Removable Orthodontic Appliance Question And Answers

Removable Appliances Important Notes

Components of removable appliances

Orthodontics Removable Appliances Components of removable appliances

Methods of activation of different components

Orthodontics Removable Appliances Methods of activation

Types of labial bows

Orthodontics Removable Appliances Types of labial bows

Types of springs

Orthodontics Removable Appliances Types of springs

Removable Appliances Long Essays

Question 1. Classify orthodontic appliances and discuss in detail various active components of removable appliance.
Answer.

Classification Of Orthodontic Appliances:

  • Mechanical: Exerts mild pressure on tooth
    • Removable appliances
    • Fixed appliances
      Myofunctional: Harness natural muscular forces
    • Removable appliance
    • Fixed appliance

Active Components Of Removable Appliances:

Bows

  • Used for incisor retraction

Types Of Bows:

  • Short labial bow: Parts
    • Bow
    • ‘U’ loop
    • Retentive arms distal to canine
      Uses:
    • Minor overjet reduction
    • Anterior space closure
    • For retention after fixed mechanotherapy

Activation: Compressions of U loops

Orthodontics Removable Appliances Short Labial Bow

Orthodontics Removable Appliances Long Labial Bow

 

 

  • Long labial bow: Extends from one 1st premolar to opposite side
    Indications:

    • Minor anterior space closure
    • Overjet reduction
    • Retaining device
    • Closure of space distal to canine
  • Split labial bow:
    • Labial bow splitted in middle
    • Have separate buccal arms
      Indications:
    • Mid line diastema
    • For anterior retraction

Orthodontics Removable Appliances Split labial bow for retraction of anteriors

  • Reverse labial bow: Free ends of U loops adapted occlusally
    Activation:

    • Opening of U loop
    • Compensatory bend at base of U

Orthodontics Removable Appliances Reverse labial bow

  • Others:
    • Robert’s retractor
    • Mills retractor
    • High labial bow with apron springs
    • Fitted labial bow

Orthodontics Removable Appliances Fitted labial bow

Springs

Classification:

  • Based on presence/absence of helix
    • Simple without helix
    • Compound with helix
  • Based on presence of loops/helix
    • Helical springs
    • Looped springs
  • Based on nature of stability of spring
    • Self supported
    • Supported

Orthodontics Removable Appliances Nature of stability of spring

Screws:

  • To bring about different tooth movement

Example:

  • Arch expansion
  • Buccal movement of teeth
  • Mesial/distal movement of teeth

Orthodontics Removable Appliances Appliance for arch expansion

Orthodontics Removable Appliances Appliance for buccal movement of a group of teeth

Orthodontics Removable Appliances Appliance for distal movement of teeth

Elastics:

  • For anterior retraction
  • May cause gingival trauma

Orthodontics Removable Appliances Elastics used as active component

Removable Appliances Short Essays

Question 1. Adam’s clasp and its modifications.
Answer.

  • By Professor Phillip Adams

Synonyms Of Adam’s Clasp:

  • Liver pool clasp
  • Universal clasp
  • Modified arrow head clasp

Wire Used:

  • 0.7 mm round stainless steel

Parts:

  • Two arrowheads – Engaging proximal undercuts
  • Bridge – Connects two arrow heads

Two Retentive Arms – Incorporated In Acrylic

Advantages Of Adam’s Clasp:

  • Rigid retentive
  • Simple to fabricate
  • Occupies minimum space
  • Can be used for
    • Deciduous and permanent teeth

Read And Learn More: Orthodontics Short And Long Essay Question And Answers 

    • Partially and fully erupted teeth
    • Incisors, premolars and molars
      • Modified in many ways

Orthodontics Removable Appliances Buccal view

Orthodontics Removable Appliances Occlusal view

Modifications Of Adam’s Clasp:

  • Adams with single arrow head
  • Adams with additional arrow head
  • Adams with J hook
  • Adams with incorporated helix
  • Adams with soldered buccal tube
  • Adams with distal extraction
  • Adams on incisors and premolars

Question 2. Canine retractors.
Answer.

U loop canine retractor:

  • Wire used – 0.6/0.7 mm

Parts Of U loop canine retractor:

  • U loop: Base is 2-3 mm below cervical margin
  • Active arm:
    • Bent at right angles
    • Passed below mesial contact point of canine
  • Retentive arm: Incorporated in acryluc
    Uses: In 1-2 mm of retraction

Helical canine retractor:

  • Wire – 0.6mm

Parts Of Helical canine retractor:

  • Coil – 3mm diameter
  • Active arm – towards tissue
  • Retentive arm

Activation: Opening of helix

Use: In shallow sulcus

Orthodontics Removable Appliances U loop canine reactor

Orthodontics Removable Appliances Helical canine reactor

Palatal canine retractor:

  • Wire – 0.6mm

Parts:

  • Coil – 3mm diameter
  • Active arm – mesial to canine
  • Guide arm

Use: Retraction of palatally placed canine

Buccal canine retractor:

Uses Of Buccal Canine Retractor:

  • Bucally placed canines
  • Highly placed canines

Parts Of Buccal Canine Retractor:

  • Coil – 3mm diameter
  • Active arm – away from tissue
  • Retentive arm

Types Of Buccal Canine Retractor:

  • Supported – with 0.5mm wire
  • Self supported – with 0.7 mm wire

Orthodontics Removable Appliances Palatal canine reactor

Orthodontics Removable Appliances Supported canine reactor

Orthodontics Removable Appliances Self supported canine reactor

Question 3. Advantages and disadvantages of removable appliances.
Answer.

Advantages Of Removable Appliances:

  • Oral hygiene maintenance
  • Useful in tipping movement
  • Less chair time
  • Convenient to operator to handle more patient
  • Less forces required
  • Not technique sensitive
  • Easy to fabricate
  • Relatively cheaper
  • Damaged appliances can be replaced

Disadvantages Of Removable Appliances:

  • Poor patient cooperation
  • Capable of only tipping movement
  • Prolonged duration of treatment
  • Difficult to treat multiple movement
  • Difficult to close residual space created due to extraction
  • Risk of damaging and misplacing appliances by patient
  • Cannot be used to treat severe cases of Class 2 and Class 3 malocclusions with unfavourable growth pattern

Removable Appliances Short Questions And Answers

Question 1. Z spring/Double cantilever.
Answer.

Uses Of Z spring:

  • Labial movement of incisors
  • Minor rotation of incisors

Wire used: 0.5 mm

Parts Of Z spring:

  • Two coils
  • Retentive arm – 10-12 mm length

Activation Of Z spring:

  • Opening of helix
  • One helix for rotation
  • Both helices for labial movement

Orthodontics Removable Appliances Z spring

Question 2. Finger Springs/Single Cantilever.
Answer.

  • One end is fixed and other end is free

Wire used: 0.5/0.6mm

  • Use
  • Mesio distal movement of teeth

Parts Of Finger Springs:

  • Active arm – 12-15mm length
  • Helix – 3mm diameter
  • Activation – Moving active arm towards teeth

Orthodontics Removable Appliances Finger spring

Question 3. Cantilever Springs.
Answer.

Double cantilever:

Uses Of Double Cantilever:

  • Labial movement of incisors
  • Minor rotation of incisors

Wire used: 0.5mm

Parts Of Double Cantilever:

  • Two coils
  • Retentive arm – 10-12mm length

Finger Springs/Single Cantilever:

  • One end is fixed and other end is free

Wire Used: 0.5/0.6mm

Uses Of Finger Springs:

  • Mesio distal movement of teeth

Parts Of Finger Springs:

  • Active arm – 12-15mm length
  • Helix – 3mm diameter
  • Activation – Moving active arm towards teeth

Question 4. Canine Retractor.
Answer.

  • Used for distalization of canines

Types Of Canine Retractor

U loop canine retractor:

  • Wire used – 0.6/0.7mm
  • Uses: In 1-2mm of retraction

Helical canine retractor:

  • Wire – 0.6mm
  • Use: In shallow sulcus

Palatal canine retractor:

  • Wire – 0.6 mm
  • Use: Retraction of palatally placed canine

Buccal canine retractor:

Uses Of Buccal Canine Retractor:

  • Bucally placed canines
  • Highly placed canines

Types Of Buccal Canine Retractor:

  • Supported – with 0.5mm wire
  • Self supported – with 0.7 mm wire

Question 5. Adam’s clasp and its advantages
Answer.

  • By professor Phillip Adams

Synonyms Of Adam’s Clasp:

  • Liver pool clasp
  • Universal clasp
  • Modified arrow head clasp

Wire Used:

  • 0.7 mm round stainless steel

Parts Of Adam’s Clasp:

  • Two arrowheads – Engaging proximal undercuts
  • Bridge – Connects two arrow heads

Two Retentive Arms – Incorporated In Acrylic:

Advantages Of Adam’s Clasp:

  • Rigid retentive
  • Simple to fabricate
  • Occupies minimum space
  • Can be used for
    • Deciduous and permanent teeth
    • Partially and fully erupted teeth
    • Incisors, premolars and molars

Removable Appliances Viva Voce

  • T spring is activated by pulling the free end of T
  • Labial movement of incisors is achieved by Z spring
  • Buccal movement of premolars and canines is achieved by T spring
  • U loop canine retractor is activated by compressing the loop
  • Finger spring is single cantilever
  • Z spring is also called double cantilever
  • Modified split labial bow is used for closure of midline diastema
  • Palatal canine retractor is activated by opening helix by 2mm
  • Adam’s clasp are most commonly used
  • Reverse labial bow is activated by opening of U loop
  • Finger spring is activated by opening helix
  • Z spring is activated by opening both helices simultaneously

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