MANDIBULAR RECONSTRUCTION
Classification (Boyd)
HCL osm system
1. H defects: Lateral defects of any length including the condyle, but not
significantly crossing the midline.
2. L defects: The same, but excluding the condyle.
3. C defects: The entire central portion of the mandible containing the 4 incisors and
the 2 canines.
4. o - neither skin nor mucosa involved.
5. s - skin involved.
6. m - mucosa involved.
7. sm - skin and mucosa involved.
 differentiation between H and L defects is condylar involvement as condyle
reconstruction is difficult and imparts a functional impairment on the patient.
 C segment has unique reconstructive demands. Reconstruction frequently leads to
lip and chin ptosis as the soft tissues slide off the bone. This ptosis is due to a
number of causes:
1.
detachment of the geniohyoid and digastric muscles- allows the
reconstructed mandible (now without these muscular attachments) to ride
up, especially if the patient is edentulous.
2.
the soft tissues are degloved off the chin which allows them to fall off
(witch’s chin defect).
3.
gravity.
4.
VII nerve may have been lost as a consequence of ablative surgery
5.
scar contracture.
The majority of mandibular blood flow is from this medullary circulation. Less than
25% of cortical vascular supply is from the periosteal arterioles.
History
 Sykoff 1900 - nonvascularized bone for mandibular reconstruction
 Lindemann stated that iliac crest was preferable to tibia as a source of donor bone.
o Became the bone of choice for the next 40 years
 Millard 1969 – rib grafts
o Because of a 30% failure rate from infection and exposure, the authors
recommended delaying definitive bone grafting for 6 weeks after
completion of the soft tissue reconstruction.
 Cummings 1980 – sterilized frozen/irradiated autogenous bone
Surgical management
 Currently, reconstruction of mandibular defects resulting from H&N Ca surgery
involves replacement of missing mandible with vascularised bone for the
following reasons:
i.
promotes primary healing
ii.
well perfused tissue can resist and withstand RT
iii.
low morbidity and mortality
iv.
allows dental reconstruction with osseointegrated implants.
v.
improves facial form, function and quality of life.
 All other methods are inferior to primary reconstruction with vascularised bone.
 Goals:
1) establishment of mandibular continuity
2) establishment of an osseous-alveolar base
3) allow for dental rehabilitation
4) correction of soft-tissue defects
5) Restore lip sensation
a. The restoration of lower lip sensation in mandibular reconstruction
is now standard procedure.
b. A suitable length of sural nerve is harvested and grafted into the
defect by microneural anastomosis to the proximal and distal
residual stumps of the inferior alveolar nerve. Nerve graft should
loop around the lower border of the reconstructed mandible to
reduce the likelihood of its being damaged during placement of the
endosseous dental implants at a later stage.
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
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segmental mandibulectomy causes collapse and instability of the residual
mandible segments due to muscle pull, and results in severe aesthetic and
functional compromise
Lateral defects can be tolerated and are compatible with life
o Letting the mandible “swing” is an adequate option for select patients.
o There may be some lateral deviation with extreme opening, but with
appropriate postoperative isometric exercise, mandibular drift is usually
not a problem.
o Alternatively, bridging the defect with a low profile reconstruction plate
and providing soft tissue lining over the plate with a regional, pedicled, or
free flap is an attractive option in patients with advanced disease, who do
not require dental restoration
Central defects which includes the symphyseal region may compromise the
patency of the airway due to loss of tongue anchorage and requires treatment
Options
1. Alloplast (Mandibular recon plates)
 mainly serves as a temporizer
 Advantages:
1) no donor site morbidity
2) expediency
3) ease of contour
4) ability to reconstruct the condyle.
 associated with high extrusion rates, particularly when used to bridge anterior
mandibular defects or in the event of poor-quality lining or irradiated soft tissues.
2. Mandibular allograft with autogenous bone chips
 Marx and others have used freeze dried mandible combined with autogenous bone
chips and multiple courses of hyperbaric oxygen to reconstruct the mandible.
 The procedure is time consuming (20 hyperbaric oxygen procedures prior to
surgery and 10 after) and frequently requires 2 operations.
3. Non vascularised bone graft
 Most effective for short bone defects (<5-6 cm), in nonirradiated tissue, and/or in
patients determined to be too medically compromised to tolerate the additional
operative time required for a free-flap reconstruction.
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Cortical bone needed to maintain skeletal strength and shape.
Cancellous bone required to ensure osteoneogenesis.
Commonest donor sites: ribs and iliac crest.
Millard (1969) noticed that immediate bone grafts were associated with a 30%
early failure rate from infection and extrusion and proposed delayed grafting as a
2nd procedure after 6 weeks.
Extrusion, infection or resorption in up to 50% of cases, with an overall Cx rate
approaching 80%.
Long bone has unreliable osteogenesis especially if the bed requires irradiation.
4. Treated Autogenous Mandible
 removed mandible can be treated (sterilised) to remove any traces of the
malignancy. The mandible is then replaced as a biologically inert scaffold for
new bone growth.
 Two methods of treatment have been used:
1. Cryotherapy (Cummings and Leipzig, 1980). Subjected the excised
mandible re-peatedly to liquid nitrogen and then replaced the freeze dried
specimen.
2. Irradiation (Hamakker, 1981). 100Gy given either in situ or in vitro.
 Both methods were associated with a high failure rate and have been abandoned
5. Vascularised bone
 Successful restoration of the mandible with vascularized autogenous bone sets the
stage for primary healing, brings well-perfused tissue that can withstand adjuvant
radiotherapy, facilitates dental restoration with osseointegrated implants, and
improves facial form and quality of life.
 Advantages include: 1) wide selection of donor site, 2) non-irradiated tissue, 3)
own vascular supply, and 4) soft-tissue for closure.
 Major disadvantages include: 1) donor site morbidity, 2) longer operation time, 3)
need for special surgical and nursing skills, and 4) longer hospitalization.
 Vital that the true and original spatial orientation is restored – this can only be
achieved when the mandible is preplated before the cancer is resected.
 almost invariably requires a number of osteotomies; this is particularly true for a
central defect, a central–lateral defect, or a lateral ramus–ascending ramus defect
 donor sites (may be free or pedicled)
1. the fibula
2. iliac crest
3. radius
4. lateral scapular border
5. spine scapular (trapezius flap)
6. Less popular techniques
o free transfer of rib
o second metatarsal bone
o clavicle with SCM flap
o ribs with serratus anterior, pec major, lat dorsi
o pec major and split sternum (better than rib)
o temporalis and outer/full table calvarium
 A comparison of free iliac crest and fibula flaps in oromandibular reconstruction
reveal similar rates of complications and cosmetic results between the two groups.

Long-term function was also similar in terms of oral continence, speech, and
contour, but oral deglutition was significantly better in the fibula free flap group
Comparison of free flap donor sites for mandibular reconstruction
Tissue Characteristics
Donor Site Characteristics
DONOR SITE
Bone
Skin
Pedicle
Location
Morbidity
A
C
B
A
A
1. Fibula
B
D
D
B
C
2. Ilium
D
A
A
C
D
3. Radius
C
B
C
D
B
4. Scapula
From Hidalgo
A = best; D = worst
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For short bone defects 6-8 cm long, especially if an osteotomy is not required, the
above bone flap options are available
Fibula or iliac crest, according to Taylor, are the only real options when the one
defect is in excess of 8 cm or osteotomies required, especially when associated
with:
1.
loss of mucosa or skin
2.
RT (pre or post op)
3.
heavily scarred recipient bed
4.
previously failed conventional technique
5.
growth anomaly (eg, hemifacial microsomia)
Fibula
 Hidalgo recommends taking most of the fibula regardless of the size of the
mandibular defect
Advantages
1. Length - enough bone (up to 25 cm) to span defects of any size
2. Shape - ability to dissect the flap with the patient supine
3. Blood Supply - numerous segmental perforators from the peroneal vessels
throughout the length of the bone flap to perform multiple osteotomies without
jeopardizing its blood supply
4. Skin - large enough for both skin and mucosal defects.
5. Bulk - FHL, largely expendable, courses with the bone and is useful to fill in
soft tissue defects.
6. Bone - adequate bone stock for incorporating osseointegrated dental implants
7. 2 teams - sufficient distance from the ablative field to allow a two-team
approach
8. Donor site morbidity - low
Disadvantage
o Skin reliability – 90% (according to Hidalgo)
Contraindications
1. severe peripheral vascular disease
2. dominant peroneal artery
Consider another flap if
3. Mandibular defect associated with a massive internal and external soft tissue
loss. The aim here is to achieve a healed wound. Accurate bone
reconstruction is of secondary importance. These patients usually have a poor
aesthetic and functional result and if these patients are operated on for cancer,
their survival is usually limited anyway. Abundant soft tissue is the priority in
these patients and Hidalgo recommends the scapular donor site.
4. Retromolar trigone lesion that extends to soft palate, oropharynx and base of
tongue. The bony defect in these cases is limited to the angle and adjacent
ramus and body. The requirements are mainly for soft tissue and a radial
forearm flap may be better. The limited bone available with a radial forearm
flap are sufficient to bridge the bony defect to restore tandem TMJ function
and normal occlusion. Osseointegrated im-plants are not required this far
posteriorly. The soft tissue defect requires a more spe-cific reconstruction.
Determining vascular disease
 Preoperative colour flow Doppler useful in predicting disease and determining
need for angiography (at least 1 vessel with a monophasic waveform or no flow)
 CT angiography becoming more useful
 Many argue that the incidence of vascular anomalies in conjunction with a normal
pulse examination is so low as to not warrant preoperative investigation.
o Lutz and FC Wei (PRS 1999) performed a prospective study examining the
use of preoperative angiography in 120 patients. Conclusion: It does not add
relevant new information about donor leg vascularity, provided that the
clinical evaluation of the pedal pulses is well conducted. The only two
conditions that may require a preoperative donor leg angiography are
abnormal pedal pulses or significant previous lower leg trauma
o Hypoplasia, or absence of the posterior tibial arter – 4%
o Hypoplasia, or absence of the anterior tibial artery – 2%
o Congenital absence of peroneal artery – 0.2%
o Peroneal arteria magna exists when both the anterior and posterior tibial
arteries are hypoplastic or absent – 0.2-8.2%. Associated with a normal pulse
examination
o Complications of angiogram - complication rate of 3-9%. The complications
include hematoma, hemorrhage, pseudoaneurysm, thrombosis, arrhythmia,
anaphylaxis, intimal damage, renal insufficiency, urticaria, distal ischemia,
and vascular spasm.
Flap Design
 Usually the ipsilateral leg is best:
1.
allows a longer, more advantageously sited pedicle (at the angle)
2.
the FHL lies under the fibula and can be used for soft tissue defect of the
upper neck
3.
skin island convenient for mucosal defect
 if only the contralateral neck vessels are available, the leg contralateral to the
defect is chosen (ie on the same side as the vessels available). The graft is sited
distally in the leg (to lengthen the pedicle) and the proximal bone is discarded.
The distal fibula will become the proximal mandible so that the pedicle is close to
the recipient vessels.
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1.
2.
3.
anterior defect  side with the longer bony defect is the preferred donor leg site.
For anterior reconstructions in which the defect does not extend to the angle, the
design is shifted more distally to lengthen the pedicle (same as (a), but more
distal).
Taylor emphasises that the bone must be taken distally for 3 reasons:
the blood supply to the bone from the peroneal artery is better
the cutaneous blood supply is more likely to be septocutaneous
the proximal portion of the fibula can be discarded to lengthen the pedicle
DCIA
 O’Brien first described taking iliac crest on the SCIA (1976).
 Taylor, Townsend and Corlett (1979) described using the DCIA.
Disadvantages (according to Hidalgo)
1) Bone - Lacks a segmental blood supply which precludes osteotomies (disputed by
Taylor - see below). The modern concept of free flap mandible reconstruction
calls for multiple osteotomized grafts to achieve optimal results. Ilium lacks the
flexibility and precision that can be achieved with osteotomised fibula. May be too
thick and require revision.
2) Skin - Has a tenuous blood supply and tends to be thick and block-like in most
individuals which does not sit well in the mouth.
3) Colour and bulk of skin is a problem (even Taylor concedes). Difficult to orient
d/t limited mobility of skin paddle.
4) Technically difficult harvest
5) Donor site morbidity - Delayed ambulation due to pain and potential for hernia
formation, contour irregularities and lower abdominal weakness. Injury to lateral
cutaneous nerve of thigh and ilioinguinal nerve.
Advantages (according to Taylor)
1. Bone - does have a segmental supply. Can sculpt the bone to form the entire
hemimandible, even crossing the middle of jaw up to the angle. Its gentle curve
parallels that of the mandible. Never require more than one osteotomy and
frequently none. 20 cm of bone is available. Ample bone mass. Accepts
osseointegrated implants.
2. Vessels - of good calibre and pedicle length.
3. Two team approach possible
4. Flap versatility - osteocutaneous, myo-osseus, osteomyocutaneous
Flap Design
 DCIA lies medial to the bone, iliacus muscle and fascia.
 6-9 cm behind the ASIS, the DCIA penetrates the transversus to supply muscle
and skin.
 The area of skin supplied lies behind the ASIS and a little above the iliac crest.
 The blood supply to the bone is via 2 sources:
1. musculo-periosteal, mainly via the iliacus
2. nutrient via multiple small foramina on the crest and blade of the medial aspect
of the ilium.
 Variations in anatomy which may trap the unwary
1.
An ascending branch (supplies inferior oblique) which arises medial to the
ASIS and passes upwards may be mistaken for the DCIA main trunk.
2.
The main trunk of the DCIA may pierce the transversus muscle medial to the
ASIS to lie in a more superficial plane than normal.
3.
The DCIA may be duplicate.
 3 flap options:
1. Free osteo-musculo-cutaneous
2. Free musculo-cutaneous
3. Free vascularised bone graft
a) either full thickness of ilium (bicortical)
b) or only the inner cortex of the ilium (unicortical) – osteointegration possible
 Iliac crest ipsilateral to the mandibular defect - ASIS will become the angle, PSIS
becomes the symphyseal area.
 Skin paddle designed as an ellipse parallel to the iliac crest. 2/3 of the width of
the flap is made above the crest; 1/3 below or over the crest. Medial end of the
ellipse is over ASIS or just medial to it.
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Radial Forearm
Advantages
1) Skin - thin pliable skin ideal for intra-oral lining.
2) Quick and easy
Disadvantages
1) Bone - The bone quality is poor (hemicortex) and cannot support osseointegrated
implants.
2) Donor site - High morbidity and poor cosmesis. Radius fractures can occur and
for this reason not more than a 1/3 of the circumference of the bone should be
removed.

available segment of bone lies distal to the insertion of the pronator teres to
insertion of brachioradialis giving a maximum length of about 10 - 12 cm in the
adult
Scapula
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Approximately 7 cm of bone can be safely taken from the scapular edge for
reconstruction of mandibular segments.
Length of the pedicle is increased to 13–18 cm using the angular artery. There are
no distinct sensory nerves available to the variety of paddles in this system
If accessory nerve taken with ND, take the contralateral scapula flap to avoid
further compromise to shoulder function.
Advantages
1) Skin - Ample hairless skin. Donor site can be expanded.
Disadvantages
1. Positioning - Patient has to be prone to harvest the flap and supine to prepare the
defect which wastes time. Can put the patient in the lateral decubitus position for
simultaneous recipient site and flap harvest.
2. Bone - Less bone available (14 cm) and that which is, does not have a segmental
supply which limits the potential for osteotomies. Bone stock is also less than that
of other donor sites.
3. No sensory nerve
4. Donor site morbidity - shoulder stiffness and ed ROM.
Other bone flaps
METATARSAL
 2nd MT carried on dorsalis pedis first described by O’Brien (1979).
 Can carry 4-7 cm of bone.
 Segmental blood supply to bone therefore osteotomies can be done.
 Donor site morbidity is a problem as SSG required.
SCM AND CLAVICLE
 A segment of clavicle can be brought up as a pedicled flap on SCM.
RIB
 Vascularised rib can be harvested via an anterior, postero-lateral or posterior
approach.
 Can be taken on the internal mammary vessels or transferred on pectoralis major,
latissimus dorsi or serratus anterior muscles.
 Only small segments of rib can be maintained on the periosteal supply.
STERNUM
 Like rib, sternum can also be transferred up on a pectoralis muscle flap.
TEMPORALIS MYO-OSSEUS FLAP
 Cranial bone carried on temporalis.
 Either the outer table or full thickness of bone can be transferred.
Hyoid Resuspension
 Aspiration may result due to prolapse of the larynx against the posterior
oesophageal wall
 Options for treatment:
1. Cricopharyngeal myotomy
2. Laryngeal or hyoid suspension
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POST-OP CARE
 Graft monitoring is not precise.
 Colour and capillary refill of intra-oral skin paddle can be monitored.
 Doppler examination may be possible.
 IMF taken down at 5 days (or 10 days if the condyle has been reconstructed) and
mouth opening exercises are begun.
 NGT feeds are maintained till the wound has healed (7-10 days) after which oral
feeds are intiated.
 Soft diet usually for 6 weeks.
 Out of bed after 2 days.
 Ambulation at 5 days if no SSG.
 Periodic panorex to monitor bone healing.
 Osseo-integrated implants placed 6-12 mths after primary surgery. Not if RT.
Mandibular reconstruction in children
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
ideal method of reconstruction used in the pediatric population should grow
commensurately with the child.
Methods:
1. nonvascularised bone – costochondral grafts and iliac crest graft
2. free vascularized bone flaps (fibula, scapular, iliac crest, and radial forearm).

Fibula
o Growth occurs in a classic endochondral pattern
o 3 ossification centers - 1 in the shaft and 1 in each of the distal and
proximal epiphyses
o growth plates lie within 1 to 2 cm of each end of the bone, proximal and
distal to where a harvesting osteotomy should be made.
o Most growth occurs in the proximal epiphyseal plate, which fuses by age
15 for girls and age 17 for boys.
o stock of bone, particularly in patients under the age of 13, may lack the
height appropriate to stabilize osseointegrated implants
o Toronto Sick Kids PRS 2005 – did not show growth of free fibula
reconstructed mandible
o little clinical evidence suggesting that long-term limb growth is adversely
affected. Experimental evidence in rats demonstrates that the fibula exerts
a restrictive effect on tibial growth such that removal of the fibula leads to
longitudinal tibial overgrowth. However, clinically, leg length
discrepancy has not been demonstrated
o most substantial delayed complication associated with fibula harvest,
particularly in children younger than 9 years, is a valgus deformity at the
donor ankle
o performing a synostosis at the time of
the harvest prevents valgus deformity in
90% of patients younger than 8 years.

Scapula
o flat membranous bone

o lateral scapular border and scapular tip develop from a large
osteocartilaginous epiphyseal plate
o At birth, the inferior 7 to 8 cm is composed entirely of hyaline cartilage.
o Ossification proceeds in a superior to inferior pattern until approximately
age 10, when the scapula is roughly 12 cm long and the distal epiphysis
has decreased to 4 cm
o Ossification centers of the scapula are located at the medial scapular
border and the glenoid fossa (darkened areas). The lateral border serves as
a traction epiphysis.
o Mainly responsible for vertical scapular growth, the superior growth plate
lies outside the range of harvested bone, and therefore should not be
directly affected
o lateral border of the scapula serves as a traction epiphysis, growing in
response to pull of the teres and triceps muscle groups
o harvesting bone from this area for congenital reconstruction results in a
moderate scapular size discrepancy, but no appreciable functional deficit
o To facilitate implant stability, iliac crest bone onlay grafts may need to
used to augment the scapular bone during the secondary placement of
osseointegrated implants
Iliac crest
o entire length of the iliac crest, from the anterior-superior to the posteriorsuperior iliac spines, is composed of cartilage at birth
o Growth occurs in an epiphyseal fashion in several areas of the pelvic
girdle, including the acetabulum and the iliac crest, which grow until the
second decade of life
o Like the lateral scapular border, the crest serves as a traction epiphysis
where the dynamic interaction between the iliac crest and its muscle
attachments plays a crucial role in acetabular development, and hence gait
stability.
o Disturbance of gait after iliac crest free flap harvest in the adult population
has been documented in up to 11% of patients.
o