Transcript Removable appliance

Appliances
Xi’an Jiao tong University
Stomatology Hospital
Orthodontic Division
Wang Xiaorong
Removable appliances
Functional appliances
Fixed appliance
No bracket appliance
Implant appliance
Questions
•
•
•
•
•
What are appliances？
What to do？
What is the influence to treatment？
Where to go？
Why to study appliances？
Overview
1．The definition of appliance
The equipment to treatment the
malocclusion
Request：
• Patients：efficient, aesthetic, comfortable,
without adversely affect
• Doctor ：easy operation, the tooth move
according to plan, use force stable,
no or little hurt
2．The source of power
• Materials have the ability to
returned to their original shape.
As we say: elastic properties.
Flexible role
•
•
•
stress
strain
stress-strain curves
Correction wire
• At flexible framework, stress-strain curve
should become a linear relationship.
Rubber products
stress-strain curve do not become a
linear relationship.
• For example ：
chain band、
orthodontic
elastics
Biology Organization
Between mechanical properties of elastic
solids and viscous liquids, and that means
also shown to demonstrate the flexibility
of the mechanical properties of viscosity,
known as viscoelasticity.
Strain lags behind the stress, strain and
stress set up the balance of the need for a
transitional phase, which is visco-elastic.
Ideal for the requirements of
orthodontic arch wires
• Good biocompatibility
• Good formability
• Good flexibility
3.Appliance Classification
• Retention mode
removable appliance, fixed appliance.
• The source of power
mechanical force, magnetic force,function
• The purpose of the role
correction, prevention, retention
Categories
removable appliance
fixed appliance
removable appliance
• Attached to the teeth and mucous
membranes, you can pick to wear.
fixed appliance
• Cement on the teeth, removal of
after the treatment.
4. The basic requirements of
appliance
• Non-toxic harmless to humans, does not
affect the growth and development and
function.
• Wear comfortable, little impact on the
appearance .
• Does not affect the oral hygiene.
• Treatment effective and efficient.
Anchorage
• The term anchorage, in its orthodontic
application, is defined in an unusual way:
the definition as “resistance to unwanted
tooth movement” includes a statement of
what the dentist desires.
Lose anchorage
Lose anchorage can lead:
1.occlusal relationship disorder
2.using space
Type of anchorage
• To provide anchorage in accordance with the
site:
Intermaxillary anchorage
Intramaxillaty anchorage
Extraoral anchorage
Intramaxillaty anchorage
Intermaxillary
anchorage
Intermaxillary
elastics
Class Ⅱ elastics
Class Ⅲ elastics
Extraoral
anchorage
To provide anchorage in
accordance to the mode of action
classification
• Easy anchorage
• Reciprocal anchorage
In accordance with the anchorage
teeth and non-anchorage tooth
movement ratio
moderate anchorage
maximum incisor retraction：maximum anchorage
minimum incisor retraction
moderate
anchorage
maximum
anchorage
minimum
retraction
（3）ways to strengthen
anchorage
• Used to increase the number of anchorage
teeth
• Anchorage teeth will be linked one to
enhance the overall role of Anchorage
• Appliance increased activity of the base
area, to maintain secret noodle and
organizations together
ways to strengthen anchorage
• Use of jaw teeth to strengthen the anchorage,
transpalatal arch, Nance arch, lingual arch
• Devices to enhance the use of extraoral
anchorage (J hook, face-bow)
• Implant anchorage
ways to strengthen anchorage
using the appropriate power
ways to strengthen anchorage
The type of tooth movement
ways to strengthen anchorage
Intermaxillary anchorage
The function of Class Ⅱ elastics
• Backward upper anterior teeth, forward lower
•
•
•
•
•
posterior teeth.
Elongate upper anterior teeth and lower
posterior teeth.
Increase anchorage.
Correct the class Ⅱ molar relationship.
Mandibular advancement, maxillary orthopedic
minor inhibition
Skeletal Class III patients went to compensatory
before surgery.
ways to strengthen anchorage
Extraoral
anchorage
Anchorage Noodles
ways to strengthen anchorage
Implant anchorage
Removable appliance
Attached to the teeth and mucous
membranes, you can pick to wear.
The applications of removable
appliance
• All the easy malocclusion correction
• Mechanical retainer
• Get rid of bad habits appliance
• Function appliance
• Assistive devices of fixed appliance
Advantages
• They can be removed on socially sensitive
•
•
•
occasions, which makes them more acceptable
to patients.
They are fabricated in the laboratory rather than
directly in the patient’s mouth.
Reducing the dentist’s chair time during the
initial part of treatment.
They allow some types of growth guidance
treatment to be carried out more readily than is
possible with fixed appliances.
Disadvantages
The response to treatment is heavily
dependent on patient compliance, since the
appliance can be effective only when the
patient chooses to wear it.
It is difficult to obtain the two-point
contacts on teeth necessary to produce
complex tooth movements.
Removable appliance
1.Retention device
2.Force part
3.Connecting part
（1） Retention device
• Adams crib
• Circumferential molar clasp
• Ball clasp
• Labial bow
• Baseplate
Adams crib
• Adams designed in 1957.
• Most used in first molars.
• Diameter is
0．8—0．9mm
Circumferential molar clasp
• Permanent teeth
•
•
0．9～1．0mm
Other teeth
0．7～0．8mm
Extending into
the mesio-buccal undercut
Ball clasp
• Between premolar
•
•
and molar
0．8mm
Extending into the
buccal embrasure
Labial bow
• 0．8—0．9mm
Baseplate
• Plastic
• Thickness 2—2．5mm
• Organize noodle base
soft tissue and hard
work closely fitting
（2） Force part
1）Spring ：double helical spring, longitudinal
spring.
2）Bow spring ：Labial bow, spring Expansion
3）Orthodontic elastics
4）Permanent magnet
5）Guide plate
（3）Connecting part
• Baseplate Will appliance parts and the
retention Afterburning even as a part
of the overall
The function of base
• Basic role
• Increase anchorage
• Afterburning part
2. Activity commonly used
mechanical appliance
• All pad-type maxillary appliance
Removable retainer
• Expansion Appliance
• Magnetic Appliance
• Get rid of bad habits appliance
Removable retainer (Hawley)
Maintained after the completion of dental
treatment does not shift.
All pad-type maxillary appliance
Removable retainer
• component：
•
Adams crib,
double helical spring,
baseplate
function：
to correct upper anterior
crossbite
expansion
appliance
Get rid of bad habits appliance
• oral screen
• Palate gill
Magnetic Appliance
• Frame：retention device, magnetic
materials, baseplate.
• Function：Elongation and low teeth,
correction of anterior openbite.
The removable appliance wear
and referral
Check the quality of appliance
Teach patients to wear
Appliance afterburning：
Forces - orthodontic force
2 weeks, 4 weeks, 3 months
Summary
• Anchorage： “resistance to unwanted tooth
movement”
• Easy anchorage, Reciprocal anchorage
• Maximum anchorage, minimum anchorage,
moderate anchorage.
• Extraoral anchorage, internal anchorage.
• Intermaxillary anchorage, intramaxillary
anchorage.
• Retention device, force part, connecting part.