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

EXPANSIONEXPANSION
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

Topics :-
Classification
History Of Expansion
Arch Width Changes (Physiologic)
Anatomy Of Maxilla and Mandible
Histology Of Suture and Symphysis
Stresses generated during Transverse Expansionwww.indiandentalacademy.com

Expansion
Transverse Antero-posterior
Dental
Skeletalwww.indiandentalacademy.com

ANATOMY
AND
HISTOLOGY

Symphysis joint
(Grays Anatomy)www.indiandentalacademy.com

Symphysis joint
Symphysis
menti
(Atlas Oral Anatomy
Holland G R)

Bone
Fibrocartilage
Collagen Fibres

Maxilla and its Articulations
(Grays Anatomy)

American Journal Of Dentofacial Orthopedics 1987;91)www.indiandentalacademy.com

Midpalatal suture

Zone Of Intense Proliferation

A-P Direction Of Collagen Fibres

Transversely oriented collagen fibres

Network Of Collagen Fibres In centre Of Suture

Sharpey fib

T
B
S
TRANSITIONAL SPACE

SINUOUS AND IMBRICATING NATURE OF SUTURE

NARROWED ZONE OF CELLULAR PROLIFERATIONwww.indiandentalacademy.com

LIGHT MICROSCOPIC VIEWwww.indiandentalacademy.com

ELECTRON MICROSCOPIC VIEW

HISTORY
(The Angle Orthodontist1999;69)
(Rapid Maxillary Expansion;Timms)

Sir Emerson C Angell

San Francisco Medical Press 1860
*14 year old girl patient with ectopic left upper lateral
and premolar.
*Importance of first permanent molars.
Dental Cosmos

Expansion appliance:-Dr Angell
Note Diastema

Appliance with contrarotating screw
Gold

We must beg leave to differ with the author in
the conclusion arrived at,that by the use of
apparatus described he succeeded in separating
the superior maxilla from each other.With no
disposition to assert that such a thing is utterly
impossible,yet,when taking into consideration the
anatomical relations existing between the two
halves of maxilla and other bones with which they
articulatesuch a result appears exceedingly
doubtful.
(J.DeH.White)

As shown in Dental Cosmos

ARCH WIDTH CHANGES
(American journal Of Dentofacial Orthopedics1997;111)
(T.M.Graber;Orthodontics –Practise and Principles)

Study Of Stress Distribution and Displacement Of
Various Craniofacial Structures Following
Application Of Transverse Orthopedic Forces:-
FEM Study
(The Angle Orthodontist2002;73)
(American Journal Of Dentofacial Orthopedics 1987;91)

Conclusions:-
•Maximum lateral displacement was 5.313mm at node 12911.
•Pyramidal displacement of the maxilla was visible from the front
view.
•The width Of the nasal cavity increased markedly.
The inferior parts of the pterygoid plates were markedly displaced or
bent laterally,but minimal displacement was observed in the region
close to cranial base.

•Maximum negative Y-displacement(backward
displacement)was 1.1599 at node 2314 corresponding
to the posterior rim of the frontalprocess of the
zygomatic bone.
•Maximum positive Y-displacement(forward
displacement) was 1.077 at node6022,which represents
the anteroinferior border of the nasal septum.

•Maximum negative Z displacement(downward
displacement was 1.22 at node52,which represents the
posterior most portion of the nasal septum.
•Maximum positive Z displacement(upward displacement
1.758mm at node241 which represents body of the
zygomatic bone.
•Thus the nasomaxillary complex rotated such that the
lateral structures had moved upwards and midline
structures downwards.
•The anterior part of maxillary bone(point A)were
displaced downwards.

Topics:
Rapid Palatal Expansion
Slow Palatal Expansion

Expansion
Skeletal Dental
Transverse Anteroposterior
Slow
Semi rapid
Rapid
Ultra rapid

Indications Of Rapid Palatal Expansion:-
Occlusion
-Full cusp crossbite with skeletal component.
-Some degree of dental as well as skeletal component.
-No open bite tendency.
-No preexisting dental expansion.
Respiration
-Poor nasal airway
-Septal deformity
-Recurrent nasal ,sinus infection
-Asthama

Hazards Of RME:-
Oral Hygiene
Dislodgment and breakage
Tissue damage
Infection(Acute ulcerative gingivitis)
Failure of suture to open

(a) Derichsweiler type

Tags are welded and soldered to the palatal aspects
of the bands to provide attachments for the acrylic
which is also extended to the palatal aspects of all
non banded teeth except the insicors.‑

(b) Haas type

A length of .045 in (1 .15 mm) stainless steel wire is
welded and soldered along the palatal aspects of the
bands The free ends are turned backand embedded
into the acrylic base.A proprietary srew is set in the
midline of the acrylic split.

Haaswww.indiandentalacademy.com

(c) lsaacson type

This appliance uses a special spring loaded screw
called a Minne. Expander which is adapted and
soldered direct to the bands without the use of
acrylic, The screw may be reduced in length to suit
narrow arches by shortening the spring, tube and
rod.

(d)Biedermann type

This appliance also required a special screw, either
Hyrax (Dentaurum 602 813). Leone 620 or Unitek‑
440 160, These have extensions in heavy gauge wire‑
which are welded and soldered to the palatal
aspects of the bands


Hyrax Screw

Forestadent Screw

Activation:-180º rotation /day(Ziebe)
Upto Age 15 years
-90º both morning and evening.
Age 15-20 years
-45º turns 4 times a day
Age over 20 years
- Same as above or 45º in the morning and 90º at night

In general,bony spicules appear at the age of 15
and 19 years(0.9% fo suture length),but these
bridges may be removed by osteoclast to suit
physiologic requirements.
A greater degree of obliteration occurs posteriorly
than anteriorly.
On average 5% of suture is closed by age 25.
(By Persson et al 1977)

Age and prognosis:
Age 7 to 15:Good
Age 15 to 20:Good although recall every other day
To check opening of suture.
Age 20 to 30:Possible but daily recall necessary,
Danger that the suture does not open and there is
overloading of the posterior segment,ulceration of
mucosa.

Treatment timing for rapid maxillary expansion
(Angle orthodontist;2001)
The group treated before the pubertal peak,in the
long term,showed significantly greater maxillary skeletal
Width,maxillary intermolar width,lateronasal width and
Lateroorbital width
The late treated group exhibited significant increase in
Maxillary and mandibular intermolar width.(thus more
Dentoalveolar than skeletal)

According to Mayoral and Aristeguinta

Slow Expansion Rapid Expansion

Maxillary Expansion by Hass(AJO;Vol 57,No8,1970)

*Correction of mouth breathing.
*Improvement of concentration.
*Mouthbreathing not influenced.
*Some improvement of nasal
breathing www.indiandentalacademy.com

Slow Expansion

Schwarz Appliance

Crozat Appliance

Fan Appliance

Wipla-type Forestadent screw

Bar type-Two way expansion screw

The Nardella eccentric expansion screw

Quad Helix
Ricketts

3 D Multiaction palatal appliance

3D Quad Helix palatal Appliance(Wilson)

Sagittal I Appliance

Sagittal II Appliance

Ultra-Rapid Expansion
•By Chaure….3mm of expansion was achieved in
one and half hour.
•Three visits.
•Anaesthesia is administered.
•Used by E.N.T. surgeons then.

NiTi GROUP RPE GROUP
Measure
ment
Mean Standard
Deviation
Mean Standard
Deviation
PWC(m
m)
0.99 0.45 1.41 1.09
IMWC(
mm)
6.26 1.65 4.76 1.55
PWC=palatal width change; IMWC=intermolar width change; PDC=palatal depth change;
AT=alveolar tipping; MR=molar rotation; MT=molar tipping

RATIO
PWC/IM
WC
0.16 0.08 0.28 0.17
AT(degre
es)
6.61 3.73 5.08 5.43
PDC(mm
)
-0.04 0.70 -0.07 0.89
MR(degr
ees)
26.61 16.29 1.58 2.74

MR(degr
ees)
26.61 16.29 1.58 2.74
MT(degr
ees)
11.69 10.47 6.08 6.25

The NiTi transpalatal loops has a transition temperature
of 94o
F. The martensitic transformation and superelastic
properties of the NiTi wires helped the insertion of the
expander into the lingual sheaths of prefitted maxillary
molar bands. Expansion occurs after insertion when the
appliance was warmed up to body temperature and the
NiTi loops return to its original shape. Over expansion
was built into the treatment to anticipate relapse
(approximately 30%) due to uprighting of the maxillary
molars after removal of appliance.

NiTi transpalatal loops were sprayed with
tetrafluoroethane refrigerant prior to
placement of the appliance.

Original Pendulum design
.032” TMA
Nance
Button
Occlusal
rests

Pendex

T-Rex Design
Mesial wire

The PHD Appliance
Pendulum Hygiene Design/devicewww.indiandentalacademy.com

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

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