications eg orthognathic, fractured mandible
  • high risk of disease
  • medical indications
  • accessibility limited for restorative work
  • patient age
  • autotransplantation
  • general anaesthetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Give examples of medical indications for extraction of third molars:

A
  • awaiting cardiac surgery
  • immunosuppressed
  • prevent osteonecrosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is pericoronitis?

A

Inflammation around the crown of a partially erupted tooth
- food and debris gets trapped under the flap resulting in inflammation & infection

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

In what age groups is pericoronitis most commonly seen?

A

20-40 yrs

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

What type of microbes are typically found in pericoronitis infections?

A

Anaerobic microbes
- streptococci

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

What are the signs and symptoms of pericoronitis?

A
  • pain & swelling
  • bad taste
  • pus discharge
  • occlusal trauma to gum flap
  • evidence of cheek biting
  • limited mouth opening
  • dysphagia
  • pyrexia
  • malaise
  • foetor oris
  • regional lymphadenopathy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the operculum of third molar?

A

Gum flap covering PE third molar

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

How is pericoronitis treated?

A
  • incision of localised pericoronal abscess
  • LA sometimes depends on patient
  • irrigation with warm saline or chlorhexidine mouthwash
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What advice should be given to patients with pericoronitis?

A
  • advice regarding analgesia
  • instruct patient to keep fluid levels up & keep eating
  • generally do not prescribe antibiotics unless systemic symptoms
  • if large extra-oral swelling, severly systemically unwell/trismus/dysphagia… refer to maxfax
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What type of radiograph would you get to assess the third molars?

A

OPT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What would you look at on an OPT when assessing third molars?

A
  • anatomy of 3M
  • depth of impaction
  • orientation of impaction
  • working distance
  • follicular width
  • perio bone levels
  • surrounding anatomy (IAN/maxillary sinus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are some signs on the OPT that may suggest that lower third molars lie close to the inferior dental canal?

A
  • interruption of lamina dura of canal
  • darkening of the root where crossed by the canal
  • diversion/deflection of the inferior dental canal
  • deflection of root
  • narrowing of IAN canal
  • narrowing of root
  • dark & bifid root
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 3 HIGHEST RISK SIGNS on an OPT of risk to inferior alveolar dental nerve during 3M surgery?

A
  • diversion of IAN canal
  • darkening of the root where crossed by canal
  • interruption of the white lines of the canal
28
Q

If you take an OPT, and there is suspected close relationship of 3M to IAN canal what might you do next?

A

take CBCT

29
Q

What different types of angulation may third molars be situated in?

A
  • vertical
  • mesial
  • distal
  • horizontal
  • transverse (sideways)
30
Q

What is the angulation/orientation of third molars measured against?

A

curve of Spee

31
Q

What orientation of third molars are the most difficult to remove?

A

distally impacted third molars

32
Q

How can the depth of impaction of third molars be described?

A
  • superficial
  • moderate
  • deep
33
Q

Where would a third molar that is considered superficial in terms of depth be positioned?

A

crown of 8 related to crown of 7

34
Q

Where would a third molar that is considered moderate in terms of depth be positioned?

A

crown of 8 related to crown and root of 7

35
Q

Where would a third molar that is considered deep (in terms of depth) be positioned?

A

crown of 8 related to root of 7

36
Q

What are the common treatment options for problematic third molars?

A
  • referral
  • clinical review
  • XLA of M3M
  • coronectomy
37
Q

What are some less common treatment options for problematic third molars?

A
  • operculectomy
  • surgical exposure
  • pre-surgical orthodontics
  • surgical reimplantation/autotransplantation
38
Q

What are the different methods of anaesthesia used for third molar treatment?

A
  • LA alone
  • conscious sedation
  • general anaesthetic
39
Q

What type of consent is needed for GA and IV sedation?

A

written consent form (done at different appt)

40
Q

What post-op complications may arise from third molar surgery?

A
  • pain
  • swelling
  • bruising
  • jaw stiffness/trismus
  • bleeding
  • infection
  • dry socket
  • numbness or tingling of lower lip, chin, tongue
41
Q

What is dysaesthesia?

A

painful, uncomfortable, unpleasant sensation of lower lip, chin, tongue
- sometimes neuralgia type pain

42
Q

What is hypoaesthesia?

A

reduced sensation

43
Q

what are the basic principles of surgery in dentistry?

A
  • risk assessment (good planning & medical history)
  • aseptic technique
  • minimal trauma to hard & soft tissues
44
Q

what are the steps of surgical removal of third molars?

A
  • anaesthesia
  • access
  • bone removal as necessary
  • tooth division as necessary
  • debridement
  • suture
  • achieve haemostasis
  • post-op instructions
45
Q

How is surgical access to third molars achieved?

A
  • raise a buccal mucoperiosteal flap
  • sometimes raise a lingual flap
46
Q

What factors apply to surgical flaps?

A
  • larger flaps heal just as well as smaller ones
  • use scalpel in one firm continuous stroke
  • avoid trauma to dental papillae
47
Q

How should flaps be reflected during surgical extractions?

A
  • commence raising flap at base of relieving incision
  • undermine/free anterior papillae before proceeding with reflection distally
  • reflect with periosteal elevator firmly on bone
48
Q

what is often used to raise papillae during a surgical extraction?

A

(curved) warwick james elevator

49
Q

what instruments are used to raise flap from bone during a surgical extraction?

A
  • mitchell’s trimmer
  • howarth’s periosteal elevator
  • ash periosteal elevator
50
Q

why are flaps retracted during surgical extractions?

A
  • better access to operative field
  • protection of soft tissue
51
Q

what instruments are used to retract flaps during surgical extractions?

A
  • Howarth’s periosteal elevator
  • Rake retractor
  • Minnesota retractor
52
Q

how do you ensure you achieve atraumatic/passive retention of flaps?

A
  • rest firmly on bone
  • have awareness of surrounding structures
  • avoid crushing
53
Q

what is used to remove bone during a surgical extraction?

A
  • electrical straight handpiece with saline cooled burr
  • round or fissure stainless steel & tungsten carbide burs
54
Q

why are air driven handpieces not used in surgical extractions?

A

risk of surgical emphysema

55
Q

what should you try to achieve when removing bone during surgical extractions of third molars?

A
  • carried out on buccal aspect of tooth & onto distal aspect of impaction
  • create a deep narrow gutter around crown of wisdom tooth (avoid shallow, broad gutter)
56
Q

when removing bone around third molars, why do you start distally and move mesially?

A

if burr slips travelling distally you risk damaging the lingual nerve

57
Q

What is the horizontal tooth division method during surgical extractions?

A

divide the crown from the roots
- some crown left (can be elevated out with roots)
- full coronectomy when divided below enamel cementum junction

58
Q

What are the different modes of debridement in oral surgery?

A
  • physical
  • irrigation
  • suction
59
Q

How is physical debridement carried out?

A
  • bone file or handpiece to remove sharp bony edges
  • Mitchell’s trimmer or Victoria curette to remove soft tissue debris
60
Q

How is irrigation debridement carried out?

A

sterile saline into socket and under flap

61
Q

how is suction debridement carried out?

A
  • aspirate under flap to remove debris
  • check socket for retained apices etc.
62
Q

what are the aims of suturing?

A
  • reposition tissues
  • cover bone
  • prevent wound breakdown
  • achieve haemostasis
63
Q

Why is a coronectomy used in third molar surgery?

A

alternative to surgical removal of entire tooth when there appears to be an INCREASED RISK OF IAN DAMAGE

64
Q

How is a coronectomy carried out?

A
  • flap raised
  • transection of tooth 3-4mm below the enamel of the crown into dentine
  • elevate/lever crown off without mobilising the roots
  • pulp left in place (untreated)
  • sometimes reduce roots futher with rose head burr
65
Q

When do you follow-up with a patient after coronectomy surgery?

A
  • review 1-2 weeks
  • further review 3-6 months
  • then review 1 year later
66
Q

What must you warn the patient of prior to coronectomy surgery?

A
  • if root is mobilised during crown removal the entire tooth must be removed
  • leaving roots behind could result in infection
  • can get a slow healing/painful socket
  • the roots may migrate later and begin to erupt through mucosa (and need XLA)
67
Q
A

BDS4 ORAL SURGERY (16 decks)

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