Principles of Exodontia 2

Question 1

How can we surgically alter the tooths natural path of removal?

Answer 1

1) Bone removal - reducing bony support locally by gutter
2) Tooth sectioning - remove impacting and section roots to alter the natural path of removal
3) Raising flaps - removal of soft tissue impaction and allows visualization of the surgical site

Question 2

How do we ensure that surgical removal is minimally invasive?

Answer 2

• Small muco-periosteal flaps
• Minimal bone removal
• Sectioning of tooth to help maintain bone

Promotes improved healing, reduction in post-operative pain, reduction in post-operative complications.

Question 3

Why do we raise flaps?

Answer 3

• Improve access visually
• Access for instrumentation
• Protect vital structures e.g. mental nerve

Question 4

What do we need to consider when making a flap?

Answer 4

• Sufficient base with vertical relieving incisions
• Appropriate design for access required
• Anatomical considerations
• Aesthetic considerations
• Margins on sharp bone
• Relieving incisions

Question 5

What can happen if the flap is too small?

Answer 5

• Flap can get under tension and may tear

- Poor healing of flap

Question 6

What anatomy do we need to be aware of when designing flaps?

Answer 6

• Mental foramen
• Lingual nerve
• Inferior alveolar nerve
• Greater palatine vessels
• Nasopalatine vessels

Question 7

What are the 3 flap designs we can use to access a tooth?

Answer 7

1) Envelope flap
2) 2 sided flap
3) 3 sided flap

Question 8

Which flap is the most common flap to be raised?

Answer 8

Envelope flap

• Incision goes within the gingival margin with a scapel. Warwick James (elevator) is used to raise muco-periosteum from bone.

Question 9

Why may we need a 2 or 3 sided flap?

Answer 9

If a better view is needed - commonly with 3rd molars or teeth impacted deep in bone

Question 10

When making an incision, how can we avoid sectioning gingival capillaries and make it less likely that a notch will be created when the gingiva heals?

Answer 10

Make vertical incisions (capillaries tend to run vertically) so this stops the formation of a knot in the gingival margin when healing.

As well as this, incise either side of the papillae rather than straight cuts down.

Question 11

What scalpel is used when making surgical excisions?

Answer 11

Blade number 15

Question 12

Why should we make one incision rather than going over incisions again?

Answer 12

To reduce the trauma to the area and helping the healing process.

Question 13

What do we need to do to the mucosa once the incisions have been made?

Answer 13

The mucosa needs to be reflected back to get the flap.
We use the elevator (Warwick James). This elevator needs to contact bone within the incision and then sweep it along the surface of the bone to raise the flap so the periosteum is still attached to the mucosa.

Question 14

After the incisions have been made and the flap has been reflected back, what happens then?

Answer 14

We need to retract the flap back with a suitable retractor to visualise the surgical flap.

Flap retractors are used to aid visualisation.

Flap retractors are help in supporting hand and should be resting on bone.

Common retractors are Minnesota, Rake and Austins retractor.

Question 15

After the incision is made, the flap has been reflected and a retractor is in place, what do we do then?

Answer 15

We then need to remove bone to access the root surface of the tooth.

This is accompanied with tooth sectioning.

Buccal bone removal is common.
Lingual bone is only removed when bone is removed circumferentially around the tooth to give an application point for another instrument such as a luxator.

Question 16

How do we remove bone once the flap is retracted?

Answer 16

Initially we remove the surface of bone along the CEJ using a rose-head bur.
This removes alveolar crest.

Rose head is then swept along the CEJ and then used a fissure bur to deepen the buccal gutter.

This creates an application point to allow the elevator and luxator to mobilise the tooth and help us to access the tooth to deliver with forceps.

Question 17

How do we do tooth sectioning?

Answer 17

• Rose head and fissure burs used
• Use them in a sweeping in and out motion
• We mainly section teeth which are multirooted
• Remove the crown, then separate the roots
• Remove each root with its own path of removal (may need to remove circumferential bone around the roots to allow forcep application points)

Question 18

What roots do we section in lower and upper molars?

Answer 18

Upper = section off crown, then seperate off the palatal roots (mesial to distal movement). Then seperate the two buccal roots (buccal to palatal movement).

Lower = seperate off crown, then seperate mesial and distal root (with a buccal-palatal movement).

Question 19

What technique can we use when sectioning third molars?

Answer 19

Mesial removal of crown to midline and then flick the crown off.
This is done to prevent the lingual nerve being touched.

Question 20

What do we need to do after surgical removal?

Answer 20

Lay the flap back down and place pressure over the area to relax the tissues and sit them in place.

Place sutures!

• Sutures help approximate wound edges and lead to healing by primary intention
• Sutures cover bone to aid haemostasis
• Minimised post-operative haemorrhage

Question 21

Which suture materials do we commonly use and why?

Answer 21

Vicryl rapide sutures resorb at a good time.

We can also use non-resorable sutures which will need to be removed.
Proline, silk and ethilon are non-resorable mono-filaments.
Silk can also be used for oro-antal communication closures.