principles of exodontia 1

Indications for extraction

1. Unrestorable - ie gross caries

2. Periodontal disease - grade 3 mobility

3. Pericoronitis - affects partially erupted teeth usually 8s lower - food gets caught under the gum - inflammation

4. Associated pathology (e.g. cysts, tumour)

5. Orthodontics - usually premolars

6. Trauma - Enamel dentine fracture involving the whole tooth

7. Interfere with construction of a prosthesis

8. Tooth within fracture line - ie if you have a fracture of the mandible - and the tooth was in that line - you may decide to remove it

9. Teeth in a fracture line

10. Abnormal/ supplemental teeth - odontomes

11. Impeding eruption of other tooth - deciduous teeth

12. Financial / phobia - pt decides

Do no harm!

what is the best treatment option for this patient ? must explore all options that are available to the pt - even if you don’t specialise it - inform the pros and cons - informed consent

Informed consent

Discuss alternative options

• Restore to function - ie fillings, crowns, RCT, apical microsurgery

• Restore but not functional - doning off retained route

• Prognosis - how successful is the treatment? Give them a timeline - restorations usually last approx 10 years

Safe to perform extraction?

• Aware of medical history?

• Contra-indications?

• Know limitations (surgeons capabilities) - when to refer

cross infection protocol

• Protect your patients

• Protect yourselves

Factors affecting difficulty of extraction 4

1. Tooth - crown and roots

2. Supporting structures - pdl and bone

3. Proximity to adjacent structures - nerves and other teeth - maxillary antrum

4. Access - how easy is the access to the surgical site?

tooth factors - crown morphology

• Grossly carious?

• Restorations?

  • Large/ subgingival

  • Crowns/ post & cores

• Endodontic treated - necrotic teeth are weaker - more likely to fracture during extraction

• Bulbous crown - difficult to apply forceps

tooth factors - root morphology

• Single vs multiple - single is easier to remove

• Long/short, wide/thin/ bulbous - thin more likely to fracture, bulbous - more difficult to remove

• Curved/ conical/ divergent/ convergent

Supporting structures - gingival soft tissues

– Gingival overgrowth

• Medication

• Chronic inflammation

• Subgingival carious cavity

supporting structures - pdl

Periodontal ligament

supporting structures - bone

• periodntal disease

• density -age/gender/ethnicity

Assessment

• Medical history assessment

  • Under care of medical/surgical specialist

  • Regular medication

  • Previous operations

  • do a systems review

• Clinical examination - extra orally, intra-orally

• Radiographic assessment – Asses surgical difficulty – tooth, root, adjacent structures

• blood tests, sensibility tests may be needed

• Working diagnosis - explore treatment options - though that you will understand if oral surgery is required - have an idea of surgical complexity - is this in your remit

Planning

Essential planning prior to commencement of procedure

will have a standard surgical equipment tray

Proximity to adjacent structures - teeth

• Impacted

• Restorations of adjacent teeth (crowns/ amalgams) - particularly if they have overhangs

• Mobile adjacent teeth

• Distal teeth

Proximity to adjacent structures - vital structures

• Inferior alveolar nerve

• mental nerve

• Infra-orbital nerve

• Maxillary antrum - where apices of teeth may be situated

access - Limited mouth opening

• anterior teeth have relatively easy access - but the difficulty comes when the patient has limited mouth opening

limited mouth opening may be due to:

1. Spread of infection - pus or cellulitis or very guarded due to pain

2. Disk displacement TMJ

3. Small mouth

4. Rare conditions (oral submucous fibrosis)

access - position of the teeth

• Impacted / unerupted - more difficult access as they are coverd with bone and mucosa

• Crowding - will have a lot of teeth buccal and lingual to the tooth in question

methods of tooth extraction 2

1. routine tooth extraction

2. surgical tooth extraction

routine tooth extraction

• Forcep extraction

• Elevation extraction

Surgical tooth extraction

• Sectioning of tooth +/-

• Raising a mucoperiosteal flap

Overview mechanisms of extraction

1. Sever periodontal ligament & dilate socket

• Elevators, luxators and/or forceps

• Force along long-axis of tooth (apical pressure)

• Position beaks apically along roots

2. Complete dilation of socket and withdraw tooth

• Lateral movement of tooth

• Buccal and palatal directions

• Figure of eight / circle movement

• Rotational movement for round, single rooted teeth

Applied force should be controlled and slow to avoid injury

Support of jaw/ alveolar bone with other hand

direction/path of tooth removal is determined by the

1. Morphology of root (curvature, shape, how many roots there are)

2. Impaction (level and position of bone, adjacent tooth)

Routine, non-surgical extraction path

Routine, non-surgical extraction removes tooth by path of removal determined by the natural root morphology and bone

Surgical extractions path

Surgical extractions remove bone and section teeth in order to alter the tooth determined path of removal. However, this natural path of removal is not removed altogether - natural root morphology will have an impact.

Forceps

• Blades in long axis of handle (upper teeth)

• Right angles to handle (lower teeth)

• Wedged shaped blades – dilate socket break PDL

• “Beak to cheek” – upper molar forceps

lever principle - long handle attached to the blade - blades hold onto the tooth during removal

holding forceps

• when positioning - put your fingers between the handles - so the surgeon can open the forceps so the blades are open

• forceps engage the tooth at the CEJ - ie the coronal portion of the root

• once the tooth is engaged, the surgeon will remove their forefingers from between the handles in order to apply apical pressure in order to remove the tooth

curvature and blades

• Blades need to fit tooth curvature for effective extraction

• blades of the forceps will be in contact with the coronal portion of the root - the rest will be encased in bone

• Hollow inner surface to fit roots for maximum contact

• If forceps appear not to have sufficient tooth contact/‘grip’ tooth well- try another pair of forceps with different sized blades or curve of blades

there are 3 main methods of routine forcep extraction:

elevation, luxation and forcep extraction

we can remove teeth just with forcep extracation but that is slightly more difficult

• Forceps

• Elevation ➔ Forceps

• Elevation ➔ Luxation ➔ Forceps - most common Elevation and luxation helps severe the pdl and dilate the tooth socket

• Luxation ➔Forceps

the foreceps help to severe the pdl and dilate the tooth socket - theyre sat on the CEJ - the blade will sit into that and damage the pdl cornally - severing it - wedge effect - will dilate the pdl space socket most coronally. In summary - the forceps will severe and dilate the socket coronally

• Disrupt PDL & dilation of bony socket – Forcep blades wedge in PDL space

• Blade tips engage root of tooth (not crown)

because they engage the tooth properly, they can move the tooth laterally in order to dilate the socket as well

teeth are delivered both in the maxilla and mandible buccally - why?

• buccal bone is Thinner compared to hard palate/ lingual bone

• Thinner compared to lingual bone (except lower 8s)

you will be moving the tooth much more buccally - then withdrawing the tooth buccally for removal

forcep extraction - order

1. application

2. apical force

3. lateral movement

4. rotational movement

5. delivery

forcep extraction - application

Separate coronal PDL from tooth:

• Probe around the gingival margin of tooth (also tests anaesthesia)

• Place blades under gingivae with minimal soft tissue damage at CEJ

• Align forcep beaks along long axis of tooth

• Push very hard forceps apically along root surface (cowhorns to engage furcation)

• Engage root surface (grip root) with beaks by closing forceps

apical pressure

throughout the whole extraction it is very important to maintain apical pressure throughout

upper premolar

upper premolar being help with premolar forceps on the left

hold in alignment with the long axis of the tooth - correct = left

holding a lower molar with forceps

both correct images

lower cowhorn forceps

what is special about these forceps?

lower cowhorn forceps - engaging the furcation of the molar

upper left molar forceps

notice how the tips of the blade go underneath the gingival cuff

lateral movement

• Expansion of socket

• buccal & palatal/lingual movement

• Figure of ‘8’/ circular movement

• Maintaining apical pressure throughout

ensures the tooth socket has expanded in a bucco-lingual direction - but then try to expand in all directions ie circular/figure of 8 movements

rotational movement

• Tear soft tissue attachment (apical granuloma/ gingival mucosa)

• Removal of circular, single rooted teeth (upper incisors, lower premolars)

delivery

after tooth is mobilised traction forces remove the tooth from socket

why do we apply apical pressure?

• Prevents beaks sliding off root

• Expands socket by positioning coronal, wider root apically

• Centre of rotation of tooth displaced apically

• Alters angle of force on roots

Centre of rotation of tooth displaced apically - wat dat mean?

this also helps to prevent tooth fracture

centre of rotation - with respect to apical pressure

when you also apply lateral pressure, eg moving the tooth buccal - the apical portion will move the other way - eg palatally - with the centre of rotation halfway up the rooth surface

if teh forceps are placed on the crown and there is limited apical pressure on the tooth - then your centre of rotation would also move coronally - a larger proportion of the rooth will move palatally - causing a root fracture

buccal pressure alone

Buccal force alone- rotation of tooth – root fracture - you also need to dilate the socket

Apical & lateral pressure

Simultaneous apical force + buccal movement rotation

• Centre rotation closer to buccal root apices

• Expansion of buccal root socket

• Palatal root delivered along curvature of root

Bone expansion through lateral movement

Pressure

• Develop ‘feeling’ through the forceps (biofeedback)

• Excessive force

  • Tooth/ jaw fracture

  • Discomfort for patient (TMJ pain)

  • Increased patient overall discomfort & anxiety

• Limited force

  • Extended extraction time

  • Inability to extract tooth

• Steady movements (not short, jerky)

Lateral excursions

Lateral excursions

• hold pressure buccally to allow time for bone to expand

• Recognise resistance to movement by feel

Tooth will move in line of least resistance pre-determined by root morphology – not always buccal! if roots want to be removed lingually - remove crwon and allow that to happen

Lower cowhorns

• Pointy blades

• Engage furcation

• Position on root surface & close forceps firm until blades engage birfurcation

• Handles will close when bifircation is completely engaged

• Apical & bucco-lingual movement

• Tooth is ‘lifted out’ of socket as handles close & tooth is delivered finally with traction.

these engage the bucco-lingual furcation

Upper cowhorns

• Grip around palatal root and engage buccal furcation - horn

• Useful for heavily broken down/ fractured upper molars.

• Used in similar manner to upper molar forceps

Positioning

• Optimal access & applied force

• Access to occlusal planes: good visualisation whilst maintaining good posture

Chair position - inclination and height

• Inclination (maxillary extraction chair is more reclined than mandibular extraction)

• Height (maxillary extraction-chair higher than mandibular extraction)

Head position

• Mandibular extraction-chin down

• Maxillary extraction – chin up

Mandibular extractions

guide - you want to see the occlusal surfaces of the teeth

image one - lower left quadrant - infront

lower right - standing behind the patient

Maxillary extractions

lhs - removing upper left tooth

rhs -

The other hand

• Supporting hand

  • Support the jaw - counteract force from forceps/ elevators to stabilize jaw.

  • Finger rest

• Retraction of soft tissue

  • Thumb and forefinger either side of arch adjacent to tooth

  • Holds retractor

• Feel adjacent tooth

• Check adjacent tooth not mobilising during extraction/ elevation

she is using her forefinger and middle finger on either side of the alveolus and thumb underneath the mandible

notice thumb and forefinger on either side of the alveolar when removing the upper right second premolar

on the rhs - the minnasota retractor is retracting the right cheek for good visualisation

elevators

elevators can severe the pdl and can dilate the socket

• Positioned horizontally (90° to long axis tooth) - contrary to luxators

• Applied to root surface (mesial, buccal or distal) - basically on pdl space

• Applied between root surface and alveolar crest (i.e. in PDL space).

• Alveolar crest (not adjacent tooth) provides fulcrum

• Accidental elevation against adjacent tooth can mobilise adjacent tooth and even extract it (especially if adjacent tooth is last standing)

• Rotation movement

• Elevate buccally not lingually due to access

what are the types of elevator?

• Couplands 1, 2 & 3

• Warwick James’ right, left and Straight

• Cryers right and left

handle, shaft, working tip/blade - which engages the tooth

holding elevators

Firm grasp of elevator, forefinger up shaft to prevent slipping.

Positioning elevators

• Pushed firmly between tooth & bone at/ below level of CEJ to engage a point of application

• see cross section of the couplands

• rotating of the instrument - lateral movement of the tooth and widening of the socket

• rhs - bad as it move the adjaent tooth in opposite direction

• reember, its used 90 degrees to long axis of the tooth - used mesial to LR6 to move it distally - widens the mesial socket but also distal as the tooth is moving that way, and severs the pdl

Couplands

• 3 sizes (start with couplands I then move to 2 then 3) - with I having the smallest cross section of the blade

• Larger handle than blade gives lever advantage

• Inserted horizontally (90 degrees to tooth long axis) between tooth & bone

• best to use mesial to the tooth you want to remove

• Sharp blade engages point of application on root, with alveolar bone as fulcrum.

• Rotation of instrument lifts tooth out of socket along its line of withdrawl (path of removal)

Diagram representing correct elevation technique for extraction of retained roots

need correct cross section size

Warwick James & Cryers

• 90 degree blade to shank/handle

• Positioned between root and bone

• good for removing retained roots and interfurcal bone

• Right angled blade allows root to be levered out

Warwick James & Cryers

Particularly useful for retained roots;

• elevator inserted in adjacent empty socket

• blade tip engages inter-radicular bone & removes it until access to root

• blade then engages root to lift it out of socket with a rotation

• sometimes the inter furcal bone must be nibbled away using creyers / WJ

Also useful for elevation upper 8s

• Contra-angled tip can engage mesial upper 8

• good for removing conical rooted upper third molars - but shouln’t be removed entirely as there is an aero risk to patients

Luxators

• Blade flatter and sharper

• Inserted in PDL space by application between root and bone

• Applied vertically, along the long-axis of tooth (not horizontally like couplands)

• functions as a sharp wedge

• worked from mesiobuccal to distobuccal - widening the socket so it can be deliverde with forceps

• Sharp blade disrupts PDL

• Gentle rotating of handle and advancement of blade towards apex of the root to mobilise tooth

tooth out - what now?

Check apices intact

• Smooth, round

• No sharp edges

• may have sharp silver points

Check socket (flush with saline)

• Retained roots

• Soft tissue

• Fragments of tooth/debris

• Hole in antrum (oral antral communication) for maxillary teeth - dark hole

• use high volume suction

‘curatage’

Tips

• Comfortable patient positioning

• Mouth-prop- may reduce myalgia post op

• Effective anaesthetic

• Continually checking-in with patient