Michael C. Alpern, DDS, MS
Ada Hinda Alpern, RDH
by Michael C. Alpern, DDS, MS, and Ada Hinda Alpern, RDH
It takes planning, patient education, and careful follow-up to maintain orthodontic results for the long-term
When asked, “How long should we retain?” many notable orthodontic teachers have replied, “How long do you want the teeth to stay straight?” This implies permanent retention. Why is this necessary?
When we attempt to treat any malocclusion, we are approaching a system of functioning muscles, teeth, and bone, all in a state of equilibrium. Our newly planned tooth positions occur as we disrupt the balance and muscle, teeth, and bone memory.
As the teeth are moved to the new positions, the bone (with periodontal ligaments) and surrounding muscles require a significant period of time to achieve a new state of equilibrium or balance. Thus, the critical need for retention.
Removable (if truly worn) or permanent retention for a number of years appears to assist in maintaining this new state of balance. The problem with removable retainers is that they are removable. Nearly every orthodontist has experienced completing a truly difficult malocclusion and pleading with patient and parents to wear their retainers full time—only to have patients return complaining that their teeth are shifting. Yet they failed to return for retention visits or “lost” their retainers.
Thus, many orthodontists are using fixed (bonded) retainers. In our practice, we try to use fixed retainers wherever possible. Our primary mandibular retainer is a braided stainless steel wire bonded to the lingual of incisors, cuspids, and/or first bicuspids.
Fixed Retainer Designs
We use two designs. Hyperdivergent patients (those with vertical skeletal patterns) receive a braided stainless steel wire bonded from cuspid to cuspid. Hypodivergent patients (those with horizontal and normal patterns) receive the same wire, only bonded from the first bicuspid.
This bicuspid-to-bicuspid design ties the anterior segment to the posterior segment, assisting in preventing deep bite relapse. Cuspid-to-cuspid bonded lingual retainers permit a slight tendency for eruption of the incisors and cuspids in open bite malocclusions. In all cases, we bond every tooth to the wire.
Additionally, only bonding the distal abutments of a bonded lingual retainer did not prevent rotations or movements of the unbonded incisors. The only ideal solution was bonding every tooth attached to the lingual retainer. This seemed a reasonable solution, since buccal or facially bonded orthodontic appliances (with rare exceptions) include bonded or banded brackets on every tooth.
Unlike labial/buccal bonded orthodontic brackets, which are monitored every 4 to 8 weeks, lingual bonded retainers must be secure enough to permit monitoring every 3 to 6 months. This prompted our office to improve the lingual bonding process to increase strength and bonding effectiveness with the following steps.
When patients are ready to have their appliances removed, we make an alginate impression of the lower anterior arch, pour a cast, and contour a braided stainless steel lingual retention wire in the laboratory. After contouring, we microetch the wire with 50-micron aluminum oxide. This makes bonding to the wire more feasible and tends to make the wire “take a set” to the contour we created. This process is most safely performed in a vacuum container with a clear window. The vented container prevents excess powder from contaminating the laboratory or being inhaled by the operator.
Before appliance removal, we air powder clean the lingual surface of the teeth with Ortho Prophy SA-85 (Danville Materials). This material cleans twice as effectively as pumice and is less abrasive. After enamel cleaning, we lightly ligate the retaining wire to the lingual surface of the teeth through the contacts points and around the mandibular archwire. We condition the teeth with etching gel, then wash each tooth surface for 10 seconds at 90° with air/water spray. We then dry with suction; bond with a light-cured, flowable compomer (Caulk’s Dyract Flow or Fuji); and cure with a Pac light.
A compomer is half glass ionomer and half composite. Glass ionomer has a stronger tendency to bond to stainless steel and the enamel. Glass ionomer composites also act as “fluoride pumps,” releasing and absorbing fluoride.
This discussion has primarily focused on mandibular lingual retainers. For a number of years, we have attempted to use maxillary anterior lingual bonded retainers as well. The primary problem is that lingual occlusal contact from opposing incisors and cuspids has limited the space available for an adequate bonded lingual retainer.
We are beginning to evaluate the use of differing materials such as those made by Ribbond. We are not cutting a groove into the lingual surface of the teeth to place such a retainer at this time.
Pros of Fixed Retention
1) By definition, bonded retainers are fixed. They retain full-time, preserving the orthodontic correction.
2) Unlike removable retainers, bonded retainers can rarely be lost, eaten by the dog, thrown in dumpsters, or stolen. The list of disasters that can befall a removable retainer is endless and only limited by the imagination.
3) Bonded retainers rarely interfere with playing musical instruments, sports, speech, or appearance.
For any patient with a vertical pattern or any open bite
tendency, we create fixed retention with a stainless steel
twisted wire bonded on the lingual from cuspid to cuspid.
Cons of Fixed Retention
1) Bonded retainers require the same oral hygiene routine as fixed facial or lingual orthodontic appliances. Thus, patients with no flossing experience and poor oral hygiene during treatment are not eligible for bonded lingual retainers. Similarly, patients who eat poor diets high in excessive junk food, with evidence of multiple decalcifications during treatment, are very high risk when wearing bonded retainers.
2) Because bonded retainers without rigid hygiene can be a source of bacteremias, we do not use any fixed retainers in patients with prolapsed mitral valves, artificial joints, or other serious medical conditions highly susceptible to bacterial infections.
3) Bonded retainers require regular observation and maintenance appointments to ensure that all bonded areas are intact and that there is no gingival infection, decalcification, or tooth decay. These observation appointments should be performed by the orthodontist and the general dentist.
It is critical to educate patients and parents that bonded retainers must be monitored. They must sign the treatment card to indicate that when they agree to bonded retainers, they also agree to appear for all retention visits as they did for active orthodontic treatment.
Once we are confident that patients are flossing the bonded retainers regularly, we see them every 3 months for 1 year, then twice a year thereafter. This must be built into the original fee or clearly listed as an additional cost after active treatment is completed.
It is very important to notify the referring dentist and hygienists why bonded retainers have been placed and request their assistance in cleaning and monitoring to see that all bonds are intact and no dental disease is developing.
Bonded retainers are high-risk from a risk-prevention standpoint. There are instances in which bonded retainers have been placed (without any follow-up) and the retainers have come loose and been swallowed or aspirated. Serious surgeries have been required in a few reported cases.
For horizontal or deep-bite growing patients, we extend the
stainless steel twisted wire from first bicuspid to first bicuspid.
Before you remove orthodontic appliances and place bonded retainers, we advise reviewing the patient’s medical history. Extensive oral hygiene requirements should be presented and dispensed in writing to patients and parents. The fact that we have the patient and parents sign our charts signifies how seriously we take this process.
We have all patients receiving fixed retainers sign an Informed Consent Form (in duplicate) signifying their adherence to threading floss under the wire or other materials every day. They agree to limit intake of junk foods containing excess sugars. They accept all responsibility for the care of the retainers, including but not limited to never biting fingernails or chewing ice or other excessively hard foods. They agree that, if any portion comes loose, to immediately contact us or any orthodontist or dentist for repair or removal.
One additional consideration. Referring dentists and their hygienists (who may not have proper education) may not like bonded retainers. As stated previously, prior to placing bonded retainers, we inform the dentists and hygienists. We regularly hold lectures in our office explaining the importance of bonded retainers, their care, and especially scaling techniques.
We stress that every bonded retainer patient must agree in writing to come to our office twice a year to have the retainers examined for disease or loss of bonding material. They also agree to see their dentist twice a year for routine prophylaxis. In this manner, every bonded appliance we place is examined four times per year.
A question that always arises is, “How long can a patient keep a bonded retainer in place?” There have been instances of patients keeping bonded retainers in for several decades. In our office, as long as the patient abides by all instructions and procedures listed above, we will permit them to keep the retainer as long as they want to do so. After 3 to 5 years, if the patient wants to maintain the bonded retainer, we do not charge a fee because it signifies our caring about patients. Other orthodontists have suggested fees for retainer observation and maintenance after 2 to 3 years.
With all these concerns aside, we still use bonded retainers in 80% of our patients with excellent, satisfying results.
In conclusion, one last critical point bears mention. When you plan your treatment, also plan your retention. Retention of any type is equally important as orthodontic diagnosis, treatment planning, and appliance placement. Many excellent clinicians have completed all the above and redirected growth, protected the temporomandibular joints, and moved teeth to an ideal aesthetic and functional position. Even in these difficult cases, retention should be planned at the beginning.
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During all this time, the orthodontist has been there performing procedures and guiding it all. Near the end of treatment, the patient and parents truly see the changes and can marvel at all the orthodontist has accomplished.
All of this can be lost without a planned and executed retention program. Patients often feel they have been “released from bondage” when braces are removed. They want to live their life without any consideration of retention. All of the good will and future referrals can be lost (even after much effort) when the patient does not comply with retention requirements. We maintain that absolute tooth stabilization is mandatory for at least a year or more after active appliance removal in the maxillary arch, and 3 to 5 years in the mandibular arch.
Thus, retention requires the same level of communication and time we apply during initial orthodontic placement. All this must occur at a time when the patients may not seriously be interested. Patients and parents must be motivated and educated that orthodontic treatment is not over with removal of braces. Retention is also part of our treatment.
Complete retention may be our Achilles’ heel. We can prevent concerns from arising by applying the same enthusiastic education and motivation for retainers that we do when orthodontic treatment began.
Michael C. Alpern, DDS, MS a member of Orthodontic Products‘ editorial advisory board, is in private practice in Port Charlotte, Fla. He can be reached at
Ada Hinda Alpern, RDH is married to Alpern and serves as the office manager and dental hygienist in his practice.