orthodontic retainers types• REMOVABLE APPLIANCES AS RETAINERS• FIXED RETAINERS
Removable appliances canserve effectively forretention against intra-archinstability and are alsouseful as retainers (ex:headgear) in patients withgrowth problems.If permanent retention is needed, a fixedretainer should be used in most Instances.
• The most common removable retainer• Designed in the as active removable appliance. adjustment loops clasps on molar labial bow
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!!
Socommon modification ofthe Hawley retainer foruse in extraction casesis: a bow soldered to thebuccal section o f Adamsclasps so that the actionof the bow helps holdthe extraction siteclosed.
Clasp locations for a Hawley retainer most be selectedcarefully, since It can disturb rather thanretain the tooth relationships established duringtreatment. So circumferential clasps on the terminalmolar may be preferred over the more effective Adamsclasp 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.BUT:A full-arch wraparound retainer is indicated primarily whenperiodontal breakdown requires splinting the teeth together.
-What’s tooth positioners?a resilient rubbery and plastic removable appliance fitted over theocclusal surfaces of the teeth to obtain limited tooth movement andstabilization, usually at the end of orthodontic treatment.-Positioners as Retainers?A tooth positioners also can beused as Retainer, either fabricatedfor this purpose alone or morecommonly, continued as a retainerafter serving initially as a finishingdevice.
This type Needs no activation at regularintervals 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 largepart to fact that its worn only asmall percentage of time .
Use in the situation where “intra archinstability” is anticipated and “prolongedretention” is planned especially themandibular incisor area.
1-does not require patient compliance.2- Reduced need for patient cooperation.3- Can be used when removable retainers. cannotprovide same degree of stability.4-Permanent retention.
1-Difficult to maintain hygiene.2-Poor patient acceptance.3-more cumbersome to insert4-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.
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 movingteeth and serving as a retainer at the same time.this usually accomplished with a removableappliance that continues as a retainers after ithas repositioned the teeth. Hence the name
The term usually reserved for two specificsituations: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 can be 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.
The use of a functional appliance as an active retainer from its use as a pure retainer. Expected The object is to control primarily growth, and tooth to move teeth movement is largely no significant skeletal an undesirable side change is expected. effect.The correctionis achieved by restraining the eruption of maxillary teethposteriorly and directing the erupting mandibular teethanteriorly.