Extraoral Bone Grafting for Implant Reconstruction










1088
39
Extraoral Bone Grafting for
Implant Reconstruction
DAVID J. DATTILO
Introduction
e pool of patients that are eligible for dental implant recon-
struction has expanded widely since Brånemarks research rst hit
the world of dentistry in the early 1980’s. Extensive research in
bone biology, coupled with newer and proven bone grafting tech-
niques, leaves almost no patient outside the boundaries of eligible
recipients. is includes patients with large bony defects resulting
from trauma, resection from pathologic lesions, and congenital
deformities, which would be classied as division E in the Misch-
Judy classication of available bone and prosthetic options.
1,2
Procedures designed to provide large quantities of bone harvested
from outside of the facial region that were previously used to only
restore continuity and primitive function now are expected to
reproduce vertical and horizontal dimensions for ideal placement
of implant xtures for the support of multiple prosthetic designs.
ese new demands on the implant surgeon make the evalu-
ation of the recipient defect, both dimensions and biologic envi-
ronment, as well as the appropriateness of the potential donor
site bone quality, of paramount importance. For instance, loss of
bone from treatment of neoplastic or other pathologic processes
represents far greater reconstructive challenges than loss of bone
from trauma or infection. Other factors important to deciding
the type and quantity of bone graft required to be harvested for
larger defects is the presence of systemic diseases and the possible
exposure to therapeutic doses of ionizing radiation. Success rates
of bone grafts in irradiated jaws have been found to be lower by
signicant amounts, as well as complication rates of 81.3%.
3
e
rich cellular components that make autogenous grafts the “gold
standard” of implant-supported bone grafts, along with tech-
niques such as hyperbaric oxygen treatment, platelet-rich plasma,
and the use of engineered growth factors such as bone morpho-
genetic protein (BMP), all act to combat and hopefully overcome
any hostile environment to provide a healthy osseous base for the
placement of dental implants.
e four major anatomic areas for harvesting of free autog-
enous bone that will be discussed in this chapter include the cra-
nium, the anterior and posterior iliac crest, and the tibial plateau.
e necessity required for the proverbial Mother of these inventive
techniques was primarily provided by the multiple facial injuries
sustained by American and German soldiers during World War I
and II. Surgeons from both countries, when faced with such large
deformities caused by the latest in wartime ballistics, searched the
body for the largest reservoirs of bone that could be used to ll
these functional and cosmetic defects. Surgical researchers Wol,
Moss, Tessier, Boyne, and Marx then took these procedures and
investigated the details of bone graft healing and the interaction
between the bone and the recipient soft tissue bed.
7,8
ese ini-
tial autogenous bone grafts, however, were characterized by rapid
and advanced bone resorption, which sometimes reached 30% to
90% in the best of conditions.
9,10
With the advent of endosteal
implants used in conjunction with autogenous grafts, research
began reporting the maintenance of the grafted bone and the
prevention of this rapid bone resorption.
11,12
Surgeons placing
extraoral autogenous bone grafts, when used in conjunction with
endosteal implants, can now expect to maintain better than 90%
of the initial grafted segment.
Autogenous free bone grafts harvested from these four donor
sites and their subsequent recipient sites have other unique bio-
logic qualities that contribute to their appropriate use for dental
implant support. Calvarium and mandibular bone are of intra-
membranous origin formed through the progressive dierentia-
tion from primordial mesenchymal cells to stem cells to osteocytes,
while the maxilla, anterior and posterior iliac crest and the tibia are
formed through endochondral ossication through the transfor-
mation and replacement of already formed cartilage.
Early studies comparing these two types of grafts on animal
models revealed superiority of intramembranous bone grafts taken
from the skull to endochondral bone grafts taken from the ilium
or the rib.
4,5
At one year, the intramembranous grafts appeared to
maintain the original grafted volume, whereas the endochondral
grafts were decreased in volume by 75%. ese ndings appeared
to be counterintuitive because the higher cancellous bone content
of the endochondral grafts would seem to welcome a much faster
revascularization than the more cortical intramembranous bone.
Follow up studies actually showed a more rapid revascularization
of these membranous grafts with complete ingrowth of vessels
from the host bone and periosteum at 14 days whereas the endo-
chondral bone still showed signicant areas of necrotic bone and
areas of resorption.
6
Ironically, it appears the mechanism of revascularization of both
the intramembranous and endochondral grafts proceeds along
the same pathway borrowing similarities from both mechanisms
with the grafted bone acting as the matrix (osteoconduction) that

1089
CHAPTER 39 Extraoral Bone Grafting for Implant Reconstruction
is subsequently replaced by osteoid generated by viable osteogenic
cells (osteogenesis) with regulation from grafted growth factors
(osteoinduction).
Each of the four major donor sites for free autogenous grafts
are unique in their ability to provide one or both of the essential
structural elements of bone, which include the strong and rigid
cortical or the softer but more cellular and regenerative cancel-
lous. ese two bone types also dier in the process in which they
regenerate new bone. e calvarial graft is predominantly corti-
cal bone and used in areas in which maintenance of a particular
dimension is essential for a longer term, bone grafts from the iliac
crest provide both cortical and cancellous bone in dierent quan-
tities, and the tibial plateau is useful for obtaining quantities of
cancellous bone only (Fig. 39.1).
All of these grafts can be augmented with a number of dif-
ferent supplemental materials, regenerated blood products, and
exogenous growth factors, which may assist in turning these
grafted sites into the ideal bone quality to support future implant
placement.
Finally, in spite of all of the positive science and technology
supporting the potential regenerative capacity of free autogenous
grafts, there will always be instances in which the size of the defect,
or the lack of sucient soft tissue cover and blood supply, or both,
prevent the use of this technique. For the sake of completeness,
the end of this chapter will discuss the use of the vascularized
composite bone grafts. Originally used to augment the largest
of facial defects with less than optimum cosmetic and functional
results, this procedure also has progressed and improved along
with the rise in dental implant technology to rene the technique
and provide more than an acceptable osseous base for an implant-
supported prosthesis.
Extraoral Donor Bone Graft Sites
Calvarial Graft
e prospect of having bone harvested from the skull (calvarial),
which is an area so close to one of the most vital structures of
the human body, makes most patients cringe at the possibilities
of such a dangerous procedure. e reality is quite the opposite.
Of all of the extraoral bone grafting procedures discussed in this
chapter, the split-thickness calvarial graft oers a very convenient
option of unlimited bone with the least amount of postopera-
tive morbidity. Access incisions are hidden inside the hairline and
postoperative pain is minimal. For implant-guided reconstruc-
tion, the donor site lies close to the recipient site, therefore the
procedure is not prolonged signicantly more than an intraoral
grafting procedure. e cortical nature and volume of the outside
table with the intervening diploe of cancellous bone provide wide
possibilities of shape, contour, and stability for reconstruction of
any potential dental implant site. is bone is particularly useful
for onlay grafting to augment the atrophic mandible and maxilla
(Fig. 39.2).
Tessier, in his landmark publication in 1982, rst championed
the use of full- and split-thickness cranial grafts for the reconstruc-
tion of congenital deformities in children and young adults.
13
For the purposes of site preparation for the placement of dental
implants, the use of the split-thickness graft will more than suce.
Cranium
Medical Illustration Drawing
Large area on
bilateral parietal
regions
Minimal
Anterior iliac crest 3x5 cm Cortico-
cancellous blocks
50cc’s
Morcilized bone
Posterior iliac crest 5x5 cm Cortico-
cancellous blocks
100 –125cc’s
Morcilized bone
Tibia None 2440cc’s Cancellous bone
Fibula Maximum of 26cm in
length and 3cm in
width of vascularized
bicortical bone
CorticalSource Cancellous
Fig. . Extraoral autogenous donor sites with the resultant quantity of cortical and cancellous bone.

1090
PART VII Soft and Hard Tissue Rehabilitation
e parietal bone, just above the insertion of the temporalis mus-
cle, is the ideal spot for harvesting because of its thickness and its
relative isolation from vital structures both above and below the
cranial vault. e thickness of the parietal bone can vary from 3 to
12 mm, and any site less than 6 mm is a contraindication because
of the possibility of dura exposure and possible tear. is procedure
is also contraindicated in children less than 9 years of age because
of the underdevelopment of the diploic space.
14
It is also recom-
mended that surgeons choose the nondominant hemisphere side
of the cranium, although postharvest magnetic resonance imaging
(MRI) studies of the underlying brain did not detect any abnor-
malities, even in cases when there was a full-thickness breach.
15
Anatomy and Technique
Incision design and placement is dependent on the amount of
graft required for the reconstruction. For a large graft, a bicoronal
incision is marked o in the hair bearing the scalp 4.0 cm poste-
rior to the anterior hairline to hide the resultant scar and to expose
as much of the parietal surface as possible. For smaller grafts, inci-
sions may be made directly over the donor sight (Fig. 39.3).
e hair is washed and prepped, however, it is not shaved. Local
anesthetic with vasoconstrictor is injected along the planned inci-
sion site. It is imperative to wait the mandatory time (5–7 min-
utes) to allow the anesthetic vasoconstriction in this very vascular
area to be eective. Electrocautery may be used from the dermis
layer down to the bone so as to not disturb the hair follicles. Raney
clips are then placed on both sides of the incision to help control
further bleeding. Bone incisions are then outlined with a surgical
marker or electrocautery, making sure all boundaries are behind
the coronal suture and well away from the midline to avoid the
superior sagittal sinus. e superior incision should be placed 2.0
cm lateral to the superior sagittal sinus, and the inferior extent of
the incision should be 2.0 cm above the squamoparietal suture
to avoid the middle meningeal artery. is area, the middle to
posterior region of the parietal bone, has been shown to exhibit
the thickest bone with the most developed diploic space.
16
For the
purposes of grafting for implant site preparation, ideal graft mea-
surements can be separated into 1 to 1.5 × 3 to 4 cm to prevent
fracture of the graft during harvesting.
With presurgical data from computerized tomography (CT) or
cone beam CT (CBCT) scans indicating the approximate thick-
ness of the skull, the initial osteotomies are initiated with a small
Steiger bur or a Piezo saw down to the underlying diploe. Copious
irrigation during the osteotomy is important so that the tempera-
ture of the bone is not increased this close to the cranial contents
and to maintain the cellular vitality of the bone graft as best as pos-
sible. e outer edge of the initial osteotomy is then beveled down
with an egg-shaped bur to provide a better access angle to allow
a curved osteotome into the appropriate plane of the underlying
diploe (Fig. 39.4). Beveling around additional sides of the initial
graft may be necessary to avoid breaching the internal table. Once
the initial graft of a multiple graft donor site is elevated cleanly,
the remaining segments can be lifted much easier having already
established the appropriate plane and angle between the outer and
inner table.
After the grafts have been removed and placed in saline,
hemostasis is obtained and the wound is closed in layers. Various
cements, putties, and bone substitutes are available to reestablish
the contour of the cranium and obtain hemostasis from the cut
edges of the bone. Closure of the periosteum and galea are per-
formed with resorbable sutures, and the skin can be closed with
staples as long as attention is paid to eversion of the scalp margins.
Drains are rarely necessary.
Complications
1. Alopecia along the incision line. is is caused by the use of elec-
trocautery and prolonged use of Raney clips, causing ischemic
hair follicle injury. Scars caused by this can be minimized by
using a zigzag incision design.
2. Bleeding from the harvest site. is can be controlled by the use
of surgical hemostatic agents such as topical microbrillar col-
lagen (Avitine) and the use of bone wax or bone cement packed
Middle meningeal a.
Middle
meningeal a.
Dura mater
Squamous suture
Squamous
suture
Parietal bone
Coronal suture
Superior sagittal sinus
Sagittal suture
Harvest site
Fig. . Cranial bone harvest graft. Ideal location of graft harvest with underlying anatomic landmarks.
(From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.)

1091
CHAPTER 39 Extraoral Bone Grafting for Implant Reconstruction
AA
B
C D
Fig. . Calvarian graft incision. (A) Bicoronal incision design for large grafts. (B) access for harvesting
grafts from both sides of the parietal cranium. (C) Smaller incision design. (D) Bone graft harvest for single site.
Harvest
Beveling
Fig. . Calvarian osteotomy. Beveling the osteotomy to prevent perforation of inner table while raising
outer table graft. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA:
Elsevier; 2015.)

PART VII Soft and Hard Tissue Rehabilitation
AB
C
Fig. . Clinical and radiographic images of patient with diffuse atrophic maxillary and mandibular bony areas
from multiple congenitally missing teeth. (A) Left lateral image. (B) Right lateral image. (C) Panoramic image.
into the diploic spaces and along the base of the bed. If bone
cement is used, make sure that the exogenic heat caused by the
chemical setup of the material does not come into contact with
the bed until it has dissipated.
3. Inner table perforations. Small inner table perforations with no
evidence of a dural tear are of no consequence and can be cov-
ered with any selection of softer llers. If a small tear exists,
then the tear will need to be sutured closed to prevent a cere-
brospinal uid leak. If the tear is large and no immediate means
of closure is at hand, then a neurosurgical consult is necessary.
4. Bleeding from major vessels. ese are very rare occasions, how-
ever, if a misadventure would result in copious bleeding from
the central sagittal sinus and continuous pressure with surgical
packing is indicated. Because this is venous blood, the hemo-
static control should not result in any brain or scalp ischemia. If
the middle meningeal artery on the inferior border of the tem-
poral border is cut, then an immediate neurosurgical consult is
necessary because this could result in an epidural hematoma.
Case Study
A 32-year-old male with a history of congenital absence of multiple
maxillary and mandibular teeth presents for implant reconstruc-
tion. e patient had previous orthognathic surgery to correct a
class III maxillary atrophic deformity. CT scans revealed severe
alveolar bone atrophy of all four quadrants (Fig. 39.5).
rough a bicoronal approach, split-thickness outer table
grafts were harvested from the parietal bone from the right and the
left cranium. e grafts were placed with two-point xation in an
onlay fashion throughout the maxilla and mandible. Additional
particulate bone pulverized from the unused grafts was used to ll
in areas between the xated grafts (Fig. 39.6).
At 6 months the grafted sites were exposed for removal of xa-
tion screws and placement of implant xtures. Note the minimal
change and resorption of the original grafts that is emblematic
of the high-density cortical grafts of the cranium. Surgical guide
splints were fabricated before the uncovering for implant place-
ment (Figs. 39.7 and 39.8; Boxes 39.1 and 39.2).
Iliac Crest Bone Graft
The ilium is historically the most popular donor site for facial
bone grafting because of the high volume of cancellous and
cortical bone. The corticocancellous block harvested from the
ilium provides the “best of both worlds” in bone grafting by
combining the high cellular transfer of the cancellous matrix
with the BMP-rich structural support of the cortical bone
(Fig. 39.9).
e anterior ilium may yield up to 50 cc of bone for augmen-
tation. is amount can reconstruct a 5.0-cm segmental defect
of the mandible using the following equation: 1.0 cm requires
10.0 cc of bone. For the purposes of implant site preparation,
this is usually sucient; however, if larger division E deformi-
ties exist, then the posterior ilium may be used. e posterior
iliac crest can be harvested for donor bone when more signi-
cant volumes are necessary for the grafting of a facial defect.
e posterior iliac crest provides the same quality and ratio of
cancellous and cortical bone but in quantities approaching 100
ml of cancellous bone and a maximum of a 5 × 5-cm cortical
block.
17
e success of endosseous implants placed in iliac crest grafted
sites is well documented. In a retrospective study by Misch pub-
lished in 1994 and updated in 1999, a total of 1364 implants
1092

A
C
B
Fig. . (A) Cortical onlay grafts to maxilla. (B) Cortical onlay grafts to mandible. (C) Morselized cortical
bone for augmenting areas between grafts.
A
B
C
Fig. . (A) Uncovered grafts at 6 months. (B) Placement of maxillary implants. (C) Placement of man-
dibular implants.

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108839Extraoral Bone Grafting for Implant ReconstructionDAVID J. DATTILOIntroductione pool of patients that are eligible for dental implant recon-struction has expanded widely since Brånemark’s research rst hit the world of dentistry in the early 1980’s. Extensive research in bone biology, coupled with newer and proven bone grafting tech-niques, leaves almost no patient outside the boundaries of eligible recipients. is includes patients with large bony defects resulting from trauma, resection from pathologic lesions, and congenital deformities, which would be classied as division E in the Misch-Judy classication of available bone and prosthetic options.1,2 Procedures designed to provide large quantities of bone harvested from outside of the facial region that were previously used to only restore continuity and primitive function now are expected to reproduce vertical and horizontal dimensions for ideal placement of implant xtures for the support of multiple prosthetic designs.ese new demands on the implant surgeon make the evalu-ation of the recipient defect, both dimensions and biologic envi-ronment, as well as the appropriateness of the potential donor site bone quality, of paramount importance. For instance, loss of bone from treatment of neoplastic or other pathologic processes represents far greater reconstructive challenges than loss of bone from trauma or infection. Other factors important to deciding the type and quantity of bone graft required to be harvested for larger defects is the presence of systemic diseases and the possible exposure to therapeutic doses of ionizing radiation. Success rates of bone grafts in irradiated jaws have been found to be lower by signicant amounts, as well as complication rates of 81.3%.3 e rich cellular components that make autogenous grafts the “gold standard” of implant-supported bone grafts, along with tech-niques such as hyperbaric oxygen treatment, platelet-rich plasma, and the use of engineered growth factors such as bone morpho-genetic protein (BMP), all act to combat and hopefully overcome any hostile environment to provide a healthy osseous base for the placement of dental implants.e four major anatomic areas for harvesting of free autog-enous bone that will be discussed in this chapter include the cra-nium, the anterior and posterior iliac crest, and the tibial plateau. e necessity required for the proverbial Mother of these inventive techniques was primarily provided by the multiple facial injuries sustained by American and German soldiers during World War I and II. Surgeons from both countries, when faced with such large deformities caused by the latest in wartime ballistics, searched the body for the largest reservoirs of bone that could be used to ll these functional and cosmetic defects. Surgical researchers Wol, Moss, Tessier, Boyne, and Marx then took these procedures and investigated the details of bone graft healing and the interaction between the bone and the recipient soft tissue bed.7,8 ese ini-tial autogenous bone grafts, however, were characterized by rapid and advanced bone resorption, which sometimes reached 30% to 90% in the best of conditions.9,10 With the advent of endosteal implants used in conjunction with autogenous grafts, research began reporting the maintenance of the grafted bone and the prevention of this rapid bone resorption.11,12 Surgeons placing extraoral autogenous bone grafts, when used in conjunction with endosteal implants, can now expect to maintain better than 90% of the initial grafted segment.Autogenous free bone grafts harvested from these four donor sites and their subsequent recipient sites have other unique bio-logic qualities that contribute to their appropriate use for dental implant support. Calvarium and mandibular bone are of intra-membranous origin formed through the progressive dierentia-tion from primordial mesenchymal cells to stem cells to osteocytes, while the maxilla, anterior and posterior iliac crest and the tibia are formed through endochondral ossication through the transfor-mation and replacement of already formed cartilage.Early studies comparing these two types of grafts on animal models revealed superiority of intramembranous bone grafts taken from the skull to endochondral bone grafts taken from the ilium or the rib.4,5 At one year, the intramembranous grafts appeared to maintain the original grafted volume, whereas the endochondral grafts were decreased in volume by 75%. ese ndings appeared to be counterintuitive because the higher cancellous bone content of the endochondral grafts would seem to welcome a much faster revascularization than the more cortical intramembranous bone. Follow up studies actually showed a more rapid revascularization of these membranous grafts with complete ingrowth of vessels from the host bone and periosteum at 14 days whereas the endo-chondral bone still showed signicant areas of necrotic bone and areas of resorption.6Ironically, it appears the mechanism of revascularization of both the intramembranous and endochondral grafts proceeds along the same pathway borrowing similarities from both mechanisms with the grafted bone acting as the matrix (osteoconduction) that 1089CHAPTER 39 Extraoral Bone Grafting for Implant Reconstructionis subsequently replaced by osteoid generated by viable osteogenic cells (osteogenesis) with regulation from grafted growth factors (osteoinduction). Each of the four major donor sites for free autogenous grafts are unique in their ability to provide one or both of the essential structural elements of bone, which include the strong and rigid cortical or the softer but more cellular and regenerative cancel-lous. ese two bone types also dier in the process in which they regenerate new bone. e calvarial graft is predominantly corti-cal bone and used in areas in which maintenance of a particular dimension is essential for a longer term, bone grafts from the iliac crest provide both cortical and cancellous bone in dierent quan-tities, and the tibial plateau is useful for obtaining quantities of cancellous bone only (Fig. 39.1).All of these grafts can be augmented with a number of dif-ferent supplemental materials, regenerated blood products, and exogenous growth factors, which may assist in turning these grafted sites into the ideal bone quality to support future implant placement.Finally, in spite of all of the positive science and technology supporting the potential regenerative capacity of free autogenous grafts, there will always be instances in which the size of the defect, or the lack of sucient soft tissue cover and blood supply, or both, prevent the use of this technique. For the sake of completeness, the end of this chapter will discuss the use of the vascularized composite bone grafts. Originally used to augment the largest of facial defects with less than optimum cosmetic and functional results, this procedure also has progressed and improved along with the rise in dental implant technology to rene the technique and provide more than an acceptable osseous base for an implant-supported prosthesis. Extraoral Donor Bone Graft SitesCalvarial Grafte prospect of having bone harvested from the skull (calvarial), which is an area so close to one of the most vital structures of the human body, makes most patients cringe at the possibilities of such a dangerous procedure. e reality is quite the opposite. Of all of the extraoral bone grafting procedures discussed in this chapter, the split-thickness calvarial graft oers a very convenient option of unlimited bone with the least amount of postopera-tive morbidity. Access incisions are hidden inside the hairline and postoperative pain is minimal. For implant-guided reconstruc-tion, the donor site lies close to the recipient site, therefore the procedure is not prolonged signicantly more than an intraoral grafting procedure. e cortical nature and volume of the outside table with the intervening diploe of cancellous bone provide wide possibilities of shape, contour, and stability for reconstruction of any potential dental implant site. is bone is particularly useful for onlay grafting to augment the atrophic mandible and maxilla (Fig. 39.2).Tessier, in his landmark publication in 1982, rst championed the use of full- and split-thickness cranial grafts for the reconstruc-tion of congenital deformities in children and young adults.13 For the purposes of site preparation for the placement of dental implants, the use of the split-thickness graft will more than suce. CraniumMedical Illustration DrawingLarge area onbilateral parietalregionsMinimalAnterior iliac crest 3x5 cm Cortico-cancellous blocks50cc’sMorcilized bonePosterior iliac crest 5x5 cm Cortico-cancellous blocks100 –125cc’sMorcilized boneTibia None 24–40cc’s Cancellous boneFibula Maximum of 26cm inlength and 3cm inwidth of vascularizedbicortical boneCorticalSource Cancellous• Fig. . Extraoral autogenous donor sites with the resultant quantity of cortical and cancellous bone. 1090PART VII Soft and Hard Tissue Rehabilitatione parietal bone, just above the insertion of the temporalis mus-cle, is the ideal spot for harvesting because of its thickness and its relative isolation from vital structures both above and below the cranial vault. e thickness of the parietal bone can vary from 3 to 12 mm, and any site less than 6 mm is a contraindication because of the possibility of dura exposure and possible tear. is procedure is also contraindicated in children less than 9 years of age because of the underdevelopment of the diploic space.14 It is also recom-mended that surgeons choose the nondominant hemisphere side of the cranium, although postharvest magnetic resonance imaging (MRI) studies of the underlying brain did not detect any abnor-malities, even in cases when there was a full-thickness breach.15Anatomy and TechniqueIncision design and placement is dependent on the amount of graft required for the reconstruction. For a large graft, a bicoronal incision is marked o in the hair bearing the scalp 4.0 cm poste-rior to the anterior hairline to hide the resultant scar and to expose as much of the parietal surface as possible. For smaller grafts, inci-sions may be made directly over the donor sight (Fig. 39.3).e hair is washed and prepped, however, it is not shaved. Local anesthetic with vasoconstrictor is injected along the planned inci-sion site. It is imperative to wait the mandatory time (5–7 min-utes) to allow the anesthetic vasoconstriction in this very vascular area to be eective. Electrocautery may be used from the dermis layer down to the bone so as to not disturb the hair follicles. Raney clips are then placed on both sides of the incision to help control further bleeding. Bone incisions are then outlined with a surgical marker or electrocautery, making sure all boundaries are behind the coronal suture and well away from the midline to avoid the superior sagittal sinus. e superior incision should be placed 2.0 cm lateral to the superior sagittal sinus, and the inferior extent of the incision should be 2.0 cm above the squamoparietal suture to avoid the middle meningeal artery. is area, the middle to posterior region of the parietal bone, has been shown to exhibit the thickest bone with the most developed diploic space.16 For the purposes of grafting for implant site preparation, ideal graft mea-surements can be separated into 1 to 1.5 × 3 to 4 cm to prevent fracture of the graft during harvesting.With presurgical data from computerized tomography (CT) or cone beam CT (CBCT) scans indicating the approximate thick-ness of the skull, the initial osteotomies are initiated with a small Steiger bur or a Piezo saw down to the underlying diploe. Copious irrigation during the osteotomy is important so that the tempera-ture of the bone is not increased this close to the cranial contents and to maintain the cellular vitality of the bone graft as best as pos-sible. e outer edge of the initial osteotomy is then beveled down with an egg-shaped bur to provide a better access angle to allow a curved osteotome into the appropriate plane of the underlying diploe (Fig. 39.4). Beveling around additional sides of the initial graft may be necessary to avoid breaching the internal table. Once the initial graft of a multiple graft donor site is elevated cleanly, the remaining segments can be lifted much easier having already established the appropriate plane and angle between the outer and inner table.After the grafts have been removed and placed in saline, hemostasis is obtained and the wound is closed in layers. Various cements, putties, and bone substitutes are available to reestablish the contour of the cranium and obtain hemostasis from the cut edges of the bone. Closure of the periosteum and galea are per-formed with resorbable sutures, and the skin can be closed with staples as long as attention is paid to eversion of the scalp margins. Drains are rarely necessary. Complications 1. Alopecia along the incision line. is is caused by the use of elec-trocautery and prolonged use of Raney clips, causing ischemic hair follicle injury. Scars caused by this can be minimized by using a zigzag incision design. 2. Bleeding from the harvest site. is can be controlled by the use of surgical hemostatic agents such as topical microbrillar col-lagen (Avitine) and the use of bone wax or bone cement packed Middle meningeal a.Middlemeningeal a.Dura materSquamous sutureSquamous sutureParietal boneCoronal sutureSuperior sagittal sinusSagittal sutureHarvest site• Fig. . Cranial bone harvest graft. Ideal location of graft harvest with underlying anatomic landmarks. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.) 1091CHAPTER 39 Extraoral Bone Grafting for Implant ReconstructionAABC D• Fig. . Calvarian graft incision. (A) Bicoronal incision design for large grafts. (B) access for harvesting grafts from both sides of the parietal cranium. (C) Smaller incision design. (D) Bone graft harvest for single site.HarvestBeveling• Fig. . Calvarian osteotomy. Beveling the osteotomy to prevent perforation of inner table while raising outer table graft. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.) PART VII Soft and Hard Tissue RehabilitationABC• Fig. . Clinical and radiographic images of patient with diffuse atrophic maxillary and mandibular bony areas from multiple congenitally missing teeth. (A) Left lateral image. (B) Right lateral image. (C) Panoramic image.into the diploic spaces and along the base of the bed. If bone cement is used, make sure that the exogenic heat caused by the chemical setup of the material does not come into contact with the bed until it has dissipated. 3. Inner table perforations. Small inner table perforations with no evidence of a dural tear are of no consequence and can be cov-ered with any selection of softer llers. If a small tear exists, then the tear will need to be sutured closed to prevent a cere-brospinal uid leak. If the tear is large and no immediate means of closure is at hand, then a neurosurgical consult is necessary. 4. Bleeding from major vessels. ese are very rare occasions, how-ever, if a misadventure would result in copious bleeding from the central sagittal sinus and continuous pressure with surgical packing is indicated. Because this is venous blood, the hemo-static control should not result in any brain or scalp ischemia. If the middle meningeal artery on the inferior border of the tem-poral border is cut, then an immediate neurosurgical consult is necessary because this could result in an epidural hematoma. Case StudyA 32-year-old male with a history of congenital absence of multiple maxillary and mandibular teeth presents for implant reconstruc-tion. e patient had previous orthognathic surgery to correct a class III maxillary atrophic deformity. CT scans revealed severe alveolar bone atrophy of all four quadrants (Fig. 39.5).rough a bicoronal approach, split-thickness outer table grafts were harvested from the parietal bone from the right and the left cranium. e grafts were placed with two-point xation in an onlay fashion throughout the maxilla and mandible. Additional particulate bone pulverized from the unused grafts was used to ll in areas between the xated grafts (Fig. 39.6).At 6 months the grafted sites were exposed for removal of xa-tion screws and placement of implant xtures. Note the minimal change and resorption of the original grafts that is emblematic of the high-density cortical grafts of the cranium. Surgical guide splints were fabricated before the uncovering for implant place-ment (Figs. 39.7 and 39.8; Boxes 39.1 and 39.2). Iliac Crest Bone GraftThe ilium is historically the most popular donor site for facial bone grafting because of the high volume of cancellous and cortical bone. The corticocancellous block harvested from the ilium provides the “best of both worlds” in bone grafting by combining the high cellular transfer of the cancellous matrix with the BMP-rich structural support of the cortical bone (Fig. 39.9).e anterior ilium may yield up to 50 cc of bone for augmen-tation. is amount can reconstruct a 5.0-cm segmental defect of the mandible using the following equation: 1.0 cm requires 10.0 cc of bone. For the purposes of implant site preparation, this is usually sucient; however, if larger division E deformi-ties exist, then the posterior ilium may be used. e posterior iliac crest can be harvested for donor bone when more signi-cant volumes are necessary for the grafting of a facial defect. e posterior iliac crest provides the same quality and ratio of cancellous and cortical bone but in quantities approaching 100 ml of cancellous bone and a maximum of a 5 × 5-cm cortical block.17e success of endosseous implants placed in iliac crest grafted sites is well documented. In a retrospective study by Misch pub-lished in 1994 and updated in 1999, a total of 1364 implants 1092 ACB• Fig. . (A) Cortical onlay grafts to maxilla. (B) Cortical onlay grafts to mandible. (C) Morselized cortical bone for augmenting areas between grafts.ABC• Fig. . (A) Uncovered grafts at 6 months. (B) Placement of maxillary implants. (C) Placement of man-dibular implants. 1094PART VII Soft and Hard Tissue RehabilitationAB• Fig. . (A) Final image, frontal at rest. (b) Final prosthesis.placed in iliac crest bone grafts (940 maxillary and 424 mandibu-lar) in either an immediate or delayed fashion revealed an overall survival rate of 96.7%18 (Table 39.1).e diversity of the iliac crest bone makes it useful not just in large segmental defects but also in routine C–w and C–h defects, which may benet from the presence of the greater osteogenic potential of the autogenous bone, such as larger unilateral or bilateral sinus lift procedures. As with any bone graft, the success depends on adherence to basic surgical principles that call for rigid immobilization with screw xation of the blocks and a rigid basket-type containment membrane (space maintenance) for all cancellous-only grafts, with minimal external pressure throughout the healing period (Box 39.3).e disadvantages of both the anterior and the posterior iliac crest grafts include the use of a distant site from the oral cavity. is may require the use of two surgical teams or an increased surgical time for a single team with meticulous attention to maintaining separate elds to prevent cross-contamination from the oral cavity. In the case of the posterior iliac crest the surgi-cal time can be doubled because the patient needs to be turned to the prone position for harvest. Contraindications to the use of the anterior or posterior ilium would be the presence of a hip prosthesis to reduce any risk of hardware failure or infection (Box 39.4).Anatomy and Techniquee surgeon needs to rst palpate the anatomic landmarks of the iliac crest, which can be dicult in obese patients, but it is absolutely necessary to prevent damage to local sensory nerves that overlay the anterior ilium. From posterior to anterior the landmarks include the iliohypogastric, the subcostal, and the lateral femoral cutaneous nerves. e iliohypogastric nerve arises from the dorsal rami of L1 and L2 (lumbar vertebrae) and passes directly over the midcrest and is in most cases unavoidable. e subcostal nerve arises from the dorsal ramus of T12 over the edge of the anterior superior spine to innervate the skin of the groin. e lateral femoral cutaneous nerve will also sometimes deviate from its usual course under the inguinal ligament in 2.5% of the population and also pass over the same area of the anterior ilium.19 erefore the anterior superior iliac spine (ASIS) is rst marked and the crest is then palpated to the widest 1. Easy access with minimal postoperative pain or morbidity 2. Onlay grafts of primarily cortical bone; can be morselized into particulate graft 3. For vertical and horizontal ridge augmentation of maxilla and mandible 4. Large quantity of bone • BOX 39.1 Calvarian Graft: Indications and Advantages 1. Metabolic bone diseases such as osteopetrosis, osteogenesis imperfecta, Paget disease 2. Radiation to the skull 3. Children under 8 years old 4. Male pattern baldness 5. Previous skull trauma or surgery • BOX 39.2 Calvarian Graft: Contraindications and Cautions• Fig. . Cross section of iliac crest showing inner and outer table of cortical bone with a large area of cellular-rich cancellous bone in between. Iliac Crest Grafts Study (1984–2005)Patients ArchesMale patients 36 42Female patients 146 179Total 182 221 TABLE 39.1 1095CHAPTER 39 Extraoral Bone Grafting for Implant Reconstruction 1. Cortical and cancellous bone in blocks and as free cancellous grafts 2. Can reconstruct large alveolar defects up to 5cm (anterior) to 12 cm (posterior) in length 3. Large sinus augmentations and horizontal and vertical ridge augmentation 4. Alveolar cleft reconstruction • BOX 39.3 Ilium Graft: Advantages and Indications 1. Second site harvest and postoperative pain 2. Contraindicated in metabolic bone disease, previous fracture site or osteomyelitis, or previous hip prosthesis • BOX 39.4 Ilium Graft: Disadvantages and CautionsIliohypogastric n.Iliacus m.Gluteus medius m.Gluteus maximus m.Subcostal n.Anterior iliac spinePosterior iliac crestInguinal ligamentLateral femoral cutaneous n.Tensor fascia lataSartorius m.BPsoas m.Anterior tubercle of the iliumAnterior superior iliac spineA• Fig. . (A) Lateral view demonstrating placement of a soft roll to elevate the anterior iliac crest. The incision (dashed line) is placed lateral to the crest and posterior to the anterior iliac spine. (B) Anterior view of the anterior iliac crest shows the relationships of the muscular and neural structures as they relate to the proposed incision (dashed line). Although not typically visualized during harvest, the iliohypogastric nerve may be encountered with posterior extension of the incision. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.)portion to the iliac tubercle. e incision is then marked 2 cm lat-eral to the iliac crest and 2 cm posterior to the ASIS to reduce injury to these two important sensory nerves19,20 (Fig. 39.10).e subcutaneous tissue and the subperiosteal plane is then inltrated with local anesthesia and vasoconstrictor. After appropriate prepping and draping, the incision is made through skin down to the supercial abdominal facia or Camper and Scarpa fascia. Once through this fascial layer, the crest is easily palpated and the bers from the medial external oblique and the lateral tensor fascia lata muscle are separated. A periosteal incision can now be made with electrocautery between these two muscles. Continuing to stay at least 1.5 cm posterior to the ASIS, subperiosteal dissection is performed to obtain access to the crest, as well as the medial wall under the iliacus muscle. Free cancellous bone can then be harvested through cortical windows created through the crest and corticocancellous blocks obtained by further exposure down the medial wall elevating the iliacus muscle. Blocks can be harvested via osteotomies 1096PART VII Soft and Hard Tissue Rehabilitationthrough the medial wall down to the cancellous layer. A paral-lel incision is then made to the rst cut at a desired distance no more than 4 to 5 cm from the rst cuts. Ninety-degree inci-sions are then made to connect these cuts on the inferior and superior margins. With the use of an osteotome the cortical cancellous blocks are lifted away carefully to not penetrate the posterior wall (Fig. 39.11).After the block graft has been elevated, additional cancellous bone for augmentation of the graft can be curettaged from the sides and the base of the graft bed. Closure of the periosteum and fascial layers is performed after hemostasis of the bone edges and any soft tissue adjacent to the donor site. Drains are not usually necessary. e use of long-acting local anesthetics can be used to help in postoperative pain control and to encourage early ambulation.e technique for posterior iliac harvest diers from the ante-rior iliac in many ways; however, the most obvious way is the prone positioning of the patient. Either before or after exposure of the recipient site, all extraoral or intraoral wounds need to be packed and isolated from contamination while the patient is turned and the graft harvested. Incisions should be rst marked beginning at least 1 cm lateral to the posterior superior iliac spine to avoid the sacroiliac ligament and then extended 5 to 6 cm lat-erally. After local and hemostatic inltration, an incision is made through skin and taken down to the superior iliac spine. Unlike the anterior technique, grafts are harvested from the lateral cortex by elevating the gluteal musculature with the superior cut being just below the crest of the ridge to avoid ilium fractures caused by weakening (Fig. 39.12).In children both the anterior and posterior iliac crests act as ossication sites and not true growth centers. e cartilaginous crest should be kept intact, and any grafts, cortical or cancellous, should be harvested from below this border. Complications 1. Seroma. A common complication surrounding the incision site usually caused by over activity in the early postoperative course. Initial aspiration and placement of drain if it continues to recur. 2. Bleeding and hematoma. A stable hematoma can arise from persistent oozing from the harvest bone beds. Hematomas can be prevented with brillary collagen packing or bone wax at the bone edges. Normally they will reabsorb. An expanding hematoma caused by an active bleeder is a much more seri-ous situation and, as in pelvic fractures, could result in a large amount of blood loss before its presence is identied. e patient should be treated for any signs of hypovolemic shock, and the wound should be reexplored to identify and control the bleed. 3. Postoperative paresthesia of the thigh. Also known as meralgia paresthetica, this is a temporary paresthesia of the distribution of the lateral femoral cutaneous nerve, which could be caused Iliacus m.Psoas m.Osteotome to harvest block graftBone graft• Fig. . Harvesting of a corticocancellous block from the medial aspect of the anterior ilium after reflection of the iliacus muscle. An osteotome or saw can be used for the corticotomies in the suggested design. After retrieval of the block, the exposed underlying cancellous bone can be harvested using bone curettes and gouges. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.) 1097CHAPTER 39 Extraoral Bone Grafting for Implant Reconstructionby pressure on the nerve from a hematoma of the iliacus muscle at the harvest site of the anterior table or pressure from retrac-tion of the anterior ap. Permanent anesthesia could be the result of a poorly placed incision. 4. Postoperative pain. is is helped by long-acting local anesthet-ics with intravenous (IV) and analgesics by mouth (PO), and aggressive physical therapy to get the patient up and walking. 5. Abdominal perforation. This is a very rare occurrence of an anterior table harvest caused by the protection from sur-rounding musculature. Overweight patients may be at higher risk because anatomy is unclear, and over aggres-sive use of rotary instruments for bone harvest may exist. An immediate general surgery consult is indicated (see Table 39.1). Case Study 1: Corticocancellous Morcellized GraftA 28-year-old female with a history of basal cell nevus syndrome presented with right-sided swelling of her face. CT scan and Pan-orex revealed a multilocular radiolucent lesion encompassing the body and ascending ramus of the left mandible. Biopsy conrmed the presence of a diuse spread of an odontogenic keratocyst (Fig. 39.13).e patient was taken to the operating room for resection of the lesion, which required disarticulation of the condyle and was immediately reconstructed with an anterior iliac crest bone graft through an external facial incision. e corticocancellous blocks were placed in a bone mill and collagen-soaked sponges of BMP were placed into the rigidly xated bone crib (Fig. 39.14).At 20 weeks with the CT scan showing good consolidation of bone, the implant xtures were placed. At 4 months the den-tal implants (Fig. 39.15) were uncovered and restored. At 5 years the grafted area continued to show good consolidation, continued support for the implant xtures, and no recurrence of the cystic tumor (Fig. 39.16). Case Study 2: Corticocancellous Block GraftsA 53-year-old female with an atrophic maxilla prefers a xed prosthesis to articulate against a partially dentate mandible, very Superior cluneal nn.Medial cluneal nn.AGluteus maximus m.Thoracolumbar fasciaGluteus maximus m.Thoracolumbar fasciaBPosterior iliac crest• Fig. . (A) Outline demonstrating incision design of posterior iliac crest harvest in relation to superior cluneal and medial cluneal nerves. (B) Outline of osteotomies. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.) 1098PART VII Soft and Hard Tissue RehabilitationAB• Fig. . (A) Large keratocyst of left mandible. (B) Preresection occlu-sion.ABCD• Fig. . (A) Resected specimen. (B) Prefabricated reconstruction plate and condylar prosthesis in place. (C) Morcellized corticocancellous bone in syringes. (D) Bone graft packed into retaining crib.AB• Fig. . (A) Computerized tomography of consolidated graft at 20 weeks. (B) Placement of implant fixtures. 1099CHAPTER 39 Extraoral Bone Grafting for Implant Reconstructionnarrow bone in the anterior, and low-lying sinus oors on the posterior bilaterally (Fig. 39.17).Corticocancellous strips were then harvested from the inner table of the anterior iliac crest. Bilateral sinus lifts were performed using cancellous bone from the residual harvest bed. e har-vested blocks were then cut appropriately and then rigidly x-ated as onlay grafts (Fig. 39.18). Additional cancellous bone was used to augment the rigidly xated grafts, and the surgical site was closed in a tension-free fashion. e bone grafts were allowed to heal and consolidate for 6 months. A full denture prosthesis was fabricated for the patient for the interim period. e site was reopened, the xating screw removed, and eight implant xtures were placed (Fig. 39.19). After integration of the implants a xed hybrid prosthesis was fabricated. Tibial Bone Grafte proximal tibial metaphysis provides an excellent source of cancellous bone. e quantity that may be harvested is close to or equal to that of the anterior ilium. e tibial graft has a low complication rate and is technically easy to perform. Compari-son of tibial versus iliac crest grafts in secondary alveolar cleft reconstruction showed similar bone densities at 6 months.21 Tibial bone grafts are most commonly used for maxillary sinus lift procedures and augmentation of existing bone for the place-ment of implant xtures.22 e rather low morbidity and easy surgical access allows skeletally mature adults to have the surgery completed on an outpatient basis. Because of possible damage to developing epiphyseal growth plates, this procedure is not recom-mended for children or adolescents; however, several authors have reported the safe and successful use of these grafts for alveolar cleft grafting in children.23As with the ilium grafting sites, it is recommended to avoid sites that have had previous surgery with orthopedic hardware or prosthetic joint replacements. It is also prudent to avoid using this procedure on patients that apply large amounts of force to the tibia on a repetitive basis, such as runners and other active athletes.Anatomy and TechniqueAfter placing support under the leg and rotating it to provide better access, the surgeon marks out a 2- to 3-cm incision site over the skin of the anterolateral aspect of the leg directly over the Gerdy tubercle, which is lateral to the tuberosity. Catone and colleagues24 described the incision as angled, with its cephalic limit superior and medial to the tibialis anterior muscle origin and extending lateral to the patellar ligament. After incising through the subcutaneous and fascial layers of the iliotibial tract, the peri-osteum is reected to expose the cortex of the tibial metaphysis. With the use of an end-cutting bur, a window is cut into the cor-tex approximately the size of a dime. is cortical layer is very thin and usually is of little use to the graft and is not replaced. Bone curettes are then used to remove the cancellous bone in all directions and down the shaft of the tibia. Careful attention in harvesting in the superior direction is taken so that the joint space is not entered. A thrombin-soaked collagen sponge can then be placed in the donor site for hemostasis, and the wound is closed in layers with the iliotibial tract closed, followed by the skin and subcutaneous tissue (Fig. 39.20).AB• Fig. . (A) Final restored occlusion. (B) Final Panorex of restored seg-ment showing consolidated graft with implants.BA• Fig. . (A) Preoperative panoramic image. (B) Clinical photo of atrophic maxillary ridge. 1100PART VII Soft and Hard Tissue RehabilitationA BCDE F• Fig. . (A and B) Full reflection of posterior maxilla, osteotomy, and bone grafting of the sinus floor. (C) Bone block harvested from iliac crest. (D) Segmented bone blocks fixated to maxilla. (E) Cancellous bone packed around cortical grafts. (F) Final closure.An alternative medial approach has been described25 with simi-lar soft tissue and bony osteotomies to harvest the donor graft. is approach, however, does not transect the iliotibial tract, resulting in less soft tissue covering the bony donor site and creat-ing the potential for wound breakdown after closure (Box 39.5).Postoperatively the patient can bear weight as tolerated with no vigorous physical activity for 6 weeks. Local wound care with peri-odic elevation of the site to prevent swelling is recommended. Rou-tine analgesia of hydrocodone or acetaminophen is usually adequate. Complications 1. Ankle swelling. Swelling and ecchymosis is caused by the natu-ral lymphatic drainage system of the lower leg. In most cases, this will spontaneously resolve. 2. Knee joint entrance or tibia fracture. is is caused by over aggressive harvesting of bone in a superior direction. Initial treatment would be splinting of the leg with staphylococcal antibiotic coverage, followed by orthopedic surgical consult (Box 39.6).  1101CHAPTER 39 Extraoral Bone Grafting for Implant ReconstructionCase StudyA 56-year-old female presented with large edentulous maxillary posterior space for implant reconstruction. A low-lying sinus oor precluded implant placement without sinus grafting. e patient was given an IV deep sedation, and the intraoral and right knee sites were prepped and draped and kept isolated from each other throughout the procedure. A 4-cm incision was designed and inltrated with local anesthesia just blow the Gerdy tubercle on the right leg (Fig. 39.21).AB• Fig. . (A) Panorex at 6 months before implant placement. (B) Final position of implants.Bone graftAIliotibial tract closedSkin closedB• Fig. . (A) Exposed osteotomy over the Gerdy tubercle and curet-tage of underlying bone. (B) Layered closure of incision (delete 123–1)caption. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.) 1. Cancellous grafts of 25–40 cc 2. Sinus grafts 3. Socket grafts and ridge preservation 4. Minimal postoperative pain 5. Outpatient procedure. • BOX 39.5 Tibial Graft: Advantages and Indications 1. Contraindicated in metabolic bone disease, history of knee surgery or osteomyelitis 2. Caution in growing child, rheumatoid arthritis, or bisphosphonate history • BOX 39.6 Tibia Graft: Disadvantages and CautionsAB• Fig. . (A) Incision design over tubercle. (B) Exposure of underlying cortex. 1102PART VII Soft and Hard Tissue RehabilitationBDAC• Fig. . (A) Outline of donor site. (B) Bone harvested from donor site. (C) Preparation of with platelet-rich plasma (PRP). (D) Donor bone mixed with PRP.e anterior wall of the tibial plateau was exposed and hemo-stasis obtained. With the use of a small round bur a circular bone incision was made and the thin cortical cap removed. en, 24 cc of cancellous bone was curetted out of the site and mixed with strips of platelet-rich brin and packed into the sinus oor bed. Enough supportive bone was available to place immediate implants at the time of surgery (Figs. 39.22 and 39.23). Vascularized Composite Graft: The FibulaAs mentioned previously, when the bed for a bone graft is com-promised by radiation therapy, lack of blood supply, extensive length of the defect, or just the compromised medical condition of the patient, a vascularized composite graft may be indicated. ese grafts dier from the free autogenous grafts because they do not depend on the recipient’s local environment to aid in the regeneration and consolidation of new bone. ese composite grafts bring their own blood supply with them and maintain normal physiologic function within all of the transferred tissues. is will include a certain amount of soft tissue that helps to cover and protect these bone grafts in compromised receptor sites. e downside of these grafts is the increased procedure time and the sometimes unavailable expertise of a microvascu-lar surgeon. Technical complications include larger defects at the donor sites and the inability of the surgeon to construct a bony bed that is any dierent from the anatomic dimensions of the grafted bone. In the past, this bone stock, while provid-ing excellent reconstruction of the continuity defect, did not always provide the best base for an implant-supported prosthe-sis. As the reconstructive surgeon and implantologist worked together over the years and realized the limitations of both, most of these problems have been resolved. ese advances in coop-eration between the surgeon and the implantologist is no better evidenced than in the emergence of the computer-aided design (CAD)/computer-aided manufacturing (CAM) technology, pro-ducing three-dimensional models for both the harvest and the implant placement, which has decreased treatment time from months to days.Since the composite bone grafts were introduced in the late 1970s many donor sites have been recommended. In 1989 Hidalgo introduced the osteocutaneous bula free ap for use in mandibular reconstruction, with 12 cases measuring defects averaging 13.5 cm.26 Since then the bula free ap has become the gold standard for reconstruction of large mandibular defects because of its consistency in size, its vascular pedicle length, and its ability to provide a reliable skin paddle with the bone ap. Its segmental blood supply also allows for in situ osteotomies, which aids in better anatomic reconstruction (Box 39.7).Regarding quality of bone for osseointegration, Frodel and Moscoso, in two separate studies, compared the bone stock and thickness as it relates to the placement of endosseous implants in the four commonly used vascularized donor sites: the iliac crest, scapula, bula, and radius. Although the iliac crest was found to have greater amount of bone stock, the results did not achieve statistical signicance and the testing relied mostly on clinical observation.27,28 1103CHAPTER 39 Extraoral Bone Grafting for Implant Reconstructione rst histologic study of the bone implant interface in a human vascularized graft was reported by Dattilo and colleagues in 1995.29 is study showed that although the implant had successfully integrated into the iliac crest grafted bone and was clinically stable, the surrounding bone resembled the ne tra-becular pattern of D4 density most commonly found in areas of the posterior maxilla (Fig. 39.24A). Sumi and coworkers in 2001 published a similar study using bula graft and found the interface and surrounding bone to be more dense and cortical, resembling the D1 and D2 of the anterior native mandible30 (see Fig. 39.24B–C). is amount of bone density that has been shown to increase the stability and longevity of implants gives the bula another distinct advantage over the other composite grafts (Box 39.8).Anatomy and TechniqueA detailed description of the surgical approach and harvest of this graft is beyond the scope of this chapter. However, a basic knowledge of the anatomic contents and its harvest is important for the implant surgeon to know, as well as the limitations and benets of its use. e graft is harvested via a lateral approach through the intermuscular septum of the peroneus longus and peroneus brevis muscles. Dissection is taken to the anterior compartment for dissection of the vascular pedicle. e com-posite graft is based o the peroneal artery, which is a branch of the popliteal artery Fig. 39.26. During this dissection of the feeding vasculature, the anterior tibial artery and the deep pero-neal nerve need to be identied and retracted medially to pre-vent injury. e diameter of the peroneal artery is 1 to 2.5 mm and matches well with the facial artery and vein, which are the most common vessels used for anastomosis in the receptive bed BCA• Fig. . (A) Maxillary sinus prepared for graft. (B) Lateral wall sinus augmentation. (C) Final wound closure. 1. Reconstruction defects with poor tissue vascularity and questionable soft tissue coverage 2. Reconstruction of defects larger than 6 cm 3. Postcancer reconstruction with provision of protective skin paddle 4. Can withstand postsurgical radiation 5. Failed large free bone grafted segments 6. Can withstand immediate placement of dental implants • BOX 39.7 Vascularized Composite Graft: Advantages and Indications 1104PART VII Soft and Hard Tissue RehabilitationBAbone marrowCcortical bonebone marrow• Fig. . (A) Implant interface with iliac crest composite graft with the fine trabecular pattern of pre-dominantly cancellous bone. (B) Implant interface with fibula graft with dense cortical bone on left cortex side and fine cortical interface on marrow side. (C) Closeup of cortical bone formation on marrow side with no intervening fibrous tissue. (A, From Dattilo D, etal. Interface analysis of hydroxyapatite-coated implants in a human vascularized iliac bone graft. Int J Oral Maxillofac Implants. 1995;10(4):405–409. B and C, From Sumi Y, Hasewaga T, Osamu M, etal. Interface analysis of titanium implants in a human vascularized fibula bone graft. J Oral Maxillofacial Surg. 2001;59(2):213–216.)region. Of maximum importance is the careful dissection of the eight perforating vessels along the bula, which are most com-monly located along the junction of the middle third and distal third of the bula. e vascularized bone is accompanied by por-tions of the peroneus longus, peroneus brevis, and the tibialis posterior muscle. e composition of the graft can change, how-ever, depending on the position of perforating vessels to the skin and musculature (Fig. 39.25). Dissection down to the bula and subsequent resection is performed while the vascular pedicle is still intact. e available bula can have a width between 1.0 and 3.0 cm and a length of up to 26 cm; however, at least 5.0 to 8.0 cm is needed to be left on the superior and inferior portion to maintain stability to the ankle and knee joint. It is at this point that CAD/CAM-generated cutting guides can be used to per-form the initial resection and subsequent segmental osteotomies using the rich blood supply to this graft.31 Custom-generated plates also can be placed at this time, as well as placement of endosseous dental implants, before separating the blood supply (Fig. 39.26).Only after all of this is completed will the microvascular sur-geon resect the peroneal artery and venous complex and reap-proximate it up to the receptor bed in the upper or lower jaw. A prefabricated plate, also generated from the custom CAD/CAM models, can now rigidly xate the composite graft in place. Complications 1. rombosis of the arterial (pale ap) and venous (blue ap). is will result in necrosis of the ap if local measures or the reanas-tomosis procedure fails. 2. Wound Infection. Treat this with antibiotics and local wound care. 3. Compartment syndrome. is is rare but serious. It is caused by internal pressure on donor site tissue. Immediate surgical intervention is indicated. Case Study 1: Fibula Reconstruction with Immediate Placement and Loading of ImplantsA 34-year-old male with a multiloculated lesion of the anterior mandible extending from #18 to #29 with tissue diagnosis of ame-loblastoma (Fig. 39.27). Virtual surgical planning (VSP) using CAD/CAM images to fabricate surgical cutting guides, custom rigid xation plates, and custom models were used to determine implant placement and positioning for immediate placement of interim prosthesis. At surgery, custom cutting guides were used for resection of the tumor at predetermined positions (Fig. 39.28). At surgery the pedicle ap was exposed through the lateral approach and the bula was osteotomized at the specic length needed using cutting cones provided by virtual planning models. Guides also were provided by the virtual planning models (Fig. 39.29). Because of the unique segmental blood supply of the bula, sepa-rate osteotomies could be made to form the necessary curvature as dictated by the presurgical models. e implants are placed and the custom plate is fastened to the graft before the in situ graft is released from the peroneal vascular blood supply. e peroneal vein and artery is then released and reanastomosed to the facial artery and vein near the reception site of the graft after the ante-rior segment is rigidly xated to the right and left proximal seg-ments of the mandible. e interim denture is then xated to the 1. Contraindicated if previous femoral artery graft in place 2. Previous fracture 3. Caution in metabolic bone disease • BOX 39.8 Vascularized Composite Graft: Disadvantages and Cautions 1105CHAPTER 39 Extraoral Bone Grafting for Implant ReconstructionFlexor digitorum longus m.Tibialis posterior m.Tibialis posterior m.Posterior tibial a./v.TibiaGastrocnemius m.Soleus m.Soleus m.Tibial n.FibulaFibulaFlexor hallucis longus m.Flexor hallucis longus m.Flexor hallucis longus m.Peroneal v.Peroneal a.Peroneal v.Peroneal a.Peroneus brevis m.Peroneus longus m.Tibialis posterior m.Peroneus brevis m.Peroneus longus m.• Fig. . Cross-sectional anatomy of the leg showing two possible sizes of osteocutaneous grafts. The upper smaller graft has septocutaneous vascular perforators running through the crural septum between the peroneus longus and brevis muscles and gastrocnemius muscles. The larger graft is necessitated when the perforators are identified partially through the flexor hallucis longus muscle requiring harvesting of parts of this muscle. (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.)transoral implants. Implants placed in the bicortical vascularized graft routinely measure greater than 35 ncm of torque to allow placement of immediate prostheses (Figs. 39.30–39.33). Case Study 2: Double-Barrel Fibula Graft with Immediate Placement of Implantse double-barrel technique is used to increase the height of the reconstructed mandible. is is a 52-year-old male with a patho-logic fracture of the mandible caused by osteoradionecrosis (Fig. 39.34). e wide excision of the necrotic bone was planned and the guides were fabricated to complete the graft and the implants in one surgery.e custom plate and the bula models were used to rst resect the bone at the proper dimension and also to osteotomize the bula in situ at the proper length. e dental implants were placed with guides into the upper segment before detaching the graft from the peroneal blood supply (Fig. 39.35). e graft is brought up to the jaw and folded on itself, maintaining the blood supply to double the height. e inferior segment is secured to the custom plate to reapproximate the natural contour of the jaw, and the upper segment has more freedom to be rotated and secured in a position that is best suited for a good functional occlusion (Fig. 39.36).Finally both segments are secured and covered with portions of the soft tissue pedicle to secure its survival. e implants are uncovered in 4 months and restored. Sometimes it is necessary to debulk thick intraoral soft tissue pedicles and perform grafted vestibuloplasties to create a more healthy, soft tissue environment around the implants (Fig. 39.37). Summarye revolution in oral reconstruction brought about by the intro-duction of dental implants has revived the art and science of bone regeneration and grafting in dentistry. From the reconstruction of major jaw deformities to the augmentation of the smallest defect around a single tooth a bone graft is almost always considered to improve the environment of an implant xture and help ensure its longevity.e autogenous bone from the donor sites described in this chapter provide the three major qualities of a successful graft: osteoconduction, osteoinduction, and osteogenesis. e trans-fer of viable primitive mesenchymal and osteoblastic cells, as well as the growth factors (BMP) place the autogenous bone graft well above any of the allografts yet developed. Pain, deformity, and complications at the harvesting site are the 1106PART VII Soft and Hard Tissue RehabilitationPopliteal a.Common peroneal n.Deep peroneal n.Superficial peroneal n.Anterior tibial a.Anterior tibial a.Peroneal a.Perforating branchof peroneal a.Nutrient a.Periosteal supplyABInterosseous membraneTibiaPosterior tibial a.Tibial n.FibulaC• Fig. . (A) Anterior view of left leg. The common peroneal nerve crosses the fibular neck, dividing into the superficial and deep peroneal nerves. The anterior tibial vessel descends with the deep peroneal nerve along the anterior medial aspect of the interosseous membrane. The distal aspect of the peroneal artery passes through the interosseous membrane into the anterior compartment. (B) Posterior view of left leg. The popliteal artery branches into the anterior tibial artery, which branches into the anterior tibial artery and the posterior tibial artery, which branches into the peroneal artery, which provides the blood supply to the fibula through a nutrient artery and numerous periosteal vessels. (C) Fibula illustrated with 6 cm marked from the fibular head and lateral malleolus. Peroneal nerve illustrated inferior to the fibular head. Perfora-tors marked in circles and a 4 × 9-cm skin paddle is drawn out (Courtesy of Fayette Williams DDS, MD.). (From Kademani D, Tiwana P, eds. Atlas of Oral & Maxillofacial Surgery. Philadelphia, PA: Elsevier; 2015.)usual arguments for using alloplastic or nonautogenous sub-stances as replacements. In a report published in 2005 a group of renowned craniofacial surgeons presented a survey of their combined 25-year experience with cranial, tibial, crest, and rib grafts. In 20,000 cases reviewed, less than 1% of complications were noted in any one area of bone harvest. e authors’ con-clusions were that the often heard statement that an alloplastic material was used to “spare the patient the added time and complications of harvesting and autogenous graft” is, in fact, not a reasonable argument for a well-trained surgeon and may actually cause a failure or a compromised result at the recon-structed site.32VSP will no doubt be a strong inuence in the future of extraoral autogenous grafting for the implant patient. From the fabrication of custom cutting guides for resection, harvesting, and placement of larger grafts to the fabrication of immedi-ate implant-borne prosthesis, these new computerized tech-nologies will continue to promote and maintain the extraoral autogenous bone graft as the gold standard of dental implant reconstruction. 1107CHAPTER 39 Extraoral Bone Grafting for Implant Reconstruction• Fig. . Panorex showing radiolucency involving anterior mandible and dentition. (Courtesy of Fayette Williams DDS, MD.)AB• Fig. . (A) Computer-aided design (CAD)/computer-aided manufacturing (CAM) images of a cut-ting guide for resection of tumor and (B) custom reconstruction plate and guide for implant placement. (Courtesy of Fayette Williams DDS, MD.)BA• Fig. . (A and B) Computer-aided design (CAD)/computer-aided manufacturing (CAM) generated models for fabrication of immediate prosthesis. (Courtesy of Fayette Williams DDS, MD.) • Fig. . Surgical specimen of anterior mandible. (Courtesy of Fayette Williams DDS, MD.)• Fig. . Incision designed on the lateral left leg over the intermuscular septum between the soleus and peroneus longus muscle. (Courtesy of Fayette Williams DDS, MD.)CBA• Fig. . (A) segmental osteotomies and dental implant placement of the graft in situ (Courtesy of Fayette Wil-liams DDS, MD). (B) Custom plate used to shape graft for placement (Courtesy of Fayette Williams DDS, MD). (C) Graft placed and fixated to mandible and reanastomosis of vessels begins (Courtesy of Fayette Williams DDS, MD). 1109CHAPTER 39 Extraoral Bone Grafting for Implant ReconstructionAB• Fig. . (A) Prefabricated custom prosthesis from Computer-aided design (CAD)/computer-aided manufacturing (CAM) models (Courtesy of Fayette Williams DDS, MD). (B) Final occlusion before leaving the operating room (Courtesy of Fayette Williams DDS, MD).• Fig. . Panorex of pathologic fracture (Courtesy of Fayette Williams DDS, MD). 1110PART VII Soft and Hard Tissue RehabilitationABC• Fig. . (A) Computerized tomographic image of lesion (Courtesy of Fayette Williams DDS, MD). (B) Virtual Surgical image of extent of resection and planned folded fibula graft (Courtesy of Fayette Williams DDS, MD). (C) Computer-aided design (CAD)/computer-aided manufacturing (CAM) (Courtesy of Fayette Williams DDS, MD).• Fig. . Fibula graft osteotomized in half in situ with dental implants place in superior portion. 1111CHAPTER 39 Extraoral Bone Grafting for Implant ReconstructionReferences 1. Misch CE. Divisions of available bone in implant dentistry. Int J Oral Implantol. 1990;7:9–17. 2. Misch CE. Prosthetic options in implant dentistry. Int J Oal Implan-tol. 1991;7:17–21. 3. Shugaa-Addin B, Al-Shamiri HM, Al-Maweri S, Tarakji B. e eect of radiotherapy on survival of dental implants in head and neck cancer patients. J Clin Exp Dent. 2016;8(2):e194. 4. Smith JD, Abramson M. Membranous vs endochondral bone auto-grafts. Arch Otolaryngol. 1974;99:203–205. 5. Zins JE, Whitaker LA. Membranous versus endochondral bone: Implications for craniofacial reconstruction. Plas Reconstr Surg. 1983. 6. Kusiak JF, Zins JE, Whitaker A. e early revascularization of mem-branous bone. J Plas Reconstr Surg. 1985. 7. Oppenheimer AJ, Ton L, Buchman SR. Craniofacial bone grafting: wol’s law revisited, craniomaxillofac. Trauma Reconstr. 2008;1:49. 8. Tessier P, Kawamoto H, Matthews D, etal. Autogenous bone grafts and bone substitutes: tools and techniques. A 20,000 case experience in maxillofacial and craniofacial surgery. Plast Reconstr Surg. 2005;116:6s. 9. Wang J, Waite D, Steinhauser E. Ridge augmentation: and evalua-tion and follow-up report. J oral Surg. 1976;34:66–602. 10. Curtis T, Ware W, Beirne OR, etal. Autogenous bone grafts for atrophic edentulous mandibles, a nal report. J Prosthet Dent. 1987;57:73–78. 11. Verhoeven JDW, Cune MS, Teriou M, etal. e combined use of end-osteal implants and iliac crest onlay grafts in the severely atrophic man-dible: a longitudinal study. Int J Oral Maxillofac Surg. 1997;26:351–357. 12. MalchiodiL QA, D’Addona A, etal. Jaw reconstruction with grafted autologous bone:early insertion of osseointegrated implants and early prosthetic loading. J Oral Maxillofac Surg. 2006;64:1190–1198. 13. Tessier P. Autogenous bone grafts taken from the calvarium for facial and cranial applications. Clin Plast Surg. 1882;9:531. 14. Koenig WJ, Donovan JM, Pensler JM. Cranial bone grafting in chil-dren. Plast Reconstr Surg. 1995;95:1–4. 15. Fearson JA. A magnetic resonance imaging investigation of poten-tial subclinical complications after in situ cranial bone graft harvest. Plast Reconstr Surg. 2000;105:1935–1939. 16. Moreira-Gonzalez A, Papay FE, Zins JE. Calvarial thickness and its relation to cranial bone harvest. Plast Reconstr Surg. 2006;117:1964. 17. Zouhary KJ. Bone grafting from distant sites: concepts and tech-niques. Oral Maxillofac Surg Clin North Am. 2010;22:301. 18. Misch CE. Extraoral autogenous donor bone grafts for endosteal implants. In: Misch CE, ed. Contemporary Implant Dentistry. 2nd ed. St Louis: Mosby; 1999. 19. Mischkowski RA, Selbach I, Neugebauer J, et al. Lateral femoral cutaneous nerve and iliac crest bone grafts: anatomical and clinical considerations. Int J Oral Maxillofac Surg. 2006;35:366. 20. Kademani D, Keller E. Iliac crest grafting for mandibular recon-struction. Atlas Oral Maxillofac Surg Clin North Am. 2006;14:161. 21. Sivarajasingam V, Fell G, Morse M, Shepaherd JP. Secondary bone grafting of alvelarclefts: a densitometric comparison of iliac crest and tibial bone grafts. Cleft Palate Craniofac J. 2001;38:11–14. 22. Peysakhov D, Ferneini EM, Bevilacqua RG. Maxillary sinus aug-mentation with autogenous tibial bone graft as an in oce proce-dure. J Oral Implantol. 2012;38:50. 23. Walker TW, Modayil PC, Cascarini L, etal. Retrospective review of donor site complications after harvest of cancellous bone from the anteriomedial tibia. Br J Oral Maxillofac Surg. 2009;47:20. 24. Catone GA, Reimer BL, McNeir D, Ray R. Tibial autogenous can-cellous bone as an alternative donor site in maxillofacial surgery: a preliminary report. J Oral Maxillofac Surg. 1992;50:1258. 25. Herford AS, King BJ, Becktor J. Medial approach for tibial bone graft: anatomic study and clinical technique. J Oral Maxillofac Surg. 2003;61:358. 26. Hidalgo DA. Fibula free ap: a new method of mandibular recon-struction. Plast Reconstr Surg. 1989;84(1):71. 27. Frodel JL, Funk GF, Capper DT, etal. Osseointegrated implants: a comparative study of bone thickness in four vascularized bone aps. Plast Recontruc Surg. 1993;92:449–455. 28. Moscoso JF, Keller J, Genden E. Vascularized bone aps in oro-mandibular reconstruction. Arch Otolaryngol Head Neck Surg. 1994;120:36–43. 29. Dattilo DJ, Misch CM, Arena S. Interface analysis of hydroxyapa-tite-coated implants in a human vascularized iliac bone graft. Int J Oral Maxillofac Implants. 1995;10:405–409. 30. Sumi Y, Hasegawa T, Miyaishi O, Ueda M. Interface analysis of titanium implants in human vascularized bula bone graft. J Oral Maxillofac Surg. 2001;59:213–216. 31. Tepper O, Hirsch D, Levine J, Garfein E. e new age of three-dimensional virtual surgical planning in reconstructive plastic sur-gery plastic a reconstructive. Surgery. 2012. 32. Tessier P, Kawamoto H, Posnick J, Raulo Y, Tulasne F, Wolfe SA. Complications of harvesting autogenous bone grafts: a group experi-ence of 20,000 cases. Plast Reconsr Surg. 2005;116:5.AB• Fig. . (A) Double layered fibula secured with custom reconstruction plate and superior portion with smaller position plates (Courtesy of Fayette Williams DDS, MD). (B) Six-week computerized tomography scan to check position. (Courtesy of Fayette Williams DDS, MD.)

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