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Mandibular reconstruction / oral surgery courses
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Mandibular reconstruction / oral surgery courses

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.


Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
00919248678078

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    Mandibular reconstruction / oral surgery courses  Mandibular reconstruction / oral surgery courses Presentation Transcript

    • MANDIBULAR RECONSTRUCTION WITH BMP & PRP www.indiandentalacademy.com
    • INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
    • INTRODUCTION  Mandibular defects in OMFS are common.  Mandibular reconstruction in OMFS is a major challenge.  Gold standard for reconstruction  Newer techniques. www.indiandentalacademy.com
    • DEFINITION OF RECONSTRUCTION :  Reconstruction refers to the rebuilding or the restoration of original form and function that have been lost owing to disease or treatment of disease. CLASSIFICATION OF BONY DEFECTS  Cantor and curtis  HCL classification www.indiandentalacademy.com
    • MANDIBULAR RECONSTRUCTION a. Immediate  Inability to detect recurrence  Increased risk of graft rejection b. Delayed  Late covering of primary site  Increase in complication  Increased hospital stay  Cost www.indiandentalacademy.com
    • GOALS OF RECONSTRUCTION :  Restore maxillofacial form  Maintain quality of tissues  Maintain oral competence  Maintain oral cavity function  Achieve coverage of soft tissue defect www.indiandentalacademy.com
    • RECONSTRUCTION TECHNIQUES : Free bone grafts Poor tolerance to infection ‘K’ Wires Failure rate of 70% Stainless steel intra meduallary pins Scarring & Contracture AO plates Excellent cosmetic result Titanium, Vitallium Good outcome Stainless steel wire mesh Good outcome Allo plast + Free bone grafts Greater potential neovascularization www.indiandentalacademy.com for
    • Osteomyocutaneous flaps :  Pec. major flap with 5th and 6th rib  Trapezius flap with scapular spine  Sternocleido mastoid flap with clavicle  Latissmus dorsi flap with iliac crest Distraction osteogenesis www.indiandentalacademy.com
    • LIMITATION OF CONTEMPORARY TECHNIQUES :  Limited application  Short supply of graft material  Risk of disease transmission  Potential morbidity at donor site www.indiandentalacademy.com
    • TISSUE ENGINEERING Definition : Construction of a device in the laboratory containing viable cells and biological mediators in a synthetic or biologic matrix that could be implanted in patients to facilitate regeneration of particular tissues.  Bone morphogenic protein - BMP  Platlet rich plasma – PRP www.indiandentalacademy.com
    • BONE MORPHOGENIC PROTEIN History :  Neuhof in 1917 and Huggisn in 1930 demosntrate “Heterotropic osteogenesis”.  In 1965 Urist unveils the concept of auto induction – Ectopic bone formation.  In 1971 the term osteoinduction was coined.  In 1988 Wozney and Colleagues clones morphogeneic protein using recombinant technology. www.indiandentalacademy.com bone
    • PRINCIPLES OF BONE REGENERATION  OSTEOINDUCTION  OSTEOCONDUCTION  OSTEOGENESIS www.indiandentalacademy.com
    • SOURCE OF BMP : CYTOKINES PDGF ; TGFb; FGF; IGF TGFb1 ; TGFb2 BMP BMP 1 - 15 www.indiandentalacademy.com
    • BMP - Present in high concentration in bone matrix, osteosarcoma tissue, dentin matrix. TGFb – Found in high concentration in platlets about 50ng / ml of whole blood, sequestred within platlets. PERIOSTEUM – Source of Osteoprogenitor cells in bone www.indiandentalacademy.com
    • TYPES OF BMP BMP1 - Regulatory molecule; activates BMP BMP2 - Ectopic bone formation; OI ; present in bone spleen, liver, brain, kidney, heart, placenta. BMP3 - OI ; Present in lung, kidney, brain, interstine. BMP4&5 - OI ; Embryogenesis BMP6 - Not Osteoinductive BMP7 - OI ; Bone differentiation BMP8&9 - OI ; Bone formation BMP 12&13- Inhibition of terminal differentiation of myoblast. www.indiandentalacademy.com
    • STEPS IN OSTEOINDUCTION :  Chemotaxis of osteoprogenitor cells.  Synthesis of Type III collagen.  Differentiation of chondroblasts.  Conversion of connective tissue into cartilage.  Invasion by capillaries.  Calcification  Synthesis of Type IV collagen  Synthesis of Type I collagen  Ossification www.indiandentalacademy.com
    • FUNCTIONS : Growth factors - Cell to cell interaction in skeletal tissue. BMP Type 2 - a. Acts on immature osteoprogenitor cells. b. Differentiate them into osteoblasts and chondroblasts for bone formation. TGFb2 - Stimulates proliferation of osteoprogenitor cells and also chemotactically attracts osteoprogenitor cells to sites of bony defects. www.indiandentalacademy.com
    • BMP in mandibular reconstruction  Pleiotropy  Bone graft - Cortical, cancellous or both  Scaffolds ; -They are the supporting or carrier materials. -They are rigid, solid, gel, paste or injectible fluid. -They can be absorbable, resorbable, osteoconductive or osteoinductive.  Matrix metallo proteinases - Biodegrades matrices and hydrogels. www.indiandentalacademy.com biodegradable,
    • FORMS OF BMP :  Bovine BMP – bBMP  Recombinant human BMP – rhBMP -‘K. Bessho’ advocates rhBMP due to consistency of safety and quality for clinical application. -rhBMP is not fully characterized -Activity of rhBMP is 1/10th of bBMP. -Synthesis of bBMP is very minimal 10 – 20mg / kg dry bone www.indiandentalacademy.com
    • APPLICATION OF BMP : - In clinical surgery BMP is applied as a paste. - It contains 1mg of purified BMP per cm3. - BMP action is decreased on sterilization by irradation - BMP is sterilized by defatting via chloroform / ehtanoland freezing to -70º. www.indiandentalacademy.com
    • LIMITATION OF BMP : - Bone inducing capacity is unpredictable - Pathologic expression of BMP (Yashika & Colleagues in CANCER in 1994) revealed 40% of osteosarcoma or osteoinductive - Osteoblast and fibrohistio cytic types account for highest level of BMP - No evidence to support BMP causes oncogenesis. - Researchers in 10 years of animal studies in rhBMP has reported no evidence of oncogenesis. - In 2004, FDA cancels sanction for use of rhBMP for clinical use in OMFS www.indiandentalacademy.com
    • CLINICAL RESEARCH : 1. Reconstruction of primate mandible with rhBMP2 and bone marrow. (Ichiro, Izumi, Shoji) JOMS, 2001 University of Japan. - Implantation of bone marrow alone, rhBMP + bone marrow and rhBMP alone in mandible of Japanese Monkey after creating segmental mandibular defects. Carrier – PGLA. - Results : rhBMP + BM > BM > rhBMP. www.indiandentalacademy.com
    • 2. Reconstruction of mandibular defects with autologous tissue engineered bone. (Bradford, B. Kaban, Maria) JOMS, 2004 University of Boston. - MSC isolated from ilium of porcine were expanded in culture and seaded to PGLA & Scaffolds. Four defects of 2x 2 cm was created and filled with autogeneous graft, only scaffold, empty as control. - Results : Mandibular defects can be successfully regenerated by MSC on polymer scaffold with penetration of bone and vessels. www.indiandentalacademy.com
    • 3. Mandibular defects repair by TGFb and IGF1 released from osteoconductive gel. (Rachmiel ; Blumenfeld, Liune) JCFS, 2005 University of Japan. - Mandibular defects in rat mandible was filled with TGFb, IGF1, both hydrogel and control and tested after 3rd and 6th weeks - Results : Defects filled with TGFb and TGFb + IGF1 showed greater bone formation with hydrogel scaffold. www.indiandentalacademy.com
    • PLATLET RICH PLASMA Definition : PRP is an autologous concentration of human platlets in a small volume of plasma. History : 1997– PRP was first introduced in OMFS by Whitman. 1998 – PRP’s role in bone formation with autogeneous bone by Marx et al. www.indiandentalacademy.com
    • COMPONENTS OF PRP :  IGF1  PGDF  TGF – b  VEGF  EGF  Cell adheshion molecules www.indiandentalacademy.com
    • FUNCTIONS :  PGDF – Mitosis of healing cells, angiogenesis, macrophage activation.  IGF – Secreted by osteoblast, mytogenic to osteoblast line of cells.  PRP – Increases the number of growth factors in the graft www.indiandentalacademy.com
    • PROCUREMENT OF PRP :  Withdraws 400 – 450ml of whole blood, 50ml per minute with a speed of 5000 rpm.  Citrate phosphate dextrose 1 : 5 for anticoagulation Layers of PRP  PPP – 200 ml  PRP – 70 ml  RBC – 180 ml  1 to 3 ml of RBC layer is also added to PRP. www.indiandentalacademy.com
    • APPLICATION OF PRP :  Initiation of clotting process  PRP is mixed with PCBM  10 ml of CaCl2 and 10,000 units of topical bovine thrombin  In 10 ml syringe 6ml of PRP + 1ml of CaCl2 + 1ml of air is added to form a gelatin mass.  A PRP count of 1 million per micro litre is the benchmark for “therapeutic dose of PRP”. www.indiandentalacademy.com
    • ROLE OF GROWTH FACTRORS IN PRP :  Stimulation of cellular activity  Release of PGDF, TGFb and IGF from platlets in the graft  PDGF stimulates mitogenesis of marrow stem cells.  Angiogenesis of capillary endothelial mitosis. budding by inducing  TGFb activates fibroblast and preosteoblast to initiate mitosis and lay down bone matrix and collagen matrix to support capillary in growth.  By day 3, capilliaries penetrate the graft  By day 14, complete permeation of capillaries takes place www.indiandentalacademy.com
    •  Life span of platlets in a site is 5 days.  Aftermath, bone regeneration is by macrophages.  Phase I Bone : a. Formed in the first four weeks b. Bone formed is disorganized woven bone c. Little structural integrity present.  Phase II Bone : a. Mature lamellar bone b. Presence of Haversion system c. Presence of structural integrity d. Formation of periosteum and endosteum www.indiandentalacademy.com
    • USES OF PRP :  Accelerated rate of bone formation was demonstrated on plain radiograph using PRP.  Rate of bone generation is not only faster but also greater, verified by histiodensitometric study. www.indiandentalacademy.com
    • CLINICAL RESEARCH : 1. PRP : Evidence to support its use (Richard E. Marx) JOMS, 2004 University of Miami Clinical Contraversy - Failures are due to inappropriate sequestration of platlets, less therapeutic platelet level, inappropriate preparation of PRP. - Benefits are continuity defects, sinus lift augmentation grafting, ridge preservation grafting, periodontal / perioimplant defects - Autologous PRP is the safest www.indiandentalacademy.com - PRP does not promote infection, pH is 6.5
    • 2. Differential growth factor retention by platlet rich plasma. (Rick ; Jenifer, Sidney) JOMS, 2005 - To evaluate an optimal substrate for extended growth factor retention. - PRP + TRAP ; PRP + Bovine thrombin ; PRP + bone substitues. - PRP + bovine thrombin results in large immediate release of growth factors which is lost via interstitium. - PRP + TRAP – release of growth factor at a slow and sustained rate for longer period www.indiandentalacademy.com
    • 3. Effect of PRP with autogeneous bone graft for maxillary sinus augmentation in a rabbit model (Kevin ; Jeffry ; Gloria) JOMS, 2005 - This study fails to find a direct stimulatory effect of PRP on healing of autogeneous bone graft using static and dynamic histomorphometric analysis. www.indiandentalacademy.com
    • SUMMARY :  Tissue engineering methods in bone regeneration is promising based on the scientific studies carried out in animals.  The hurdles of large bone reconstruction by tissue engineering has yet to be explored especially in in humans.  With strides of advancement in technology and global research there is little down that reconstruction of bony defect will be a reality. www.indiandentalacademy.com
    • REFERENCE :  Tissue engineering – Richard E Marx ; Lynch  Bone morphogenic protein – Lindholm  JOMS ; 2001, 2004, 2005  JCFS ; 2005  IJOMS ; 2004 www.indiandentalacademy.com
    • Thank you www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com