The combination retainer

Dr. Larry W. White discusses a retention strategy that avoids common causes of relapse

Introduction
The retention of an orthodontic correction has no less importance than the diagnosis and treatment planning that precede it. Yet, this important topic seldom generates much interest among patients or orthodontists. Take the White Quiz and receive CE credits.

After extending their best efforts and, in some cases, truly heroic innovations, orthodontists simply cannot do that much for patients during retention. At this point, orthodontists pretty much have to remain satisfied with what they have done and hope patients at least maintain the achievement.

However, several factors conspire against the status quo, such as:
•    continual natural occlusal changes that have nothing to do with relapse, because they involve teeth that were not manipulated during treatment
•    occlusal changes related to growth and/or maturation
•    occlusal instability from orthodontic treatment
•    patients’ refusal to use retainers as intended.     

Orthodontists should remain skeptical about any system of therapy that guarantees stability in the retention phase. Right now, no orthodontic system can ensure stability, nor can it guarantee stability of patients who receive the finest therapy. Orthodontists are dealing with living, dynamic, and chaotic systems that offer no promises, only assurances of changes. Realistic professionals simply hope to minimize those changes.
Only a few have been so bold as to suggest patients do not need retention.¹ In fact, several studies indicate orthodontic patients may suffer a greater amount of relapse than we might expect,^2-4 and this has led some to advocate permanent retention of one kind or another.^5,6

The orthodontist’s dilemma
Sheridan⁷ provides his patients with clear plastic retainers and has suggested that doctors delegate the retention phase to the patient since, “I am the creator not the guarantor of the finished orthodontic product…I will not and should not assume any responsibility for the aftermath of non-retention.”
On the surface, this seems like a reasonable approach to retention; however, as Thomas Huxley noted, “The tragedy of science is the slaying of a beautiful hypothesis by an ugly fact.”  The ugly fact is that patients still refuse to wear their retainers, and they and their parents often return, blaming the orthodontists for the relapse and asking for treatment (of course at no additional fee) and specifically for fixed retainers. They want a retention strategy that protects their investment rather than jeopardizes it. And I understand their dilemma and have formulated the following retention regimen that has worked well for a few decades.

The mandibular combination retainer construction
The laboratory technician will adapt a thin 0.018 × 0.014 stainless-steel ribbon arch (available from Highland Metals) to the mandibular anterior teeth—canine to canine—and microetch the ends of the wire (Figure 1). This thin wire lies flat against the teeth and provides a low profile that will not irritate the tongue or encourage breakage. The technician next enmeshes the microetched ends of the wire in light-cure composite pads and polymerizes the pads with an intense light (Figures 2 and 3).
The technician will then remove the assembly of composite pads and wire and trim the pads to discrete sizes, and microetch them to increase the bonding surface area (Figures 4 and 5). The pad and wire assembly is placed back on the model and secured by filling in any undercuts with brush-applied stone between the wire and model that might entrap Essix^® material when it is pressed over the model (Figure 6). The technician will then place two coats of separating liquid over the model and wire composite assembly (Figure 7).
The technician will vacuum or pressure-form the Essix C+^® plastic (Dentsply Raintree Essix) used in this case over the prepared model and then trim the Essix® retainer in the usual manner (Figures 8 and 9). If the 3 – 3 assembly releases from the Essix^® retainer, the clinician can replace it and secure it to the plastic retainer with a small amount of soft wax.
Only the canines have attached pads rather than all six anterior teeth since this is a more hygienic arrangement and more likely to catch the attention of the patient should one pad loosen. Also, having all six teeth attached to the wire gives the patient an uncomfortable feeling of having one giant tooth. An exception to this protocol occurs when the incisors have periodontal mobility and need splinting.
The Essix® will serve as a vehicle to convey the 3 – 3 to the teeth in a predictable fashion. Clinicians will find that microetching the lingual surfaces of the canines before acid-etching will increase the enamel surface area and will better secure the 3 – 3 (Figure 10). Clinicians should prepare the mouth with a routine bonding protocol and isolate the teeth. The canines are etched and sealed, sealant is lightly painted on the canine pads, and a miniscule amount of composite is also added to the pads. The clinician will then place the combination retainer in the mouth and quickly polymerize the sealant and composite on the canine pads with a curing light. Removal of the Essix^® overlay is easily done with a scaler (Figures 11 and 12).
After bonding of the combination retainer, patients receive a container to safeguard the Essix^® retainer, and instructions about caring for the bonded retainer. Assistants ask patients to store the removable Essix^® retainer in a safe place so that the patient can use it in the event of bonded-retainer breakage. Patients also receive a pamphlet regarding the use of the clear Essix^® retainer and a syringe of enamel bleaching gel, which they can apply by using the removable Essix®. Patients are encouraged to bleach only the maxillary teeth for a couple of weeks so they can see the difference the gel makes.

Maxillary combination retainer
Maxillary combination retainers, while less frequently used, can be made with the same procedure, but four incisors will receive pads instead of only the canines (Figures 13 and 14). If clinicians wish, they can include the maxillary canines and hopefully gain more stability. Nevertheless, the sharp incisal occlusion makes the maxillary combination retainer a much riskier process and more prone to breakage. Fortunately, the maxillary incisors ordinarily present less post-treatment relapse than do the mandibular incisors, and clinicians can rely more on removable retainers.

Summary
Although no retention protocol offers complete security, combination retainers offer doctors and patients several advantages:
•    the patient receives fixed security for the retention of aligned teeth
•    the patient doesn’t have to contend with removable retainers
•    the doctor avoids confrontations with unreasonable and uncooperative patients and parents
•    in the event of a broken 3 – 3, the patient can use the Essix^® as a backup retainer and avoid the cost of a new retainer and also a period of no retention
•    the Essix® can serve as a vehicle for bleaching solution.

References

1. Williams R (1985) Eliminating lower retention. J Clin Orthod 19(5):342-349.

2. Joondeph DR, Riedel RA. Retention (1985) In: Graber TM, Swain BF, eds. Orthodontics: Principles and Techniques. C.V. Mosby; St. Louis, MO:857-898.

3. Little RM, Riedel RA, Artun J (1988) An evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention. Am J Orthod Dentofacial Orthop 93:423-428.

4. Riedel RA (1970) A review of the retention problem. Angle Orthod 30:179.

5. Parker W (1989) Retention--retainers may be forever. Am J Orthod Dentofacial Orthop 95:505-513.

6. Zachrisson B (1995) Third-generation mandibular bonded lingual 3-3 retainer. J Clin Orthod 29:31-38.

7. Sheridan JJ (1991) The three keys of retention. J Clin Orthod 25:717-718.

Larry W. White, DDS, MSD, FACD, graduated from Baylor Dental College and then served in the US Air Force from 1959 to 1961. He practiced general dentistry in Hobbs, New Mexico, from 1961 to 1966 and returned to Baylor to receive an MSD degree in orthodontics in 1968. He is a diplomate of the American Board of Orthodontists, a fellow in the American College of Dentists, past director/president of the Rocky Mountain Society of Orthodontists, and past president of the New Mexico Orthodontic Society and the Texas Orthodontic Study Club. He reviews for American Journal of Orthodontics, was editor of the Journal of Clinical Orthodontics for 17 years, and has contributed more than 100 original articles to the dental literature, and lectured in over 35 countries. Dr. White was the first director of the University of Texas Health Science Center in San Antonio Orthodontic Residency Program. He is also a contributing editor for the Orthodontic CyberJournal. He practices in DeSoto, Texas, and serves as an adjunct professor at Baylor Dental College in Dallas. He can be reached at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .