presented by:

Dr Rahul tiwARI

FINAL MDS

OMFS - SIDS

Contents: Introduction

Process of healing

Phases of wound healing a. Primary healing

b. Secondary healing

Factors influencing wound healing

Complications of wound healing

Commonly used wound healing materials

New concepts

New Research

References 2

Wound is defined as “disruption of normal structure andfunction”.

Healing is the body response to injury in an attempt torestore normal structure and function.

Injury to tissues may results in cell death and tissuedestruction.

Wound healing is a complex and dynamic process ofrestoring cellular structures and tissue layers.

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Wound healing involves 2 distinct processes:

Regeneration- healing by proliferation of parenchymal cells and

usually results in complete restoration of the original tissue (structuraland functional).

Repair- healing takes place by proliferation of connective tissue

elements resulting in fibrosis and scarring. At times both the processtakes place simultaneously.

REGENERATION Some parenchymal cells are short-lived while others have

a longer life-span. In order to maintain proper structure oftissues, these cells are under the constant regulatorycontrol of their cell cycle.

Cell cycle - Period between two successive cell divisions.

Divided into 4 unequal phases .

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Cell Cycle

√

√

√

The cell cycle completes in 16-24 hours.

M (Mitosis) phase: Phase of mitosis.

G1 (gap1) phase: The daughter cell enters G1 phase after mitosis.

S (synthesis) phase: During this phase, the synthesis of nuclear DNAtakes place.

G2 (gap 2) phase: After completion of nuclear DNA duplication, the cellenters G2 phase.

G0 (gap 0) phase: resting phase of the cell after an M phase.

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REPAIR

► Repair is the replacement of injured tissue by fibrous tissue. Two processesare involved

1. Granulation tissue formation

2. Contraction of wounds.

Repair response takes place by participation of mesenchymal cells,endothelial cells, macrophages, platelets, and the parenchymal cells of theinjured organ.

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Phase of inflammation

Phase of clearance

Phase of ingrowth of granulation

tissue a. Angiogenesis

b. Fibrogenesis

1.Granulation Tissue Formation:

Granulation tissue derives its name from slightly granular and pink appearanceof the tissue.

3 phases-

Phase Of Inflammation:Following trauma, blood clots at the site of injury. There is acute inflammatoryresponse with exudation of plasma, neutrophils and some monocytes within24 hours.

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Phase Of Clearance:Combination of proteolytic enzymes liberated from neutrophils, autolyticenzymes from dead tissues cells, and phagocytic activity of macrophages clearoff the necrotic tissue, debris and red blood cells.

Phase Of Ingrowth Of Granulation Tissue:

consists of 2 main processes

a)Angiogenesis

b) Formation of fibrous tissue

A. Angiogenesis:

Formation of new blood vessels by proliferation of endothelial cells from

the margins of severed blood vessels.

Initially, the proliferated endothelial cells are solid buds but within a few

hours develop a lumen and start carrying blood.

B. Fibrogenesis:

The new fibroblasts originate from fibrocytes as well as by mitotic division

of fibroblasts.

Collagen fibrils begin to appear by about 6th day.

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2.Contraction of wounds: Wound starts contracting after 2-3 days.

90% Process is completed by the 14th day.

During this period, the wound is reduced by approximately 80% of its

original size.

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Two ways:

1.Healing by first intention (primary union);

2.Healing by second intention (secondary union).

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Features Primary Union Secondary Union

Cleanliness of wound Clean Unclean

Infection Generally uninfected May be infected

Margins Regular Irregular

Sutures Used Not used

Healing Scanty granulation tissueat the incised

Exuberant granulationtissue gap and alongsuture tracks to fillthe gap

Outcome Neat linear scar Contracted irregularwound

Complications Infrequent, epidermalinclusion cyst formation

Suppuration, mayrequire debridement

1. Primary Intention:

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Healing by First Intention (Primary Union)

1.Initial haemorrhage: Immediately after injury, the space betwe

en the approximated surfaces of incised wound is filled with blood which t

hen clots and seals the wound against dehydration and infection.

2.Acute inflammatory response: This occurs within 24 h

ours with appearance of polymorphs from the margins of incision. By

3rd day, polymorphs are replaced by macrophages.

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3.Epithelial changes:

The basal cells of epidermis from both the cut margins start proliferating and migrating towards incisional space in the form of epithelial spurs.

A well-approximated wound is covered by a layer of epithelium in 48 hours.

The migrated epidermal cells separate the underlying viable dermis from

the overlying necrotic material and clot, forming scab.

The basal cells from the margins continue to divide.

By 5th day, a multi-layered new epidermis is formed which is differentiated into superficial and deeper layers.

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4. Organisation:

By 3rd day, fibroblasts also invade the wound area.

By 5th day, new collagen fibrils start forming which dominate till healing is

completed.

In 4 weeks, the scar tissue with scanty cellular and vascular elements, a

few inflammatory cells and epithelialised surface is formed

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A, The incised wound as well as suture track on either side are filled with bloodclot and there is inflammatory response from the margins.B, Spurs of epidermal cells migrate along the incised margin on either side as wellas around the suture track. Formation of granulation tissue also begins from below.C, Removal of suture at around 7th day results in scar tissue at the sites of incisionand suture track.

2. Secondary Intention:

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1. Initial haemorrhage:

The wound space is filled with blood and fibrin clot which dries.

2. Inflammatory phase:There is an initial acute inflammatory response followed by

appearance of macrophages which clear off the debris as inprimary union.

3. Granulation tissue:

Granulation tissue is formed by proliferation of fibroblasts and

neovascularisation from the adjoining viable elements.

4. Wound contraction:Not seen in primary healing.

Occurs at a time when active granulation tissue is being formed.24

A, The open wound is filled with blood clot and there is inflammatory responseat the junction of viable tissue.

B, Epithelial spurs from the margins of wound meet in the middle to cover thegap and separate the underlying viable tissue from necrotic tissue at the surfaceforming scab.

C, After contraction of the wound, a scar smaller than the original wound is left.

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1.Infection of wound due to entry of bacteria delays the healing.

2.Implantation (epidermal) cyst formation may occur due to persistence of epithelial cells i

n the wound after healing.

3.Pigmentation Healed wounds may at times have rust-like colour due to staining with h

aemosiderin.

4. Deficient scar formation due to inadequate formation of granulation tissue.

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28Hypertrophied scar keloid

5. Hypertrophied scars and keloid formation the scar formed is excessive, ugly a

nd painful.

Excessive formation of collagen in healing may result in keloid formation

More commonly in Blacks

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A). Local Factors:

Infection is the most important factor acting locally which delays theprocess of healing.

Poor blood supply to wound slows healing e.g. injuries to face heal quicklydue to rich blood supply while injury to leg with varicose ulcers havingpoor blood supply heals slowly.

Movement delays wound healing.

Exposure to ionising radiation delays granulation tissue formation.

Exposure to ultraviolet light facilitates healing.

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B. Systemic Factors:

Age- Wound healing is rapid in young and some what slow in aged

Nutrition Deficiency of constituents like protein, vitamin C (scurvy) andzinc delays the wound healing.

Systemic infection delays wound healing.

Uncontrolled diabetics are more prone to develop infections and hencedelay in healing.

Haematologic abnormalities like defect of neutrophil functions(chemotaxis and phagocytosis), and neutropenia and bleeding disordersslow the process of wound healing.

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Primary Union: Bony union takes place with formation of medullary callus without

periosteal callus formation.

There is more extensive bone necrosis and slow healing.

Secondary Union: Common process of fracture healing.

It is a continuous process.

i) Procallus formation

ii) Osseous callus formation

iii) Remodelling

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Fracture Healing

I. Procallus formation

1. Haematoma-

Forms due to bleeding from torn blood vessels.

Loose meshwork is formed by blood and fibrin.

2. Local Inflammatory Response-

Site of injury with exudation of fibrin, polymorphs and macrophages.

3. Ingrowth Of Granulation Tissue-

Begins with neovascularisation and proliferation of mesenchymal cellsfrom periosteum and endosteum.

A soft tissue callus is formed which joins the ends of fractured bonewithout much strength.

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II. Osseous Callus Formation: In place of soft callus , newly-formed blood vessels and osteoblasts

invade, laying down osteoid which is calcified.

III. Remodelling: The formation of lamellar bone, osteoblastic laying and osteoclastic

removal are taking place in remodelling the united bone ends.

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Oxidised regenerated cellulose (Surgicel):

Oxidised regenerated cellulose is used as a hemostatic agent, working

primarily by chemical interaction with blood.

It forms a gelatinous mass when mixed with blood that functions as an

artificial blood clot.

Due to its low pH, it may also have some antimicrobial effects.

Whitehead's varnish: It prevents capillary oozing, helps in relieving postoperative pain and

allowing the patient to be fed orally.

Also used as a pack for cystic cavities of the jaw, to reduce pain

following wisdom tooth removal, and with the surgical management of

osteomyelitis.

Constituents of Whitehead's varnish are lodoform, Benzoic acid, Storax,

Balsam of Tolu, Ether.

Carnoy's solution:

Carnoy's solution is used in the mouth as a tanning agent in order to facilitatethe removal of cyst linings.

Commonly used in marsupialization of OKC.

It is made up of chloroform, acetic acid and ferric sulphate, in an alcoholsolvent

http://www.intechopen.com/books/a-textbook-of-advanced-oral-and-maxillofacial-surgery

Zinc oxide based dressing:

It used to cover the gingival tissues or extraction sockets.

These materials function to provide a physical barrier against the entryof food or other materials.

They are divided into eugenol-containing and non-eugenol-containingmaterials

Alvogyl:

Alvogyl is a proprietary material that has butamben, iodoform and eugenol

as its active ingredients.

It is primarily used for the treatment of alveolar osteitis. It is placed into an

extraction socket with the aim of reducing pain and infection.

Low level laser therapy:

Low-level laser therapy (LLLT) has been promoted for its beneficial effects on

tissue healing and pain relief.

Abrasions, turf burns, labial herpes, thrush, surgical incisions, and ulcerations.

Low level laser (lll) in dentistry/ International journal of medical and dental imaging/ OMICS publishing groups

Negative-pressure wound therapy (NPWT):

Negative-pressure wound therapy (NPWT) is a therapeutic techniqueusing a vacuum dressing to promote healing in acute or chronicwounds and enhance healing of second and third degree burns.

The therapy involves the controlled application of sub-atmosphericpressure to the local wound environment, using a sealed wounddressing connected to a vacuum pump

https://en.wikipedia.org/wiki/Negative-pressure_wound_therapy

Apligraft:

http://www.apligraf.com/patient/what_is_apligraft/what_is_apligraft.html

Apligraft is a unique, advanced treatment for healing. It is created fromcells found in healthy human skin.

It is used to heal ulcers such as diabetic foot and venous leg ulcers thatare not healing after 3-4 weeks, despite treatment with conventionaltherapies.

Alloderm (life cell): Processed human cadaver skin with a cellular dermal matrix and intact

basement membrane

Advantages: Permanently cover full thickness burns and deep ulcers.

Disadvantages: not suitable for infected wounds.

In surgery: Root coverage Gingival augmentation Soft tissue ridge augmentation. Soft tissue augmentation around

implants.

Tegaderm:

Used for simple shallow wound dressing Protects from water loss mechanical injury and drying

Wai-Ping Linda Fan, Mamun Rashid, Stuart Enoch,Current advances in modern wound healing,Wounds uk, 2010, Vol 6, No 3

TransCyte:

Allogenic human fibroblasts cultured on nylon mesh coated with porcinecollagen

Advantages: To cover surgically excised full-thickness burns and non-excised

partial thickness burns

Disadvantages: Temporary (may need skin grafting after 2–3 weeks); notsuitable for infected wounds and patients allergic to porcine collagen.

Wai-Ping Linda Fan, Mamun Rashid, Stuart Enoch,Current advances in modern wound healing, Woundsuk, 2010, Vol 6, No 3

ORCEL: Allogenic cultured skin containing keratinocytes, fibroblasts, and bovine

collagen

Advantages: Acute and chronic deep dermal ulcers, partial-thickness burns

and donor site wounds.

Disadvantages: Not for infected wounds or patients allergic to bovine

collagen.

Wai-Ping Linda Fan, Mamun Rashid, Stuart Enoch,Current advances in modern wound healing,Wounds uk, 2010, Vol 6, No 3

Dermagraft:

Approved device in US, several European countries, Canada, Australia, and

others

Burns, diabetic venous and pressure ulcers.

Good resistance to tearing

Wai-Ping Linda Fan, Mamun Rashid, Stuart Enoch,Current advances in modern wound healing,Wounds uk, 2010, Vol 6, No 3

OASIS:

Comprised of small intestine sub mucosa, acellular collagen matrix.

Indicated for the management of wounds including: partial and

full-thickness wounds, pressure ulcers, venous ulcers, diabetic ulcers,

trauma wounds (abrasions, lacerations, second-degree burns, skin tears),

draining wounds, and surgical wounds

Wai-Ping Linda Fan, Mamun Rashid, Stuart Enoch,Current advances in modern wound healing,Wounds uk, 2010, Vol 6, No 3

MAX8 or Novel hydrogel:

A novel hydrogel, used to seal wounds and at the same time deliver anantibacterial punch

Wai-Ping Linda Fan, Mamun Rashid, Stuart Enoch,Current advances in modern wound healing,Wounds uk, 2010, Vol 6, No 3

35 medicinal plants

hyperbaric oxygen, negative pressure wound therapy and laser

collagen, silicon, chitosan, and hyaluronic acid

Mouth wash

CONCLUSION

SURGEON

TREATS MAKES

BASICHEALING

ADVANCEDMATERIAL

KNOWLEDGE

References Harsh Mohan “Essential Pathology for Dental Students 4th Edition, Jaypee Brothers Medical

Publishers (P) Ltd. New Delhi. 2002.

Neville B.W, Damm D.D, Allen C.M, Bouquot J.E, “Oral and Maxillofacial Pathology”, 2nd Edition. 2002.

Shafer W.G, Hine M.K, Levy B.M, “A text book of “Oral Pathology” 4th Edition, W.B. Saunders company, Philadelphia, 1997.

Ahmad-Reza Noroozi, Rawle F. Philbert, Modern concepts in understanding and management of the “dry socket” syndrome: comprehensive review of the literature, Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107:30-35

Michael Freedman,Leo FA Stassen, Commonly used topical oral wound dressing materials in dental and surgical practice -a literature review, journal of the irish dental association, August/September 2013 vol-59 (4) : 190-195.

www.google search/images.com, accessed on 7th October 2016.

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