Principles of Oral Surgery

Question 1

Causes of tissue damage?

Answer 1

1. Physical (insicion, cutting, crushing) 2. Chemical (Non-physiologic pH, induced ischamiea)

Question 2

What is epithelialization?

Answer 2

Growth of the epithelium over a denuded surface

Question 3

What are the stages of wound healing

Answer 3

1. Inflammatory stage - initial haemostasis
2. Fibroplastic stage
3. Remodelling stage

Question 4

What are factors that impair wound healing

Answer 4

1. Foreign material
2. Necrotic tissue
3. Ischemia
4. Tension

Question 5

What is healing by primary intention?

Answer 5

Occurs when the edges of a wound (in which there is no tissue loss) are placed and stabilized in essentially the same anatomic position they held before injury and are allowed to heal

Question 6

What is healing by secondary intention

Answer 6

Occurs when a gap is left between the edges of an incision or laceration, or when tissue loss has occurred, preventing approximation of wound edges (Extractions)

Question 7

What is healing by tertiary intention

Answer 7

Refers to the healing of wounds with tissue grafts to cover large areas of missing tissue

Question 8

5 healing stages of extraction sockets

Answer 8

1. Red and white blood cells form an initial blood clot immediately after extraction is completed
2. Within few days blood clot begins to break down via fibrinolysis. Blood clot transforms into granulation tissue
3. Granulation tissue is replaced with connective tissues
4. Calcification commences - osteoid formation at base of socket, most of the alveolus filled with woven bone. Complete epithelial closure of the socket
5. Complete bony fill

Question 9

What is bony healing by primary intention

Answer 9

Occurs when the bone is incompletely fractured (greenstick fracture) or when a surgeon closely reapproximates and rigidly stabilizes the fractured ends of a bone (anatomic fracture reduction)
Benefit = minimal callous formation, increased speed of healing, less scar tissue formation

Question 10

What is bony healing by secondary intention

Answer 10

Occurs when bone is fractured and the free ends are more than 1 mm apart
Disadvantage = larger bony callous, decreased speed of healing, and increased scar tissue formation

Question 11

3 types of nerve damage

Answer 11

1. Neuropraxia
2. Axonotmesis
3. Neurotmesis

Question 12

What is neuropraxia

Answer 12

Compression or blunt injury to the nerve - segmental demyelination

Question 13

What is Axonotmesis

Answer 13

Compression or blunt injury to the nerve - disruption of myelin sheath and nerve cell axon

Question 14

What is neurotmesis

Answer 14

Severe contusion, stretching or laceration - disruption of myelin sheath, nerve cell axon, and endo/peri/epineurium

Question 15

Two phases of nerve healing

Answer 15

1. Degeneration
   * Segmental degeneration
   o Where the myelin sheath is dissolved in isolated segments
2. Regeneration
   * Can begin almost immediately after nerve injury
   * The proximal nerve stump sends out a group of new fibers (growth cone) which progresses at a rate of 1.0 to 1.5 mm per day, and continues until the site innervated by the nerve is reached, or (more often) blocked by fibrous connective tissue or bone

Question 16

How to achieve haemostasis

Answer 16

Pressure
Heat
Suture
Vasoconstriction substance
Tranexamic acid
Collagen + Cellulose

Question 17

What is dead space and how is it managed

Answer 17

Dead space in a wound is any area that remains devoid of tissue after wound closure
It is created by removing tissue in the depths of a wound or by not reapproximating all tissue planes
Managed by:
- Suturing
- Pressure dressing
- Place packing
- Drains

Question 18

What is the downside of plain gut sutures

Answer 18

Highly inflammatory