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Original Article
Factors affecting orthodontists’ management of the retention phase
Kevin Bibonaa; Bhavna Shroff b; Al M. Bestc; Steven J. Lindauerd
ABSTRACT
Objective: To test the null hypothesis that orthodontist characteristics and factors related to
retainer choice do not influence the management of the retention phase with regard to frequency
and duration of follow-up care provided.
Materials and Methods: Orthodontists (n 5 1000) were randomly selected to participate in an
online survey divided into three categories: background, retainer choice, and time management.
Results: Of the 1000 selected participants, 894 responded. When deciding the type of retainer to
use, the following were considered most frequently: pretreatment malocclusion (91%), patient
compliance (87%), patient oral hygiene (84%), and patients’ desires (81%). Orthodontists who
considered the presence of third molars (P 5 .03) or ‘‘special needs’’ patients (P 5 .02) had
significantly more follow-up visits than those who did not. When vacuum-formed retainers (VFRs)
were prescribed, there were significantly fewer visits (P 5 .02) compared to when other types of
retainers were used. As practitioner experience increased, so did the number of visits (P , .0001).
Orthodontists who considered the primary responsibility of retention to fall on the patient had
significantly fewer follow-up visits (P , .0001) than those who considered it either a joint or
orthodontist-only responsibility.
Conclusions: The null hypothesis was rejected because the number of follow-up visits during the
retention phase was affected by practitioner experience, whether VFRs were used, whether the
orthodontist considered the presence of third molars or special-needs patients when choosing the
type of retainer, and to whom the orthodontist attributed responsibility during the retention phase.
(Angle Orthod. 2014;84:225–230.)
KEY WORDS: Orthodontist; Retention; Management
INTRODUCTION
back to their original positions, including supracrestal
and gingival PDL fibers, eruptive forces, and deleterious habits developed by patients.1,2 Therefore, some
type of retention is thought to be required indefinitely
to prevent relapse.2 Because of the importance of
retention, a systematic organization of the retention
phase, including choice of retainer and time management, is essential to the success of both the
orthodontic treatment and the orthodontic practice.
Many factors should be considered when deciding
what type of retainer to give each patient.2–4 Orthodontists in the Netherlands consider the following
factors in descending order of frequency: pretreatment
situation, interdigitation after treatment, oral hygiene,
end result, periodontal tissue, patient motivation, and
patient age.4 Studies in the United States have been
limited to determining the frequency with which
retainers are used and comparing types of retainers
to each other.5–12 Keim et al.5 found that the use of the
Hawley retainer has recently decreased while the use
of clear retainers and bonded retainers has increased.
Valiathan and Hughes13 showed that the Hawley
Retention is a necessary therapeutic phase following active orthodontic treatment, with the goal of
maintaining the obtained intra-arch alignment and
interarch relationships. After the conclusion of active
treatment, many physiological forces can move teeth
a
Resident, Department of Orthodontics, Virginia Commonwealth University, Richmond, Va.
b
Professor and Graduate Program Director, Department of
Orthodontics, Virginia Commonwealth University, Richmond,
Va.
c
Professor, Department of Biostatistics, School of Dentistry,
Virginia Commonwealth University, Richmond, Va.
d
Professor and Chair, Department of Orthodontics, Virginia
Commonwealth University, Richmond, Va.
Corresponding author: Dr Bhavna Shroff, Department of
Orthodontics, VCU School of Dentistry, 520 North 12th St, Suite
111, Richmond, VA 23298
(e-mail: [email protected])
Accepted: July 2013. Submitted: May 2013.
Published Online: August 14, 2013
G 2014 by The EH Angle Education and Research Foundation,
Inc.
DOI: 10.2319/051313-372.1
225
Angle Orthodontist, Vol 84, No 2, 2014
226
Figure 1. Breakdown of the number of years in practice of the
survey participants.
retainer is the most common retainer used in the
maxillary dentition, whereas a fixed lingual retainer is
the most common retainer used in the mandibular
dentition. Essix retainers have been shown to be
equally as effective in preventing relapse, more costeffective, and more preferred by patients when
compared to Hawley retainers.6,14
According to Hughes et al.,15 businesses that thrive
in a competitive environment have defined and
effective strategies for clinical practice. More specifically, an efficient, successful orthodontic practice is
one that capitalizes on a high number of active cases
and minimizes overhead.16 Because the retention
phase often involves four appointments over a 2-year
period,5 missed appointments may impact the clinical
efficiency of the orthodontic practice. Schulman and
McGill17 found that patients are three times more likely
to miss an appointment during retention than during
active treatment. Therefore, it is critical that orthodontists have a protocol for patient visits during the
retention phase.
Despite the inherent importance of retention, how
orthodontists choose the type of retainer to use for
each patient and how this choice affects the retention
recall schedule have not been examined. The goal of
this study was to test the null hypothesis that there is
no influence of orthodontist characteristics and factors
related to retainer choice on the management of the
retention phase with regard to frequency and duration
of follow-up care provided.
MATERIALS AND METHODS
A Web-based survey was developed to examine
how orthodontists manage the retention phase. Questions asked about participant demographics, the types
of retainers used, how the choice of retainer was made
for each patient, and how frequently and for how long
participants scheduled appointments. Following approval by the Institutional Review Board of Virginia
Angle Orthodontist, Vol 84, No 2, 2014
BIBONA, SHROFF, BEST, LINDAUER
Figure 2. Breakdown of the age in years of the survey participants.
Commonwealth University, the American Association
of Orthodontists randomly selected 1000 orthodontists
throughout the United States to receive the survey.
The online link to the survey was then sent via e-mail
to those selected, with a follow-up e-mail sent 4 weeks
later in an effort to increase participation.
The results were collected and summary descriptive
statistics were calculated. In order to determine the
variables that were associated with the duration or
frequency of the retention phase, univariate analyses
(analysis of variance or correlation, as indicated) were
performed using SAS software (JMP 9.0.2; SAS
Institute Inc, Cary, NC).
RESULTS
The survey was sent to 1000 orthodontists and had
a return rate of 89.4% (n 5 894). The demographic
characteristics of the participants in the survey are
shown in Figures 1 and 2. While the male-to-female
ratio of participants was 4:1, the number of years in
practice of each participant was evenly distributed
between 0 and .35 years. Since age, number of years
in practice, and year of graduation from orthodontic
residency were highly correlated (|r| . .92), practitioner experience will be described by year of graduation
from orthodontic residency.
Retainer Choice
When asked if there should be a standard of care
regarding retention procedures and appliances, 56%
of participants responded Yes, and 44% responded
No. When determining the type of retainer to use, 54%
of the respondents indicated that they do so at the end
of treatment, while 43% decided during initial treatment
planning, and 3% decided during treatment. Over 81%
of respondents stated they use bonded, Hawley, and
vacuum-formed retainers (VFRs) in their practice. The
frequency of various factors considered that pertain to
retainer choice and prescription are shown in Figure 3.
ORTHODONTISTS’ MANAGEMENT OF THE RETENTION PHASE
227
Figure 3. Frequency of factors considered by orthodontists when
choosing the type of retainer.
Pretreatment malocclusion, compliance, oral hygiene,
and the patient’s desires were considered by more
than 80% of participants, whereas the presence of
third molars, gender, and insurance were each
considered by less than 10% of participants. Though
not statistically significant, patient desires were considered less frequently as practitioner experience
increased. The participants discussed the choice of
retainer 3% of the time with the patient’s dentist
compared to 41% of the time with the patient’s
periodontist, when applicable.
For those respondents who prescribed removable
retainers, 52.3% prescribed them to be worn on a parttime basis. Of this group, 99.6% asked the patients to
wear the retainer only at night, as opposed to during
the day only or every other day.
Time Management
Over 90% of orthodontists saw their patients for
15 minutes or less at each appointment. Figure 4
shows the frequency of appointments and duration of
follow-up care during the retention phase. Follow-up
care for #12 months was offered by 28% of
orthodontists. For these orthodontists, the frequency
of visits was predominantly quarterly (74%). This is in
contrast to the orthodontists who offered follow-up for
13–24 months (42%) or more than 24 months (31%),
with frequency of visits being predominantly semiannual (56% and 55%, respectively). Yearly visits were
rare (less than 6%). For all of the following results, the
number of follow-up visits was calculated by combining
frequency of visits and duration of retention phase, as
shown by the numbers atop each bar in Figure 4.
The presence of third molars and whether the
patients were ‘‘special needs’’ were the only factors
considered when choosing the type of retainer that had
a significant impact on the number of follow-up visits
(Table 1). Orthodontists who considered the presence
of third molars had significantly more follow-up visits
Figure 4. Duration and frequency of follow-up care offered during the
retention phase. The height of the bars is proportional to the number
of orthodontists chosing each combination of frequency of visits and
duration of retention phase. The number atop each bar is the total
number of visits calculated for each combination.
than those who did not (mean 5 5.4 visits vs 4.8 visits;
P 5 .03). Orthodontists who considered special needs
had significantly more follow-up visits than those who
did not (mean 5 5.1 versus 4.7; P 5 .02).
The type of retainer chosen was unrelated to the
number of follow-up visits (P . .08) except for
orthodontists who used a VFR (Table 2). For orthodontists who used a VFR, the average number of visits
was eight, compared to five for orthodontists who did
not use a VFR (P 5 .02). Full- versus part-time
removable retainer use was not related to the number
of follow-up visits (P . .07).
As practitioner experience increased, so did the
number of prescribed retention visits (P , .0001;
Table 3). Those who graduated prior to 1980 averaged
5.4 visits, which was significantly greater than the
average number of visits (4.5) for those who graduated
as recently as 1990.
Slightly more than half (51%) of the surveyed
orthodontists considered retention as a joint responsibility between the orthodontist and the patient, while
47% considered the responsibility to fall on the patient,
and less than 3% considered the responsibility to fall
solely on the orthodontist. Orthodontists who considered the primary responsibility of retention to fall on the
patient had significantly fewer (P , .0001) follow-up
visits than those who considered it either a joint or
orthodontist-only responsibility (mean 5 4.5 vs 5.2,
respectively). Of those who graduated prior to 1990
and viewed retention as fully or partially their own
responsibility, 44% recommended more than a 2-year
follow-up period. Of the recent graduates (1990 and
after) who viewed retention as fully or partially their
Angle Orthodontist, Vol 84, No 2, 2014
228
BIBONA, SHROFF, BEST, LINDAUER
Table 1. Number of Follow-up Visits vs Factors Considered When
Choosing the Type of Retainera
Number of Visits
Factor Considered
Percentage
(n)
Mean
SD P Value
Pretreatment malocclusion
Yes
No
90.4
9.6
(808)
(86)
4.85
4.90
2.24
2.58
.8663
86.2
13.8
(771)
(123)
4.89
4.63
2.30
2.16
.2356
83.3
16.7
(745)
(149)
4.89
4.67
2.30
2.17
.2737
80.4
19.6
(719)
(175)
4.84
4.90
2.31
2.16
.7576
69.6
30.4
(622)
(272)
4.94
4.65
2.33
2.14
.0773
65.4
34.6
(585)
(309)
4.94
4.68
2.31
2.21
.1039
48.3
51.7
(432)
(462)
5.05
4.66
2.37
2.18
.0114
16.4
83.6
(147)
(747)
4.92
4.84
2.57
2.22
.7238
8.7
91.3
(78)
(816)
5.41
4.80
2.82
2.21
.0232
8.1
91.9
(72)
(822)
4.93
4.84
1.94
2.31
.7225
6.4
93.6
(57)
(837)
5.11
4.83
2.32
2.28
.3955
0.7
99.3
(6)
(888)
4.50
4.85
1.76
2.28
.6450
Type
Percentage
(n)
Mean
SD
P Value
93.7
6.3
(837)
(56)
4.83
5.25
2.25
2.62
.2436
93.5
6.5
(835)
(58)
4.85
4.83
2.28
2.31
.8267
91.0
9.0
(813)
(80)
4.79
5.46
2.20
2.89
.0204
16.1
83.9
(144)
(749)
5.15
4.79
2.26
2.28
.0859
Bonded
Yes
No
Yes
No
Yes
No
Other
Patient’s desires
Yes
No
Number of Visits
Essix
Oral hygiene
Yes
No
Number of Follow-up Visits vs Type of Retainer Useda
Hawley
Compliance
Yes
No
Table 2.
Yes
No
a
SD indicates standard deviation.
Posttreatment occlusion
Yes
No
Age
Yes
No
Special-needs patients
Yes
No
Family situation
Yes
No
Presence of 3rd molars
Yes
No
Sex
Yes
No
Other
Yes
No
Insurance
Yes
No
a
SD indicates standard deviation.
own responsibility, 28% recommended more than a 2year follow-up period.
DISCUSSION
The null hypothesis was rejected because the
frequency and duration of follow-up visits during the
retention phase was affected by practitioner experience, whether VFRs were used, whether the orthodontist considered the presence of third molars or
special-needs patients when choosing the type of
retainer, and to whom the orthodontist attributed
responsibility during the retention phase.
Angle Orthodontist, Vol 84, No 2, 2014
Orthodontists rarely considered the presence of third
molars when deciding what type of retainer to
prescribe. However, despite evidence that the presence or absence of third molars does not impact
alignment of incisors following retention,18 orthodontists who did consider the presence of third molars had
significantly more follow-up visits (P 5 .03) during the
retention phase than those who did not. This increase
in visits may have been in part due to patient concerns
and the general perception that third molars cause
anterior crowding, even without supporting scientific
evidence.
Although orthodontists considered whether the
patients were special needs only 48% of the time
when deciding what type of retainer to prescribe, those
that did had significantly more follow-up visits than
those who did not (mean 5 5.1 versus 4.7; P 5 .02).
Special-needs patients are often more challenging to
treat due to behavioral issues,19 so it was not
surprising that orthodontists wanted to see these
patients more often to ensure that the final results of
treatment were maintained.
When a VFR was prescribed, there was a significantly smaller average number of visits compared to
when other retainers were prescribed (P 5 .02). These
findings were consistent with those from the study of
Valiathan and Hughes13 that showed retention appointments were scheduled at longer time intervals
when orthodontists prescribed VFRs. VFRs have been
shown to have smaller increases in the Irregularity
Index and smaller decreases in PAR (peer assessment rating) scores six months following debonding.20
Therefore, it is reasonable to assume that when
orthodontists prescribed VFRs, they were less worried
about the relapse than they would have been had they
prescribed other retainers. However, because patient
compliance with VFRs has been shown to decrease
229
ORTHODONTISTS’ MANAGEMENT OF THE RETENTION PHASE
Table 3. Number of Follow-up Visits vs Year of Graduation From Orthodontic Residencya
Mean, y
Graduation Decade
1950s and 1960s
1970s
1980s
1990s
2000 to present
n
31
162
224
216
242
Percentage
3.5
18.5
25.6
24.7
27.7
Age
70.0
65.1
56.1
46.7
36.8
Number of Visits
Practice
Mean
36.8
35.0
25.3
15.7
5.1
SD
5.90
5.30
5.01
4.50
4.58
3.49
2.64
2.16
2.06
2.04
*
(b)
(b)
(b)(c)
(c)
(c)
a
SD indicates standard deviation.
* Average numbers of visits significantly different (ANOVA P 5 .0001). Means with only (b) are significantly different than means with only
Means with both (b) and (c) are not significantly different from the means that have only (b) or (c) (Tukey Honestly Significant Difference).
more rapidly 2 years after debonding than with Hawley
retainers, it would be prudent to monitor patients who
receive VFRs for more than 2 years.21
Overall, most orthodontists averaged the same
number of visits (approximately four) for the patients
during the retention phase, indicating that orthodontists placed a similar importance on retention. However, the distribution of the visits varied greatly. For those
orthodontists who saw patients for #12 months, the
patients were typically seen quarterly, thus averaging
four visits. For those orthodontists who saw patients
for 12–24 months, the patients were typically seen
semi-annually, also averaging four visits. However,
when examining orthodontists with regard to experience level, the number of visits significantly increased
(P , .0001) as practitioner experience increased.
These results were similar to the findings of Valiathan
and Hughes13 that orthodontists with less than 16 years
of experience scheduled retention appointments less
frequently. More experienced practitioners might have
been more dubious of patient compliance over the long
term, having seen more cases of relapse over the
length of their career.
Furthermore, when examining orthodontists with
regard to their belief as to who bears responsibility
during the retention phase, those who believed that the
patient bears sole responsibility had significantly fewer
visits (P , .0001). The number of visits increased as
orthodontists’ perception of their own responsibility
increased. Orthodontists who considered retention a
joint or orthodontist-only responsibility probably wanted to keep a closer watch on their patients than those
who believed otherwise.
CONCLUSIONS
N The number of follow-up visits increased if the
orthodontists considered the presence of third
molars or special needs patients when deciding the
type of retainer to use.
N The number of follow-up visits increased as practitioner experience increased.
(c)
.
N The number of follow-up visits decreased when a VFR
was used and when orthodontists considered the
primary responsibility for retention to fall on the patient.
ACKNOWLEDGMENTS
This study was supported in part by the AD Williams Student
Research Fellowship and by the Medical College of Virginia
Orthodontic Education and Research Foundation.
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