Facial asymmetry /certified fixed orthodontic courses by Indian dental academy

CRANIOFACIAL
ASYMMETRY
www.indiandentalacademy.com

INDIAN DENTAL ACADEMY
Leader in continuing dental education


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Introduction & Definitions
Epidemiology of Asymmetries
Etiology a nd Development of
Asymmetries
Cra niofacial
Dentofacial

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Classification of Asymmetries
Diagnosis & Treatment Pla nning
Treatment
Conclusions

Introduction to Facial
Asymmetries






Human beings like any other creation of god
display bilateral symmetry except for some
minor negligible variations.
Concern of symmetry dates back to the
ancient civilizations which are evident in their
paintings and sculptures.








By strict definition a mirror
image of right to left is
referred to as symmetry.
Due to various environmental or
developmental imperfections :ASYMMETRIES develop
Asymmetries within some
reasonable range cannot be
considered abnormal and
doesn’t need to be treated.








Asymmetry in the craniofacial region was
first recognized by an artist Hasse in 1887.
Since then many anatomists, anthropologists
and biologists like Hilton, Huxley, Woodger,
Leibrich, Hellman, Woo, etc have found
asymmetry of form, function, and
proportions in animals and humans………
Classical concept of facial symmetry was
depicted in the paintings of Leonardo da
Vinci and Albercht Durer in 1507


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



Orthodontists are usually preoccupied with
lateral facial aspect while general public judge
beauty, symmetry & harmony from frontal
aspect
Thompson: “normal asymmetry is not very
evident, whereas abnormal asymmetry is quiet
obvious ”
Alton Moore: “In some cases what is pleasing
esthetically to some one is displeasing to other.”




Stedman's Medical Dictionary
defines Symmetry as

“equality or correspondence
in form of parts distributed
around a centre or an axis, at the
two opposite sides of the body”.

Asymmetry is defined as any deviation
from normal or difference in size or
relationship between two sides of the body



American College Dictionary
defines symmetry as
“the correspondence in size,
form, and arrangement of parts
on opposite sides of a plane , line,
or point”.

SYMMETRY = BALANCE
ASYMMETRY = IMBALANCE

Epidemiology of
Asymmetries






In most individuals the right side of the
face is slightly larger than the left ,and
usually there is some asymmetry in
facial animation.
In persons with asymmetry, the lower
face is affected much more frequently
than the middle or upper thirds.


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Asymmetry of the upper face
was seen in only 5%,
36% had a middle third
asymmetry, usually just the
nose but sometimes including
the zygoma
75% had lower third especially
a deviation of the chin.
About half of the patients with
asymmetry in the upper or
middle third also had
mandibular asymmetry.




Prevalence of orthodontic asymmetries:
Peck & Peck. 1991: studied bilaterally facial asymm. In 52 adult
white people with exceptionally well- balanced facial appearance
 Decrease in asymmetry occurrence as approached cranially
 Deformities were very mild and were identified by clinicians
sense of balance and patients perception of imbalance
 Woo 1931: evaluated ancient Egyptian skulls and found cranial
asymmetry
 Vig and Hewitt 1975 evaluated 63 PA cephs. Of 9 year old
children clinically normal
 They had mild degrees of unnoticeable asymmetries
 Melnik et al 1991 noted significant gender differences in the
occurrence of asymmetries





According to LUNDSTROM in 1961

QUANTITATIVE
ASYMMETRY

QUALITATIVE
ASYMMETRY

includes differences in
the no. of teeth on
each side or the
presence of a cleft lip
and palate.

could be difference in
size of the teeth,
their location in the
arches or the position
of the arches in the
head.

Proffit & White : Pg: 574 - 644





A. Dental Asymmetries:
can be due to Local factors such as loss of
deciduous teeth, congenitally missing teeth,
habits and lack of exactness in genetic
expression.
B. Skeletal Asymmetries:
Their deviation may involve one bone such as
maxilla or mandible or it may involve a no. of
skeletal and muscular structures on one side of
the face.
Bishara et al AO 1994:64:2





C) Muscular Asymmetries :
Hemifacial atrophy or cerebral palsy,
abnormal muscle functional
D) Functional Asymmetry:
can result from the mandible being
deflected laterally or antero - posteriorly, if
occlusal interferences prevent proper
intercuspation in centric relation.









Eyes : unilateral micropthalmia , anopthalmia
Nose : unilateral arhinia, heminasal aplasia, absence
of one nostril, blind dimple, skin tag, proboscides,
nasal coloboma, etc
Mouth : supernumerary mouth, ectopically placed
mouth, teeth, etc
Ears : dimorphism, hypoplastic, angulated, Low set,
with tissue tags, pits, sinuses, etc.


Based on Morphology

:-Derek Henderson et al

Tessier’s Clefts (1976)


Subramani & Murthy
Indian J Plast Surg: Dec :2005


Etiology & Development
of Asymmetries




Two main cause of asymmetries are
Genetic
imperfections


Environmental
factors



Hemifacial microsomia,



Retinoic acid and thalidomide teratology,



Clefting syndromes,



Craniosynostoses.



Multiple Neurofibromatosis


(dominant gene)





Intra –uterine pressure during pregnancy and
significant pressure in the birth canal during
parturition.
Pathologic:
 Osteochondroma of the mandibular condyle



Trauma and infection



Untreated fracture of mandible



Trauma and infection of TMJ



Ankylosis of TMJ



Damage to nerve



Clinically significant asymmetry is etiologically and pathologically
heterogeneous and may be localised or generalised
MALFORMATIONS
GENE MUTATION

EMBRYOPATHIES

CRANIOSYNOSTOSIS

DISRUPTIONS

FETOPATHIES

CAUSES
HAMARTOSES

TRAUMA

PATHOLOGIES
INFECTIONS
CYSTS
TUMORS
FIBRO OSSEOUS

HEMI-ASYMMETRIES
HEMI HYPERPLASIA
HEMI HYPOPLASIA
HEMI ATROPY

Skeletal Asymmetries


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

CHIN
MANDIBLE
MANDIBLE + CHIN
MAXILLA + MANDIBLE
MAXILLA + MANDIBLE + CHIN
ZYGOMA + NOSE + FRONTAL



To visualize the 3
dimensional alteration of
mid facial and mandiblular
complex to specifically
identify the asymmetry.






Transverse asymmetry
Cant of lower border of chin
AP asymmetry


Acc to Souyris et al. 1983:
1.
Infections :
2.
Trauma and fractures
3.
Defective musculature
4.
Cysts and tumors
5.
Fibro-osseous lesions
Resulting in:
1.
Hemi hyperplasia
2.
Hemi hypoplasia
3.
Hemi atropy
4.
Ankylosis







Usually is a resultant
of mandibular defects
or a defect in itself or
associated structures.
These are usually seen
as defects in transverse
dimension, AP or
vertical resulting in
cant of the occlusal
plane.

Dental Asymmetries







Midline deviations
Sub division cases
Unilateral posterior cross bites
Unilateral impacted teeth
 Resulting in mesial migration of

distal teeth


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

Arch form deviation
Frontal dental cants
Unilateral mesial movement of
posterior teeth
Missing teeth
Shape and size alteration of the
teeth


• A thorough clinical examination and radiographic examination are
necessary to determine the extent of the Soft tissue, Skeletal,
Dental and Functional involvement.

Guidelines to achieve a specific diagnosis:






It revels asymmetry in vertical, AP &
lateral dimension.
STEPS IN CLINICAL EVALUATION:
i.
Evaluation of the dental midlines
ii. Vertical occlusal evaluation: The
presence of a canted occlusal plane
could be the result of a unilateral
increase in the vertical length of the
condyle and ramus.
iii. Transverse and antero posterior
occlusal evaluations .
iv. Transverse skeletal evaluation
v. Soft tissue evaluation.

RULE OF FIFTHS AND THIRDS






A no. of projections are available to properly identify the
causes and location of the asymmetry
Lateral cephalogram:




To find ramal height, mandibular length and gonial angle.

Postero anterior projections:



Hewitt (1975)



Svanholt & Solo (1977)

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Chierici (1983)

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Multi planar ceph. Analysis – Grayson and Bookstein (1983)



Grummons & Kappeyene analysis(1987)




Rocky mountain analysis- Ricketts (1972)

Proffit (1991)

Panoramic radiograph:


To find presence of gross pathology, missing or supernumerary
teeth.

CRANIOFACIAL ASYMMETRY BY MULTIPLANE CEPHALOMETRY

-Barry H. Grayson, Joseph G. McCarthy, Fred Bookstein,

1. Lateral ceph tracing

2. PA ceph tracing

3. Basal cranium tracing

Grummon’s frontal analysis


CRITERIA

RIGHT

LEFT

DIFFERENCE

HORIZONTAL PLANE
ZA line to MSR
(angular)
ZA to MSR (linear)
ZA to outer cranium
(linear)
MANDIBULAR MORPHOLOGY

TRIANGLE- Co- Ag- Me

Co – Me (linear)
Co – Ag (linear)
Ag – Me (linear)
Co – Ag – Me (angular)
VOLUMETRIC COMPARISON

POLYGON – Co – Ag – Me –MSR

Co – MSR
Area of polygon
MAXILLO – MANDIBULAR COMPARISON
Cg – J
Cg – Ag
J – MSR
Ag – MSR
J on MSR
Ag on MSR
Area of Cg – J - MSR
Area of Cg – Ag – MSR


LINEAR ASSYMETRY
MSR – Co
MSR – NC
MSR – J
MSR – Ag
MSR – Me
MAXILLO – MANDIBULAR ASSYMETRY
A1 offset
B1 offset
A6 to J
(perpendicular)
FRONTAL VERTICAL PROPORTIONS
Cg – ANS : Cg – Me
ANS – Me : Cg – Me
ANS – A1 : ANS –
Me
ANS – A1 : Cg – Me
B1 – Me : ANS – Me
B1 – Me : Cg – Me
ANS – A1 : B1 – Me




Jug Handle projection: sub-mento vertex view




The exact position of the chin and rest of the mandible to
the maxilla , zygoma and the cranium can be analysed.

Occlusal radiograph:


To analyse dental malocclusion and its co-relation with
the adjacent bony structures.


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CT scans
CBCT (cone beam CT)
CAT scan (computer axial tomography)
Laser scanning
OrthoCAD and E-Models
3 D occlusograms
MRI for soft tissue asymmetry
Stercophotogrammetry
Digital photography
Skeletal Scintigraphy

Treatment of Asymmetries






These conditions are heterogeneous and require
extensive multi speciallity approach to achieve
comprehensive treatment results.
The team include:


Treatment is divided into 3 stages:
stages




Preadolescent children
Adolescent
Adults




Principles of treatment:
In pre-adolescent children , 2 major problems
cause severe asymmetry:
A) Hemifacial Microsomia
B) Growth deficiency secondary to
trauma







In both conditions the maxilla is affected
secondarily as deficient vertical growth of
the mandible leads to distortion of the
alveolar process.
In Hemifacial Microsomia, both soft and
hard tissue elements are missing and growth
potential is likely to be deficient because of
the missing soft tissue.
Condylar fracture may produce partial
ankylosis that restricts what otherwise
would been normal growth.





The major reason for early surgical
intervention would be to improve the
chances of subsequent favorable growth
Surgery should be growth neutral ( no
deleterious effects on growth)


Treatment options

A) Growth modification with Asymmetric
functional appliance
 Asymmetric (Hybrid) functional appliance
Eg: Bite block on normal side to prevent over
eruption and buccal and lingual shield on the
affected side where vertical development is
desired with out bite blocks.
In major defects soft and hard tissue
simply do not have the potential and are less
likely to respond favorably.
B) Progressive asymmetry
is an indication for early surgical intervention



Hybrid appliance


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Complex congenital condition with
an extremely variable phenotype
Incidence: 1: 5600 birth
Male: Female = 3:2
Right : Left = 3:2
10 – 30% of cases have bilateral
defects

BJ Plast Surg: 1997: 536 – 551

Clinical Features:
 Represented by the acronym: “OMENS”

 O- orbital dysphasia
 M- mandibular hypoplasia
 E- ear defects
 N- cranial nerve defects
 S- soft tissue defects

BJ Plast Surg: 1997: 536 – 551

BJ Plast Surg: 1997: 536 – 551
Proffit & White 580 – 587
J P Reyneke : 233
Bishara

et al AO 1994:64:2

Three grades
1)
Grade I: The soft tissue and mandible are
present but deficient on the affected side
2)
Grade II: the mandibular condyle, ramus
and glenoid fossa may be present or absent
but when present are severly hypoplastic
and displaced. The soft tissue, including the
muscle of mastication, also are hypoplastic.
3)
Grade III: there is complete absence of
the condyle and ramus and a commensurate
soft tissue defect BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233






In general, children with grade I AND mild
grade II problems may respond favorably to
functional appliance therapy and this
conservative approach should be tried
before surgery
Pt with severe grade II and Grade III
problems are candidates for early surgery
either to lengthen the ramus on the
affected side or to construct a
condyle/ramus unit.
BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233


Principle

stages & techniques
applicable to treatment of HFM

B J Plast Surg: 1997: 536 – 551



Surgical correction:
correction
Three stage of surgical intervention
described by Converse et al
1) Stage I : Tissue augmentation
Augmenting deficiencies in the mandible,
reconstructing missing skeletal elements &
improving three-dimensional symmetry


BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233

2) Stage II: Orthognathic surgery
3) Stage III: contour modification is done to
III
enhance the contour of the skeletal and soft
tissue.


Newer Trends:
Distraction Osteogenesis !!


BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233

By far the most frequent growth problem due
to trauma in a child is asymmetric deficiency
secondary to an early fracture of the
Condylar process.
1) Acute management of condyle # in children
Immobilization of the jaw for 7 to 14 days


BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233

2) Post treatment asymmetry:
early surgery to make translation of condyle
possible to guide subsequent
growth
3) Reconstruction of the TMJ in growing pt:
a) use local tissue, such as stump of the
remaining ramus or
b) Employ a costochondral graft


BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233



3rd major cause of asymmetry



Affected in an multi articular form





Treatment with functional appliance is not
recommended for JRA
Surgery to lengthen the mandible, either
with conventional Orthognathic surgery or
distraction osteogenesis.


BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233

Excessive verses deficient mandibular growth
•

Functional appliance until growth is complete or all
complete, to prevent the development of maxillary
as well as mandibular asymmetry if possible . This
is followed by corrective surgery as necessary.


Clinical management of
Hemi- Mandibular Hypertrophy

• Remove the growth site at the head of the affected

condyle
• Hybrid appliance to block further eruption of teeth on
affected side and allowing teeth to erupt on the
unaffected side


Hemimandibular hypertrophy





In adults skeletal asymmetry can not be managed
orthodontically.
Initial alignment followed by jaw surgery
MAXILLARY PROCEDURES:
 LE FORT 1 WITH ASYMMETRIC CORRECTION WITH OR

WITHOUT NASAL AND OTHER MIDFACIAL PROCEDURES



MANDIBULAR PROCEDURES:
 BSSO WITH ASYMMETRY CORRECTION
 SURICAL REMOVAL OF THE POTENTIAL GROWTH CENTER

ESPECIALLY IN CONDITIONS LIKE HEMI FACIAL
HYPERTROPHY DUE TO CONDYLAR OVERGROWTH.



CHIN PROCEDURES:
 ASYMMETRIC GENIOPLASTIES



DISTRACTION OSTEOGENESIS


BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233






BSSO
BSSRO
CONDYLECTOMY
CONDYLAR
AUGMENTATION


Surgery to improve asymmetry



LE FORT 1 WITH OR
WITHOUT ROTATION
CORRECTION &
ASSOCIATED STRUCTURAL
CORRECTION




GENIOPLASTIES
 AUGMENTATION
 REDUCTION
 ROTATION

OR


COMBINED WITH
MAXILLARY OR
MANDIBULAR
PROCEDURES


•Often treated only with orthodontics
•Asymmetric extraction sequence and asymmetric mechanics such as
•Class III elastics on one side and Class II elastics on other with
oblique anterior elastics
•Unilateral headgears / jasper jumper etc
•Unilateral tipback bends
•Composite buildups and prosthodontic restorations in pronounced
asymmetries
•In arch constructions due to dental causes SME and RME can be
used with appliances like HYRAX, HASS, Quad helix, etc
•Distalization of molars with appliances like pendulum appliance,
distal jet, implants, etc.





Proper diagnosis & treatment planning is must.
A detailed and precise evaluation of the force systems
to be used.
Orders of correction:


Molar rotation : 1st order
 Correct mesial migration and mesial in rotations due to premature

loss of decidious counterpart



Molar tipping : 2nd order
 To correct abnormal mesial angulation and migration; ectopic

eruptions



Posterior crossbite : 3rd order
 CO- CR discrepancies



Achieved by:
 Asymmetric extractions
 Differential anchorage preparation
 Asymmetric space closure mechanics


Sem Orthod 1998 :3









In severe cases - to provide space necessary to
correct pronounced asymmetries.
This is done in order to overcome the side effects of
asymmetric mechanics
Before proceeding, it is crucial to determine whether
the observed asymmetry is genuine & not the
product of a functional or habitual shift of
mandible.
Anchorage must be critically reviewed


Sem Orthod 1998 :3

Sem Orthod 1998 :3





To correct asymmetries due to
unilateral extrusions or intrusion
or mild skeletal defects
producing occlusal cants.
Here the brackets are positioned
progressively gingivally /
occlusally to correct the canted
occlusal plane.

Sem www.indiandentalacademy.com
Orthod 1998 :3

Conclusions








Although a myriad of factors contribute to
facial aesthetics, symmetry may be the
quintessential ingredient.
In the management of dental arch
asymmetries, the clinician should select the
appropriate force system and the appliance
design necessary to address the asymmetry
while minimizing undesirable side effects.
Surgical correction of Dentofacial
asymmetries necessitates corresponding
orthodontic treatment.





A primary goal of surgical orthodontics is to
eliminate the dental compensations for the
skeletal deformity in all three planes of
space.
The three-dimensional skeletal, dental, and
soft-tissue alterations required for the
surgical and orthodontic correction of dento
facial asymmetries are among of the most
challenging and rewarding treatments to plan
and accomplish.


KEY TO TREATMENT
SUCCESS
“RIGHT DIAGNOSIS AND TREATMENT AT
THE RIGHT TIME TO GET RIGHT
RESULT”.


References


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BJ Plast Surg: 1997: 536 – 551
J P Reyneke : 233
Facial asymmetry : A Review :Bishara et al AO
1994:64:2
Asymmetries : diagnosis and treatment : Sem Orthod
1998 :3 : 133 -198
A classification of cranio facio cervical clefts:
Subramani & Murthy :Indian J Plast Surg: Dec :2005
Use of triangular analysis: K W Butow Peter van der
Walt: J Max Fac Surg 12 1984 62- 70

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AJO 1981 Sep 263 - 288 Tridimensional planning for
surgical/orthodontic treatment of mandibular excess - Bell and
Jacobs
AJO 1981 May 535 - 548 Dental arch shape - Sampson
AJO 1982 Jul 68 - 74 Hemifacial microsomia treated with
Herbst appliance - Sarnäs, Pancherz, Rune, and Selvik
AJO 1983 May 382 - 390 Analysis of errors in orthodontic
measurements - Houston
AJO 1984 Mar 224 - 237 Diagnosis and treatment planning of
skeletal asymmetry with submental-vertical radiograph Forsberg, Burstone, and Hanley
AJO 1985 Mar 240 - 246 Progressive facial asymmetry Arvystas, Antonellis, and Justin
AJODO 1988 Jan 38 - 46 Facial and dental arch asymmetries Alavi, BeGole, and Schneider


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
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
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

AJODO 1991 Jul 19 - 34 Assessment of structural and
displacement mandibular asymmetries - Schmid, Mongini, and
Felisio
AJODO 1994Aug 191 - 200 mand and facial asymmetrys
REVIEW ARTICLE - Pirttiniemi
AJODO 1994 May 489 - 495 Mandibular skeletal and dental
asymmetry in Class II malocclusions - Rose, Sadowsky,
BeGole, and Moles
AJODO 1994 Jan 73 - 77 Prepubertal trauma and mandibular
asymmetry - Skolnick, Iranpour, Westesson, and Adair
AJODO 1994 Sep 250 - 256 Assessment of craniofacial
asymmetry with S-V radiographs - Arnold, Anderson, and
Lilyemark
AJODO 1995 Apr 394 - 400 Unilateral crossbite and
mandibular asymmetry in adults O'Bym, Sadowsky,Schneider,
and BeGole


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Facial asymmetry /certified fixed orthodontic courses by Indian dental academy

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