Normal and compromised wound healing

Question 1

Factors that dictate healing process

Answer 1

• Anatomical site
• Type of tissue
• Wound margins

Question 2

Types of healing progression

Answer 2

First, second and third intention

Question 3

First intention

Answer 3

Wound heals w/ no scar formation

Question 4

Second intention

Answer 4

-Prolonged
Severe tissue loss
-Poor healing of margins
- Granulation and connective tissue formation

Question 5

Third intention

Answer 5

-Treatment method -In traumatic wounds with severe tissue loss -Wound allowed to granulate and heal by second intention→ delayed primary closure

Question 6

Phases of normal wound healing

Answer 6

• Inflammatory phase
• Proliferation phase
• Maturation/remodelling phase

Question 7

Inflammatory phase

Answer 7

• Fibrin clot formed
• Coagulation factors(fibrinogen, fibronectin and thrombospondin) initiate coagulation cascade
• Wound healing modulators released→ platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor β (TGF-β
• Cytokines and chemo-attractants recruit inflammatory cells

Question 8

Main cells in inflammatory phase

Answer 8

Neutrophils→ 2-3 days

-Replaced by macrophages

Question 9

Proliferation phase

Answer 9

• Intense replication of cells
• Fibroblasts produce collagen to restore tissue strength and proteoglycans aid fluid storage
• Neoangiogenesis and lymphatics restored

Question 10

Maturation and remodelling phase

Answer 10

Continual turnover of collagen to restore strength→ Cross linking

Question 11

Specialised healing

Answer 11

• Oral mucosa
• Extraction wounds
• Implant healing

Question 12

Healing in Oral mucosa

Answer 12

• First or second intention
• Rapid
• Minimal scar tissue

Question 13

Healing in extraction wound

Answer 13

• Clot formation in 24-48 hours→ dilation of vessels
• Temporary scaffold for cell migration and angiogenesis
• Osteoclast resorption crest
• Granulation tissue after 3 weeks
• Radiographic evidence of bone formation after 6-8 week

Question 14

Wound healing adjuncts

Answer 14

• Growth factors
• Hyperbaric oxygen therapy
• Skin substitutes

Question 15

Causes of compromised wounds

Answer 15

• Irradiated tissue
• Old age→ Osteoporosis
• Diabetes mellitus
• Drugs-Bisphosphonates

Question 16

Irradiated tissue

Answer 16

Reduced cell turnover→ Reduced blood supply and bone repair ability

Question 17

Old age-Osteopororis

Answer 17

• Increased risk of fractures due to reduced mineral content of bone
• Reduced vascularity→ impaired healing

Question 18

Diabetes mellitus

Answer 18

• Increased infection
• Delayed healing

Question 19

Bisphosphonate

Answer 19

• Apoptosis of osteoclasts
• Antiangiogenic effect