CLINICAL GUIDELINES – ORTHODONTIC RETENTION

CLINICAL GUIDELINES: ORTHODONTIC RETENTION

 

ORTHODONTIC RETENTION

 

1. INTRODUCTION

Retention is the phase of orthodontic treatment which maintains the teeth in their orthodontically corrected

positions following the cessation of active orthodontic tooth movement. Orthodontic retainers resist the

tendency of teeth to return to their pre-treatment positions under the influence of periodontal, occlusal and soft

tissue forces, and continuing dentofacial growth. Very few prospective controlled studies have evaluated the

effectiveness of retention. A recent systematic review concluded that there was a need for randomised

controlled trials in this area of orthodontic practice.1

Retention is advisable for almost all treated malocclusions. A recent survey carried out in the UK found that

the most commonly used retention period was 12 months.2 This approach is supported by histological studies

which have shown that the supracrestal periodontal fibres remain stretched and displaced for more than 7

months after the cessation of orthodontic tooth movement,3,4 suggesting that the retention period should

generally be at least 7 months. However, individual patient factors can often modify the length of the retention

phase.

2. OCCLUSAL AND OTHER FACTORS WHICH MAY MODIFY THE RETENTION PROTOCOL

 

2.1 Lower incisor alignment

Increases in lower incisor irregularity occur throughout life in a large proportion of patients following

orthodontic treatment and also in untreated subjects. Recent evidence suggests that most change will take

place by the middle of the third decade.5 It has been suggested that prolonged retention of the lower labial

segment until the end of facial growth may reduce the severity of lower incisor crowding.6

Patients’ expectations of the stability of their lower incisor alignment should be considered on completion of

orthodontic treatment. If an individual is unwilling to accept any deterioration in lower incisor alignment

following orthodontic treatment then permanent fixed or removable retention may have to be considered.

2.2 Corrected rotations of anterior teeth

As the supracrestal gingival fibres are known to take the longest amount of time to reorganise, prolonged

retention of corrected rotations may be helpful in reducing relapse. While the use of adjunctive

circumferential supracrestal fibrotomy has been shown to be effective in reducing relapse within the first 4-6

years after debonding, the additional long term clinical benefit from the procedure is relatively small.7

2.3 Changes in the antero-posterior lower incisor position

Any intentional or non-intentional change of more than 2mm indicates the need for long-term or indefinite

retention.8

2.4 Correction of deep overbite

Following the correction of a very deep overbite, the use of an anterior biteplane until the completion of facial

growth has been recommended.8 This may be particularly useful when there is evidence of an anterior

mandibular growth rotation.9

2.5 Correction of anterior open bites

While the use of retainers incorporating posterior biteblocks has been recommended for prolonged retention

of anterior open bite malocclusions with unfavourable growth patterns8, there is currently a lack of scientific

evidence to support this.

2.6 Patients with a history of periodontal disease or root resorption

In patients with previously treated severe periodontal disease, permanent retention is advised. For those with

minimum to moderate disease, a more routine retention protocol can be used.10 There is evidence of an

increased risk of deterioration of lower incisor alignment post-retention in cases with root resorption or crestal

bone loss.11 These cases may therefore benefit from prolonged retention.

2.7 Growth modification treatment

Following the use of headgear or functional appliances, retention using a modified activator appliance has

been reported as effective in maintaining Class II correction.12 However, no comparative studies have

confirmed the usefulness of this form of retention.

2.8 Correction of posterior and anterior crossbites

When the incisor overbite and posterior intercuspation are adequate for maintaining the correction, no

retention is necessary.13

2.9 Adult Patients

When the periodontal supporting tissues are normal and no occlusal settling is required, there is no evidence

to support any changes in retention protocol for adult patients compared with adolescent patients.

2.10 Spaced dentitions

Permanent retention has been recommended following orthodontic treatment to close generalised spacing or a

midline diastema in an otherwise normal occlusion.14

3. RETAINER DESIGN

 

3.1 Removable retainers with a labial bow (Hawley and Begg type retainers)

These retainers are robust and can be worn during eating. Hawley retainers have been shown to have the

advantage of facilitating posterior occlusal settling in the initial three months of retention.15 The labial bow

can be used to accomplish simple tooth movements if required, and an anterior biteplane can easily be

incorporated for retention of a corrected deep overbite. A retention regime with Hawley retainers of 6 months

full time wear followed by 6 months nights only has been recommended as it has been shown to be associated

with less relapse than 3 months full time wear and 3 months nights only.16

3.2 Removable vacuum formed retainers

Vacuum formed retainers (VFRs) are relatively inexpensive and can be quickly fabricated on the same day as

appliance removal. They are discreet and can be modified to produce tooth movements if required. Full

posterior occlusal coverage (including second molars if present) is advisable in order to reduce the risk of

overeruption of these teeth during retention. There is evidence that they are preferred by patients compared

with Hawley retainers.17

One study has shown that VFRs were significantly less likely to allow posterior occlusal settling than Hawley

retainers.15 However, this is likely to be of little importance if good posterior intercuspation has been

established by the time of debonding.

3.3 Fixed bonded retainers (Smooth wire, Flexible spiral wire)

Fixed retainers are indicated for long-term retention of the labial segments, particularly when there is reduced

periodontal support, and for retention of a midline diastema.8 Fixed retainers are discreet and reduce the

demands on patient compliance. However, they are associated with failure rates of up to 47%,19 particularly

on upper incisors when there is a deep overbite.20,21 In addition, calculus and plaque deposition is greater than

with removable retainers.22 Fixed retainers, therefore, require long-term maintenance.

Flexible spiral wire retainers allow differential tooth movement and are particularly useful for patients with

loss of periodontal support. Current orthodontic opinion recommends either the use of 0.0215 inch multistrand

wire,22 or 0.030 – 0.032 inch sandblasted round stainless steel wire.23

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ABSCESSED TOOTH !!

What is an abscessed tooth?

When you have tooth decay or gum disease, you can get infection deep within the tooth or gum. This infection is an abscessed tooth and can be very painful. If it is not treated, the infection can spread and you can lose your tooth or have other health problems.

What causes an abscessed tooth?

Damage to the tooth, an untreated cavity, or gum disease can cause an abscessed tooth.

If a cavity is not treated, the inside of the tooth (called the pulp) can become infected. Bacteria can spread from the tooth to the tissue around it, creating an abscess.

Gum disease causes the gums to pull away from the teeth, leaving pockets. If food builds up in one of these pockets, bacteria can grow, and an abscess can form. Over time an abscess can cause the bone around the tooth to dissolve.

What are the symptoms?

You may have:

  • Throbbing pain, especially when you chew.
  • Red, swollen gums.
  • A bad, salty taste in your mouth.
  • Swelling in your jaw or face.
  • A fever.
  • A bump (gumboil) that looks like a pimple on the cheek side or tongue side of the gum near the tooth.

Over time as the infection spreads, the bone in your jaw may begin to dissolve. When this happens, you may feel less pain, but the infection will remain. If you lose too much bone, your tooth will become loose and may have to be removed.

If you have a severe toothache or notice drainage of pus, call your dentist right away. You may have an abscessed tooth. If it is not treated, the infection could spread and become dangerous.

How is it treated?

If you have an abscessed tooth, your dentist will give you antibiotics to kill the bacteria causing the infection. Antibiotics may help for a while. But to get rid of the abscess, your dentist will need to get rid off the source of infection. This is done by making hole in the tooth or gum to drain the infection. Usually this will relieve your pain.

If the inside of your tooth is infected, you will need a root canal or to have the tooth removed. A root canal tries to save your tooth by taking out the infected pulp. If you don’t want a root canal or if you have one and it doesn’t work, the dentist may have to remove your tooth. You and your doctor can decide the best step to take.

You may be able to reduce pain and swelling from an abscessed tooth by putting an ice pack wrapped in a towel against your cheek. You can also try over-the-counter pain medicine, including aspirin, acetaminophen (such as Tylenol) or ibuprofen (such as Advil or Motrin). But you still need to see your dentist for treatment.

DENTAL BRACES

Dental braces comes under orthodontic dentistry, these are the device to correct the teeth alignment and their position with regard to bite.

USES: 1.) the primary use of these braces is to correct malocclusions like; overbites, under bites, cross bites and open bites.
2.) They are used in widening of the palate and jaw’s.
3.) Create spaces between teeth, shapes the teeth and jaws.

Working:
Fact to be known: A mechanical force foreplays the tooth movement, pushes the tooth in a specific direction, by which a stress is created in the periodontal ligament , this stress modifies the periodontal blood supply and a biological response is created which leads to bone remodeling.

Bone remodeling procedure: It’s a two way process in which the bone is formed on one side by osteoblast cells- these are the cells which form bone, and on the other side the bone is resorbed by osteoclast cells- these are cells which undergo bone resorption.

PROCEDURE:

Step 1: According to the facial symmetry the dentist determines whether the braces are suitable for the patient, he then visualizes the teeth.

Step 2: If the dentist is satisfied with all the requirements stated above, he then files an record appointment, where impressions, moulds, and x-rays are made.

Step 3: He then takes a look on the records for further treatment and proper course of action.

Step 4: He cannot judge the perfect treatment time it may be six months or can also be extended to one and half year, depending upon the complexity of the patient.

ADVANCED TREATMENTS AVAILABLE:
Braces are available in different textures, such as; metallic or ceramic.
Advanced treatment is available and is known as Envisaging treatment, the treatment is not applicable for all only to those patients who have a natural spacing in their teeth’s. The main advantage of this treatment is, the braces are invisible they go unnoticed and it does not involve any kind of metallic wires, brackets or brands.
Article posted by M. Vishwa kumar