April 2, 2011
ScienceDaily (Mar. 24, 2011) — Have you been
wearing your retainer? It’s a question countless parents ask of their children
post-braces. Now Case Western Reserve University School of Dental Medicine
researchers are getting serious about the question.
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“We found little written about the kinds of
retainers prescribed and how compliant patients are in using them,” said
Case Western Reserve’s Manish Valiathan, an assistant professor of orthodontics
and a member of the American Board of Orthodontics. He notes that there is a
dearth of information despite the devices being common in orthodontics
Consequently Valiathan and fellow researchers
embarked on three studies that examined how people are using retainers, which
types are prescribed and what happens when patients don’t follow up orthodontic
work with a retainer.
After randomly sending 2,000 surveys to orthodontists
throughout the country, researchers received responses from 658 practitioners
regarding the kinds of retainers they prescribe. The majority (58.2 percent)
prescribed removable retainers; about 40 percent opted for fixed lingual
retainers that,once in place,are worn for life.
Post-braces, the majority of orthodontists said
they required wearing removable retainers full-time for the first nine months
and then part-time after that. They also encouraged part-time retainer use
Valiathan said that without retainers specific
prior conditions may return but that definitive research does not exist as to
what conditions require ongoing retainer use. More evidence is needed, he said.
Another survey study of 1,200 patients from four
practices focused on patient compliance two years after prescribing retainers.
Patients self-reported and 36 percent responded to the researchers’ questions
regarding type of retainer used, age, gender, length of time since braces were
removed, and hours per day and night retainer is worn.
The overall responses showed that 60 percent wore
retainers more than 10 hours a day in the first three months and 69 percent
wore them every night. By the time retainer users reached 19 to 24 months, 19
percent were not wearing retainers but 81 percent were — even if it was only
one night a week. About 4 percent never wore their retainer at all.
Research indicated that many patients were still
using their original retainers two years later — a sign that teeth had not
moved, Valiathan said. Additionally, researchers found that age, gender and the
type of retainer did not impact compliance.
The third study was a pilot research project. It
examined the ramifications of no retainer use within the first four weeks after
braces removal. Researchers measured patients’ teeth before and after for
spacing issues, overbites, under bites and tooth crowding.
Thirty patients had the wires removed from their
braces but kept the appliances affixed to the teeth to monitor any changes
without a retainer. Nearly half of the participants showed no movement, and
many showed positive settling of the back teeth including the molars. Some did
require additional orthodontic treatment at the end of the four weeks.
“Further studies with a larger study population
will let us know if some patients can go without using retainers,”
He added that orthodontic researchers need to study
what kinds of conditions require long-term retainer use.
Kurtis A. Kacer, Manish Valiathan, Sena Narendran,
Mark G. Hans. Retainer wear and compliance in the first 2 years after active
orthodontic treatment. American Journal of Orthodontics and Dentofacial
Orthopedics, 2010; 138 (5): 592 DOI: 10.1016/j.ajodo.2008.12.027
Manish Valiathan, Eric Hughes. Results of a
survey-based study to identify common retention practices in the United States.
American Journal of Orthodontics and Dentofacial Orthopedics, 2010; 137
(2): 170 DOI: 10.1016/j.ajodo.2008.03.023
Nadia Lyotard, Mark Hans, Suchitra Nelson, Manish
Valiathan. Short-term postorthodontic changes in the absence of retention.
The Angle Orthodontist, 2010; 80 (6): 1045 DOI: 10.2319/010210-7.1