Expansion in orthodontics /certified fixed orthodontic courses by Indian dental academy

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EXPANSION IN
ORTHODONTICS

INDIAN DENTAL ACADEMY
Leader in continuing dental education


INTRODUCTION
The prime objective of expansion is to
coordinate
the
maxillary
and
mandibular bases


Historical background
Hippocrates

“Among those individuals where heads are
long shaped, some have thick necks, strong
members and bones, others have strongly
arched palates, their teeth are disposed
irregularly crowding one over the other
and they are suffering with headaches and
ottorrhea”.

 Fauchard 1728

 Shange 1841

 Bourdet 1757

 Robinson 1846

 Fox 1803

 Tomes 1848

 Delabarre 1819

 Allen 1850

 Cefaulon 1839 to 1841  Whitel and Westcott

1859


 Emerson Colon Angell 1860,

San Francisco
 San Francisco Medical Journal and
Dental Cosmos
 Editor of dental Cosmos: John Deh
White


 A.Coleman

1877 described coffin

spring
 Field: coffin can cause separation of
MPS in very young children
 Farrar: “separation of superior maxilla
at the symphysis”
 Supported by Clark L Goddard,
E.S.Talbot and A.E.Matteson.1893

 C.H.Hawley
 H.A.Pullen

 E.H.Angle
 V.H.Jackson

 M.Dewey
 G.V.I.Brown

 Ketchem
 Prof. M.H.Cryer

 V.E.Barnes
 G.H.Write
 F.A.Faught
 L.W.Dan
 W.H.Haskin

Anatomical considerations
 MAXILLA


SUTURES

 Melsen’s study 1975


INDICATIONS
Marked narrowing of the arches
Unilateral or bilateral cross bite
Mand prognathism with reduced anterior
development of the maxillary base
 Steep palate with septal deviation and mouth
breathing due to enlarged adenoids
 Cleft lip and palate
 Mild arch length to tooth material deficiency.
(1mm of expansion in post = 0.7 mm increase in
arch perimeter)





CONTRAINDICATIONS
 Uncooperative patients
 Pts with anterior open bites, and steep

mandibular plane angles


CLASSIFICATION OF APPLIANCES
 According to the rate of expansion
– Slow
eg W arch, Quad helix, Coffin spring
– Rapid
eg Hyrax, Minn, Isaacson
– Ultra rapid
– Surgically assisted




According to appliance attachment
– Removable
eg Active plate and Functional appliances
– Fixed:
•
Tooth borne
eg, Biedeiman appliance, Minn expander
•
Tooth/Tissue borne
eg Derichsweiler type, Haas type.

 According to modality employed
– Orthodontic expansion
– Passive expansion
– Orthopedic expansion


REGULATION OF EXPANSION
 Rate of expansion
 Form of the appliance
 Age of the patient


Rapid maxillary expansion
 Orthopedic expansion
 Force levels of upto 10-20lbs per day
 Active phase 2-4 weeks


REQUIREMENTS OF AN RME
APPLIANCE
 Rigidity
 Tooth utilization
 Expansion( dilating unit and action)
 Economy of time and material
 Hygiene


Banded type of appliances
 Hass type
 Derichsweiler type
 Isaacson type
 Biedeimann type


Bonded type

Mundro et al 1977


Instructions on how to expand
Zeibe in 1930 : 180 degree rotations per day
 Upto age of 15 years : the turn 180 degree is
given as 90 degree in the morning and 90
degree in the evening.
 15-20 years : overall rotation of 180 is
possible by splitting the rotation into 4 turns
of 45 degree each with approx equal time
lapse between them.
 Age over 20 years : 45 degree turn in the
morning and 45 in the night initially

Zimring and Isaacson in 1965 :
 Young or growing patients: two turns each day
for the first 4-5 days and one turn each day for
remainder of rme treatment.
 Adult patients: two turns each day for the first
two days and one turn each day for the next 5-7
days and one turn eac other day for the
remainder of the rme treatment.


How much to expand
 Stanely et al in 1985

+1.6mm (male) and 1.2mm (females)

HAZARDS OF RME
 Oral hygiene
 Length of fixation
 Dislodgement and breakage
 Tissue damage
 Infection
 Failure of suture to open


Reaction to expansion
 IN BONE
 SUTURES
 DENTAL CHANGES


Relapse and Retention
 The object of retention is to hold the

expansion while all other forces generated
by the expansion have decayed away.
 It is essential for the fixed appliance to act
as the retention appl in the first three
months.
 Wertz observed that some relapse is seen
in the forward and downward movement of
the max.

SLOW MAXILLARY EXPANSION
Story and Ekstrom: Slow expansion allows
physiologic adjustments and reconstitution of
sutural elements over a period of about 30 days.
 2-4 lbs of force, a little higher for older
patients.
 1 mm expansion per week.
S. E. has also been associated with more
physiologic stability and less potential for relapse
than with R. M.E.

Appliances used for S. M. E.
 Jackscrews


TYPES OF SCREW





Broad classification:
Encased type
Skeleton type
Special screw
Eccentric screws


 Coffin spring


 W - Arch


 Quad helix


OTHER METHODS OF EXPANSION
 ULTRA RAPID EXPANSION
 NITI AND OTHER ARCH WIRES
 MAGNETS
 TRANSPALATAL ARCH
 SURGICALLY ASSISTED EXPANSION


Ultra-rapid maxillary expansion
of Chatellier
 The procedure involves local anesthesia

and results are obtained within 1 to 3
days
 As a rule, the ultra-rapid method is

performed over a period of 3
appointments

Niti expander
Wendell Arndt


Functional appliances


Magnets
 M. ALI DARENDELILER
 Two repelling samarium cobalt magnets

Pins and tubes were placed to guide the
separation of the palate.
 The midpalatal magnets (each 10mm×5mm×5mm)
produced 500g of force, which declined to 250g
during the three weeks between activations



Transpalatal Arches
 An important auxiliary used in fixed appliance

therapy with several indications one of which
is expansion or constriction but of small
measures of upto 1-2 mm.


Surgically assisted maxillary
expansion
The resistance in the maxilla separation can
be due to either of the following reasons:
 mid palatal synostosis
 mid palatal interlocking
 circum maxillary rigidity


The tech has been described in 3 stages:
 Stage 1 A and B
 Stage 2 A and B
 Stage 3 A and B


Stage 1


Stage 2 (over the age of 30)


Stage 3 (over the age of 40)


Expansion of cleft palate
cases
 Excessive anterior collapse coupled to little or no

posterior collapse
 More fan wise expansion needed to restrict
posterior Expansion. Screws of longer thread of
upto 18mm expansion
 More difficult to retain due to clinical crowns not
developed properly
 Unilateral expansion both cap splints and bands
can be used
 Formation of fistula could be a complication

Expansion of the mandibular arch
 Stable expansion is difficult to attain in the

lower arch
 Present studies state that expanding the upper
arch allows for spontaneous expansion of the
lower arch.


CONCLUSION
Expansion of the arches has seen its ups and downs in the
past. More and more documentation of the effects and
stability of this procedure has thrown a new light on its
clinical application.
Whether it is slow, rapid or ultra rapid expansion, proper
diagnosis and case assessment is very essential to ensure
consistent results. As more and more cases are being
treated without extractions due to profile considerations,
expansion of the arches forms a valuable adjunct to treat
a wide variety of clinical presentations.

Leader in continuing dental education


Expansion in orthodontics /certified fixed orthodontic courses by Indian dental academy

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