Principles of Exodontia

Question 1

What are indications for extractions?

Answer 1

• Unrestorable teeth
• Periodontal disease
• Orthodontics
• Associated pathology e.g. cysts or tumours
• Trauma
• Interferes with a prosthesis
• Tooth within fracture line
• Impending eruption of another tooth

Question 2

How do we ensure informed consent for an extraction?

Answer 2

Patient needs to know all alternative options.
Telling the patient the benefits and risk.
If the prognosis is poor.

Question 3

What factors affect the difficulty of extraction?

Answer 3

1) Tooth
- Crown (how much is left, any restorations, is the crown bulbous)
- Root (single or multiple, long/thin/bulbous, divergent/convergent)
2) Support structures
- Gingival soft tissue (any overgrowth)
- PDL health
- Bone (density/age)
3) Proximity to adjacent structures
- any teeth? impacted? mobile adjacent teeth?
- inferior alveolar nerve
4) Access
- limited mouth opening
- small mouth
- impacted and crowded teeth

Question 4

What are the two methods for extraction?

Answer 4

• Routine extraction

- Surgical extraction

Question 5

Before the tooth can be extracted, what are the two things that need to occur?

Answer 5

1) PDL needs to be severed and tooth socket dilated. done using forceps and elevators maintaining pressure along the long axis of tooth
2) Socket is dilated using lateral pressure, figure of 8 and rotation movement

Question 6

What determines the path of removal?

Answer 6

The root morphology and number.

If the tooth is impacted and bone level.

Question 7

What do we use forceps for in extraction?

Answer 7

They are used to curve around the CEJ and pull the tooth out.

Question 8

What are the 4 routine sequences of instruments for removal?

Answer 8

1) Forceps only
2) Elevators, forceps
3) Elevators, luxators, forceps
4) Luxators, forceps

Question 9

What is the role of elevators and luxators?

Answer 9

To help severe the periodontal ligament and dilate the tooth socket.

Question 10

Why are teeth delivered out bucally?

Answer 10

The buccal bone is thinner than lingual/palatal bone.

Question 11

How do we apply forceps to the tooth?

Answer 11

1) Probe around the gingival margin of the tooth
2) Place blades under gingivae
3) Align forcep beaks with long axis of tooth
4) Push forceps apically along root surface
5) Engage root surface with beaks
6) Apply apical pressure

Question 12

What do we need to do to the tooth once the forceps are engaged?

Answer 12

1 - undergo lateral movement with forceps to remove the tooth bucally, expand the tooth socket bucco-lingually

2 - rotational movement to tear soft tissue attachment

3 - after tooth is mobilised traction forces remove the tooth from socket

Question 13

Why do we apply apical force?

Answer 13

• Prevents break sliding of root
• Expands socket by positioning coronal, wider root apically
• Centre of rotation of tooth displaced apically
• Alters angle of force on roots

Question 14

What will happen if we only apply buccal force to remove a tooth?

Answer 14

Root fracture

Question 15

Why is providing apical pressure along with lateral pressure important?

Answer 15

Apical and lateral pressure will expand roto sockets, give a good centre of rotation apically and ensure the palatal root is delivered along its curvature.

Question 16

Why is too much or too little pressure a problem?

Answer 16

Too much = can lead to tooth or jaw fracture, discomfort for patient, increased patient overall discomfort and anxiety

Limited force = extended extraction time, inability to extract tooth

Question 17

Why do we give lateral excursions to the tooth?

Answer 17

We hold pressure buccally to allow time for bone to expand.

We recognise resistance to movement by feel.

Question 18

In what line will the tooth move when being extracted?

Answer 18

Tooth will move in the line of least resistance with is determined by tooth morphology.

Question 19

How do we recognise lower cow horns?

Answer 19

• Pointy blades
• Engage furcation
• Position on root surface and close forceps firm until blades engage bifurcation
• Handles will close when the bifurcation is completely engaged
• Apical and bucco-lingual movement
• Tooth is lited out the socket

Question 20

How do we recognise upper cowhorns?

Answer 20

Grip around palatal root and engage buccal furcation.
Useful for heavily broken down upper molars.
Used in similar manner to upper molar forceps.

Question 21

How do we position for maxillary and mandibular extractions?

Answer 21

Maxillary teeth = lower the chair down, chin up
Mandibular teeth = chair is higher, chin down

Maxillary extractions = patients is more reclined back. Stand in front of the patient.

Mandibular extractions = lower right you stand behind the patient.
Lower left you stand in front of the patient.

Question 22

What do we do with our other hand when extracting?

Answer 22

Support the jaw to counteract the forcep forces.

Retraction of soft tissue - using thumb and forefinger either side of arch adjacent to tooth.

Feeling adjacent tooth - check adjacent tooth not mobilising during extraction.

Question 23

What do we use elevators for?

What are the 3 types of elevators?

Answer 23

Used to help mobilise the teeth.

• Positioned horizontally (90 degrees to long tooth axis)
• Applied to root surface
• Applied between root surface and alveolar crest
• Accidental elevation against adjacent tooth can mobilise adjacent tooth
• Elevate bucally due to access

1) Couplands 1,2 & 3
2) Warwick james
3) Cryers
All have a handle, shaft and working tip to engage the tooth to mobilise it.

Question 24

How are elevators positoned?

Answer 24

All elevators push in the PDL.
You place the instrument into the coronal part of the PDL to widen the socket coronally.

Used at 90 degrees to long axis of tooth.

It is used mesially to widen the distal portion by pushing the tooth distally.

Question 25

Give details on the these 2 types of elevators
1 - Couplands
2 - Warwick James

Answer 25

Couplands:

• 3 sizes
• Larger handle than blade gives lever advantage
• Inserted horizontally (at 90 degrees to long tooth axis) between tooth and bone
• Sharp blade engages point of application on root, with alveolar bone
• Rotation of instrument lifts tooth out of socket along its path of removal

Warwick James

• 90 degree blade to shank/handle
• Positioned between root and bone
• Right angled blade allows root to be levered out
• Useful for retained roots (elevator inserted into the empty socket and engages inter-radicular bone and removes it until access to root, blade engages root and lifts it out socket)

Question 26

How do luxators work?

Answer 26

Blade is flatter and sharper.
Inserted into PDL space by application between root and bone.
Applied vertically, along the long axis of tooth.
Sharp blade disrupts PDL.
Gentle rotating of handle and advancement of blade towards apex of root to mobilise tooth.

Places along long axis of tooth (controversial to the elevators which are placed at 90 degrees).

Question 27

Once a tooth is taken out, what do we needs to examine?

Answer 27

• Examine root apex are smooth, round and no sharp edges
• Check socket for retained roots, soft tissue, fragments of tooth and hole in antrums (oral antral communication)
• Flush the socket with saline and high volume suction
• Area can be curretaged to remove any granulation tissue