Functional appliances

HOW FUNCTIONAL
APPLIANCES WORK????
HOW FUNCTIONAL
APPLIANCES WORKS
??????????
www.indiandentalacademy.com

CONTENTS
INTRODUCTION
HISTORICAL PERSPECTIVE
THEORIES OF CRANIOFACIAL GROWTH
ACTIVATOR
BIONATOR
FUNCTION REGULATOR
TWIN BLOCK
FUNCTIONAL APPLIANCES AND EXTRAORAL FORCE
FIXED FUNCTIONAL APPLIANCES
ROLE OF VEGF IN FUNCTIONAL APPLIANCE
TREATMENT
GROWTH RELATIVITY HYPOTHESIS
CLINICAL IMPLICATIONS
STUDIES ON FUNCTIONAL APPLIANCES
CONCLUSION
REFERENCES www.indiandentalacademy.com

INTRODUCTION
“Functional appliances” are defined
as loose fitting or passive appliances
which harness natural forces of the
orofacial musculature that are
transmitted to the teeth and alveolar
bone through the medium of the
appliance.

Procedures involved in functional therapy include
•Use of muscle exercises
•Playing of wind musical instruments
•Use of myofunctional appliances
•Removal of pernicious oral habits
INTRODUCTION

INTRODUCTION
CLASSIFICATION
Tooth borne active appliances
Tooth borne passive appliances
Tissue borne passive appliances
Myotonic appliances
Myodynamic appliances
Removable functional appliances
Fixed functional appliances
Group I appliances
Group II appliances
Group III appliances
Appliances – force application
- force eliminationwww.indiandentalacademy.com

INTRODUCTION
• Correction of malocclusion, primarily by means
of controlled movement of the developing and
mature dentition into a desirable occlusal
relationship.
• Control and modification of growth of skeletal
structures of the craniofacial complex,
especially via tooth borne or tissue borne
appliances.

4 men who came with a fundamentally new approach to orthodontic
treatment were –
• NORMAN W. KINGSLEY – Ist to use forward positioning of
mandible
PIERRE ROBIN - first designed an appliance to
influence muscular activity
ALFRED. P. ROGERS - recognized the importance of
orofacial system for problems
of orthodontic treatment
VIGGO ANDRESEN -designed a loosely fitting appliance

The influences of natural forces and functional
stimulation on form were first reported by Roux
in 1883 – tail fins of dolphins
His hypothesis became the background –
general orthopedic and functional dental
orthopedic procedures
According to the theories of Roux and Wolff,
“changes in function bring with them changes in
internal bone structure and external bone form”

• Late 1890s: Wolff’s law and Roux hypothesis:
changes in functional stress produced changes in
internal bone architecture and external shape
• Early 1900s: Pierre Robin: monobloc
- passive positioning device
• Modified from “bite jumping” vulcanite maxillary guide
planes designed by Norman Kingsley (1880)
• Vorbissplatte: Hotz – used in cases of deep bite
retrognathism

• Viggo Andresen : Activator – biomechanical
orthodontics functional jaw
orthopedics Norwegian
system
• Andresen’s concept of loose fitting appliance
was rejected by many people

THEORIES OF CRANIOFACIAL
GROWTH
&
MECHANISM OF ACTION OF
FUNCTIONAL APPLIANCES

METHOD OF OPERATION OF FUNCTIONAL APPLIANCES
Genetic Control Theory :
Genotype supplies all information required
for phenotypic expression
Inheritance and immutability of normal and
abnormal facial form

Cartilage directed growth theory
Scott (1953, 1954, 1967) – Cartilage is the primary
factor in craniofacial growth control.
synchondroses, nasal septum and mandibular
condyle are centers of growth
Sutural growth theory
Sicher (1947): growth at the sutures results in
growth of cranial vault and downward and forward
growth of the midface
Sutural growth is considered compensatory in
cartilage directed growth

Functional matrix hypothesis
Melvin Moss 1960
• Craniofacial skeleton develops initially and grows in
direct response to its extrinsic, epigenetic environment
• Functional matrix and skeletal unit
• “ Bones do not grow, bones are grown.” - Moss
(1972)

Servosystem theory of growth (1970)
- Charlier, Petrovic and Stutzmann

Primary and Secondary Cartilage

Primary and Secondary Cartilage
Factors
influencing
Growth
Primary
Cartilage
Secondary
Cartilage
Hormones Yes Yes
Local Factors No
(Chondroblasts
surrounded by
matrix)
Yes (Pre-
chondroblasts not
surrounded by
matrix)
Orthopaedic
appliances
Only Direction Direction and
Amount

According to this theory –
The influence of the STH somatomedian complex
on the growth of the primary cartilages ( epiphyseal
cartilages of long bones, cartilages of the nasal
septum and Sphenoccipital synchondrosis, lateral
cartilaginous masses of ethmoid,) has a cybernatic
form of command
The influence of the STH somatomedian complex
on the growth of the secondary cartilages (condylar,
coronoid, and angular cartilages of the mandible,
cartilages of MPS ) comprises direct and indirect
effects on cell multiplication.
Servosystem theory of growth (1970)
- Charlier, Petrovic and Stutzmann

ACTIVATOR

Origin of activator
•Modified Kingsley plate retainer
•Biomechanic working retainer –
Andresen
•Vorbissplatte – Hotz
•Pierre robin - monobloc
•In 1925 director of orthodontic department
of dental school in Oslo
•Karl Haupl & Viggo Andresen – activator

ACTIVATOR
Mode of action:
Wolff and Roux : “Bone shaking hypothesis”
Andresen : loose (passive) in mouth to provoke orofacial
muscles – protractors and elevators of mandible
to bite into place
Selmer-Olsen : muscles cannot be stimulated at night
opening the mandible beyond the position of
equillibrium – closing muscles remain stretched
and pressure is applied against the foreign
body through the teeth – viscoelastic property
(woodside)www.indiandentalacademy.com

Viscoelastic property – Harvold and woodside
•Viscoelastic property of muscle and
stretching of soft tissues -potential energy
•Emptying of vessels
•Pressing out of interstitial fluid
•Stretching of fibers
•Elastic deformation of bone
•Bioplastic adaptation of bone
ACTIVATOR

ACTIVATOR
Mode of action:
Herren (1953)

The direction of force
acting
On the activator
depends
On the spatial
relationship
Between the
momentary
Rest position and the
position
Prescribed by the
activator
ACTIVATOR

Effect of placing a functional appliance that postures the mandible
forward.
The condyle is brought forward and downward on the eminence, which
Removes the usual functional stresses. The retractor muscles are
activated,
Exerting some force against the maxillary arch.
- Fanghanel J et al (EJO 20:468, 1998)

Neuromuscular and skeletal adaptations that occurred during the
functional protrusion experiments
A. Change in sensory stimuli
B. Stimulus to CNS
C. Change in activity of craniofacial muscles
D. Forward displacement of mandible
E1 and E2 . Dentoalveolar movement and
Condylar growth
F. To the CNS
G. Normal structure and function attained
By McNamara

Eschler – EMG studies (1952)
Response as a result of stretch reflex
Mandible is elevated by isotonic muscle contractions
Cyclical process of contraction and relaxation
Ahlgren (1972)
Elevators and retractors subjected to stretch beyond their
resting length.
The muscles respond by passive tension
ACTIVATOR

Petrovic et al 1975
On basis of experimental studies – concluded that
the activity in the lateral pterygoids stimulates the
mitotic division of the condylar prechondroblasts
The lateral pterygoids – final common pathway to
the condylar cartilage for hormonal and
biomechanical stimuli

Mechanism of action of activator
The neuromuscular basis

INTRUSION
EXTRUSION AND
LATERAL MOVEMENT

RETRACTION AND
PROTRACTION
DISTAL MOVEMENT
OF MAXILLARY
DENTITION

BALTER’S BIONATOR

Developed in early 1950’s
Less bulky activator
According to Balters’s concept the essential factor is the
“TONGUE”
Tongue is the centre of reflex activity
BIONATOR

BIONATOR
According to Balters –
Lip closure
Enlarge oral space
Incisors in edge to edge relation
Elongation of the mandible
Improved relationship of the jaws

Position of the tongue:
posterior displacement: class II
low anterior displacement: class III
Narrow arches and crowding:
low outward pressure
Open bite: hyperactivity and forward
posture
BIONATOR

Bionator
Effects:
Modulation of muscle activity of tongue
Elimination of abnormal influences of perioral
musculature
Stimulation of myotactic muscle activity and
isotonic muscle contractions
BIONATOR

Effects
No vertical component except for guiding
eruption of teeth
No viscoelastic response
Prevention of deleterious parafunctional activity
at night : relaxation of lateral pterygoid ( used for
TMJ problems)
BIONATOR

BIONATOR
Buccinator loops Trimming

FUNCTION
REGULATOR

FUNCTION REGULATOR
Rolf Frankel philosophy
Vestibular area of operation
Sagittal correction via tooth borne maxillary
anchorage
Differential eruption guidance
Minimal maxillary basal effect
Periosteal pull by buccal shields and lip padswww.indiandentalacademy.com

FUNCTION REGULATOR
Mode of action of FR
Increase of transverse and sagittal intraoral space
Increase of vertical intraoral space
Forward positioning of the mandible
Development of new patterns of motor function,
improvement of muscle
Tonus and establishment of oral sealwww.indiandentalacademy.com

Effect of buccal shield on lateral
Expansion and bodily buccal
Movement of teeth
Areas of trimming for relief of
Buccinator mechanism
FUNCTION REGULATOR

Cheeks kept away from
The buccal shield
Effect of appliance on
The musculature
FUNCTION REGULATOR

FUNCTION REGULATOR
Effect of u-loop and lingual plate on
Mandibular positioning through pressure
sensation
Periosteal bone deposition

Twin block

William J Clark ,1977
Modification of occlusal inclined planes by
means of acrylic inclined planes on bite blocks
Guide mandible downward and forward
Favorable proprioceptive contacts of inclined
planes
Adaptation of the muscles of mastication
Vertical and transverse control
Twin block

Mode of action
Rapid neuromuscular response
Gradual dentoalveolar response
Pterygoid response: pain while retracting
the mandible (McNamara 1980, Petrovic), or
Formation of a “tension zone” distal to condyle
(Harvold and Woodside)
Twin block

Twin block
Twin block response with animal experiments
Harvold (1983)
The placement of appliances results in an immediate
change in the proprioceptive response
The resulting muscular changes are very rapid and can
be measured in terms of minutes, hours and days
Structural alterations are gradual to restore a functional
equillibrium

Twin block
Muscular response to twin block – an EMG study
Aggarwal et al (1999)
The increased activity is attributed to enhanced
myotactic reflex of elevator
Muscles, contributing to isometric contractions
Viscoelastic hypothesis – Voudouris and Kuftinec
(2000)

Harvold (1973) and Petrovic – area distal
to condyle as “tension zone”
Proliferation of connective tissue and blood
vessels in the retrodiscal area
Johnston (1976) - unloading of the condyle
Discomfort on removal of appliance due to
compression in the tension zone behind the
condyle
Twin block

FUNCTIONAL APPLIANCES
&
EXTRAORAL FORCE

Use of only functional appliances – no major
changes in nasomaxillary complex
(Mc Namara 1977)
Maxillary orthopedic force (HPHG) + Activator
( Hasund 1969, Pfeifer 1984, Grobety 1984,
Stockli 1982, Teuscher 1982, Stockfish 1977)
FUNCTIONAL APPLIANCES & EXTRAORALFORCE

• Center of resistance
– Tooth
– Dentition
– Maxilla
• Rotations
– Clock wise-posterior-
caudal
– Counter clock wise-
anterior-cranial

Cervical pull force inferior to both the
centers of resistance

Cervical pull force passing between
centers of resistance

Functional appliances and extraoral force:
Class II div 1 with excessive vertical
growth
Unloading of the condyle by forward
posture of mandible
Retardation of horizontal and vertical
maxillary growth by headgear
Margolis ACCO(1976); Jacobson splint
(1967); Stockli and Teuscher activator-
headgear combination

Cells and fibres parallel (a) and
Perpendicular (b) to the bony surface.
(oc) are the osetoclasts
Intermaxillary suture showing
Variation in the fibre structure

Suture
Fibrous tissue with osteogenic layers
Extension of periosteal layer of bone
Fibres – collagenous type III

Sutural response to orthopedic forces
RME – Circumaxillary sutural system
Mechanical traction – widening of suture and changes
in orientation of fibre bundles
- intracellular influx of Ca and/or
Na, which decreases cAMP and
triggers DNA synthesis – cellular
proliferation

Restriction of both horizontal and vertical growth increments can be a
Desirable orthopedic effect on the maxilla

FIXED
FUNCTIONAL
APPLIANCES

Herbst, 1909- Scharnier
Mandible was kept forward
continuously, eliminating the need for
patient compliance
Herbst and Schwarz, 1934
Pancherz, 1979
FIXED FUNCTIONAL APPLIANCE

Sagittal changes:
Restraint of maxillary growth: headgear like
effect
Stimulation of mandibular growth:
- remodeling on lower border of mandible
(Pancherz and Ruf,1997)
- modification of TMJ fossa( Paulsen,1997;
Buschang,1998)
- ultimate condylar position in fossa is
unaffected

Sagittal changes
Proclination of lower incisors
Posterior movement of upper molars:
headgear like effect
Vertical changes
Eruption of lower molars; intrusion of lower
incisors: reduction of overbite
Proclination of lower incisors contributing to
overbite reduction

Soft tissue changes
Reduction of soft tissue convexity,
excluding the nose
Increase in soft tissue convexity,
including the nose, because of normal
nasal growth
Retrusion of upper and lower lips in
relation to esthetic line due to normal
chin and nose growth

Jasper jumper
James Jasper, 1987
Effects:
- functional effect similar to Herbst
appliance
- dentoalveolar changes

Mode of action:
Condylar growth:
Forward positioning of mandible
Increased activity of LPM
Intensification of repetitive activity
of retrodiscal pad

Mode of action
Condylar growth:
- increase in growth stimulating factors:
enhancement of local mediators
Reduction of local regulators
- change in condylar trabacular orientation
- additional growth of condylar cartilage
- additional subperiosteal ossification of
posterior border of mandible
- lengthening of mandible

Mode of action:
Increased activity of LPM
Retrodiscal pad- mediator of response
Blood circulating effect:
- increase in blood and lymph flow,
- increase in nutritive and growth stimulating
factor supply
( STH-somatomedin, testosterone and
estrogen in low doses, insulin, prostaglandin
F2, mitogenic peptides)

Mode of action:
- decrease in locally produced
catabolites and other negative
feedback factors
( prechondroblast’s multiplication
restraining signal, cAMP,
prostaglandin E2, somatostatin-like
substance)

Mode of action
2. Biomechanic effect:
- Accentuated concavity at the posterior
border of mandibular ramus due to
increase in condylar growth and more
posterior directed growth
- piezoelectric effect: increase in negative
charges along posterior border, causing
increased periosteal bone formation and
vice versa
- supplementary lengthening of mandible

PIEZOELECTRIC EFFECT

VEGF and bone formation in the glenoid fossa
during forward mandibular
Positioning
- Rabie.M , Lily Shum AJO DO
2002;122:202-09
• VEGF - central regulator of angiogenesis –
induces cell migration and proliferation
• Study conducted to identify relationship b/w
vascularization and bone formation
in the glenoid fossa during natural growth and
functional appliance therapy

Results
VEGF is secreted by chondroid cells in response to forward mandibular
Positioning.
Highest amount – early stages of advancement
It enhances neovascularization
Perivascular c.t. surrounding the new blood vessels are repository sites
Of mesenchymal cells
These replenish the population of osteoprogenitor cells
VEGF stimulates VE cells to secrete growth factor and cytokines that
Influence differentiation of mesenchymal cells thereby causing
Osteogenesis (Triffit et al)
Highest amount of new bone formation – posterior fossa

VEGF expression and bone formation in posterior
glenoid fossa during
Stepwise mandibular advancement
- Rabie.M, Lily shum AJODO 2004;125:185-90
Mechanical strain caused by forward mandibular positioning
stimulates the bone
Cells in the subperiosteal c.t. of glenoid fossa to secrete VEGF
Neovascularization
Differentiation of mch cells - osteogenesis

VEGF expression and bone formation in posterior
glenoid fossa during
Stepwise mandibular advancement
- Rabie.M, Lily shum AJODO
2004;125:185-90
After 2nd
advancement – this pull effect again delivers
mechanical strain that triggers another cycle of VEGF
expression……….
Thus stepwise advancement delivers a series of
mechanical stimuli that produces tissue response that
lead to increased vascularization and bone
formation

Improved clinical use of Twin block and Herbst as a
result of radiating viscoelastic tissue forces on the
condyle and fossa in treatment and long term
retention : Growth Relativity
- John.C.Voudouris, Kuftinec. M (AJODO 2000;
117:247-66)
How does condylar modification occur?
-Genetic theory
-Lateral pterygoid muscle hyperactivity – Charlier, Petrovic,
McNamara

LPM hyperactivity theory
J. Minimal attachment of the SHLP to the articular disc

Growth Relativity : refers to the growth that is relative to the
displaced condyles from actively
relocating fossae
A. Displacement B. Viscoelasticity C. Transductionwww.indiandentalacademy.com

Growth Relativity Hypothesis
The glenoid fossa promotes condylar growth with the use of
Mandibular advancement therapy.
The displacement affects the fibrocartilaginous lining in
Glenoid fossa to induce bone formation locally
Stretch of non muscular viscoelastic tissues
New bone formation some distance from actual retrodiskal
Tissue attachments in the fossa

The retrodiskal articular complex
Is pulled in the opposite direction
Of the arrows for fossa modification
New bone formation extends a
Large distance beyond the actual
Attachment of the retrodiskal tissues
Toward the height of the articular
eminence

Microscopic examination of TMJ
• Fibrocartilage caps the condyle in 3 dimensions:
posterior, anterior and 2 collateral along with
fibrous capsule and synovial fluid
• Advancement: engorgement of blood vessels,
influx of nutrients and biodynamic factors
• Reseating of condyle in fossa: expulsion of
these factors
• Resulting metabolic pump-like action

• Disoccluding appliances cause low intra-
articular subatmospheric pressures within TMJ
in open position ( Nitzan 1994)
• Shift of synovial fluid perfusion on a posteriorly
displaced direction
• Negative pressures are below capillary
perfusion pressure
• Greater flow of blood to the C-GF region

Displacement+ viscosity+ referred force
Three growth stimuli:
1. Anterior orthopedic displacement
2. Posterior viscoelastic tissues between
condyle and fossa
3. Transduction of forces over the
fibrocartilage cap of the condylar head,
increases radiating endochondral bone
formation beneath condylar fibrocartilage
and periosteal bone formation in the fossa

Epiphysis Vs Condyle

Condyle acts like a light
bulb on a dimmer switch
Lights up during
advancement, dimming
back to near normal
levels during retention
Growth potential
diminishes with age
while remodeling
potential last long into
adulthood
Condylar light bulb analogy

Prevention of condylar compression by using
Herbst with thin posterior bite blocks
Rapid maxillary expander to reduce occlusal
interferences and functional shifts due to the
anterior positioned mandible
Clinical implications

Class II correction
Condylar growth amount during treatment: 1-3mm
Fossa displacement, growth and adaptation : 3-5mm (Buschang et al
1998)
Functional retrusion
More favorable growth direction : trabecular orientation 0.5-1.5mm
Withholding of downward and forward maxillary growth : 1-1.5mm
Differential upward and forward eruption of lower buccal segments :
1.5-2.5mm, depending on depth of overbite
Headgear effect : 0.5-0.0 mm

Activator:
Charlier et al 1968, 1969, Petrovic et al 1975:
Distribution of dividing cells in sagittal section of
condylar cartilage of juvenile rats
Histologic and radiographic study
Results: Treatment with both postural
hyperpropulsor and and growth hormone STH
produced increase in growth rate of condylar
cartilage as compared to controls
Studies on functional appliances

Activator:
Location of increase of dividing cells:
- more posterior in hyperpropulsor
- more anterior in STH

Histologic study:
- growth of bony trabaculae formed in
parallel and posteriorly oriented condylar
cartilage

Activator:
Petrovic and Stutzmann (1977), rat
experiment
Administration of growth hormone and
treatment by postural hyperpropulsor:
- increase in condylar cartilage growth
rate
- hyperpropulsor: opening of Stutzmann
angle
- growth hormone: closing of Stutzmann
angle www.indiandentalacademy.com

Activator:
- lengthening of mandible measured from
posterior edge of condylar cartilage to mental
foramen is greater in case of opening of angle
Administration of testosterone:
male rats for 3 weeks; stimulation in growth
rate of condylar cartilage and lengthening of
mandible
(Stutzmann 1976, Petrovic, Stutzmann
1977, 1978)

Sessle et al 1990: longitudinal effect of
functional appliances on jaw muscle activity
using 6 female monkeys
- pre appliance and post appliance levels
compared with controls
- Herbst and functional protrusive appliances
inserted
- decreased activity in superior and inferior
head of LPM, superficial masseter, anterior
digastric; persisted for 6 weeks returning to
previous levels after 6 week observation period

McNamara, Hinton and Hoffman AJO-DO 1982 Oct
(288-298)
Histologic analysis of temporomandibular joint
adaptation to protrusive function in young adult rhesus
monkeys (Macaca mulatta)
- twelve young adult female rhesus monkeys were
fitted with functional protrusive appliances for periods
ranging from 2 to 24 weeks.

A proliferative chondrogenic response
accompanied by deposition of new bony
trabeculae at the bone-cartilage interface,
though greatly reduced in magnitude as
compared to juvenile monkeys

Bionator:
Mandibular response to orthodontic treatment with the
Bionator appliance - Mamandras and Allen (AJO-DO
1990 Feb (113-120)
- A group of 20 subjects who underwent successful
Bionator treatment was compared with 20 subjects who
were treated less successfully with the same appliance.
Both groups had similar advancements in their bite
registrations, as well as similar treatment times and
growth-prediction parameters

Arch width development in Class II patients
treated with Fränkel appliance - McDougall,
McNamara, and Dierkes (AJO-DO 1982 Jul
(10-22)
60 treated with FR 1 and 2 and 47 untreated
cases
changes in lingual, buccal, and alveolar arch
widths were compared.

Expansion of the maxillary and
mandibular dental arches and their
supporting structure occurs routinely with
a functional regulator (FR-1 or FR-2)
largest expansion in the premolar and
molar regions, lesser in the canine region;
in the maxilla narrower arches tend to
expand more than wider arches

Comparison of Herbst and Frankel
appliances - McNamara, Howe, and
Dischinger (AJO-DO 1990 Aug (134-144)
A comparison of the Herbst and Fränkel
appliances in the treatment of Class II
malocclusion
- 45 pts with acrylic splint Herbst and 41 pts
with FR2
- cephs compared with 21 untreated class II
patients

Significant skeletal changes were noted in
both treatment groups, with both groups
showing an increase in mandibular length and
in lower facial height, as compared with controls
Greater dentoalveolar treatment effects were
noted in the group wearing the tooth-borne
functional appliance than in those wearing the
tissue-borne appliance

Proffit, Tulloch AJODO, June 2002
Optimal timing of treatment for Class II
malocclusion
- can jaw growth really be modified, by how
much, with what predictability, in which
patients?
- do different appliances produce different
effects?
- would early intervention make later
treatment simpler and with better treatment
results?

Results:
Small mean reduction in jaw relationship with
early treatment
Mechanism of change:
- headgear group: restriction in forward
movement of maxilla
- functional appliance: increase in mandibular
length and increase in chin projection
75% of early treatment pts had highly
favourable changes as compared to 25%
of untreated patients

Proffit, Tulloch AJODO,June 2002
Discussion
Early treatment produced an initial differential
growth change
Not effective in correcting later skeletal and
dental class II malocclusion
No advantage in final treatment outcome or
simplification of later treatment procedures

Early treatment
Psychological distress
Accident prone children
Skeletal maturity is ahead of dental development
Children with vertical and class II problems
Conclusion: no clear advantage for early treatment

REFERENCES
Orthodontics current principles and techniques – Graber
Vanarsdall Vigg
Contemporary orthodontics – William R Proffit
Dentofacial orthopedics with functional appliances –
Graber Petrovic Rakosi
Removable orthodontic appliances – Graber Neuman
New vistas in Orthodontics – Lysle Johnston
Twin block – William J clark

Text book of Orthodontics – SI Bhalaji
Improved clinical use of twin block and herbst as a result
of radiating viscoelastic tissues forces on the condyle and
fossa in treatment and long term retention: growth
relativity. John Voudouris. AJODO 2000;117:247-66
VEGF and bone formation in the glenoid fossa during
forward mandibular
Positioning. Rabie, lily shum. AJODO 2002;122:202-9
VEGF expression and bone formation in posterior glenoid
fossa during stepwise mandibular advancement. Rabie,
lily shum. AJODO 2004;125:185-90

Functional appliances

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Functional appliances

Similar to Functional appliances (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Functional appliances