Third Molars 4

Question 1

3 basic principles of surgical removal

Answer 1

risk assessment

aseptic technique

minimal trauma to hard and soft tissues

(and informed consent)

Question 2

risk assessment for surgical removal of 3rd molars needs

Answer 2

good planning

medical history

Question 3

minimal trauma to hard and soft tissues during surgical removal of 3rd molars how?

Answer 3

care when raising mucoperiosteum flap - when raising soft tissues with underlying periosteum in one go rather than separate/multiple goes

removing right amount of bone - not too little which limits access, but not too much

Question 4

3 anaeshtesia options for surgical removal of 3rd molars

Answer 4

Local anaestheisa (always placed for local pain relief and haemostasis)

IV sedation and LA

GA

depends on pt and difficulty of extraction

Question 5

surgical removal of 3rd molars stages

Answer 5

• basic priniciples and consent
• anaesthesia
• access
• bone removal and/or tooth division as necessary
• extract - ensure all apices are out
• debridement
• suture
• achieve haemstasis
• post-op instruction (verbal and written)

Question 6

options for tooth division

2

Answer 6

Horizontal - crown and roots
Vertical - mesial and distal sections

Question 7

reason for debridement

basic

Answer 7

ensure no fragments of bone/tissue left in socket

Question 8

before commencing surgical extraction

Answer 8

• assess tooth with mirror and probe
• have suction set up
• give anaesthesia
• lignocaine for IDB, articaine for long buccal

Question 9

how is access to the tooth gained

Answer 9

raising a buccal mucoperiosteal flap

+/- raising a lingual flap (some debate/depends on surgeon and the clinical situation – risk to lingual nerve)

AIM: Maximum access with minimal trauma
* Larger flaps heal just as quickly as smaller ones
* Needs to be adequate to allow you to see tooth

Use scalpel in one firm continuous stroke
* Minimise trauma to dental papillae

Question 10

how is access to the tooth gained

Answer 10

raising a buccal mucoperiosteal flap

+/- raising a lingual flap (some debate/depends on surgeon and the clinical situation – risk to lingual nerve)

AIM: Maximum access with minimal trauma
* Larger flaps heal just as quickly as smaller ones
* Needs to be adequate to allow you to see tooth

Use scalpel in one firm continuous stroke
* Minimise trauma to dental papillae

Question 11

reflection

raising the flap

Answer 11

Commence raising flap at base of relieving incision
* already gaping / bone visible (here mesial relieving incision)

Undermine / free anterior papilla before proceeding with reflection distally (avoid tears)
* Often done with Warwick James

Reflect with periosteal elevator firmly on bone in one piece
* Avoid dissection occurring superficial to periosteum
* Reduce soft tissue bruising / trauma

Most difficult reflection (reflect with minimal trauma)
* Papilla
* mucogingival junction

Question 12

instruments used for raising the flap

4

Answer 12

• Mitchell’s trimmer (spoon one and end and sharp the other)
• Howarth’s periosteal elevator
• Ash Periosteal Elevator (flat end, useful for raising)
• Curved Warwick James elevator

Question 13

what is retraction

Answer 13

hold flap out the way

done with care, flap design facilitates retraction

Question 14

why do retraction

2

Answer 14

access to operative field

protects soft tissues

Question 15

instruments used for retraction

Answer 15

howarth’s periosteal elevator
rake retractor
minnesota retractor

Question 16

atraumatic/passive retraction is

Answer 16

rest firmly on bone

awareness of adj structures e.g. mental nerve

Question 17

tool used to do bone removal

Answer 17

Electrical straight handpiece with saline cooled bur (stand alone unit)
* Air driven handpieces may lead to surgical emphysema

Round or fissure stainless steel & tungsten carbide burs
* Round used around the margin to create a buccal gutter
* Fissure used for sectioning the tooth

plenty of irrigation
* maintain visibility
* avoid bony necrosis

Protection of soft tissues

Question 18

intention of bone removal

Answer 18

deep, narrow gutter around the crown of the wisdom tooth
* Not a shallow, broad gutter
* Keep round bur in close contact with tooth from distal to mesial around buccal surface (ensure narrow), ensure not damaging adj tooth

Distal first to ensure not loose control in retromolar area and plunge in soft tissue (contain lingual nerve)

Want at least depth of bur head

Question 18

intention of bone removal

Answer 18

deep, narrow gutter around the crown of the wisdom tooth
* Not a shallow, broad gutter
* Keep round bur in close contact with tooth from distal to mesial around buccal surface (ensure narrow), ensure not damaging adj tooth

Distal first to ensure not loose control in retromolar area and plunge in soft tissue (contain lingual nerve)

Want at least depth of bur head

Question 19

site of bone removal

Answer 19

buccal aspect of the tooth including the distal aspect of imapction (start distal and move mesial to ensure control maintained in lingual nerve region, careful around adj tooth)

deep, narrow gutter

Question 20

reason for bone removal

Answer 20

allow proper application of elevators on the mesial/ distal and buccal aspects of the tooth

Question 21

after bone removal

Answer 21

assess if remove tooth in entirity with elevators or combo elevators and forceps

or

need to section tooth

Question 22

tooth division

most common

Answer 22

crown of the tooth is sectioned from the roots and the crown and roots are elevated as individual items

Sometimes further separation of the roots with a bur is required following elevation of the crown, and each root is elevated as an individual item

Question 23

horizontal crown section

Answer 23

When sectioning to remove entire tooth section above the enamel – cementum junction. This leaves some crown behind and allows orientation and elevation.
* Ensure drill doesn’t slip out mesial or distal aspect of tooth (soft tissue or adj tooth)
* Height of tip of bur into tooth, no more as don’t want it coming out the lingual aspect
* place a narrow elevator instrument in (Warwick James) and turn clockwise or anticlockwise to crack crown of tooth

*When carrying out coronectomy – section below enamel – cementum junction.
More – don’t want to leave any enamel behind *

Question 24

vertical crown sectioning

Answer 24

May require further sectioning of roots - Split roots and elevate one at a time tooth may be sectioned longitudinally/vertically after vertical sectioning * This allows removal of the distal portion of the crown and distal root, followed by elevation of the mesial portion of the crown and mesial root

Question 25

what must you do before closing

Answer 25

account for all apices and parts of the tooth

Question 26

debridement | reason for

Answer 26

Ensure no sharp edges or bony spicules around socket When the tooth is removed any debris must be cleaned out and any follicular tissue or granulation tissue from chronic infection should be curetted – especially that hidden behind the second molar as it heals pt may become aware of some edges (normal) but ensure nothing obvious at the time of surgery use instruments to smooth bone

Question 27

3 types of debridment

Answer 27

physical irrigation (thorough) suction

Question 28

physical debridement

Answer 28

Bone file (file over) or handpiece to remove sharp bony edges (Bone nibblers can be useful for the odd spike) Mitchell’s trimmer or Victoria curette to remove soft tissue debris

Question 29

irrigation debridement

Answer 29

sterile saline into socket and under flap ** must irrigate below the flap before you reposition it (debris, tooth under)**

Question 30

suction debridement

Answer 30

aspirate under flap to remove debris check socket for retained apices etc

Question 31

aims of suturing | 4

Answer 31

* reposition bone * cover bone * prevent wound breakdown * achieve haemostasis achieve anatomical repositioning of tissues variety of combination, guided clinicallly | approximate tissues & compress blood vessels

Question 32

what to do after surgical closure

Answer 32

ensure haemostasis and deliver post op instructions (usually done whilst pt biting on damp gauze) give written doc careful whilst numb - eating, drinking, biting * IDB generally lasts 3 hours, tongue and buccal and then everywhere else * Still area of numbness – get in touch analgesia advice bleeding instructions rinsing - next day

Question 33

when to do coronectomy

Answer 33

alt to surgical removal of entire tooth when there appears to be an increased risk of IAN damage with surgical removal | AIM: reduce risk of IAN damage

Question 34

what is coronectomy

Answer 34

crown is removed with the deliberate retention of the root adjacent to the IAN

Question 35

coronectomy procedure

Answer 35

Flap design as necessary to gain access to tooth. Generally – standard wisdom tooth flap designs Transection of tooth 3-4mm below the enamel of the crown into dentine * **No enamel left behind** Elevate/lever crown off without mobilising the roots Pulp left in place – untreated * Majority heal over fine If necessary – further reduction of roots with a rose head bur to 3-4mm below alveolar crest (not always possible) Socket irrigated Flap replaced – some reposition flap leaving socket open, some close flap completely (primary closure with periosteal release if necessary) Antibiotics not prescribed routinely

Question 36

follow up for coronectomy

Answer 36

1-2 weeks review Further review 3-6 months then 1 year. *Some review at 2 years but most discharge back to GDP after 6 months or 1 year review* Radiographic review – 6 months or 1 year; or both. Thereafter if symptomatic. *Some take an immediate or 1 week post op radiograph* variable

Question 37

specific key warnings to pt about coronectomy | 3

Answer 37

If the root is mobilised during crown removal the entire tooth must be removed (more likely with conical fused roots) * Leaving roots behind could result in infection (rarely seen), hence why need getting out Can get a slow healing/painful “socket” * Dry socket symptoms The roots may migrate later and begin to erupt through the mucosa; and may require extraction * But safer to remove them as less likely closely related to IDC

Question 38

upper third molars removal

Answer 38

Generally easier to remove Although occasionally very difficult Removed by elevation only or elevation and forceps extraction * Elevation with straight or curved Warwick James elevator, or Coupland's (with care) * Forceps – generally upper third molars (Bayonets) used **Support the tuberosity with finger and thumb** * If there is undue resistance to elevation/extraction then excessive force can fracture the tuberosity – the use of forceps and support to the tuberosity should reduce this risk in these circumstances If it is not possible to get access to the partially erupted upper third molar a buccal flap may be raised and appropriate bone removal carried out. **Essential to have radiograph before** * Variable root morphology * Number, shape, divergence, curves, proximity to maxillary sinus, supernumerary *Do not underestimate the upper third molar. Grossly carious, partially erupted upper 8s, with diverging roots, in large patients – can be extremely challenging!!!! *