BONE GRAFT
INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
Bone graft in maxillofacial surgery are used to correct or replace missing bone. Bone defect can be
Consequence of congenital and developmental deformities
Originate from tumour surgery, trauma or infection
Bone graft in cosmetic surgery.
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Types of graft a.
Auto graft transplanted from one region to another in same
individuals. Allograft (Homograft) – is transplated from one individual to a genetically non identical individual of same species. Xenograft
(Heteorgraft) – transplant from one species to
another species.] Isograft – graft exchanged between genetically identical individual such as identical things. www.indiandentalacademy.com
Anatomical Classification of Bone graft 1.
Cortical bone (as block, chip)
2.
Cancellous bone
3.
Cortico cancellous bone
4.
Periosteal and osteoperiosteal graft
5.
Marrow graft
6.
Segment of shaft of long bone such as clavicle, ribs, scapula or tibia.
7.
Whole bone graft
8.
Osteoarticular graft
9.
Pedicle bone graft
10. Free vascularized bone graft involving microvascular ananstomosis. www.indiandentalacademy.com
Clinical uses and function of bone graft
Delayed and nonunion of fracture
Filling of cavities in bone
Replacement of bone and joint loss
Augmentation of skeletal deficiency in the forehead, nose, maxilla and mandible.
Fusion of growth graft cartilage
Function of bone graft in mandible
Restore normal continuity and function
Restore an overall satisfactory appearance of face
Furnishes a source of viable osteogenesis cells www.indiandentalacademy.com
Principles of Bone graft in mandible
State of health and nutrition of patient
Aseptic technique – surgical techniques should be extra oral
to prevent contamination of oral flora.
Graft Bed
- tissue scar from previous wound should be
excises to ensure quality and quantity of recipient site. Submandibular incision should be placed as low as possible. It will move
superiorly owing to increased contour of face as a
result of graft.
Handling of the graft – graft must be handled carefully to
prevent contamination and mechanical injury. www.indiandentalacademy.com
Storage media – isotonic normal saline, tissue culture medium. Osteoprogenitor cells are hardly capable of withstanding the trauma of removal upto 4 hours. ď ś
Fixation and immobilization of the graft a. Reconstruction plate b. Maximum mandibular fixation
c. If there is no teeth proximal to the canine area on side of defect a lingual splint should be fabricated with an extensive area engaging the maxillary teeth above the defect. This prevent the torque between graft host interface. Tension can be relieved by removing the coronoid process. This will eliminate temporalis muscle influence on the proximal fragment. www.indiandentalacademy.com
Wound Closure Wound should be closed in layers without tension.
Antibiotic Coverage
BIOLOGIC BASIS OF BONY GRAFT Most effective form of bone grafting is cancellous cellular bone. Mechanism of bone formation in a cancellous cellular bone emanate from survival of the osteoprogenitor cells (osteoblst & marrow cells). Transplanted osteoprogenitor cells survive within the recipient tissue for first 3-4 days by a nutritional diffusion from the surrounding vascular tissue envelop. www.indiandentalacademy.com
From 3rd day – capillary buds start proliferation from surrounding tissue. This establish oxygen gradient and acidosis, lactate in the graft signals macrophages to form macrophage derived angiogenesis factor. Between 3rd and 14th day – complete revascularization occur. Endosteal osteoblast survive transplant and proliferate neoosteoid upon the surface of the cancellous bone trabeculae. Mineral component undergoes a gradual physiologic resorption mediated by osteoclast. Osteoclasts resorbs the bony trabeculae pattern, they release bone morphogenetic protein (BMP) from non-collagenase mineral matrix of bone. BMP direct stem cells transferred within the graft, stem cell within the local tissue and circulatory stem cells to differentiate into functional bone forming cell. www.indiandentalacademy.com
Phase I Bone formation
It arise from the survival endosteal osteoblast and marrow
stem cells transferred within the graft material which form bone in a random haphzard fashion. Phase II Bone formation
The revascularization dependent resorption of transplated
bone trabeculae in the early phase I bone followed by remodeling and replacement with new bone.
Phase II Bone begins about the third week after placement of
graft. Via endosteum and periosteum of bone. www.indiandentalacademy.com
Importance of phase I bone arise from the knowledge that
the maximum quantity of bone available to the graft is formed in this phase.
The importance of phase II bone is remodeling of phase I
bone to a long lasting bone capable of self renewal.
Usually phase II bone replaces phase I bone in a one to one
ratio.
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Type of free bone graft Donar site
Chin
Retromolar area
Nasal aperture
Skull
Rib
Iliac graft
Tibia www.indiandentalacademy.com
ILIAC GRAFT Ilium is major source of graft for maxilllofacial reconstruction. Anatomy of Iliac Medially
-
iliac muscle, ceacum, ascending colon
Laterally
-
Abductor muscle of hip (gluteas muscle)
Nerves
-
Lateral Femoral nerve innervate lateral thigh. Subcostal nerve over anterior iliac spine Iliohypogastric nerve over iliac tubercle www.indiandentalacademy.com
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Approach to Iliac crust
Lateral approach stripping tensor fascia lata and gluteas
medius
Medial approach stripping iliac muscle
Crystal approach splitting or removing proportion of iliac crest
Disadvantages of Lateral Approach
Dissection of tensor fascia lata muscle laterally create gait
disturbance.
Difficult to the strip muscle from the lateral aspect of ilium
Failure to appose the muscle to the ilium can results in gait
disturbance. In extreme situation dragging limp or gluteal gait occur www.indiandentalacademy.com
Disadvantages of Crestal Approach
In long term will usually result in irregularity of crest - below
the age of 20. Disadvantages of Medial Approach
It is associated with greater risk of damage to lateral fermoral
cutaneous nerve of thigh. Meralgia paraesthesia in the upper lateral thigh.
Increased incidence of post operative ileus.
Increase post operative pain from disruption of abdominal
wall musculature www.indiandentalacademy.com
Surgical Approach
Guideline to length of incision is depend on the maximum
width of bone to be harvested. Types of Incision
Lateral incision
Medial incision
Lateral Incision Approach
Incision is less likely visible than medial incision
Incision are made lateral to crest to avoid lateral fermoral
nerve, 1cm posterior to anterior ilia spine to avoid subcostal nerve, extend upto 2cm posterior iliac tubercle. www.indiandentalacademy.com
Incision carried down through – skin, subcutaneous fact,
scarpa’s fascia to the muscular aponeurosis.
Iliac bone is approach 1cm below the crest in young. (Where
the crest is cartilaginous and growth is expected) and 5mm below in adult. VARIOUS APPROACH TO PARTICULATE CANCELLOUS BONE MARROW
Clamshell approach – expand medial and lateral cortex to
gain access to cancellous bone.
Trap door approach – pedicle the medial or lateral cortex on
muscle to gain access. www.indiandentalacademy.com
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Tschopp approach – pedicle the iliac crest on the external oblique muscle to gain access. Tessier approach – pedicle the medial and lateral portion of the crest by mean of oblique osteotomy. TREPHINE TECHNIQUE
Incision is 2cm in length
No medial lateral stripping and incision carried down to iliac crest. Trephine is used to perforate iliac crest and cancellous bone is harvested upto depth of 3cm using a rotatary action. Trephine is angulated 30° to vertical proceed between medial and lateral cortex. www.indiandentalacademy.com
Approach to posterior Iliac Bone Posterior approach is used when a greater quantity of particulate bone is required. Advantage More cancellous bone is available – approx. 2 to 2.5times the quantity taken from anterior iliac.
Less bleeding, less gait pain and disturbance
Disadvantage
Overall operative time increased
Nerve damage (cluneal nerve) www.indiandentalacademy.com
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Approach Incision is made at well defined bone prominence laterally, where gluteaus maximumus inserts. Curvilinear incision course medially about 3cm lateral to midline ending at length of about 10cm. Direct approach avoid damage to superior cluneal and middle cluneal nerve. RIB GRAFT Principles and indication
Rib graft -
Combined orbital floor and medial orbital wall. Zygomatic arch and body reconstruction www.indiandentalacademy.com
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Nasal bridge reconstruction
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Chondral cartilage is an ideal reconstruction for the mandibular condyle.
-
Split rib used for brain coverage
Anatomy of Rib
There are 12 ribs on each side of thorax
Seventh is longest rib
Eleven and Twelve rib are not attach anteriorly
Eighth, Ninth and Tenth do not join the sternum directly but
articulate with each other costal cartilage. www.indiandentalacademy.com
Vascular supply by internal mammary (internal thoracic)
Cartilages is a relatively inert tissue and therefore resorp slowly. Cartilage has inherent stress which are not manifest immediately. Cartilage should be carved the left out of the body for thirty minutes to deform prior to final carving and placement in the recipient site. Surgical Approach A 5cm long incision is made in the submammary crease, starting approximately 4mm from the midline. Muscles encountered first is the lower edge of pectoralis major. Lateral part of the wound, slips of seratus anterior can be seen inserting on to the rib. www.indiandentalacademy.com
Curved Doyen rib raspatory used to strip full length of the rib.
Tudor Edward rib shear are introduced with their protector
and slid along the surface of the rib to make the lateral cut first.
When cartilages harvested in continue with rib then a
diamond of periosteum and perichondrium is left attached to the anterior surface of the adjacent rib and costeal cartilage to prevent disarticulation of bone and cartilage.
If large volumes of ribs are required a posterolateral
thorocohomy incision is used. www.indiandentalacademy.com
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POST OPERATIVE CARE
Respiratory , pulse and blood pressure should be carried out
every 15mins for first two hours then every 30mins for four hours.
Pain is controlled initially with Bupivacaine injection via
epidural cannula. Complication
Plural tear - detect by placing water the wound and then
exert positive pressure ventilation to see any bubbling in the wound.
If there is an air leak, a temporary chest drain inserted low in
the anterior axillary line. www.indiandentalacademy.com
SKULL BONE Indication 1.
Defect in orbital floor
2.
Zygomatic prominence
Anatomy
Skull consists of inner and outer table and a separated by
vascular diploe.
Graft is taken from posterior part of skull, in the region of
parietal and occipital bone
Approach – bicoronal or hemicoronal flap www.indiandentalacademy.com
Complication
Extra dural haematoma
Direct intracerebral damage
Counter coup injury
Osteomyelitis may develop in complete removal of cranial
bone and it is treated by titanium cranioplasty.
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MICROVASCULAR GRAFT
Iliac graft
Fibula graft
Radial forearm flap – Chinese flap
Scapula flap – French flap
ILIAC GRAFT
History – in 1972 McGregor describe gran flap based on
superficial iliac www.indiandentalacademy.com
IAN TAYLER – explained iliac crest has primary vascular anatomy of descending circumflex iliac artery. Anatomy
Iliac graft is based on vascular pedicle of DCIA and DCIV
DCIA originate laterally from the external iliac artery and passes laterally on the deep surface of inguinal ligament. Surgical Landmark
Iliac crest
Pubic tubercle
Inguinal ligament
External iliac artery. www.indiandentalacademy.com
Technique of identifying DCIA
Inguinal ligament
Ascending branch of DCIA from internal oblique muscle
Surgical Technique Skin is incised around the circumference of the flap and edge is elevated at the level of external oblique fascia towards a obligatory abdominal muscular cuff. Incision extended to tubercle passing 1-2cm above the inguinal ligament. Fibers of internal oblique and transverse abdominals muscles are divided at the same level least to identification of external iliac artery.
On the medial site bone cut is made 1cm below the DCIA www.indiandentalacademy.com
ILIAC GRAFT FOR MANDIBULAR RECONSTRUCTION
Iliac crest to form the lower border of the mandible
Anterior superior iliac spine – angle of the mandible
Anterior inferior iliac spine - condyle
Ipsilateral iliac crest is harvested pedicle emerges from the
newly constructed angle to recipient vessels in the same side of the neck.
Contralateral crest – pedicle is positioned anteriorly and is
positioned for vessel in apposide of the neck. www.indiandentalacademy.com
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Complication
Hernia formation is 12% in osteocutaneous flap and 4% pure
osseous flap. Advantages
Iliac provides 6-16cm graft in length which allows three
dimensional carving the shape of hemimandible. Disadvantage
Iliac crest is not ideal for angle to angle defect
Intra oral defect is not handle well by the bulk is skin paddle
Color match of iliac skin to fascia skin is poor www.indiandentalacademy.com
FIBULA GRAFT First reported by Ueba and Fujikawa in Japan and O’Brien & Morrison in Melbourne in 1977. Hidalgo was the first to describe fibula transplantation for reconstruction of the mandible. Surgical Anatomy
Fibula head articulated with tibia 2cm below the knee joint.
A fibula is 40cm long bone this provide upto 26cm for transplantation. Peroneal nerve run around the fibula head. Damage to the peroneal nerve are avoided by leaving 8cm of cranial fibula and angle joint by leaving 8cm of distal end. www.indiandentalacademy.com
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Anterior to fibula – extensor hallucis longus muscle and extensor digitorium longus muscle.
Laterally
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Peroneus longus and peroneus brevis muscle.
Dorsally
-
Soleus muscle and centrally flexor hallucis
Distally
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Peroneus brevis muscle
Vascular supply
Fibula is supply by peroneal artery
It is a branch of posterior tibial artery and it run dorsal to intraosseous membrane and medial to fibula between tibialis posterior muscle and flexor hallucis longus muscles. www.indiandentalacademy.com
Anterior
crural
septum
–
between peroneus and extensor lodge
Posterior crural septum –
Fibula is accessed by dissection
on the front or rear surface of the posterior crural septum.
peroneus and flexor lodge Incision
Fibula is situated at the point
of attachment of triceps fermoralis tendon.
Straight line connecting the
fibula head and lateral malleolar mark the posterior crural septum. www.indiandentalacademy.com
Detachment of anterior crural septum is followed by
detachment of extensor digitorium longus and extensor hallucis longus as far as intraosseous band.
Peroneal artery is ligated and is dissected with the bone in
lateral dorsal direction. Advantage
Constant topography
Long bone
High stability www.indiandentalacademy.com
Disadvantage
Short vascular pedicle
Low height of bone
Low height of recipient site for endosteal implant
Complication
Damaged peroneal nerve will result in foot drop, loss of
arches of the foot. Flaccid foot Radial forearm flap - Chinese flap
Flap originate in China, it was used to cover burn surface.
It was introduces to Western country by Muhlbauer www.indiandentalacademy.com
Indication
Mandible
Anterior wall of maxillary (orbital rim and floor are maintain)
Palatal defect
Anatomy
Flap depends on ascending vascular radicals from radial
artery to the over line fascia and skin and descending branch to the underlying periosteum of the radius.
Venous
–
superficial
cutaneous
vein
and
accompanying the radial artery.
Radial osteocutaneous flap provide upto 16cm. www.indiandentalacademy.com
comitants
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Advantages It is ideal for elderly patient with an edentulous mandible with vertical height of 13 cm. Disadvantages Inadequate bone for mandibular reconstruction Two weak to withstand normal masticatory force. Limbs is immobilized for 8 weeks Incision on forearm hypertrophy and unsighty.
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PEDICLE GRAFT Parietal osteofascial free pedicle flap Serratus rib free osteocutaneous flap Sternocleidomastoid osteomyocutaneous flap Pectoralis major rib osteocutaneous flap Temporals osteomuscular flap PARIETAL OSTEOFASCIAL FREE PEDICLE FLAP Flap is based on superficial temporal vessel Partial or full thickness parietal calvarial bone is transferred with an apron of galea and parieto temporal fascia for restoration of upper and middle facial defect. arch of rotation of pedicle.
Removal of zygomatic arch increase the www.indiandentalacademy.com
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Advantages Minimal donor site morbidity Disadvantages Minimal amount of bone stock available Associated morbidity of craniotomy Serratus rib free osteocutaneous flap Described by ostrup and Fredrickson in 1974.
Mckee performed a
clinical free rib graft for mandibular reconstruction. Anatomy Serratus pedicle flap is based on thoracodorsal vessel and muscle belly receive is best supply from the lateral thoracic artery. www.indiandentalacademy.com
Serratus anterior muscle orginate from 6 – 10 ribs and insert on to the costal of surface of medial aspect of scapula. Approach Anterior approach is most reliable as vascular pedicle may be length by relying on the intercostal vessel, which branches from internal mammary artery. Posterior approach Damage blood supply to the thoracolumbar spinecord. Advantages Used for reconstruction of rib and syphyseal defect
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Disadvantages Less amount of corticocancellous bone Weak to handle funcdtional masticatory post Poorly suited for implant reconstruction Skin vascular pedicle is unreliable Winged scapular deformity Sternocleidomastoid osteomyocutaneous Described by Conely and Gullan Technique for raising SCM flap is to use contralateral muscle and bone for reconstruction. Two third clavicle may be harvested.
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SCM has tripartiat blood supply -Thyrocervical -Superior thyroid -Occipipal artery Advantages
Easy
flap
for
one
stage
immediate
reconstruction
of
oromandibular defect. Disadvantages Exposure of great vessel of neck after mobilization and resulting contour deformity of neck.
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Pectoralis major rib osteocutaneous flap Described by Cuono – Ariyan PM flap depends on vascular supply of thoraco acrominal artery, lateral thoracic artery and perforating braches from 1 to 6 intercostal by internal mammary artery. Incision – Inframammary incision Skin island is chosen to lie in a transverse axis over 5th rib Muscle dissected from 6th, 7th, 8th and proceed cephalad toward 5th and 6th intercostal. Lateral flap is dissected from pectoralis minor to expose vascular pedicle. Intercostal muscle between 5th and 6th rib are dissected www.indiandentalacademy.com
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Rib is section at lateral and medial extent with rib cutter
Increase mobilization of flap is gained by dividing humeral,
sternal and clavicular attachment. Advantage Ease of harvest Vesatile and durable flap containing long pedicle Disadvantags Increase risk of pleural tear and pneumothorax formation Temporal osteomuscular flap Described by Conley McCarthy and Zide designed in the flap for orbital and frontal reconstruction.
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Flap depend on deep temporal artery Dissection done through sub galeal plane to expose superficial artery and vein. Full or partial thickness bone graft are harvested with bur Advantages Superior viability of bone Greater bone availability Minimal associated morbidity and cosmetic effect Disadvantages Poor anterior mobilization
Donar site volume defect that may affect jaw function and
ranging of motion.
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www.indiandentalacademy.com Leader in continuing dental education
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