Does Retainer Interfere with Correct Tongue Resting Posture?

My friend  is trying to figure out if an ortho retainer might interfere with the tongue rest position by “inviting” the tongue to explore the lower retainer, therefore defeating the attempts to keep the tongue in a more neutral rest position. The scientific literature is scant on the subject (an article from 2008 by Booth, Edelman and Profitt re: 20 year follow up of retainers but unrelated to tongue position). What is your experience and do you know of an article that we might have overlooked, dealing with this issue?   Thank you in advance for your expertise.

Response provided by Dr. Robert Mason, D.M.D., Ph.D. Our friend and colleague raises an interesting question. Inherent in the question is the appropriate concern that explorations of the tongue forward or down in retention can open the freeway space and lead to dental changes. Increasing the freeway space dimension while wearing retainers is not desirable. Although this is not a typical problem involved in the retention phase, the scenario described could present a problem. In an article by Lou Norton and Milt Gellin in the Dental Clinics of North America, V. 12: 363-382, 1968, entitled “Management of digital sucking and tongue thrusting in children”, they advocated cutting a half-moon shaped groove in an upper retainer at the area of the incisive papilla as a reminder for where the tongue tip should rest. There is a photo in this article that shows the grooved appliance.  I have reported on this a few times at meetings and have found this to be a useful reminder for any patient who has had a tongue thrust tendency or pattern – either at rest or in function. These authors, along with John Mink, later advocated for what is known as the “Bluegrass appliance”, consisting of a raised bar at this same level with a few small cylindrical rotating beads on the bar, also to be used as a reminder. I object this to reminder technique because it serves to open the freeway space, which is not what you would want to accomplish with a retainer. (FYI, the appliances from the University of Kentucky by Mink, Spedding, Gellin and Norton are called “Bluegrass appliances” since Kentucky is known as the “Bluegrass State”). I have cut a groove into maxillary appliances many times and have been pleased with the success of using this simple procedure as a reminder. Each of us has probably had the experience of losing a dental filling or crown, and finding your tongue moving into that area to explore. That same principle is involved with grooving an appliance. I cut the groove all of the way through the appliance – extending about 15 mm side to side across the retainer and about 4 mm wide. A side benefit of a groove, or even a hole, cut through an upper retainer is that it keeps the patient from being able to play with the upper retainer by sucking it down into the mouth as many patients are seen to do. In patients without any history of thrusting or a tongue forward rest posture, but who play with their retainer by sucking it down, I cut a small hole anywhere along the midline of the upper retainer. This prevents the sucking opportunity by breaking the suction seal – a simple trick that many orthodontists may not be aware of. I hope that these comments are useful. Thanks for asking.