Stages of Wound Healing
1- Haemostasis Stage:
few minutes upon injury, the platelets (thrombocytes) tends to aggregate at the wound site to form what is called "fibrin clot" that controls the bleeding to finish the process of hemostasis.
2- Inflammatory Stage:
Vasodilatation and increase in vascular permeability occurs in 0-3 minutes, where inflammatory cells enter the wound site from the blood. Neurtophils and Phagocytes release cytokines that tends to remove infections and dead tissue by phogocyting the bacteria, while the phagocytosed bacteria and dead cells will cause migration, proliferation and collagen production.
3- Proliferation Stage:
Angiogenesis: New blood vissels are formed from the vascular endothelial cells.
Granulation tissue formation and fobroblasia: fibroblasts grow and form what is called "provisional extacellular matrix" by excreating collagen and fibronectin.
Re-Epithelialization of the epidermis: where the epithelial cells will proliferate to cover the wound
Contraction: is the grip of the wound edges together by the action of the myofibroblasts (contains Actin) to become smaller.
4- Remodeling and Maturation:
The collagen is remodelled and realigned along tension lines and cells that are no longer needed are removed by apoptosis.
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1- Local Factors:
few minutes upon injury, the platelets (thrombocytes) tends to aggregate at the wound site to form what is called "fibrin clot" that controls the bleeding to finish the process of hemostasis.
2- Inflammatory Stage:
Vasodilatation and increase in vascular permeability occurs in 0-3 minutes, where inflammatory cells enter the wound site from the blood. Neurtophils and Phagocytes release cytokines that tends to remove infections and dead tissue by phogocyting the bacteria, while the phagocytosed bacteria and dead cells will cause migration, proliferation and collagen production.
3- Proliferation Stage:
Angiogenesis: New blood vissels are formed from the vascular endothelial cells.
Granulation tissue formation and fobroblasia: fibroblasts grow and form what is called "provisional extacellular matrix" by excreating collagen and fibronectin.
Re-Epithelialization of the epidermis: where the epithelial cells will proliferate to cover the wound
Contraction: is the grip of the wound edges together by the action of the myofibroblasts (contains Actin) to become smaller.
4- Remodeling and Maturation:
The collagen is remodelled and realigned along tension lines and cells that are no longer needed are removed by apoptosis.
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Factors affecting Wound Healing:
- Mechanical Factors
- Edema
- Ischemia and Necrosis
- Foriegn Bodies
- Low Oxygen Tension
2- Systemic Factors:
- Inadequete Perfusion
- Inflammation
- Nutrient
- Metabolic Diseases
- Immunosuppression
- Connective Tissue Disorders
- Smoking
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Types of wound healing:
1- Primary Intension Wound Healing:
Healing by epithelialization when the wound edges are brought together by sutures (stitches),staples or adhesive tape, causing fast healing with no scaring left behind.
Examples: well-repaired lacerations, well reduced bone fractures, healing after flap surgery
2- Secondary Intention Wound Healing:
Healing by granulation tissue when the wound is covered with a gauze or use a drainage system , causing slower healing time, with larger scar formation results after healing, where the patient should always be care to encourage wound debris removal to allow for granulation tissue formation.
Examples: gingivectomy, gingivoplasty, tooth extraction sockets, poorly reduced fractures.
3- Tertiary Intention Wound Healing:
The wound left purposly opened, with 4-5 days of cleaning, debriding and observing for any abnormal changes (delayed primary closure OR secondary suturing), then sutured.
Examples: healing of wounds by use of tissue grafts.
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Healing by epithelialization when the wound edges are brought together by sutures (stitches),staples or adhesive tape, causing fast healing with no scaring left behind.
Examples: well-repaired lacerations, well reduced bone fractures, healing after flap surgery
2- Secondary Intention Wound Healing:
Healing by granulation tissue when the wound is covered with a gauze or use a drainage system , causing slower healing time, with larger scar formation results after healing, where the patient should always be care to encourage wound debris removal to allow for granulation tissue formation.
Examples: gingivectomy, gingivoplasty, tooth extraction sockets, poorly reduced fractures.
3- Tertiary Intention Wound Healing:
The wound left purposly opened, with 4-5 days of cleaning, debriding and observing for any abnormal changes (delayed primary closure OR secondary suturing), then sutured.
Examples: healing of wounds by use of tissue grafts.
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Complications of Wound Healing:
- Deficient Scar Formation: Result in wound dehiscence or rupture of the wound due to inadequate formation of granulation tissue.
- Excessive Scar Formation: Hypertrophic scar, Keloid, Desmoid.
- Exuberant Granulation (Proud Flesh).
- Deficient Contraction (in skin grafts) or excessive contraction (in burns).
- Others: Dystrophic calcification, pigmentary changes, painful scars, inscisional hernia etc.
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Authored By,
:: World Of Dentistry :: TEAM
If You Have Any Questions In The Topic, Please Don't be Hesitate To Ask Back ..
Authored By,
:: World Of Dentistry :: TEAM
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