1. The study surveyed 150 Norwegian orthodontists on their retention protocols after orthodontic treatment. 2. It found that the most commonly used retainers were fixed retainers in the lower jaw and a combination of fixed and removable retainers in the upper jaw. 3. There was disagreement among orthodontists about the duration of retention and need for common guidelines, though retainers in the lower jaw were often worn for over 5 years, longer than in the upper jaw.

1. Retention: type, duration and need for
common guidelines. A survey of Norwegian
orthodontists
Vaska Vandevska-Radunovic, Lisen Espeland, Arild Stenvik
Department of Orthodontics, University of Oslo

2. Fig. 1. Vacuum pressed retainer
Fig. 2. Fixed 33-43 retainer
Maintenance of the orthodontic
treatment result and prevention of
relapse require the use of some type of
retention appliances (Figs. 1 and 2).
However, among orthodontists, there is
no agreement about the type, duration
or follow-up of a common retention
protocol.
Surveys conducted in Australia/New
Zealand, the Netherlands, the United
Kingdom, and the United States show
certain similarities between the countries
when it comes to the type of maxillary
and mandibular retention devices, but
show disagreements when it comes to
duration of retention, follow-up and need
for common guidelines

3. AIMS:
1. To survey retention protocols among orthodontists in
Norway and compare the results with similar studies in other
countries
2. To examine the perceived need for common guidelines
related to retention type, duration and follow-up

4. Materials and Methods
A postal questionnaire with addressed, pre-stamped return envelops were sent to all
orthodontists listed by the Norwegian Association of Orthodontists (NAO). The final
version of the questionnaire consisted of 14 questions, grouped as follows :
1. Background of the participants: gender, years in practice as a
specialist, number of days/week in practice, place where speciality
was obtained
2. The most commonly used type of retainers
3. Duration of retention and scheduling of follow-up appointments
4. Information provided to the patients
5. Factors influencing the choice of and/or changes in retention
protocols
6. Manufacturing of orthodontic retention devices
At the end, the participants were asked if they felt there is a need for common
guidelines regarding retention procedures. Space was also provided for additional
comments if desired.

5. Results
Sample characteristics
Of the 193 questionnaires that were
mailed, 150 forms were completed and
returned (77.7%).
Forty-six (30.7%) orthodontists were women
and 104 (69.3%) were men. The majority
obtained their speciality training in
Norway (58.1% in Oslo and 33.1% in
Bergen), while 8.8% were educated
abroad (not specified).
As for the number of years in orthodontic
practice, 58.7% worked >20 years, and
41.3% worked <20 years in practice.
Most of the orthodontists worked 5
days/week (47.9%), 32.6% worked 4
days/week, whilst the remaining 19.5%
worked 3 days or less per week
Retention procedures
All orthodontists used some form for
retention.
The most commonly used retainer in the
upper jaw was a combination of fixed and
removable retainer, followed by a clear
thermoplastic retainer only, and a Hawley
retainer (Fig. 3a).
In the lower jaw, a fixed retainer bonded to all
anterior teeth was most common (Fig.
3b). Inter-maxillary retention (activators
or positioners) was used by less than 20%
of the orthodontists.

6. Lower jaw
Fixed retainer
bonded to canines
only
Fixed retainer
bonded to all
anterior teeth
Other form for
retention66.4
22.6
11
b
Upper jaw
Hawley retainer
Thermoplastic
retainer
Fixed retainer
Fixed+removable
retainer
40.6
18.6
32.4
8.8
a
Fig. 3. Percentage of the most commonly used retainers in the upper (a) and
in the lower (b) jaw.

7. Tables 1 to 3 summarize the results concerning the
duration of retention (Table 1) and factors influencing the
choice of retention (Tables 2 and 3).

8. Retention time % orthodontists
Upper jaw Lower jaw
< 2 years 15 2
2-3 years 34.7 10.2
3-5 years 23.7 27.9
> 5 years 18.4 41.5
permanently 8.2 18.4
Table 1. Duration of retention in the upper and lower jaw

9. Factors % orthodontists
Original malocclusion 95.2
Oral hygiene 49.7
End result 54.4
Patient’s motivation 33.3
Patient’s age 43.5
Periodontal health 34.0
Wisdom teeth 23.1
Oral habits 27.9
Tooth morphology 8.2
Table 2. Factors influencing the choice of a certain retainer type

10. Factor % of orthodontists
Specialty training 27.7
Clinical experience 57.4
Literature 3.5
Courses 5.0
Colleagues 6.4
Table 3. Factors influencing the decision for the retention protocol in use

11. Female orthodontists were significantly more in favor of having common
guidelines than males . They also differed in their choice of retainer in
the upper jaw, as they used a combination of fixed and a removable
retainer significantly more often than their male colleagues (p<0.05).
The length of clinical experience had a significant effect on the choice of
retention appliance in the lower jaw. Orthodontists working >20 years in
practice more commonly used retainers bonded to canines only, while
those working <20 years preferred retainers bonded to all anterior teeth.

12. Conclusions
1. The most commonly used retention appliances in Norway
are fixed retainers in the mandible, and a combination of a
fixed and a removable retainer in the maxilla.
2. The choice of retention devices is similar to those reported
in the other surveys. There are, however, disparities related
to duration of retention, follow-up regimens and the
perceived need for common retention guidelines.
3. Retainers in the mandible are kept much longer than in the
maxilla, and most often more than 5 years.
4. Half of the orthodontists desire common retention
guidelines, women being significantly predominant.