third molars

Question 1

What are some indications for extracting third molars?

Answer 1

a) resorption of tooth/ adjacent tooth
b) abscess, osteomyelitis
c) extensive or nonrestorable caries in 7s
d) disease of tooth follicle such as cyst , tumors
e) tooth in line of jaw surgery
F) PERICORONITIS

Question 2

What is pericoronitis?

Answer 2

soft tissue inflammation related to crown of partially erupted teeth as a result of food, debris and plaque accumulation in gingivae resulting swelling and erythema

Question 3

What are some bacteria present in pericoronitis?

Answer 3

a) streptococci and anaerobic bacteria

Question 4

When is pericoronitis worse?

Answer 4

pts. stress and feeling run down.

Also, severity increases in immunocompromised pts.

Question 5

Describe symptoms of acute pericoronitis.

Answer 5

a) pain and swelling localized to the tooth
b) radiation of pain possibly.

Question 6

Explain examination findings of acute pericoronitis

Answer 6

a) trismus
b) swollen tender to the operculum
c) EO swelling and lymphadenopathy

Question 7

Describe symptoms of chronic pericoronitis

Answer 7

a) pus released from beneath operculum
b) radiological sign of enlargement of pericoronal space and sclerosing osteitis.

Note: traumatised operculum from opposing over erupted third molar

Question 8

What is sclerosing osteitis?

Answer 8

is abnormal bone growth and lesion in the jaw due to infection or inflammation.

Question 9

How to manage episode of pericoronitis?

Answer 9

a) OH
b) single stuffed brush to clean around the tooth
c) irrigate and prescribe chlorhexidine mouthwash
d) grind or extract opposing third molars.

If systemic involvement : prescribe antibiotics

Question 10

What antibiotics are given to pts. with pericoronitis?

Answer 10

1st line: metronidazole 400mg orally three times a day for 5 days can be given IV 500mg every 8 hrs given over 20 mins.
children: 200-250mg orally every 8 hours for up to 5 days.

Question 11

What happens if 1st line antibiotics fail or is not possible?

Answer 11

prescribe 2nd line which is amoxicillin 500mg orally three times a day for 5 days can be given IV 500 mg every 8 hours

for children: 500mg 3 times a day

Question 12

What are the most frequent reason for removing third molars? (NICE and other)

Answer 12

NCIE: one or more severe episodes of pericoronitis

Other: 1) if pt. having GA for extracting other 8s and is likely to be symptomatic
2) non-functional upper 8
3) lower 7s caries distally consider removing 8.

Question 13

Is there evidence thast removing third molars reduces anterior crowding and improves anterior open bite?

Answer 13

No, also u need to always eliminate TMD (temporomandibular disorder) and myofascial pain

Question 14

What do the new FDS guidelines state?

Answer 14

a) post-op with chlorhexidine gel
b) 8s mesioangular between 30-90 degrees may cause caries in 7s.
c) support the use of pre-op steriods
d) CBCT has no effect on outcomes

Question 15

What are factors that are taken into consideration in extracting third molars?

Answer 15

a) mouth opening (trismus?)
b) bone density (bisphosphonates?)
c) tooth (angulation, crown size, caries)
d) surgical anatomy (id nerve, cystic changes?)
e) adjacent teeth (caries, restorations, periodontal status)

Question 16

If it’s hard to assess the depth of 3rd molar in the alveolar bone what do you do?

Answer 16

insert and elevator to the roots of lower 7s to assess its depth.

Question 17

Is all of the third molars close to the ID canal?

Answer 17

No, the main three that are found to mainly related to IDN injury is
a) diversion of canals
b) darkening of the tooth (banding)
c) interruption of tramline of the nerve

Question 18

Even though CBCT is 10x radiation dose of OPT, when is it indicated?

Answer 18

a) only when conventional radiographs don’t show a relationship of 8s and ID
b) cysts
c) trauma and TMJ

Question 19

What is coronectomy?

Answer 19

partial odontectomy where u remove the crown at CEJ (as root lies -4mm below crestal bone level) and you don’t leave enamel however if the roots are mobilized you proceed to removal,

Question 20

When is coronectomy necessary?

Answer 20

high risk 8s which are close to IDC.

Question 21

Why do you have to remove enamel in coronectomy?

Answer 21

Because gums don’t grow over enamel as enamel pushes through it therefore leaving no soft tissues.

Question 21

Why do you have to remove enamel in coronectomy?

Answer 21

Because gums don’t grow over enamel as enamel pushes through it therefore leaving no soft tissues.

Question 22

What are the aims of surgery? (remove 8s)

Answer 22

minimize trauma (sectioning tooth)
remove tooth
better vision of flap/ bone removal
create application point
promote healing (debridement and closure)

Question 23

What are the types of flap designs for third molars? and what are the principles behind it?

Answer 23

triangular and envelope flaps,
mainly to maintain blood supply, suture over bone, avoid vital structure , preserve papillae and ability to close and extend when necessary.

Question 24

How do you section the tooth?

Answer 24

a) start furcation , section to remove part by part
b) bur’s depth ONLY if you pass (damage to the lingual nerve)
c) use space for elevation

Question 25

What do you usually use to debride and curettage the socket?

Answer 25

mitchell’s trimmer

Question 26

List some complications that could happen intra-op removing third molars.

Answer 26

Tooth/alveolar bone fracture
Fracture of maxillary tuberosity
OAC (oral mantra communication)
Hemorrhage
Tooth/root displacement
Damage to adjacent teeth
Damage to soft tissues
Inhaled/swallowed roots
Lip burn
(Fractured mandible)

Question 27

List some complications that could happen post-op removing third molars.

Answer 27

Pain
TMJ injury
Abscess/spread to tissue spaces
Dry socket (higher risk with 8s/bone removal)
Bleeding
Reactionary (clot lost <48 hours) Secondary (infection)
Haematoma
Nerve damage
Osteomyelitis is rare (infection of bone post tooth extraction)

Question 28

What is pain?

Answer 28

unpleasant sensory or emotional experience associated with actual or potential tissue damage.

Question 29

How is pain when removing third molars and removing bone controlled?

Answer 29

prescribing ibuprofen or paracetamol plus or minus other opiods.