Third Molars 4 Flashcards
3 basic principles of surgical removal
risk assessment
aseptic technique
minimal trauma to hard and soft tissues
(and informed consent)
risk assessment for surgical removal of 3rd molars needs
good planning
medical history
minimal trauma to hard and soft tissues during surgical removal of 3rd molars how?
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
3 anaeshtesia options for surgical removal of 3rd molars
Local anaestheisa (always placed for local pain relief and haemostasis)
IV sedation and LA
GA
depends on pt and difficulty of extraction
surgical removal of 3rd molars stages
- 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)
options for tooth division
2
Horizontal - crown and roots
Vertical - mesial and distal sections
reason for debridement
basic
ensure no fragments of bone/tissue left in socket
before commencing surgical extraction
- assess tooth with mirror and probe
- have suction set up
- give anaesthesia
- lignocaine for IDB, articaine for long buccal
how is access to the tooth gained
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
how is access to the tooth gained
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
reflection
raising the flap
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
instruments used for raising the flap
4
- 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
what is retraction
hold flap out the way
done with care, flap design facilitates retraction
why do retraction
2
access to operative field
protects soft tissues
instruments used for retraction
howarth’s periosteal elevator
rake retractor
minnesota retractor
atraumatic/passive retraction is
rest firmly on bone
awareness of adj structures e.g. mental nerve
tool used to do bone removal
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
intention of bone removal
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
intention of bone removal
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
site of bone removal
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
reason for bone removal
allow proper application of elevators on the mesial/ distal and buccal aspects of the tooth
after bone removal
assess if remove tooth in entirity with elevators or combo elevators and forceps
or
need to section tooth
tooth division
most common
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
horizontal crown section
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 *
vertical crown sectioning
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
what must you do before closing
account for all apices and parts of the tooth
debridement
reason for
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
3 types of debridment
physical
irrigation (thorough)
suction
physical debridement
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
irrigation debridement
sterile saline into socket and under flap
** must irrigate below the flap before you reposition it (debris, tooth under)**
suction debridement
aspirate under flap to remove debris
check socket for retained apices etc
aims of suturing
4
- reposition bone
- cover bone
- prevent wound breakdown
- achieve haemostasis
achieve anatomical repositioning of tissues
variety of combination, guided clinicallly
approximate tissues & compress blood vessels
what to do after surgical closure
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
when to do coronectomy
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
what is coronectomy
crown is removed with the deliberate retention of the root adjacent to the IAN
coronectomy procedure
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
follow up for coronectomy
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
specific key warnings to pt about coronectomy
3
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
upper third molars removal
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!!!! *
