RETENTION AND RELAPSE

Orthodontic retainers types

orthodontic retainers types

• REMOVABLE APPLIANCES AS RETAINERS

• FIXED RETAINERS

• ACTIVE RETAINERS

Removable appliances can serve effectively for retention against intra-arch instability and are also useful as retainers (ex: headgear) in patients with growth problems.

If permanent retention is needed, a fixed retainer should be used in most Instances.

REMOVABLE APPLIANCES AS RETAINERS

• The most common removable retainer • Designed in the 1920 as active removable

appliance.

clasps on molar

labial bow

adjustment loops

HAWLEY RETAINERS

1. Close band spaces between the incisors.2. keep the extraction space closed When first

premolars have been extracted.

• which the standard design of the Hawley retainer cannot do!!

USES OF HAWLEY RETAINERS

So common modification of the Hawley retainer for use in extraction cases is:

a bow soldered to the buccal section o f Adams clasps so that the action of the bow helps hold the extraction site closed.

Clasp locations for a Hawley retainer most be selected carefully, since It can disturb rather than retain the tooth relationships established during treatment. So circumferential clasps on the terminal molar may be preferred over the more effective Adams clasp if the occlusion is tight.

Advantages:1-Can be used in most cases.2-Hygiene not an issue.3-can be modified.

Disadvantages:1-Requires patient compliance.2-Visible labial bow.3-interproximal wire may cause opening of spaces.4-High incidence of breakage and loss.

• The 2nd major type of R.O.R. • Consists of wire that passes along the labial as well as

lingual surfaces of all erupted teeth which is embedded in a strip of acrylic.

Not routinely used because:1. Its often Less comfortable than

Hawley retainer.2. May not be effective in

maintaining overbite correction.

REMOVABLE WRAPAROUND RETAINERS

BUT:A full-arch wraparound retainer is indicated primarily when periodontal breakdown requires splinting the teeth together.

-What’s tooth positioners?a resilient rubbery and plastic removable appliance fitted over the occlusal surfaces of the teeth to obtain limited tooth movement and stabilization, usually at the end of orthodontic treatment.

-Positioners as Retainers?A tooth positioners also can be used as Retainer, either fabricated for this purpose alone or more commonly, continued as a retainer after serving initially as a finishing device.

POSITIONERS AS RETAINERS

This type Needs no activation at regular intervals and it is durable.

But The major problem are:

1. its bulk, patients often have difficulty wearing a positioner full-time or nearly.

2. Positioners do not retain incisor irregularities and rotations as well as standard retainers.

3. Over bite tends to increase while a positioner is being worn.

These all are probably relates in large part to fact that its worn only a

small percentage of time .

Use in the situation where “intra arch instability” is anticipated and “prolonged retention” is planned especially the mandibular incisor area.

FIXED RETAINERS

Advantages:

1-does not require patient compliance.

2- Reduced need for patient cooperation.

3- Can be used when removable retainers. cannot provide same degree of stability.

4-Permanent retention.

Disadvantages:1-Difficult to maintain hygiene.

2-Poor patient acceptance.

3-more cumbersome to insert

4-Increased chair-side time and more expensivepotential for becoming de-bonded.

1. Maintenance of lower incisor position during late growth of mandible (age 16-20) . Especially if the lower incisors have previously been irregular. A relapse into crowding is almost always accompanied by lingual tipping of the central and lateral incisors in response to the pattern of mandibular growth.

MAJOR INDICATIONS

An excellent retainer to hold these teeth in alignment is a fixed lingual bar, attached only to canines (or to canines and 1st premolars) and resting against the flat lingual surface of the lower incisors above the cingulum.

Its also possible to bond a fixed lingual retainer to one or more of incisor teeth, the major indication for this variation is a tooth or teeth that had been severely rotated.

2. Diastema maintenance. A second indication for a fixed retainer is a situation were teeth most be permanently or semi-permanently bonded together to maintain the closure of a space between them. The best retainer for this purpose is a bonded lingual section of Flexible wire as shown in the figure.

A removable retainer is not a good choice for prolonged retention of central Diastema. In trouble some cases, the Diastema is closed when the retainer is removed but opens up quickly. The tooth movement that accompanies this back and fourth closure is potentially damaging over a long period.

3. Maintain of Pontic or Implant Space. Using a fixed retainer for a few months reduces mobility of teeth and often makes it easer to place the fixed bridge that will serve among other functions as a permanent orthodontic retainer.

-Use a heavy intracoronal wire and bonded it to the adjacent teeth. Obviously, the longer span the heaver the wire should be.

4. Keeping Extraction Spaces Closed in Adults. A fixed retainer is both more reliable and better tolerated than a full-time removable retainer, and spaces re-open unless a retainer is worn consistently.

-Bringing the wire down out of occlusion decrease the chance that it will displaced by occlusal forces.

Is a contradiction in term !Since the device can not be actively moving teeth and serving as a retainer at the same time.

this usually accomplished with a removable appliance that continues as a retainers after it has repositioned the teeth.

Hence the name

ACTIVE RETAINERS

The term usually reserved for two specific situations:

1) Realignment of irregular incisors with spring retainers.

2) Management of class II or class III relapse tendencies with modified functional appliance.

Spring Retainers Its a variation type from Removable Wraparound

Retainer knows also as clip-on retainer The major indication for this retainer is re-crowding of

the lower incisors which is usually caused by late mandibular growth.

if late crowding has developed, it often necessary to reduce the interproximal width of lower incisors so that the crown do not tip labially into an obviously unstable position.

Its not indicated as a routine procedure.

just 0.25mm on each.

interproximal enamel can be removed with abrasive strips or thin flame-shaped diamond stone.

Modified Functional Appliance as Active Retainers

When functional appliance used as retainer it known as Modified F.A.

EX: The Bionator which is a 1 piece removable appliance designed to produce a forward positioning of the mandible correcting a skeletal Class II relationship.

A typical use for bionator as an active retainer would be a male adolescent who had slipped back 2 to 3 mm toward a Class II relationship after early correction.

functional appliance as an active retainer canbe used in teenagers but is of no value in adults!!

This is because differential anterioposerior growth is not necessary to correct a small occlusal discrepancy (because tooth movement is adequate) but some vertical growth is required to prevent downward and backward rotation of the mandible.

Expected primarily to move teethno significant skeletalchange is expected.

The object is to control growth, and tooth movement is largelyan undesirable side effect.

The use of a functional appliance as an active retainerfrom its use as a pure retainer.

The correctionis achieved by restraining the eruption of maxillary teethposteriorly and directing the erupting mandibular teethanteriorly.

DIFFERS

Pure retainer active retainer

THANK YOU

Done by Israa Awadh