Distraction osteogenesis /certified fixed orthodontic courses by Indian dental academy

DISTRACTION OSTEOGENESIS – A
FAREWELL TO MAJOR OSTEOTOMIES ?
--- Dr. Chetan Jayade
Asst. Professor
Department of Orthodontics
S.D.M. College of Dental Sciences

www.indiandentalacademy.com

DISTRACTION OSTEOGENESIS – A
FAREWELL TO MAJOR OSTEOTOMIES ?

INDIAN DENTAL ACADEMY
Leader in continuing dental education


The treatment of craniofacial deformities
poses a great challenge to the
Orthodontist and the Oral Surgeon alike.


Treatment modalities
•Functional appliances in the growing
years.
•Orthognathic Surgery.


The latest technique for combating the
same is a procedure termed
“DISTRACTION OSTEOGENESIS”


SCOPE OF THE TALK
• A look at the origins of DO
• DO in the long bones
• DO in the craniofacial region


SCOPE OF THE TALK
• Biologic effects of DO
• Factors affecting DO
• The role of an Orthodontist in DO


DISTRACTION OSTEOGENESIS
(Transosseous synthesis)
(Osteodistraction)
DEFINITION: A process of new bone
formation between the surfaces of bone
segments

gradually

incremental traction

seperated

by

- COPE (1999)


Steps involved :
a) Corticotomy/Osteotomy
b) Latency period

Rate
c) Distraction phase

Rhythm

d) Consolidation phase


Steps involved :


Steps involved :
a) Corticotomy/Osteotomy : A low energy
osteotomy of the cortex preserving the
local blood supply to both the cortex and
the medullary canal.


Steps involved :
b) Latency period : The time following the
osteotomy when initial fracture healing
bridges the cut bone prior to initiating the
distraction.


Steps involved :
c) Distraction phase :
i) Rate – the number of millimeters/day at
which the bone surfaces are stretched.
ii) Rhythm – The number of incremental
distractions per day.


Steps involved :
d) Consolidation phase : The time following
distraction, for which the device is stabilized.


DISTRACTION HISTOGENESIS
The sequence of adaptive changes in the soft
tissues, adjacent to the distracted segments.
Healing Index: The number of days or months
from the surgery to full, unprotected load
bearing for each centimeter of bone length.


HISTORICAL PERSPECTIVE

•

ALESSANDRO CODIVILLA – 1905

•

LEROY ABBOT – 1927



ALESSANDRO CODIVILLA – 1905



LEROY ABBOT – 1927



KAZANJIAN -- 1937


Problems with the earlier attempts:
a) Lack of control of the bone segments
b) Inadequacy of the appliances
c) Instability of fixation and complications


GAVRIIL ILIZAROV (1951) rejuvenated the
procedure when he accidentally found that
new bone growth was possible.


Theories favouring Compression in Bone healing:
i.

Roux’s hypothesis

ii. Wolff’ doctrine
iii. Huter-Volkmann theory


ILIZAROV’S TECHNIQUE
Foundations laid via rigorous experimentation
a) Dog experiments (Long bones)– 7 groups
•

Group I,II and III differed in the type of fixation

•

Group IV and V in the amount of marrow

•

Group VI and VII
distraction

underwent transverse


Foundations laid via rigorous experimentation
b) Dog experiments (Membrane bones)
Distraction results were similar to that seen in the
long bones.



Membrane bone experiment


•

Limb lengthening procedures

•

Correction of angular deformities

•

Repair of fracture, mal-union

•

Miscellaneous


ILIZAROV’S EXTERNAL RING FIXATOR

ILIZAROV’S CRITERIA
a) Surgical procedure must involve minimum
marrow; hence, corticotomy preferred.
b) Fixity of the device: Rigid fixation is a must.
c) Rate: Optimal to be 1 mm per day
d) Rhythm: Optimum of 2-4 activations/day


THE TENSION-STRESS EFFECT
The histologic evidences of Ilizarov’s work form
the basis of distraction procedures in any part
of the body.
These histologic findings were coined by Ilizarov
as the ‘Tension-Stress’ effect.


THE TENSION-STRESS EFFECT

FZ- Fibrous Inter-zone
MZ- Mineralising Zone

SNYDER (1972,73) resected a dog mandible and
performed distraction successfully.
10 week healing period followed by distraction
of 1mm/day for 14 days.
MICHELLI and MIOTI (1977) and PANIKAROVSKI
(1982)carried out modified experiments in the
canine mandibles


Mc’Carthy– (1989) conducted the first reported
human trial of craniofacial distraction using
external fixators.


4 children with craniofacial anomalies
subjected to a distraction protocol of
three weeks followed by a 8-10
consolidation.

were
upto
week

Long-term studies of the same patients indicate a
successful result.


MOLINA and ORTIZ MONASTERIO(1995) used bidirectional appliances
Mc’CARTHY
demonstrated the efficacy of a
mulitdirectional appliance.
GUERRERO (1990) used an intra-oral appliance to
widen mandibular arches.


Evolution of distraction appliances



GUERRERO –Intra-oral devices


Midface distraction – RACHMIEL (1993) carried
out midface distraction on sheep

A BIRD’S EYE-VIEW THE ORIGINS AND
EVOLUTION OF DO IN THE CRANIOFACIAL
REGION
a) Phase of traction without surgery
b) Upsurge in limb-lengthening procedures
c) Progression from Extra-oral Unidirectional to
Extra-oral Multidirectional distraction.


A BIRD EYE-VIEW THE ORIGINS AND
EVOLUTION OF DO IN THE CRANIOFACIAL
REGION
d) Progression from extra-oral to intraoral devices
e) Progression from manual devices to motorized
devices
f) Progression from the removable fixators to
biodegradable fixators

CURRENT SCOPE OF DO
 Correction of Maxillo-Mandibular deformities
a) Maxillary lengthening
b) Mandibular lengthening
c) Maxillary and Mandibular widening
d) Lengthening of the Hard palate
e) Distraction in other cranio-facial areas.

CURRENT SCOPE OF DO
 Alveolar ridge augmentation
 Transport
disc
osteogenesis.

and

 Dental Distraction.


Transformation

CURRENT SCOPE OF DO
 Alveolar ridge augmentation


TRANSFORMATION OSTEOGENESIS
The conversion of non-osseous interpositions
into normal bone by combined compression
and traction forces, sometimes augmented by
a nearby corticotomy.


BONE TRANSPORTATION
The regeneration of intercalary bone defects by
combined distraction and transformation
osteogenesis.
i.

Bifocal transportation

ii. Trifocal transportation


BONE TRANSPORTATION


TISSUE CHANGES FOLLOWING DO
a.

Skeletal changes – Formation of Regenerate

b.

Soft

tissue

adaptations

Histogenesis


–

Distraction

HISTOLOGIC CHANGES
•

During latency phase – formation of a fibrous
bridge.

•

During distraction phase – distinct zones seen


BIOCHEMICAL FEATURES OF REGENERATE
•

Increased levels of alkaline phosphate, pyruvic
acid.

•

TGF-

Beta

1

levels

increase

upto

the

consolidation phase; Osteocalcin after the
consolidation phase.


Sinusoidal

•

Neovascularization

•

Neomyogenesis

Transport

Atrophy seen is transient


•

Nerve growth as during embryogenesis was
reported by Ilizarov.

•

However, studies by Block and Ippolito have
shown mild nerve injury due to stretching

•

Mild pathoogic changes have been reported on
the TMJ by a few authors like Mc’Carthy.
These are again reversible with time


FACTORS AFFECTING DO

Biologic

Biomechanical


BIOLOGIC FACTORS
•

AGE

•

SITE OF SURGERY

•

LATENCY PERIOD

•

RATE AND RYTHM


BIOLOGIC FACTORS
•

Increased micromotion by increasing rhythm
causes

increased

vasculogenesis

and

enzymes and decreases the tissue damage and
the degenerative changes


CONSOLIDATION PHASE
Assessment of new bone is by:
I. Plain radiography
ii. Quantitaive Computed Tomography (QCT)
iii. Ultrasonography
iv. Dual energy X-ray absorptimetry

CONSOLIDATION PHASE
Assessment of new bone by Plain radiography


CONSOLIDATION PHASE
Clinical assessment of consolidation
•

Distraction Consolidation index

This however, is applicable to the long bones.
•

6-8 weeks optimal in the craniofacial region
– SACHDEVA, COPE (1999,2000)

BIOMECHANICAL FACTORS
•

Planning the distraction vector

•

Device fixity

•

Need for ‘ Bone moulding’


PLANNING THE DISTRACTION VECTOR

VERTICAL

HORIZONTAL


OBLIQUE

PLANNING THE DISTRACTION VECTOR


BIOMECHANICAL EFFECTS OF THE
DISTRACTION VECTOR


Mandibular Distraction
INDICATIONS:
Hemifacial Microsomia
Treacher Collin Syndrome etc.
TMJ ankylosis and condylar fractures
Transverse deficiency of the mandible


MANDIBULAR DISTRACTION


MANDIBULAR DISTRACTION
Intra-oral Devices


MAXILLARY DISTRACTION

TOTH – Le-Fort III osteotomy


MAXILLARY DISTRACTION


DENTAL DISTRACTION


TOOTH MOVEMENT THROUGH REGENERATE
The earlier views suggested that tooth
movement should not be initiated into the
regenerate.
Present views as supported by Liou and Cope
point out to the possibility of initiating
tooth movement immediately after or even
during the distraction period.

Our experiences with distraction


The Orthodontist’s role
a. Decompensation of the dentition
b. Planning the distraction vector
c. Bone Moulding using intermaxillary
elastics

Functional

d. Post-distraction Orthodontics

Fixed

Currently Unresolved issues
a. Effects of distraction on growth
b. Limits of distraction osteogenesis
c. Effects of distraction on eruption and
movement of teeth.
d. Long term stability of regenerate bone.

Directions for the future
a. Refinements in the distraction protocol
b. Improvement in distraction devices
c. Enhancement of regenerate maturation


Thank you
For more details please visit


Distraction osteogenesis /certified fixed orthodontic courses by Indian dental academy

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