3rd molar treatment planning

Question 1

What nerves are at risk during surgical extraction of lower 3rd molars?

Answer 1

Lingual nerve
Inferior alveolar nerve
Mylohyoid nerve
Long buccal nerve

Question 2

What are the indications for XLA of 3rd molars?

Answer 2

1 or more episode of pericoronitis, cellulitis, abscess formation or untreatable pathology
Risk of caries/periodontal disease 7/8
Caries present in 3rd molar and is unlikely to be useful restored or if caries cannot be treated in 7 due to position of 8
Presence of periodontal disease due to position of 8n
Cases of dentigerous cyst formation
Cases of external resorption
In fractured mandible cases involving 3rd molar region
For implant placement

Question 3

What is checked when assessing for risk of nerve damage for extracting Lower wisdom teeth?

Answer 3

• darkening of root crossed by canal
• diversion of IAN canal
• interruption of white lines/lamina dura
• deflection of the root
• narrowing of IAN canal
• juxta apical area

Question 4

What type of angulation makes extraction more difficult?

Answer 4

Distal angulation due to vector of Movement

Question 5

What factors affect complexity of extraction of wisdom teeth?

Answer 5

• angulation of winters lines
• height of mandible
• angle of 2nd molar
• root form and development
• size of follicular sac
• exit path of tooth to be extracted

Question 6

What are the options of treatment for 3rd molars?

Answer 6

Asymptomatic:
- monitor and review

Symptomatic:

• XLA or surgical extraction
• extraction of opposing 3rd molar
• coronectomy if close relationship with IAN

Question 7

What is pericoronitis?

Answer 7

Inflammation of the soft tissue around the crown of the tooth which only occurs when there is a communication between the tooth and oral cavity.
Food and debris gets trapped under operculum resulting in inflammation or infection occurring.

Question 8

How is pericoronitis managed?

Answer 8

• incision of pericoronal abscess if required
• irrigation with warm saline or CHX under operculum
• use of antiseptic Talbot’s iodine beneath operculum
• extraction of upper 8 causing trauma or extract tooth once acute episode is resolved
• analgesics and CHX use

Antibiotics prescribed if symptoms are severe, patient is systemically unwell or immunocompromised

If pt has large extra oral swelling, systemically unwell, trismus or dysphagia should be referred to MaxFacs

Question 9

What is the risk of temp and permanent IDN anaesthesia?

Answer 9

Temp:
- 10-30%

Permanent:
- <1% (high risk cases <2%)

Question 10

What is the risk of temp and permanent lingual nerve anaesthesia?

Answer 10

Temp:
- 0.25-23%

Permanent:
- 0.14-2%

Question 11

What are the Principle surgical access aims?

Answer 11

1. Wide based incision to protect circulation
2. Use scalpel in one firm continuous stroke to prevent sharp edges and angles
3. Flap should be adequate size (large heals same as small)
4. Flap reflection down to bone and done cleanly
5. Minimise trauma to dental papilla
6. No crushing of tissues
7. Ensure tissues are kept moist
8. Ensure flap margins and sutures lie on sound bone
9. Wound is not closed under tension
10. Aim for healing by primary intention to minimise scarring

Question 12

What instruments are good for soft tissue retraction?

Answer 12

Howarth’s periosteal elevator

Rake retractor

Question 13

Why should an electric hand piece with saline coolant be used for bone removal?

Answer 13

Prevents surgical emphysema and protects soft tissues

Question 14

What is used for debridement of bone and soft tissue ?

Answer 14

Bone file or hand piece to remove sharp bone

Mitchell’s trimmers or Victoria curette to remove soft tissue debris

Question 15

What are the principle suturing aims?

Answer 15

1. Approximate the tissues
2. Compress blood vessels
3. Reposition the tissues
4. Cover the bone
5. Prevent wound breakdown
6. Achieve haemostasis
7. Encourage healing by primary intention

Question 16

What are the 2 most common flap designs for 3rd molar removal?

Answer 16

3 sided:
- distal and mesial relieving incision

2 sided (envelope flap) 
- distal relieving incision

Question 17

What are peri operative haemostatic aids?

Answer 17

Pressure with finger or biting on gauze
La with vasoconstrictor 
Artery forceps
Diathermy 
Bone wax

Question 18

What are post operative haemostatic aids?

Answer 18

Pressure with finger or biting on gauze 
La with vasoconstrictor 
Diathermy 
Haemostatic agent - surgicell and kaltostat 
Suturing 
Bone wax on socket wall 
Haemostatic forceps/artery clips

Question 19

What are the risks associated with coronectomy?

Answer 19

Mobilisation of roots - XLA
Infection as pulp remains
Migration of roots
Cystic changes

Question 20

Name 2 types of resorbable sutures?

Answer 20

Monofilament: monocryl (poliglecaprone 25)

Multifilament: vicryl rapide 3.0 (polyglactin 910)

Question 21

Name 2 types of non resorbable sutures?

Answer 21

Monofilament: prolene (polypropylene)

Multifilament: Mersilk (black silk)

Question 22

What scalpel is best used in oral surgery?

Answer 22

Use 15 or 11 narrow blade scalpel

Question 23

How long do vicryl sutures take to lose 50% tensile strength?

Answer 23

2-3 weeks

Question 24

How long do vicryl sutures take to absorb fully?

Answer 24

56-70days

Question 25

What is the man issue with using polyfilament sutures?

Answer 25

They are prone to wicking and bacteria can migrate along the length of the suture.