impacted 3rd molars

Question 1

indications for surgical removal of teeth 6

Answer 1

When you can’t remove the tooth conventionally with elevators and forceps

Gross caries

Complex root morphology

Retained roots below the alveolar bone

Impacted, displaced and ectopic teeth

Pathology e.g. cysts

Question 2

define an impacted tooth

Answer 2

tooth prevented from completely erupting into a normal functional position. Can involve only soft tissue or hard and soft tissue.

Question 3

a tooth can be impacted due to what? 2

Answer 3

lack of space in arch and lack of an abrasive diet

Question 4

commonly impacted teeth

Answer 4

mandibular 8s, premolars, canines. Maxillary canines, incisors, 8s

Question 5

define ectopic teeth

Answer 5

malpositioned due to congenital factors

Question 6

define displaced teeth

Answer 6

malpositioned due to pathology e.g. cyst

Question 7

define ankylosed teeth

Answer 7

fused with the alveolar bone

Question 8

what guideline do u follow for indications to remove mandibular 3rd molars?

Answer 8

NICE 2000 guidelines

Question 9

define pericoronitits

Answer 9

inflammation of the tissues around the crown of any partially erupted/impacted tooth

Question 10

when is pericoronitis an indicator for referral?

Answer 10

2 or more episodes of it

Question 11

local management of pericoronitis 3

Answer 11

irrigate with saline, OHI small headed toothbrush, remove cause of trauma

Question 12

general management of pericoronitis 3

Answer 12

analgesics, antibiotics if systemic symptoms/ immunocompromised, admission in severe airway threatening cases

Question 13

what bacteria are present in pericoronitis

Answer 13

anaerobic - strep, actinomyces, prevotella

Question 14

what are the treatment choices for impacted 3rd molars 4

Answer 14

conservative - monitor
operculectomy - not recommended as grows back
removal - can make TMJ pain worse
coronectory - if close relationship to IDC

Question 15

what do u have to warn pt with a coronectomy? 3

Answer 15

root removal may be unavoidable

Risk of root infection post-operatively

Risk of root migration post-operatively

Question 16

in a coronectomy why do u need to remove all enamel

Answer 16

enamel wont incorporate into bone

Question 17

what do u need to asses radiographically for impacted 3rd molars

Answer 17

depth
relationship to 7
angulation to adjacent teeth
signs of close relationship to IDC

Question 18

signs of a close relationship between third molar and IDC 6

Answer 18

Diversion of IDC

Root darkening as its crossed by IDC

Loss of lamina dura of IDC

Narrowing of IDC

Deflection of roots as they approach the IDC

Juxta apical area

Question 19

what is used to image high risk relationships between 3rd molars and IDC

Answer 19

CBCT

only done if its going to change management

Question 20

what do u have to warn pt about when removing mandibular 3rd molars

Answer 20

altered sensation in the lower lip and tongue

Question 21

what is the risk of short term and long term altered sensation in the lower lip following 3rd molar extraction?

Answer 21

short term 5%
long term <1%

Question 22

what is the risk of short term and long term altered sensation in the tongue following 3rd molar extraction

Answer 22

short term 10%
long term <1%

Question 23

what are the general principles to consider when planning surgical removal of mandibular 3rd molars 5

Answer 23

path of eruption

obstacles - extrinsic and intrinsic

required bone removal

point of instrument application

flap design

Question 24

name this flap design

Answer 24

triangular mucoperiosteal flap

Question 25

name this flap design

Answer 25

envelope mucoperiosteal flap

Question 26

what pre-operative warnings are given to pt before surgical removal of mandibular 3rd molars 6

Answer 26

pain, swelling, bruising, possible hypoaesthesia of lip/tongue, trismus, diet advice

Question 27

u have to warn patients of post-operative complications with an incidence of what

Answer 27

greater than 5% incidence

Question 28

what do u do if the patient declines treatment to remove the 3rd molar

Answer 28

inform pt of likely long-term problems e.g. caries, periodontal problems, cysts, external root resorption, Pericoronitis

Question 29

how many sutures is better to secure primary closure and haemostasis

Answer 29

as little as possible

Question 30

where is the most important suture after mandibular 3rd molar surgery

Answer 30

between lingual and buccal tissues distal to the 2nd molar

Question 31

what sutures are used for suturing the flap after mandibular 3rd molar surgery

Answer 31

Resorbable suture - 3/0 vicryl rapide

Question 32

understand the image

Question 33

what complications can arise from mandibular 3rd molar surgery? 5

Answer 33

Haemorrhage- primary or secondary Loose teeth or damage to adjacent teeth/restorations periodontium Fractured mandible Dry socket or infection with purulent discharge Sensory deficit - IDB 5%, lingual 10%, permanent <1%

Question 34

what flap design is used for maxillary 3rd molar

Answer 34

buccal flap