Removable OrthodonticRemovable OrthodonticAppliancesAppliances

Gregory Jackson DDS, MSD Preclinical Orthodontics ORTD 323

May 31, 2002

Removable AppliancesRemovable Appliances

• Advantages & disadvantages• Brief history & development• Major uses of removables

• Growth modification• Limited tooth movement• Retention• Adjuncts to treatment• Mild to moderate malocclusions

AdvantagesAdvantages

• Appealing to patients especially adults• Inexpensive• Easy to make and adjust• Initially less chair time• Allow for some types of growth

guidance

DisadvantagesDisadvantages

• Totally cooperation dependant !!!• Limited to less complex movement• Limited range of movement

Development of RemovablesDevelopment of Removables

• USA- fixed appliances- Edward Angle• Minimal usage of removable appliancesPrecise positioning of teeth

• Europe-removable appliances• Geographic separation • Social welfare systems-limited tx. for masses• Scarcity of precious metals for fixed

appliancesAlterations in function produced by

removables give stable correction of malocclusion

Removables in EuropeRemovables in Europe

• Growth Guidance with Functional Appliances

• Change mandibular posture • Open & forward

• Pressure from stretch of muscle & soft tissues transmitted to teeth & bone

moving teeth and modifying growth

Today Dichotomy DisappearedToday Dichotomy Disappeared

Instantaneous exchange of ideas & info.Politics, economics, travel, electronic age

Can We Grow Mandibles?Can We Grow Mandibles?

Chapt. 8 Contemporary Orthodontics

“An acceleration of (mand) growth often occurs when a functional appliance is used … , but the final size of the mandible is little if any larger than it would have been without treatment.”

Other functional appliance tx. effects:• Mand. teeth forward, max.teeth back- Cl. II el. effect• Restraint of forward growth of maxilla- HG effect

Tooth-borne Functional AppliancesTooth-borne Functional Appliances

• Activator (Andresen)

• Bionator(Balters)

• Herbst

• Twin Block(Clark)

Tissue-borne Functional AppliancesTissue-borne Functional Appliances

Functional Regulator (Frankel)

Limited Tooth MovementLimited Tooth Movement

Appliance Design

• Acrylic plate – stability

• Active portion – force application

• Clasps & occlusal rests- retention

Acrylic PlateAcrylic Plate

Maintenance Plate

•Stabilize•Space maintenance•Replace tooth•Bite Plane•Posterior overlay

Be Creative!Be Creative!

Active PortionActive Portion

• Expansion – screws• Repositioning teeth – springs• Space closing – labial bow & springs

Expansion ScrewsExpansion Screws

SpringsSprings

Anterior Alignment

Anterior Cross-bite Primary DentitionAnterior Cross-bite Primary Dentition

Anterior Cross-bite Mixed DentitionAnterior Cross-bite Mixed Dentition

SpringsSprings

Posterior space regaining

correct incorrect

Spring winding

SpringsSprings

Space Closure

Adjustable Labial BowAdjustable Labial Bow

Clasps & RestsClasps & Rests• Adams

• C

•Occlusal rest

•Ball

•Arrowhead

RetentionRetention

• Hawley• Circumferential• Spring• Invisible – Essix• Positioner

Hawley RetainerHawley Retainer

With or without ant. or post. biteplate

Circumferential RetainerCircumferential Retainer

Spring RetainerSpring Retainer

Invisible Essix RetainerInvisible Essix Retainer

Vacupressureformed

Biostar Machine

PositionerPositioner

Adjuncts to TreatmentAdjuncts to Treatment

Biteplate

Nightguard

Removable Appliances Used in Removable Appliances Used in Mild to Moderate MalocclusionMild to Moderate Malocclusion

More to come