口 腔 病 理 科口 腔 病 理 科 wound healing 傷口癒合 陳玉昆副教授 :...
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學 習 目 標1. Regeneration & repair2. Epithelium & connective tissue3. Extraction wound4. Bone fracture
參考資料 (1)參考資料 (1)References
1. Ibsen OAC: Oral Pathology for the dental hygienist. 4th ed., pp. 36- 522. Avery JK: Oral Development & Histology, pp. 192-2123. Horwitz AF: Integrins and Health. Sci Am 1997;May, 68-754. Singer AF et al: Evaluation and management of traumatic lacerations. New Eng Med J 1997;337:1142-85. Habeck M: Wound-healing genes promote cancer progression. Lancet Oncol 2004;5:1386. Epstein FH: Cutaneous wound healing. New Eng Med J 1999;341:738-467. Kaohsiung Medical University, Oral Pathology Department8. Sompayrac L. How the immune works Lecture 1. An overview 1999:p.5-169. www.mybiology.com/archive_movies10. http://www.bu.edu/woundbiotech/WoundHealingProcess/
參考資料 (2)參考資料 (2)References
11. http://connection.lww.com/products/taylor/documents/cc37figure37- 1.jpg12. http://ls.berkeley.edu/bio/gallery_mcb/wound.html13. www.nchmd.org14. http://www.ma.hw.ac.uk/~jas/researchinterests/scartissueformation.html15. http://www.malp-research.de/16. http://www.imakenews.com/mvius/e_article000210982.cfm17. Awang MN. The aetiology of dry socket: a review. Int Dent J 1989;39:236- 4018. 徐博文、謝耀東 拔牙後齒槽骨傷口之癒合 中華民國口腔植體學會會訊 1997 年 5 月 第 4 期 p.27-3019. Shafer WG. A textbook of oral pathology. 1st edition, p.609-1020. www.unireptile.com/amphibian/newt/newt_web.htm21. Nanci A. Ten Cate’s Oral Histology 7th ed., pp. 388-9
Regeneration
Wound Healing( 再生 )
1
2
When tissue damage is slight, the inflamedarea may return completely to its normalstructure and functionThis is the most favorable end to acuteinflammation and involves:1.Complete removal of all cells, by-products inflammatory exudate that enter the tissue2. Return of microcirculation to its preinflammatory state
蠑螈Ref. 20
Repair
Wound Healing( 修復 )
Bruxism - AttritionBrushing-cervicalabrasion
Repair takes place when complete return ofthe tissue to normal is not possible becausethe damage has been too great
Some tissues, such as epithelium, fibrous connective tissue, and bone have the abilityto undergo repair. Other tissues, such asenamel, dentin, cementum do not
Ref. 1
Repair
Wound Healing
Traumatic ulcer
Sharp edgetoothFungus infection
Tumor
Repair is the body’s final defense mechanism in itsattempt to restore injured tissue to its original state
During repair process, destroyed cells & tissue arereplaced with live cells & new tissue components
Repair process cannot be completed until thesource of injury is removed or the injurious agentsare destroyed Refs. 1, 7
Repair
Epithelium and connective tissue Extraction wound Bone fracture
Wound Healing
Repair
Wound Healing
Injury
1. Inflammation
2. Epithelization
4. Granulation tissue3. Neurovascularization
5. Contraction
6. Collagen formation 7. Scar remodeling
Events of wound healing
Ref. 1
Repair
Wound Healing
Microscopic events that occur during repair1. Occurs in both epithelium & connective tissue2. These events are different for each of thesetissues but occur almost simultaneously andare dependent on each other for optimal healing
If the source of injury is removed, the repair processis usually completed in 2 weeksRepair process is slightly different in mucosa than inskin because mucosal tissue are wet & a scab doesnot form
Repair
Wound Healing
Day of Injury. A clot forms as the blood flows intothe injured tissue.The clot or meshwork of fibrin is produced in the area of injury as a result of activation of theclotting mechanism
The clot consists of locally produced fibrin, clumpedred blood cells and platelets (thrombocytes)Platelets are found in blood are important in theformation of a clot
Repair
Wound HealingClotting mechanism
Blood
(Factor XII)
1
2
3
4
Clot
Ref. 2
Repair
Wound Healing
NeutrophilNeutrophil
One Day After Injury. Acute inflammation takesplace in the area of repairNeutrophils emigrate( 攅入 )from microcirculationinto the injured tissue, phagocytosis of foreignsubstance & necrotic tissues
Ref. 1
Repair
Wound HealingEngulf
Phagosome
Phagolysome Excretion
Refs. 1, 2
www.sumanasinc.com/webcontent/animations/biology.html www.sumanasinc.com/webcontent/animations/biology.html
Repair
Wound Healing
Stem Cell Differentiation
Repair
Wound Healing
Monocyte(Blood)
Macrophage(Tissue)
Ref. 1
Repair Wound Healing
Macrophage
Foot
Bacterium Refs. 8, 15
Repair
Wound Healing
Ref. 8
Repair
Wound Healing
2 Days After Injury. Monocytes emigrate frommicrocirculation into the injured area asmacrophageMacrophages continue phagocytosisNeutrophils are reduced in number as chronicinflammatory process proceeds
Fibroblasts increase in number within the injuredconnective tissueProducing new collagen, using fibrin meshwork asa scaffold ( 鷹架 )
Repair
Wound Healing
Need to be removed for proper healing
Initial tissue formed in connective tissue iscalled granulation tissueIt has more capillaries & fibroblastsSometimes the growth is excessive
Repair
Wound HealingEpithelial new surface
Granulation tissue
If the surface epithelium is destroyed by injury,epithelial cells create a new surface tissueat the same time that granulation tissue formsin the injured connective tissue
Epithelial cells from borders of the healing injuredarea lose their cell junctions and become mobileThey can divide and migrate across injured tissue,using fibrin meshwork as a guide to form a newsurface layer
Ref. 2
Repair
Wound Healing
Functions of fibrin meshwork1. Guide for migrating epithelial cells2. Scaffold for forming connective tissue3. Protect the two newly formed tissues
Clot remains in place is important:1. Allow optimal repair in both tissues2. Dressing placed over the clot may be beneficial to healing process
Repair
Wound Healing
Inflammatory phase
Ref. 6
Repair
Wound Healing
A: Cell Adheres
Infectionor injury
Detressingsignals
RestingActivated
Neutrophil B: Cell rolls
C: Cell stops & flattens
D: Cell emigrates
ICAM: Intercellular adhesion molecules
ICAM
From one selectin
to adjacent selectin
Ref. 3
http://multimedia.mcb.harvard.edu/media.htmlhttp://multimedia.mcb.harvard.edu/media.html
Repair
Wound Healing
Reepithelization & neovascularization
1. Guide for migrating epithelial cells2. Scaffold for collagen3. Protection
Ref. 6
Repair
Wound Healing
pithelium
Contact inhibitio
n
Epithelium
Ref. 4
Repair
Wound Healing
Abnormal mitosis
Capillaryspouts
Ref. 4
Repair
Wound Healing
At the end of 2 days. Lymphocytes & plasma cellsemigrate from surrounding blood vessels into theinjured area as chronic inflammation and immuneresponse begin
Macrophages present in the area assist lymphocytesin the immune response occurring at the site injury
Ref. 1
Repair
Wound Healing
Two Days
Ref. 1
Repair
Wound Healing
7 Days After Injury. Fibrin is digested by collagenase& sloughs off, and the initial repair is completed
Clinically, surface of repaired injury remains redderbecause of the thinness of new epithelium andincreased vascularity of new connective tissue
Two Days
Seven Days
Repair
Wound Healing
Ref. 1
Repair
Wound Healing
Contraction
2 Wks After Injury. The initial granulation tissue& its fibers have been remodeled, giving the tissue its full strength
The new tissue is called scar tissue and appears whiter or paler at the surface of the repaired injurydue to increased collagen and decreased vascularity
Refs. 2, 14
Repair
Wound Healing
Ref. 9
Repair
Wound Healing
Amount of scar tissue depends on:Heredity, strength & flexibility needed, type ofrepairOral mucosa is lesser scar formation than skin
Repair
Wound Healing
Types of repair:Healing by primarily intentionLittle loss of tissue, clean edges are joined withsutures to form a small clot, & little granulationtissueLess scar tissue & higher retention
Repair
Wound Healing
Sutured injury (Primary wound healing)
Small clot Decreasedgranulation tissue
Less scar tissue
Ref. 1
Repair
Wound Healing
Simple Suture
( 前旋 )
Ref. 4
Repair
Wound Healing
Deep Suture
Ref. 4
Repair
Wound Healing
Ref. 4
Common techniques of wound closureTreatment
Advantage Disadvantage
Sutures
TissuesAdhesives
Staples( 釘書釘 )
SurgicalTapes
Repair
Wound Healing
Healing by secondary intentionThere is loss of tissue, so the edges of injurycannot be joinedA large clot slowly forms, resulting increased granulation tissue (e.g. extraction site)
Ref. 7
Repair
Wound Healing
Large injury (Secondary wound healing)
Large Clot Increasedgranulation tissue
Increasedscar tissue
Ref. 1
Repair
Wound Healing
Healing by tertiary intention (delayed primary)If infected wound left open for a few days,edges not surgically joined until infectionis controlledWaiting to close as if primary until infectionis resolved
Repair
Wound Healing
Tertiary Intention
Wound Increasedgranulation
Late suturingwith wide scar
Ref. 11
Repair
Wound Healing
keloid
KeloidExcessive scarring in skin, sometimes needsurgically removed
Ref. 1
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
維他命 C
Refs. 13, 16
高壓氧
Repair
Wound Healing
Ref. 10
Repair
Wound Healing
Extraction WoundExtraction Wound
Repair
Wound Healing
Extraction Wound
Ref. 18
Repair
Wound Healing
Extraction Wound
Ref. 18
Repair
Wound Healing
Ref. 18
Repair
Wound Healing
Extraction Wound
Ref. 18
Repair
Wound Healing
Extraction Wound
Ref. 21
Comparison of Repair Responses in Skin and TeethRepairResponse In skin In teeth
Repair
Wound Healing
Extraction Wound
Ref. 21
The tooth in situ
Repair response after tooth extraction
Hemostatic response: The socket fills with clot
Repair
Wound Healing
Extraction Wound
Ref. 21
Epithelial response: 1. Proliferation & migration of cells to epithelialize the socket (10 days)
Inflammatory response: 2. Polymorph response 3. Macrophage response 4. Cells with osteogenic potential invade the clot from adjacent bone marrow (10 days)
Repair
Wound Healing
Extraction Wound
Ref. 21Proliferative and synthesizing phase:
New osteoblasts differentiateand proliferate, and form newbone to fill the extraction(10-12 weeks)
Repair
Wound Healing
Extraction wound
Normal Healing
Delayed Healing(dry socket)
Extraction Wound
Ref. 17
Repair
Wound Healing
Repair of a bone injury is similar to the process thattakes place in fibrous connective tissue except thatit involves the creation of bone tissue, produced by osteoblasts
Repair
Wound Healing
Mechanisms of Bone Healing:Formation of new bone at fracture site
Clotting of blood and formation of hematoma; 6-8 hr Organization of hematoma: 10 days to complete a. fibrin b. phagocytic activity c. granulation tissue Formation of fibrous callus
Repair
Wound Healing
Formation of primary bony callus; 10-30 days to complete a. Stages of primary bony callus 1. Anchoring callus 2. Sealing callus 3. Bridging callus 4. Uniting callus b. Low calcium; no radiographic image
Repair
Wound Healing
Anchoring callus
Bridging callus Uniting callus
Sealing callus
Fra
ctu
re s
ite
Formation of Primary Callus
Ref. 19
Repair
Wound Healing
Formation of secondary bony callus 20-60 days a. Irregular bone; influx of calcium radiographic image b. Removal of cast; 4-5 week for jaw bone
Reconstruction and remodeling a. Alignment to stress b. Removal of excess
Repair
Wound Healing
Healing of bone depends onInterrupted by removal of osteoblast-producingtissuesIncreased movement of bonePresence of edema or infection
Repair
Wound Healing
Fixation 2Fixation 1
Repair
Wound Healing
Wound healing genespromote
cancer progressionRef. 7
It has long been recognized thatcarcinoma cells & their surroundingstroma behave in a remarkably similarway to cells in a healing wound withcharacteristics such as rapid division,migration, remodelling & invasionof connective tissue, and in abilityto induce angiogenesis.
In 1986, Harold Dvorak (Berth IsraelDeaconess Medical Center, Boston,MA, USA) made the most graphic analogy between wound healing & cancer when he said that tumors are wounds that do not heal.
It has long been recognized thatcarcinoma cells & their surroundingstroma behave in a remarkably similarway to cells in a healing wound withcharacteristics such as rapid division,migration, remodelling & invasionof connective tissue, and in abilityto induce angiogenesis.
In 1986, Harold Dvorak (Berth IsraelDeaconess Medical Center, Boston,MA, USA) made the most graphic analogy between wound healing & cancer when he said that tumors are wounds that do not heal.
口 腔 病 理 科
1. Regeneration & repair2. Epithelium & connective tissue3. Extraction wound
SUMMARIES
Processes, types, characteristics
4. Bone fracture