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URA

AF

Ahmad Firdaus

Transcript

ORTHODONTIC REMOVABLE

APPLIANCE

(ACTIVE APPLIANCE)

DR. AHMAD FIRDAUS

INTRO

REMOVABLE ORTHODONTIC APPLIANCE ARE :

  • DESIGNED TO APPLY FORCES TO THE TEETH BY MEANS OF SPRINGS, SCREWS AND OTHER MECHANICAL COMPONENTS.

  • DIVIDE INTO TWO:
  • Active appliances
  • Functional appliances

  • TYPE OF MOVEMENT
  • Tipping
  • Block of teeth
  • Influence eruption of opposing teeth

COMPONENT

  • Retentive Components
  • Active components
  • Baseplate
  • Anchorage

COMPONENT

RETENTIVE (CLASP)

RETENTIVE

'Resist displacement of appliance'

Advantages

Advantage

  • Unobtrusive
  • Close contact to the tooth
  • Usable in both deciduous and permanent dentition
  • Adequate retention
  • No active force on the anchor tooth
  • Rigid
  • Easy to fabricate and also replace if needed
  • Not interfere in the growth of jaws and eruption of teeth

Usage

Usage

  • To secure the appliance in position

  • To prevent rolling of appliances

  • To resist forces of displacement

  • To provide retention & anchorage

  • For engaging elastics

Mode of action

Mode of action

Clasp engage onto the undercuts

(constricted areas on the teeth.)

• Two types of undercuts.

– Buccal / Lingual Cervical undercuts.

– Mesial / Distal Proximal undercuts.

Types of commonly used clasp

Types

  • Circumferential Clasp (0.9 mm)

  • Adam’s Clasp (0.7 mm)

  • Southend Clasp (0.7 mm)

Circumferential

Clasp

Circumferential Clasp

  • Fabricated using wire 0.9mm

-Also known as ‘C’ clasp or Three Quarter Clasp

  • Simple clasp used to engage buccocervical undercut

  • Cannot be used in partially erupted teeth

Southend Clasp

Southend Clasp

  • 0.7 mm wire

  • Spans two adjacent margins of anterior teeth

  • Adapting into interdental area

  • Esthetically more pleasing

Adam's

Clasp

ADAM'S CLASP

Intro

Adam's Clasp

Also known as

  • Liverpool Clasp
  • Universal Clasp
  • Modified Arrowhead Clasp

Components

  • Bridge
  • Arrowhead
  • Retentive arms

Adam's Clasp

  • Invented by C. PHILIPS ADAMS in May 1950

  • Most widely used clasp

  • Distobuccal and mesiobuccal undercuts.

.

  • 0.7mm posteriors

  • Engage about 1 mm of undercut

Advantage

Advantages

  • Small neat and unobtrusive.

  • Both deciduous and permanent dentition, even on semi erupted tooth.

  • No specialized pliers required.

  • Numbers of variations are available.

Modifications

Modification

  • Adams clasp with single arrowhead

  • Adams clasp with J hook

  • Adams clasp with additional arrowhead

  • Adams clasp with distal extension

  • Double clasp on maxillary central incisors

Labial

Bow

LABIAL BOW (0.7 mm)

  • For anterior retention

  • Acrylic may be added to the labial bow to provide additional retention

Active Component

  • Springs

  • Screws

ACTIVE

Springs

Single Cantilever Spring (0.5 mm)

  • Parts
  • Active arm
  • Coil
  • Retentive arm

  • Coil with internal diameter of 3mm

  • Used to move teeth labio-lingually or mesio-diatally

Double Cantilever Spring / Z spring (0.5mm)

  • Spring perpendicular to palatal surface of tooth

  • Indicated where incisors are to be proclined

  • Activation: Opening both coils

Screws

SCREWs

  • Less versatile than springs - direction of tooth movement

is determined by the position of the screw

  • Bulky and more expensive
  • Indications
  • Crossbite corrections
  • Buccal movement of one or two buccal segment

  • Activation
  • Turning the screw a one quarter turn (0.25 mm)
  • Twice a week
  • Opened too far, screw will come apart

Baseplate

  • Connecting individual component
  • Can be passive or active

BASEPLATE

Bite plane

Posterior Bite Plane

  • Eliminate occlusal interferences to:
  • Allow tooth movement
  • Reduction of overbite

  • Carrying the acrylic over occlusal surface of buccal segment teeth

Anterior bite plan

  • Increasing the thickness of acrylic behind upper incisors

  • Reduction of overbites:
  • Induce eruption of the buccal segment while holding eruption of labial segment
  • Elimination of possible occlusal interferences

DEFINITION

  • Resistance to unwanted to movement

  • Equal in magnitude

  • Opposite in direction

  • Two types : 1) Intra Oral

2) Extra Oral

ANCHORAGE

INDICATIONS

INDICATIONS

  • Unilateral cross bite

  • Tooth that require tipping movement

  • Arch expansion.

  • Single malpositioned teeth

  • Simple movement required to correct malocclusion

  • Influence development of buccal segment and/or to free occlusion with lower arch (baseplate)

  • Space maintaners

  • Retainers following fixed appliance treatment

CONTRAINDICATIONS

CONTRA

INDICATIONS

  • Severe skeletal discrepancy

  • Severe tooth rotation

  • Tooth need bodily movements

  • Severe crowding

  • Very dens bone

Patient's factors

  • Not motivated to wear( wear part time instead of full time)

  • Habit of clicking the appliance (increase breakage potential)

  • Eating hard/sticky food habit

ADVANTAGES

  • Can be removed for tooth brushing

  • Palatal coverage increases anchorage

  • Easy to adjust

  • Less risk of iatrogenic damage than fixed

appliance

  • Acrylic can be thickened to form flat bite plane

  • Useful as passive retainer or space maintainer

  • Can be used to transmit forces to block of teeth

ADVANTAGES

LIMITATIONS

LIMITATIONS

  • Only simple malocclusion can be corrected

  • Affects speech

  • Appliance can be left out

  • Multiple tooth movement

- one at a time- prolongs Rx duration

  • Lower appliance not well tolerated