Distraction osteogenesis

INDIAN DENTAL ACADEMY
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Events in Distraction
Osteogenesis
-Initiation with incremental traction to
the reparative callus
-Tension within the callus stimulates

new bone formation parallel to the
vector of distraction.

•Tension is created in the surrounding

soft tissues leading to Distraction
Histogenesis(active histogenesis in
skin, fascia,blood vessels , nerves ,
muscle , ligament,cartilage &
periosteum.)

It was introduced by Ilizarov
in 1951.
It is a unique form of tissue
engineering
Using easily controlled
mechanical

condition that is slow gradual
distraction of the corticotomized

Or osteotomized bone fragment
A clinician is able to guide the
formation of new bone and its
spatial orientation to form a
structural part of distracted
bone.

This happens without application
of any growth factor or other

controlling agent.
Distraction can be done of various

cranio-facial structures like
Mandible,mid-facial ,zygomas ,
cranium related to dental field

DEFINITION
“It is the regeneration of bone
between vascularized bone
surface that are separated by
gradual distraction”


DENTOFACIAL TRACTION
- As early as 1728, fauchard used
expansion arches
- Ideally shaped metal plates ligated
to the crowded dentition
- Wescott in 1859 reported
- mechanical force on maxilla

- He used double clasp seperated
By a telescopic bar to correct a
Cross-bite
- Angel in 1859 first achieved rapid
palatal expansion
- Goddard in 1893,further
standardized the palatal expansion

INITIAL PHASE OF
DISTRACTION
-In 1905 Codvilla performed first
bone distraction-femur
-In 1927,Abbott applied same
concept for tibia

-Wassmund,rosenthal in1927

performed first osteodistraction


In 1937, Kazanjian also
performed mandibular
osteodistraction by using
gradual incremental traction
instead of acute
advancement .After
performing modified Lshaped osteotomies in the
corpus, he attached a wire
hook to the symphysis,
thereby providing direct
skeletal fixation to the bone
segment to be distracted.


With the introduction of D.O.G
craniofacial surgery entered the
latest phase
It is ironical that Ilizarov spend
his professional carrier in
developing the technique on the
long bones

The craniofacial skeleton are much
more suited for distraction
- membranous in embryological
origin
- smaller in dimension
- richer blood supply
He utilized a primitive external ring
fixator to compress the injured
bone ends

By chance ,a patient reversed
the compression rod, thereby
distracting the bone fragment
Ilizarov observed new bone
formation radiologically and
pursued this new method
experimentally and clinically

All early studies were done in
long bones like Tibia,femoral,
ulnar,radius e.t.c
Distraction of craniofacial
skeletal by synder et al in 1973
at 1mm/day for 14 days

Next applied by michieli and miotti
in italy to increase mandibular
length by 15mm at the rate of
0.5mm/day followed by 40 days of
fixation
In 1990 Karp et al at new york
performed a unilateral angular
osteotomy in the canine mandible.

 Bone is a dynamic organ that can
regenerate.
 Regeneration may be defined “as
restoration of form and function
indistinguishable from that derived
embryological ”.
 Developmental insufficiency ,
pathology ,surgical resection and
avulsion can lead to osseous defects.

 Regenerative capacity of bone
help in correcting these deficits.
 Various biological factors as
hormones,prostaglandin,
cytokines and growth factor


 Bone fracture repair requires
remodeling of cortical and cancellous
components
Cortical bone remodeling includes
(B.M.U) synchronized team of
osteoblast and osteoclast

 Osteoclast-cutting cone of
BMU burrow through cortical
plate. Originates from
circulating mononuclear
precursor.
 Osteoblast-produces over
abundance bone the callus.And
there,after excess callus is
again removed by osteoclast

Critical factors of the process appears to
be
1. Stability of fixation
2. Rate of daily distraction
3. Preservation of local soft tissue envelope
4. Vascular supply

 Pure lengthening procedure

 Corrective distraction
osteotomies
 Transportation distraction
 Stimulation of growth within
growth plate in growing children

DISTRACTION
FORCES

FIXATOR
STIFFNESS

PHYSIOLOGICAL
LOADING

SOFT TISSUE
PROPERTIES

Regulating
Mechanical
forces


-Vector depends on orientation of
distraction device to skeletal
anatomy
-Devices are oriented to occlusal
plane
-In case of significant irregularity
occlusal plane long axis of body
of mandible is used

 VERTICAL
 HORIZONTAL
 OBLIQUE

 The pin-bone interface is most
critical factor for the performance
of external fixation
 Loosening of external fixation
pins

 Pin tract problem can be
controlled, but established
regimens must be followed during
insertion and post operative care
Most important factor single
factor causing pin loosening is
unstable fixation

A.Orthofix ,B.Hoffmann ,C.Ace
D.Apex blunt ,E.Apex sharp

INDICATION FOR D.O
Craniofacial microsomia
uni-bilateral
Nager’s syndrome
Treacher collins syndrome
Pierre robin syndrome
TMJ ankylosis

Post traumatic disturbance
Developmental microsomia
Midfacial hypoplasia (craniofacial
synostosis syndrome)
Condylar regeneration
Expansion of mandibular
symphis
(brodie syndrome)

CHARACTERSTICS OF
DISTRACTION DEVICE
Type of
device

Extra oral

Intra oral


- Initially all experimental works in
membranous bone lengthening
was performed on mandible
- The protocol for correction
depends on degree and type of
deformity

-Treatment choice depends purely
on individual patient need
-In 1990 Karp et al performed a
unilateral angular osteotomy in
canine mandible
-After 10 days of external fixation
mandible was distracted at
1mm/day for 20 days and held in
fixation for 56 days

DISTRACTION ON DOGS


DEVELOPMENT OF BONY
REGENERATION


PRE OPERATIVE CLINICAL
EXAMINATION
• Extra oral and intra oral
examination should be done with
extra care
• Check for asymmetries and
deformities in detail
• Function of TMJ before distraction
• Mouth opening.

DIAGNOSTIC RECORDS

PHOTOGRAP
H


RADIOGRAPHIC

P-A VIEW


•Placement of head in cephalostat is altered
in unilateral craniofacial microsomia.
•The ear is placed down and forward in
affected side.
•The technician
should make clinical
evaluation of a line
perpendicular to the
Mid sagittal plane

3-DIMENSIONAL
CEPHALOGRAM


3-D CT SCANNING


OCCLUSAL CANT


DEPENDING ON PLANE
EXTRA-ORAL
APLIANCES

UNI-PLANAR

A. External uni planar distraction
appliance
In 1992,mcCarthy et al introduced this
appliance to successfully lengthen
the mandible unilaterally in 3 children
and bilaterally in 1 child
Approx. 20-24mm of bone stock
posterior to last tooth bud is necessary
to place this device.

Ortiz-monasterio and molina
modified illizarov technique by
performing incomplete
corticotomy.
 They left internal cortical plate
and cancellus layer intact and
used semi rigid distractor.

B. External bi-planar distractor


 Bi planar distractor provides an additional
plane of correction
 More severe mandibular hypoplasia, such
as Nager’s syndrome involves deficiency
in more than one plane
 Following a single or double osteotomy,
one can distract both vertically and
horizontally

 In very difficult cases of mandibular
hypoplasia, a double osteotomy may be
undertaken in order to obtain two callus
sites. This allows a more rapid distraction
as well as the development of a
mandibular angle.
Klein and Howaldt introduced a device
capable of achieving controlled changes
in angulation.

C. External multi planar distractor


 Multi planar devices has capability to
do correction in all three planes.
The hypo plastic mandible not only
deficient in ramus height and body but
effected ramus may lie in more medial
position, resulting in decreased bigonial
distance.

SURGICAL PROCEDURE
 Buccal surface of hypoplastic
ramus is approached via either an
intra-oral or extra-oral
 Initial cases were done through an
extra-oral incision but as clinical
experience increased intra-oral
approach was used

 In either incision area

is anesthetized
 In intraoral approach
incision is made over the
external oblique line and
buccal surface is exposed
in sub periosteal plane.
 Raise a full-thickness flap, separating the
muscle from the overlying periosteum.
Identify the area of bone deficiency. Identify
and mark the area of preplanned mandibular
osteotomy.

 In transcutaneous approach, a 3-cm
incision is made in the skin lines of the
submandibular fold at a position along the
angle and inferior border of mandible


- Selection of pin-hole site requires careful
attention
- As drill hole determines position of device
and vector of distraction.
- One must be sure that pin projects
sufficiently above the skin
- After the pin holes
are drilled saline
irregation should be
done to prevent bone
necrosis

 Then 50mm half pins are inserted

 In intra oral approach a trocar is used
to permit percutaneous drilling of holes
as well as insertion of half pins.


 It is technically best to perform or
complete osteotomy after distraction
appliance is tightened.
 A mechanical saw supplemented by
saline irrigation can be used
 The osteotomy is
is completed by
inserting and rotating
An osteotome by
Separating bone
Segment.

 Irrigate the wound and close it with 4-0
cat gut suture.


TO MOVE A RAIDER
 Loosen the fixation screw
("F") by turning the screw
turn counter-clockwise using
the provided screwdriver.
 Using the screwdriver, turn
the advancement screw
("M") to move the rider in the
desired direction.
The distance the rider is
moved is indicated by the scale
(marked in 1mm increments)
etched on the geared rod.


Once the desired position of the rider is reached,
the rider must be stabilized by tightening the
fixation screw ("F"). This is done by turning the
screw clockwise.
Because the distraction process will be carried
out primarily by home-caregivers (relatives or
friends of the patient), the fixation and
advancement screws are clearly marked with the
letters "F" and "M", respectively.


• In 1987, Guerrero applied the first
intraoral tooth-borne appliance for
osteodistraction of the mandibular
symphysis.
• In 1990 , he reported the results of intraoral
mandibular widening on eleven patients
with transverse deficiencies ranging from 4
to 7 mm.He used the same principles that
Bell and Epker described for palatal
expansion of the maxilla .

• After a vertical
symphyseal osteotomy, a
custom made Hyrax
appliance was placed
and initially activated 48
hours after surgery.
Depending upon the
resistance of the soft
tissues, 2 to 4 activations
were applied per day to
achieve the desired
expansion

• In 1994, McCarthy and co-workers
developed a miniaturized bone-borne
Uniguide™ Mandibular Distraction
Device suitable for intraoral placement .Similar
to his extraoral appliance, the device consisted
of two clamps that were attached to the bone
via pairs of pins connected by a telescopic
distraction rod.


• At the same time, Wangerin in
Germany designed a similar appliance
– the Intraoral Titanium
Mandibular Distraction Device .
The device consists of two mini plates
for bone fixation connected by a
square-shaped distraction cylinder.


WIDENING OF SYMPHYSIS


RAMUS OSTEOTOMY
DISTRACTION


INTRAORAL MAXILLO-MALAR
DISTRACTION TECHNIQUES
•Maxillary malar
deficiency is a common
deformity.
•U shaped palatal
osteotomy performed
•A-P distractor placed
after completion of malar
maxillary osteotomy

-Osteotomy includes malar bone.
-Extends posteriorly
pterygomaxillary suture ,
posterior aspect of
zygoma.Same cuts are made on
opposite side.


-Then malarmaxillary complex
is displaced using
curved osteotome
behind maxillary
tuberosities

Maxillary Distraction Procedure
Maxillary Distraction procedures
deliver traction forces through the

dentition to the maxillary bone. To
apply traction through the dentition
a rigid intraoral splint is required.

The Intraoral Splint:
• Orthodontic bands with 0.050inch
headgear tubes are fitted either on first
permanent molars or second primary
molars(below 6yrs). The splint is made
with 0.045/0.050 SS rigid wire.
•Two straight pieces of
0.050 SS wire are
soldered perpendicular
to the labial wire.

• The long ends of these
wires are bent anterior
to the lips in a circle to
have a rigid eyelet to
apply traction.
• To control the direction
of traction forces relative
to the approximate
center of resistance of
the maxilla and also to
avoid irritation to the lip.

The RED Device :

After completion of the osteotomy, the halo
portion of the RED device is adjusted and
rigidly fixed around the head with scalp
screws. A vertical bar was connected to the
halo and a horizontal bar with the distraction
screws.


-The traction hook and traction screws were
connected with a 25guage surgical wire.
-Latency period :4 to 6 days after osteotomy.
-Active distraction :1 to 1.5mm per day
-Rigid retention :without active distraction for
2 to 3 weeks
-final retention : elastic retention with face
mask for
4 to 6 weeks
two 6-oz elastics

 The orthodontist has an extremely
important role to play right from
diagnosis and treatment planning
till the end of the treatment

1.
2.
3.

It is divided into 3 stages
Pre distraction orthodontics
During distraction orthodontics
Post distraction orthodontics.

Pre distraction orthodontics
A. Removal of dental compensation- teeth
should be moved to ideal position relative
to the basal bone so that ideal maxilomandibular relationship is not
compromised.
B. Preliminary alignment- crowding,rotation,
extruded and intruded teeth should be
corrected before distraction procedure is
initiated


C. Coordination of archwidth-patients with
severe mandibular retrognathism will have
transverse maxillary deficiency also. It is
appropriate to expand maxilla before
distraction.
D. Surgical hooks-passive rigid rectangular
full size wires are placed with surgical
hooks for use of intermaxillary guiding
elastics during active stage of
distraction

During distraction orthodontics
A. Orientation of device-depending upon
type of deficiency, orientation should be
done based on occlusal plane to obtain
predictable changes (bilateral or
unilateral)
B. Distraction device can be uni-directional,
bi-directional, multi-directional
C. Application of external influence-this is
applied by clinician by activating the
device to achieve desired results

Post distraction orthodontics
-After consolidation and removal of
appliance orthodontist has to give final
finishing of occlusion
-In cases of unilateral distraction patient
has canted occlusal plane which can be
corrected by selective tooth eruption

- Unilateral distraction patients have
tendency of laterognathism causing
posterior cross-bite which can be
corrected by combination of TPA,
lingual arch, cross elastics,palatal
expansion appliance


Alveolar Distraction
• Alveolar deformities and defects
may result from a variety of pathological
processes including 1) developmental
anomalies, such as cleft palate and
congenital tooth absence, 2)
maxillofacial trauma, which often
involves damage to the teeth and
associated jaw structures, and 3)
periodontal disease leading to bone and
tooth loss from the alveolar process.

These deformities may be
managed by a variety of
surgical techniques ,
such as autogenous onlay
bone grafting, alloplastic
augmentation, connective
tissue grafting, guided
tissue regeneration or
non-surgical techniques
such as facilitation of
supraeruption in
periodontally compromised
alveolar ridges.

Distraction Of The Periodontal
Ligament(Dental Distraction)
• To achieve rapid canine retraction in 3 weeks,
the first premolar was extracted and the
interseptal bone distal to the canine was
undermined, grooving vertically inside the
socket with a bone bur

AJO/1998/ERIC LIOU
AND C.SHING

Then, an intraoral distraction device was placed
to distract the canine distally, with an activation of
0.5 to 1.0 mm/day. The anchor units were,
second premolar and first molar. The canines
were bodily distracted 6.5 mm into the extraction
space in 3 weeks . Anchor loss was nil in 73%
and 0.5 mm in 27% of the cases.


Future Of Distraction
Osteogenesis
• Development of osteotomy techniques that
allow division of bone without disruption of
periosteum, endosteum,neurovascular bundle
& blood supply.
• Motorized distraction units with remote
activation & monitoring for precise dimensional
control and calibration of distraction forces.

• Use of bioresorbable materials such as
Lactosorb(a copolymer of poly-l-lactic acid-82%
& poly glycolic acid-18% ).

IMPLANT PLATES

SCREWS

Distraction Osteogenesis has taken
many different forms and has evolved
into its own super-speciality of
orthognathic treatment for various
congenital and post-traumatic incidences
of mandibular and maxillary fracture and
deformity.
As an Orthodontist we should know
that how to proceed in various stages of
distraction to achieve the best results.

Thank you
For more details please visit

Distraction osteogenesis

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