The document discusses wound healing and its various aspects in 3 parts. It begins by defining a wound and the process of healing. It describes the 4 main phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. It then discusses different types of wounds, tissues involved in healing, and factors that affect the process. The document concludes by noting the complexity of wound healing and importance of addressing underlying issues to ensure proper repair.
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Wound healing
1. Presented by:
Dr U Bharath kumar
1st year PG trainee
Moderator :
Dr Abhivyakti Tewari
Assistant professor 1
2. Introduction
Types of wounds
Types of wound healing
Mechanism of wound healing
Wound healing in specialized tissues
Factors affecting wound healing
Complications
Advancements
conclusion 2
3. A wound is a disruption in the normal
anatomic structure and function of
tissue and is accompanied by cellular
damage
Healing is a tightly choreographed array
of cellular, physiologic, biochemical,
processes directed toward restoring the
integrity and functional capacity of the
damaged tissue (peterson’s principles of surgery)
3
4. Physical
• Incision
• Crushing
• Over heating
• Over cooling
• Desiccation
• Irradiation
• blood flow↓
Chemical
• agents with unphysiologic
pH
• agents with unphysiologic
tonicity
• vasoconstrictors
• proteases
• thrombogenic agents
4Ref: contemporary peterson
5. Injury to
normal cell
Reversible injury
Regeneration
Repair
Adaptations
Atrophy
Hypertrophy
Hyperplasia
Metaplasia
Irreversible
injury
Cell death
5Ref : Robin’s basic pathology
6. When restitution occurs by means of tissue that is
structurally and functionally indistinguishable from
native tissue, it is regeneration
If tissue integrity is reestablished primarily through
the formation of fibrotic scar tissue , it is known as
repair
Repair is the body’s version of a spot weld
With the exception of bone and liver, tissue
disruption invariably results in repair rather than
regeneration.
6Ref: Peterson’s principles
8. Usually lasts for seconds to minutes
Tissue trauma and local bleeding
activate factor XII (Hageman factor)
complement, plasminogen, kinin,
and clotting systems are induced
primary platelet plug organized
within a fibrin matrix
9Ref: laskin, contemporary peterson
10. Under the influence of histamines,kinins and prostaglandins, vasodilation
occurs followed by diapedisis of neutrophils
The cytokines released by perishing neutrophils, like TNF-α and
interleukins serves as chemotactic agents for lymphocytes and monocytes.
Macrophages break down injured tissue and phagocytose bacteria and cell
debris
Macrophages taper off by the 5th post injury day
Lag phase- wound strength
11Ref: Peterson’s principles
12. The remodeling/maturation phase can
last for several years
On and off sequence of matrix
degradation and formation.
Type III collagen is replaced by
stronger type I collagen
Tensile strength gradually increases to
form 80% of original tissue strength
13Ref: peterson’s principles., contemporary omfs
13. Type of collagen Commonly seen in
Type 1 Bone
Type 2 Cartilage
Type 3 Skin, lung, liver, intestine
Type 4 Basement membrane
14
15. Healing by primary intention
Healing by secondary intention
Healing by tertiary intention
16
16. Healing by first intention occurs when a clean laceration or surgical
incision is closed primarily with sutures or other means
Healing proceeds rapidly with no dehiscence and minimal scar
formation.
Strictly speaking, healing by primary intention is only theoretically
ideal, impossible to attain clinically
17Ref: Peterson’s principles
18. If conditions are less favorable, wound healing is more
complicated and occurs through a protracted filling of the
tissue defect with more granulation and connective
tissue.
It is commonly associated with avulsive injury, local
infection,or inadequate closure of the wound
19Ref: Peterson’s principles
20. For more complex wounds, healing is acheived
through a staged procedure that combines
secondary healing with delayed primary closure.
wound is debrided and allowed to granulate and
heal by second intention for 5 to 7 days
Once adequate granulation tissue has formed,
wound is sutured close to heal by first intention.
Using of grafts also considered as tertiary intention
21Ref:Peterson’s principles
21. FEATURES PRIMARY SECONDARY
CLEANLINESS CLEAN UNCLEAN
INFECTION UNINFECTED INFECTED
MARGINS SURGICALLY CLEAN IRREGULAR
SUTURES PLACED NOT PLACED
HEALING MINIMAL GRANULATION TISSUE LARGE GRANULATION
OUTCOME LINEAR SCAR IRREGULAR
COMPLICATIONS NOT FREQUENT FREQUENT
22
23. There are notable intrinsic and extrinsic factors that differ between dermal
and oral mucosal tissue repair which result in scar less healing.
Saliva supports wound repair by assisting oral fibroblasts in wound
closure, increasing cell turnover and stimulating the release of growth
factors in order to achieve rapid oral wound healing.
Saliva contains EGF, histatins, peptides with antimicrobial properties that
promote fibroblast and keratinocyte migration, further enhancing the
minimally scarring wound healing response in the oral cavity.
24Ref: shafers oral pathology
28. Haversian remodelling
Little to no callus
Good bone opposition and no motion at fractured or osteotomy site
Contact healing
Direct contact between cortical bone ends laid down by lamellar bone
at fractured site parallel, by direct union of osteons
Gap healing
Osteoblast differentiate and deposit osteoids on exposed fractured
fragments that convert into lamellar bone later.
29
32. Sockets heal by secondary intention
Occurs in 5 stages
Complications –
Drysocket
septic periostitis
Complete healing is achieved by roughly
4-6 weeks
33Ref: Laskin vol 1, contemporary omfs
33. The discovery of osseointegration forced us to rethink
basics of wound healing
Wound healing in implants involves
Healing of bone to the implant
Healing of alveolar soft tissue to the implant
Healing should occur on implant interface first
Minimal implant force loading during healing time
Bone implant interface should be contaminant free
Implant –bone
interface
Epithelium
neovascularisation
Medullary
bone
34Ref: contemporary omfs, misch
37. It is a well known fact that healing is impaired in diabetes
mellitus.
higher incidence of wound infection associated with
diabetes has less to do with the patient having diabetes and
more to do with hyperglycemia
It is attributed to the fact uncontrolled blood glucose
hinders red blood cell permeability and impairs blood flow
through the critical small vessels at the wound surface
In diabetes the terminal collagen formation is also impaired
so wound proliferation occurs but wound maturation is
impaired.
38
38. Following grafting, nutritional support for a free skin graft is initially
provided by plasma that exudes from the dilated capillaries of the host bed.
A fibrin clot forms at the graft-host interface, fixing the graft to the host
bed
Host leukocytes infiltrate into the graft through the lower layers of the
graft.
Graft survival depends on the ingrowth of blood vessels from the host into
the graft (neovascularization) and direct anastomoses between the graft
and the host vasculature (inosculation)
Reinnervation of the skin graft occurs by nerve fibers entering the graft
through its base and sides.
39
40. KELOID
Proud flesh
Extends the boundary of wound
Occur on the sternal, shoulders
upper arms, earlobes, and cheeks
Appear at three months or later
HYPERTROPHIC SCAR
With in the wound margin
Regress with time
commonly occur on extensor
surfaces of joints
Appear within one month
41Jackson IT, Bhageshpur R, DiNick V, Khan A, Bhaloo S. Investigation of recurrence rates among earlobe keloids utilizing various postoperative therapeutic modalities. Eur J
Plast Surg. 2001;24(2):88,
41. Growth factors
Gene theraphy
Dermal mucosal substitutes
42Ref: Wound Healing and Perioperative Care Vivek Shetty, DDS, DrMedDenta,T, Harry C. Schwartz, DMD, MD, FACS
42. Through their central ability to orchestrate the various cellular activities
that underscore inflammation and healing, cytokines have profound effects
on cell proliferation, migration, and extracellular matrix synthesis.
Exogenous growth factors, such as PGDF, angiogenesis factor, epidermal
growth factor (EGF), TGF, bFGF, and IL-1, applied directly to the wound.
To date only a single growth factor, recombinant human platelet-derived
growth factor-BB (PDGF-BB), has been approved by the United States
Food and Drug Administration
Experimental studies suggest potential for the use of growth factors in
facilitating peripheral nerve healing.
The bone morphogenetic proteins (BMPs) belonging to the TGF-β
superfamily have osteoinductive capacities
43
43. It should be clearly understood that the healing of wound is not an
isolated, solitary phenomenon but actually a very complex series of
biologic events.
Wound healing in the maxillofacial region occurs in the presence of
many challenges, usually proceeds undisturbed and with preserved
oral function.
When a facial or intra-oral wound presents a disturbed healing
process, it is recommended to conduct a thorough and judicious
examination to eliminate or correct underlying local or general
factors.
44
44. Robbins basic pathology
Peterson’s principles of oral and maxillofacial surgery
Laskin volume 1
Shafer’s oral pathology
Contemporary omfs
Misch : Implantology
Wound Healing and Perioperative Care Vivek Shetty, DDS, DrMedDenta,T, Harry C.
Schwartz, DMD, MD, FACS
Investigation of recurrence rates among earlobe keloids utilizing various
postoperative therapeutic modalities. Eur J Plast Surg. 2001;24(2):88
Jackson IT, Bhageshpur R, DiNick V, Khan A, Bhaloo S.
45
47. Types of callus
Delayed union vs mal unioun
Contact and gap healing distance
Local and systemic factors
3 types of nerve degeneration
Osteoconduction vs osteo
induction
How keloid forms
Healing in diabetic patients
Factors promoting wound
healing(growth factors etc)
Flaps on wounds
Types of collagen
48
Editor's Notes
Contemporary omfs -peterson
Hypertrophy: increased cell and organ size, often inresponse to increased workload; induced by growthfactors produced in response to mechanical stress orother stimuli; occurs in tissues incapable of cell division• Hyperplasia: increased cell numbers in response to hormones and other growth factors; occurs in tissues whosecells are able to divide or contain abundant tissue stemcells• Atrophy: decreased cell and organ size, as a result ofdecreased nutrient supply or disuse; associated withdecreased synthesis of cellular building blocks andincreased breakdown of cellular organelles• Metaplasia: change in phenotype of differentiated cells,often in response to chronic irritation, that makes cellsbetter able to withstand the stress; usually induced byaltered differentiation pathway of tissue stem cells; mayresult in reduced functions or increased propensity formalignant transformation
Searcharticles on point number 4 .
Ref: laskin, contemporary peterson
The cytokines and growth factors secreted during the inflammatory phase stimulate the succeeding proliferative phase
Starting as early as the third day post injury and lasting up to 3 weeks, the proliferative phase is distinguished by the formation of pink granular tissue (granulation tissue) containing inflammatory cells, fibroblasts, and budding vasculature enclosed in a loose matrix.
Local microcirculation to supply the oxygen and nutrients necessary for the elevated metabolic needs of regenerating tissues. The generation of new capillary blood vessels (angiogenesis) from the interrupted vasculature is driven by wound hypoxia as well as with native growth factors, particularly VEGF, fibroblast growth factor 2 (FGF-2), and TNF-β
Around the same time, matrix-generating fibroblasts migrate into the wound in response to the cytokines and growth factors released by inflammatory cells and wounded tissue. The fibroblasts start synthesizing new extracellular matrix (ECM) and immature collagen (Type III )
What resulted is now called as immature scar
Ref: Contemporary
add systemic and local factors
Shafers oral pathology
With either of these types of primary bone healing, no external callus would be found along the outside of the fragments if they were rigidly immobilized
Misch
contemporary
contemporary
contemporary
Online image
Jackson IT, Bhageshpur R, DiNick V, Khan A, Bhaloo S. Investigation of recurrence rates among earlobe keloids utilizing various postoperative therapeutic modalities. Eur J Plast Surg. 2001;24(2):88,
Wound Healing and Perioperative Care Vivek Shetty, DDS, DrMedDenta,T, Harry C. Schwartz, DMD, MD, FACS