Retention And Relapse In Orthodontics Question And Answers

Retention And Relapse Definition

• Retention
  • Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction.
• Relapse
  • It is the loss of any correction achieved by orthodontic treatment.

Retention And Relapse Important Notes

Types of retention:

• Limited retention:
  • Class 1 non-extraction
  • Deep bites
  • Class 1, Class 2 Div. 1 and Div. 2 extraction
• Natural retention:
  • Anterior cross bites
  • Serial extraction
  • Highly placed canines
  • Posterior crossbite
• Permanent retention:
  • Midline diastemas
  • Rotation
  • Class 2 div.2 deep bites
  • Abnormal musculature
  • Cleft palate patients

Types of retainers:

• Removable:
  • Hawely’s appliance
  • Begg retainers
  • Clip on retainers
  • Wrap-around
  • Kesling tooth position
  • Invisible retainers
• Fixed:
  • Fixed appliance
  • Banded canine to canine
  • Bonded lingual
  • Band and spur retainer

Causes of relapse:

• Periodontal ligament traction
• Growth related changes
• Bone adaptation
• Muscular forces
• Failure to eliminate the original cause
• Role of the third molar
• Role of occlusion

Retention And Relapse Long Essays

Question 1. Enumerate theories of retention. Add a note on causes of relapse.
Answer.

Retention

Definition of retention: By Moyers

• Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction.

Theorems: 9 theorems by Riedel and 10th Moyers

• Moved teeth return to their former position
• Elimination of cause prevents relapse
• Malocclusion should be over-corrected
• Proper occlusion should be achieved
• Bone and adjacent tissues should be provided time to readapt around moved teeth
• Lower incisors must be placed upright
• Corrections carried out during growth periods are less likely to relapse
• Farther the teeth have been moved, the lesser the risk of relapse
• Arch form, particularly mandibular, cannot be permanently altered by appliance therapy
• Many treated malocclusions require permanent retaining devices

Types of retention

Limited retention:

• Class 1 non-extraction
• Deep bites
• Class 1, Class 2 Div. 1 and Div. 2 extraction

Natural retention:

• Anterior crossbite
• Serial extraction
• Highly placed canines

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

• Posterior crossbite

Permanent retention:

• Midline diastema
• Rotation
• Class 2 div.2 deep bites
• Abnormal musculature
• Cleft palate patients

Retainers: Passive appliances that help in maintaining and stabilizing the position of teeth long enough to permit readaptation of supporting structures

Types of retainers

• Removable retainers
  • Hawely’s appliance
  • Begg retainer
  • Clip on retainer
  • Wrap-around
  • Kesling tooth position
  • Invisible retainer

• Fixed retainers
  • Fixed appliance
  • Banded canine to canine
  • Bonded lingual
  • Band and spur retainer

Relapse: It is the loss of any correction achieved by orthodontic treatment

Causes of Relapse:

• Periodontal ligament traction:
  • Due to orthodontic tooth movement, PDL and gingival fibres are stretched
  • They readapt to the newly moved teeth
  • Different fibres require different periods for it
  • Principle fibres – 4 weeks
  • Gingival fibres – 40 weeks
  • If not provided sufficient time, leads to relapse
• Growth-related changes:
  • Due to the continuation of abnormal growth pattern
• Bone adaptation:
  • Normal, bony trabeculae are arranged perpendicular to the long axis of teeth
  • During orthodontic treatment, arranged parallel to the long axis of teeth
  • After treatment returns to original position
• Muscular forces:
  • Abnormal muscle balance
• Failure to eliminate the original cause:
  • The cause should be properly diagnosed and a treatment plan must be done accordingly
• Role of the third molar:
  • Eruption time – 18-21 years i.e. usually after completion of orthodontic treatment
  • Produces pressure
  • Results in crowding recurrence
• Role of occlusion:
  • Failure to eliminate habits like bruxism
  • Failure to achieve centric occlusion

Retention And Relapse Short Essays

Question 1. Define retention, and explain schools of retention.
Answer.

Retention: Maintaining newly moved teeth in position long enough to aid in stabilizing their correction – By Moyers

Schools Of Retention:

• Occlusion School – By Kingsley
  • Proper occlusion is important as it safeguards the stability in the new position of patients
• Apical base school:
  • By Alex Lundstorm, Mc.Cauley and Nance
    • By Alex Lundstorm – Suggest apical base as an important factor in the correction of malocclusions
    • Mc. Cauley – Added inter-canine and intermolar width should be maintained
    • Nance – Noted arch length cannot be permanently increased to a major extent.
• Mandibular Incisor School – Grieves and Tweed
  • Stability increases if mandibular incisors are placed upright
• Musculature School – Rojer
  • Functional muscle is necessary for post-treatment stability.

Question 2. Permanent retention.
Answer.

Conditions of Permanent Retention:

• Midline diastema
• Severe rotations
• Generalized spacing
• Patients with abnormal musculature
• Arch expansion
• Cleft palate patients
• Class 2 div.2 deep bite

Appliances Used:

Retainers: Passive appliances that help in maintaining and stabilizing the position of teeth long enough to permit readaptation of supporting structures

Types of Retainers:

Removable Retainers

Removed and reinserted at patient’s will

• Hawely’s Appliance – By Charles Hawley
  • Consists of – short labial bow, Adam’s clasps on molars

        Modifications of Hawely’s appliance:

• • Long labial bow – for space closure distal to the canine
  • Fitted labial bow – Excellent retention
  • Soldered labial bow
  • Anterior bite plane – for deep bite

       Advantages of Hawley’s appliance:

• • Simple and easy to fabricate
  • Comfortable to patient
  • Acceptable

Begg retainer – By P.R. Begg

Consists Of Begg retainer:

• Labial wire till last erupted molar, curves around it
• Spans palate – Acrylic portion

Advantage of Begg retainer: Eliminate risk of spacing between canine and premolar

Clip on retainer:

• Labial wire covering incisors and canine then wrapped around same teeth lingually

Wrap around retainer:

• Wire wrapped around all erupted teeth labially as well as lingually

Keeping tooth position – By H.D. Kesling

• Thermoplastic rubber covering the clinical crown of upper and lower teeth
• This leads to difficulty in speech and TMJ problems

Invisible retainers: Covers clinical crowns and part of the gingiva on a transparent thermoplastic sheet

Fixed retainers

• Fixed appliance itself
• Banded canine-to-canine retainer
  • Thicker wire over lingual surface soldered on canine bands
• Bonded lingual retainers
  • Stainless steel/Etglioy wire is etched and bonded lingually over interiors
• Band and spur
  • For rotation
  • The moved tooth is bands and spur are soldered over it.

Retention And Relapse Short Questions And Answers

Question 1. Define retention.
Answer.

By Moyers

• Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction

Question 2. Define relapse.
Answer.

• It is the loss of any correction achieved by orthodontic treatment

Question 3. Causes of relapse.
Answer.

• Periodontal ligament traction
• Due to orthodontic tooth movement, PDL and gingival fibres are stretched
• They readapt to the newly moved teeth
• Different fibres require different periods for it
• Principle fibres – 4 weeks
• Gingival fibres – 40 weeks
• If not provided sufficient time, leads to relapse

Growth-related changes:

• Due to the continuation of abnormal growth pattern

Bone adaptation:

• Normal, bony trabeculae are arranged perpendicular to the long axis of teeth
• During orthodontic treatment, arranged parallel to the long axis of teeth
• After treatment returns to the original position

Muscular forces:

• Abnormal muscle balance

Failure to eliminate the original cause:

• The cause should be properly diagnosed and a treatment plan must be done accordingly

Role of the third molar:

• Eruption time – 18-21 years i.e. usually after completion of orthodontic treatment
• Procedures pressure
• Results in crowding recurrence

Role of occlusion:

• Failure to eliminate habits like bruxism
• Failure to achieve centric occlusion

Question 4. Conditions where retention is not required/Natural retention.
Answer.

• Anterior crossbite
• Serial extraction
• Highly placed canines
• Posterior crossbite

Question 5. Permanent retention.
Answer.

• Midline diastema
• Rotation
• Class 2 div.2 deep bites
• Abnormal musculature
• Left palate patients

Retention And Relapse Viva Voce

• According to Alex Lundstorm, the apical base is the key to retention
• According to Grieves and Tweed, mandibular incisors are a key factor in retention
• Full-time retention after comprehensive orthodontic therapy is needed for 4-5 months
• Upper anterior crossbite correction with no adequate overbite requires retention of 3-6 months
• Opening of premolar space is a drawback of standard Hawley retainer
• Prevention of wedging effect on extraction site by Hawley retainer can be attempted by long labial bow
• Relapse is the loss of any correction achieved by orthodontic treatment