Do retainers contain gluten?

Do parents of children with celiac disease really have to worry that their children’s retainers contain gluten?

Amy Jones, MS, RD and Tricia Thompson, MS, RD

Many of you may have heard about the article “An Orthodontic Retainer Preventing Remission in Celiac Disease” recently published in the journal Clinical Pediatrics. In short, this is a case presentation of a 9 year old girl diagnosed with celiac disease. IgA tTG at diagnosis was 172 U/mL (normal defined as < 20). The authors state that despite a strict gluten-free diet her tissue transglutaminase remained elevated. However, when she removed her retainer which was found to contain a plasticized methacrylate polymer which may contain gluten her serology normalized.

A close look at the patient’s serology provided by the study authors shows that at her 6^th month follow-up the patient’s tTG level had fallen to approximately 50 U/mL. At her 7^th month follow-up, the patient’s tTG level was up slightly to approximately 55 U/mL. At her 8^th month follow-up her tTG was approximately 52 U/mL. At this point the retainer was removed. By her 10 month follow-up tTG levels were around 0.

We are concerned that this case study may unnecessarily worry parents over their children’s retainers especially if only the title or the abstract of the study is read (Note to bloggers: it is irresponsible to write about a study if you have NOT read the ENTIRE article).

The lead author was contacted with the following questions:

• Might these tTG levels represent a normal progression?
• Did the child have the retainer the entire time she was on a gluten-free diet? If so, this would suggest the retainer had nothing to do with the “blip” that was seen in tTG levels.
• Was it established that the retainer actually contained gluten or that it was “just” made with a material that may include gluten?
• If it was established that the retainer did in fact contain gluten was the manufacturer of the retainer contacted to ask how much gluten was used to make it?

Zebunnissa Memon MD, responded that yes, the child had the retainer the entire time she was on a gluten-free diet but, “Only when she removed the retainer did her serology and symptoms improve.” Dr. Memon went on to say that, “The retainer was not tested. The ingredients from the manufacturer listed methylmethacrylate: a plasticized methacrylate polymer, in which gluten is a common additive. The manufacturer was contacted but they did not give us information.”

Amy and I responded further that, “Based on the information you provide in table 3, this child’s serology fell from 172 U/mL at diagnosis to 50 U/mL at her 6 month follow -up. If she was getting gluten from her retainer it seems unlikely that this would have happened.”

Dr. Memon responded, “This is actually a case that had puzzled us because it was very atypical of the usual celiac cases that we see. On the diet that this child was following, you would expect the serology to have normalized. We can say this because we knew how vigilant the mother was. The only factor that changed from the serology of 50 to the follow up where it had gone down significantly was that the retainer was removed. The diet remained the same. It is possible that the gluten source in the container (sic) was so minimal that it was just enough to prevent normalization of both serology and symptomatology.”

We are still not convinced that the retainer had anything to do with the slight increase seen in this patient’s tTG levels. According to Beth Israel Deaconess Celiac Disease Center, tTG has a half life of 6 months so it would be expected that levels should fall by half 6 months after diagnosis (http://www.bidmc.org/Centers-and-Departments/Departments/Digestive-Disease-Center/Celiac-Center/FAQ/DiagnosingCeliacDisease.aspx#normal). This patient’s tTG levels fell from 172 U/mL at diagnosis to approximately 50 U/mL (It is difficult to read the graph and exact numbers are not provided) at her 6 month follow-up. This is a fairly significant drop. It also is the case that by the time the patient’s retainer was removed at 8 months, tTG levels had decreased from about 55 U/mL to about 52 U/mL. In addition, the reference regarding methylmethacrylate as containing gluten is from 1971. We have been unable to find any additional references indicating that this substance contains gluten. Even if it does, methylmethacrylate is one product used to make this child’s retainer and gluten would be a “sub-ingredient” of this product. That enough gluten would leach from the retainer to cause an increase in tTG levels seems a bit extraordinary.

There is so much fear in the celiac disease community regarding unintentional sources of gluten especially among parents of children. We would hate to have parents worrying unnecessarily about their children’s retainers. There does not seem to be enough information provided in this case to demonstrate a true cause and effect between retainer use and tTG levels.

©Copyright November 2013 by Amy Jones, MS, RD and Tricia Thompson, MS, RD for www.glutenfreedietitian.com