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Relapse tendency after orthodontic correction of upper front teeth retained with a bonded retainer

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To investigate the amount and pattern of relapse of maxillary front teeth previously retained with a bonded retainer. The study group consisted of 135 study casts from 45 patients. Recordings from study models before treatment (T1), at debonding (T2), and 1 year after removal of the retainer (T3) were present. All patients had been treated with fixed edgewise appliances. The irregularity index (sum of contact point displacement [CPD]) and rotations of front teeth toward the raphe line were calculated at T1, T2, and T3. The mean irregularity index at T1 was 10.1 (range 3.0-29.9, SD 5.4). At T2 it was 0.7 (range 0.0-2.1, SD 0.7), and at T3 it was 1.4 (range 0.0-5.1, SD 1.2). Fifty-five teeth in 42 patients were corrected more than 20 degrees between T1 and T2 (mean correction 31.4 degrees range 20.0-61.7), and mean relapse in this group was 7.3 degrees (range 0.0-20.5). Regarding alignment of the maxillary front teeth, the contact relationship between the laterals and centrals seems to be the most critical. A significant positive correlation was found between the amount of correction of incisor rotation and the magnitude of relapse but not between the amount of correction of CPD and the magnitude of relapse. Eighty-four percent of the overcorrected CPDs returned to a desired position. Minor or no relapse was noted at the 1-year follow-up.
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570
Angle Orthodontist, Vol 76, No 4, 2006
Original Article
Relapse Tendency after Orthodontic Correction of
Upper Front Teeth Retained with a Bonded Retainer
Sasan Naraghi
a
; Anders Andre´n
b
; Heidrun Kjellberg
c
; Bengt Olof Mohlin
d
ABSTRACT
Objective: To investigate the amount and pattern of relapse of maxillary front teeth previously
retained with a bonded retainer.
Materials and Methods: The study group consisted of 135 study casts from 45 patients. Re-
cordings from study models before treatment (T1), at debonding (T2), and 1 year after removal
of the retainer (T3) were present. All patients had been treated with fixed edgewise appliances.
The irregularity index (sum of contact point displacement [CPD]) and rotations of front teeth toward
the raphe line were calculated at T1, T2, and T3.
Results: The mean irregularity index at T1 was 10.1 (range 3.0–29.9, SD 5.4). At T2 it was 0.7
(range 0.0–2.1, SD 0.7), and at T3 it was 1.4 (range 0.0–5.1, SD 1.2). Fifty-five teeth in 42 patients
were corrected more than 208 between T1 and T2 (mean correction 31.48 range 20.0–61.7), and
mean relapse in this group was 7.38 (range 0.0–20.5). Regarding alignment of the maxillary front
teeth, the contact relationship between the laterals and centrals seems to be the most critical. A
significant positive correlation was found between the amount of correction of incisor rotation and
the magnitude of relapse but not between the amount of correction of CPD and the magnitude of
relapse. Eighty-four percent of the overcorrected CPDs returned to a desired position.
Conclusions: Minor or no relapse was noted at the 1-year follow-up. (
Angle Orthod
2005;76:
570–576.)
KEY WORDS: Retention; Rotation; Crowding; Irregularity; Incisors
INTRODUCTION
Morphologic stability is one important goal after or-
thodontic treatment, and from the patients point of
view, stability of the upper front teeth is of consider-
able importance.
1,2
Relapse, the tendency for teeth to
return toward their pretreatment positions, has been
the subject of many studies,
3–9
the long-term results
a
Consultant Orthodontist, The County Orthodontic Clinic in
Va¨xjo¨, Kronoberg, Sweden.
b
Consultant Orthodontist, The County Orthodontic Clinic in
Mariestad, Va¨stra Go¨taland, Sweden.
c
Associate Professor, Faculty of Odontology Orthodontics,
The Sahlgrenska Academy at Goteborg University, Goteborg,
Sweden.
d
Professor, Faculty of Odontology Orthodontics, The Sahl-
grenska Academy at Goteborg University, Orthodontics, Gote-
borg, Sweden.
Corresponding author: Dr. Sasan Naraghi, The County Or-
thodontic Clinic, Klostergatan 16 B, Va¨xjo¨, Kronoberg S-352 31,
Sweden (e-mail: sasan@telia.com)
Accepted: July 2005. Submitted: April 2005.
Q 2005 by The EH Angle Education and Research Foundation,
Inc.
reported from Seattle being the most extensive.
3,17
Be-
cause of type of malocclusion, treatment procedure,
cooperation during and after treatment, growth, etc,
5,7–9
variability in long-term treatment outcome is quite
common. Additional factors are type and duration of
retention.
10
There is some information in the literature
regarding maxillary irregularity after retention with a
maxillary Hawley retainer,
6,7,11,12
but many stud-
ies
8,9,10,12
do not specify the retention method in the
upper arch, the duration of retention, or the length of
the postretention period at the time of examination.
Bonded multistrand wire has been used as a meth-
od of retention for 30 years
13,14
and is now a reason-
ably reliable form of retention
15,16
in a short-term per-
spective. Bonded retainers appear to be accepted well
by patients and are relatively independent of patient
cooperation. The relapse tendency of the upper front
teeth after correction of contact point displacements
(CPDs) and rotations and after use of bonded retain-
ers has yet to be reported.
Surbeck et al
17
found that the pattern of pretreat-
ment rotational displacement of maxillary anterior
teeth had a tendency to repeat itself after retention.
571RETENTION AND STABILITY
Angle Orthodontist, Vol 76, No 4, 2006
TABLE 1. Distribution of Extraction and Nonextraction Treatments
Nonextraction 12
Four premolar extraction 14
Two upper premolar extraction 10
Other extracted teeth/agenesis 9
TABLE 2. Extension of Retainer
No. Patients
Eight teeth 22
Seven teeth 3
Six teeth 14
Five teeth 1
Four teeth 5
FIGURE 1. Duration of retention in months.
FIGURE 2. Irregularity index: the sum of five frontalcontactdisplace-
ments in millimeters (A 1 B 1 C 1 D 1 E).
However, relapse of CPD because of labial or lingual
position only was random relative to the pretreatment
positions. The authors also held that incomplete align-
ment during treatment was a risk factor for relapse and
suggested slight overcorrection during active treat-
ment of severely rotated teeth; however, they did not
specify the method of retention. Several questions
arise when studying the relapse tendency of the upper
front teeth after retention with a bonded retainer. For
instance, does overcorrection of rotations or labial/lin-
gual displacements retained with bonded retainer de-
crease the amount of relapse? Does overcorrection
result in teeth remaining in overcorrected positions?
How large is the relapse of rotated or displaced (or
both) maxillary front teeth after a period of bonded re-
tention?
Objectives of this study
Study the amount of relapse of the maxillary front
teeth after retention with a bonded retainer;
Investigate the pattern of relapse regarding type of
movement after correction of rotations and labial/lin-
gual displacements;
Examine the effect of overcorrection of CPD in sta-
bility outcome;
Analyze the influence of expansion of the intercanine
distance on stability outcome.
MATERIALS AND METHODS
The study group consisted of 45 patients treated
with fixed orthodontic edgewise appliances. The pa-
tients were selected from The County Orthodontic
Clinic in Mariestad, Sweden, when their upper bonded
retainer was removed. The wire used was 0.0195-inch
Wildcat (GAC International Inc., Central Islip, NY).
Their mean age at the 1-year follow-up was 18.8 years
(range 15.8–21.5). Extraction or nonextraction cases
with various diagnoses and whose upper arches were
retained with a bonded retainer only were included. All
six front permanent teeth had to be present before
treatment and presenting irregularity. Spaced denti-
tions in the upper front teeth and treatments started
as adults were excluded. Study models before treat-
ment (T1), after active treatment (T2), and 1 year out
of upper retention (T3) had to be available.
The extraction and nonextraction distribution and
number of patients is shown in Table 1, and the ex-
tension of the retainers in Table 2. The mean duration
of the retention period was 33 months (range 23–48
months) (Figure 1). Of 306 teeth with bonded retain-
ers, the bonding failed on six teeth in five patients (2%)
during the retention period. No wires fractured during
the retention period.
Method for studying CPD
Labiolingual displacements of the anatomic contact
points from the mesial of the right canine through to
the mesial of the left canine were measured with a
digital caliper on the casts from T1, T2, and T3, with
0.1 mm accuracy. CPDs less than 0.5 mm were
judged to be zero.
The irregularity index (Figure 2), ie, the sum of the
five CPDs (A 1 B 1 C 1 D 1 E), was calculated as
described by Little.
18
Method for studying rotations and
intercanine distance
An Agfa DuoScan F40 (Agfa-Gevaert N.V., Mortsel,
Belgium) scanner was used to scan the casts at 300
DPI (dots per inch) resolutions. All 45 3 3 casts were
scanned in 300 DPI and then placed on the upper third
part of the glass, with almost the same size of the
572 NARAGHI, ANDRE
´
N, KJELLBERG, MOHLIN
Angle Orthodontist, Vol 76, No 4, 2006
FIGURE 3. Teeth angles on right side to the raphe line and inter-
canine distance.
FIGURE 4. Contact point displacements before treatment (T1), after
treatment (T2), and 1 year after retention (T3).
scanned area. To avoid distortions, all front teeth were
optimally in contact with the glass surface of the scan-
ner. To measure rotation changes and intercanine dis-
tance, a computer program (Scion Image) was used
to mark points on the pictures of the scanned casts.
The rotations were measured as the angle between a
line through the mesial and distal points on the incisal
edge of the teeth and the raphe line. The intercanine
distance was measured between the cusp tips of the
upper canines (Figure 3).
Statistical analysis
Paired
t
-tests were applied to test differences in
CPD, rotations, and intercanine distance between T1,
T2, and T3. Pearson’s product-moment correlationtest
was applied to test correlations between CPD and ro-
tations at T1 and changes during treatment and the
follow-up period. The SAST v8.2 program (SAS Insti-
tute Inc, Cary, NC) was used for all statistical analysis.
For all statistical analyses, the statistical significance
level was set to 5%.
Measurement error
The reproducibility of the measurements for rota-
tions and intercanine distance was determined by dou-
ble measurements of 45 scanned models from 15 pa-
tients at T1, T2, and T3. The error of the method was
calculated using Dahlberg’s equation.
19
2
D
O
S 5
Î
x
2N
Where D is the difference between repeated measure-
ments and N is the number of measurements. The
errors were 3.18 for canines, 2.88 for laterals, and 2.48
for centrals. The error of measuring the intercanine
distance was 1.1 mm.
Double measurements of 60 models in 20 patients
were used to calculate the error of measuring CPD.
Using this procedure, the measuring error for CPD
was 0.14 mm.
RESULTS
Contact point discrepancies
Before treatment (T1).
The mean irregularity index
at T1 was 10.1 (range 3.0–29.9, SD 5.4). The largest
displacements were recorded between laterals and
centrals followed by the displacement betweenlaterals
and canines, whereas the smallest deviations were
found between the centrals (Figure 4).
After treatment (T2).
At T2, the mean irregularity in-
dex was 0.7 (range 0.0–2.1, SD 0.7). There was a
significant difference in the index between T1 and T2
(
P
, .0001). Forty-three contacts were overcorrected
(Figure 5a). When overcorrections were excludedfrom
the calculation, the mean irregularity index was 0.3.
Eighteen overcorrections were less than 0.5 mm (all
were nonmeasurable) and could only be detected at
close inspection.
After retention (T3).
The mean irregularity index at
T3 was 1.4 (range 0–5.1, SD 1.2), ie, 14% of the ir-
regularity at T1. There was a significant difference in
the index between T2 and T3 (
P
, .0001). Of the 225
CPDs from 45 patients, those with the largest CPD at
T1 (5–11 mm, n 5 17) had a mean CPD at T3 of 0.5
(range 0–1.8). The intermediary CPD at T1 (3.0–4.9
mm, n 5 33) had a mean CPD at T3 of 0.4 (range 0–
1.5). The smallest CPD at T1 (1–2.9 mm, n 5 97) had
a mean CPD at T3 of 0.3 (range 0–1.5). None of these
differences was statistically significant (
P
5 .733).
Sixteen contacts in 11 patients were displaced more
than 1 mm, 1 year after retention.
Four CPDs changed from T2 to T3 in the opposite
direction to their pretreatment positions.
Seven of 25 contacts remained overcorrected. Six
of these seven contacts were displaced because of
rotations and one because of buccolingual displace-
ment at T1.
Four overcorrected CPDs at T2 had relapsed de-
573RETENTION AND STABILITY
Angle Orthodontist, Vol 76, No 4, 2006
FIGURE 5. (a) Overcorrected contacts after treatment and 1 year after retention. (b) Patient JB: overcorrected contact between 22/23, no
rebound, overcorrection remains. (c) Patient EH: 22/21 overcorrected 0.5 mm and relapse of 1.5 mm.
spite overcorrection; three of these were because of
rotations recorded at T1 (Figure 5a–c).
Rotations
There was a significant correlation between the
amount of rotational change (for all six teeth) because
of treatment and relapse (
P
, .0001). However, when
looking at each tooth, group centrals (
P
, .0130) and
laterals (
P
, .0001) showed significant correlations
but not the canines (
P
5 .0622).
Totally, 55 teeth in 42 patients were corrected more
than 20.08 between T1 and T2 (mean correction 31.48,
range 20.0–61.7). Mean relapse in this group was 7.38
(range 0.0–20.5) (Figure 6). Of these 55 teeth, 18 re-
lapsed more than 108 (Table 3).
Intercanine distance
The intercanine distance in 31 patients did not
change during treatment. In 14 patients, the intercan-
ine distance was expanded equal to or more than 1.5
mm (range 1.5–6.4). Four of these 14 patients showed
a reduction of the intercanine width at T3 of 1 mm or
more (range 1.0–2.3). Patients in this small group
were not more irregular regarding CPDs and rotations
than the rest of the sample.
Fiberotomy
Three laterals and six centrals were subjected to cir-
cumferential supracrestal fiberotomy. This technique
resulted in a mean correction of 338 (27–41) and a
574 NARAGHI, ANDRE
´
N, KJELLBERG, MOHLIN
Angle Orthodontist, Vol 76, No 4, 2006
FIGURE 6. Patient A
˚
G: tooth 22 corrected 438; 22 relapse 20.58, highest rotational relapse.
TABLE 3. Teeth That Were Derotated More Than 20.08 (n 5 55)
n
x¯
Correction
in Degrees
x¯
Relapse
in Degrees % Relapse
Cuspids 13 28 6 21
Laterals 23 34.8 9 26
Centrals 19 26.3 6.5 25
relapse of 7.68. If the nine teeth subjected to fibero-
tomy were excluded from the group of 55 corrected
rotations, the 46 remaining teeth had a mean relapse
of 7.18.
DISCUSSION
This study has demonstrated that 89% of the pa-
tients had a score of less than 3 for the maxillary ir-
regularity index, 1 year out of retention. The change
from a mean irregularity index of 0.7 after treatment to
1.4 after retention can be regarded as a minor relapse
compared with the corrections achieved during treat-
ment. No correlations were observed between the se-
verity of pretreatment irregularity and the amount of
relapse.
Of 306 teeth with bonded retainers, there were a few
bonding failures (six teeth in five patients) during the
retention period. Bonding failures may occur in cases
when lower teeth interfere with the retainers. In this
study, most patients achieved a proper overbite with
almost no interferences. In cases with pointed lower
canines, the technicians were informed to position the
wire more cervically on the upper canine and on the
distal part of the upper lateral. In patients with short
upper clinical crowns, the wire was placed more cerv-
ically.
Difficulty in locating the raphe line equally on the
pretreatment, posttreatment, and postretention study
models is probably the main reason for the relatively
large measurement errors when measuring rotations.
By using fixed reference points such as implants, this
problem could have been easily avoided. Variation in
the quality of the plaster casts is another factor that
might have increased the error. Changes in archform,
which frequently occur during both the treatment and
posttreatment period, may have also influenced the
measurements. If the arch changes to a wider form,
the angular measurement will tend to increase, even
if no contact point discrepancy has occurred relative
to the dental arch. The position of the incisors in buc-
colingual direction gives different angles to the raphe
line, meaning that more proclined teeth give a smaller
angle and more retroclined teeth give a larger angle.
A computer-generated archform as a reference is a
method used by Surbeck et al.
17
Rotation of the inci-
sors relative to the dental arch was measured as the
angle between the line connecting the points repre-
senting the mesial and distal point angles and the line
connecting the projections of these points on the arch,
recorded as positive if mesially rotated and negative if
distally rotated. Surbeck et al
17
state that this method
indicates CPD and incisor rotations even in a group
selected for perfect alignment. This shows that a com-
puter-generated archform may not represent the ac-
tual dental arch.
Because the follow-up period was short, being only
1 year, the results are to be considered as short term.
Of course, we believe that 1-year postretention control
is short and not sufficient, but registrations 1-year
postretention were done within the routine treatment
program. A recall visit 1 year out of retention was, in
most cases, the patients’ last visit to the orthodontist.
However, small contact displacements 1 year after re-
tention may be potential starting points for increasing
irregularity. The failure rate of bonded retained teeth
(2%) is consistent with the findings of Zachrisson
15
and
must be considered acceptable, especially because
four of six loose retainer bonds in our study affected
premolars. Fortunately, none of the bond failures
caused any measurable relapse.
The contact relationship between laterals and cen-
trals showed the largest CPD at T1, which is in ac-
cordance with the earlier findings.
7
The mean irregu-
larity index after treatment was 0.7, including overcor-
rections that accounted for most of the displacements.
The irregularity 1 year after retention was 14% of the
value before treatment. In comparison with other stud-
575RETENTION AND STABILITY
Angle Orthodontist, Vol 76, No 4, 2006
ies
6,7,10,11
using Hawley retainers, our results seem to
be favorable; ie, less postretention changes were ob-
served in our study. However, the studies are very dif-
ficult to compare because of different follow-up peri-
ods. The severe displacements at T1 did not rebound
more than the medium CPD at T1. Four CPDs
changed from T2 to T3 in the opposite direction of the
expected relapse with some rotations involved. There-
fore, we cannot posit that only labiolingual displace-
ments relapsed at random to the pretreatment posi-
tions. Our data do not confirm the finding of Surbeck
et al
17
that rotations and labiolingual displacements
have different relapse patterns.
Regarding alignment of the maxillary anterior teeth,
the contact relationship between the lateral and central
seems to be most critical. The correction of a bodily
displaced tooth, often laterals, includes selective root
torque to minimize the relapse tendency. In patient EH
(Figure 5c), the torque of the left lateral was not quite
successful. During the postretention period, the crown
tended to upright over the root resulting in a small re-
lapse despite overcorrection.
The most severe rotations were found among the
laterals. The number of severely rotated laterals and
centrals were slightly higher than for the canines,
which confirm the trend reflected in the CPD mea-
surements (Figure 4). This finding, together with a
larger error of method when measuring canine rota-
tions, might be a plausible explanation for the lack of
significant correlations between rotational correction
and relapse of canines.
Only a few individuals exhibited an increased inter-
canine width during treatment. No obvious changes
could be recorded in the intercanine distance between
T2 and T3, which is in accordance with other studies.
6–
8,17
Because four subjects showed a decreased width,
no firm conclusions can be drawn from these findings.
Fiberotomy was performed on only nine incisors.
Their degree of relapse was not different from the re-
maining 46 teeth corrected more than 208. However,
because of the small number of teeth treated with fi-
berotomy, it is hard to draw any conclusions as to
whether fiberotomy has any influence on the relapse
tendency. Studies that used Hawley retainers
11,20
as
retention found less relapse in a group with fiberoto-
mies as compared with a group without fiberotomies.
Of the 25 measurable overcorrections at T2, 14 had
returned to zero CPD at T3. We do not know if the
four overcorrections that relapsed toward the original
position (T1) would have been of a different magnitude
without overcorrection, but it is unlikely that the influ-
ence of overcorrection was negative. The seven re-
maining overcorrections were so small (0.5–1.1 mm)
that they probably did not cause the patients any dis-
satisfaction. It can be concluded that overcorrections
should be small because there is a risk that some do
not rebound to zero CPD. It is uncertain how much the
result can be improved by overcorrection.
From a clinical point of view, only 11% of the pa-
tients had an irregularity index of more than 3 at the
follow-up. The patient with the largest index (5.1) had
a deviant growth pattern after treatment, which caused
an open bite and an asymmetric mandible, resulting in
instability. This could account for the relapse in this
specific case. A combined orthodontic and surgical
treatment approach is now planned for this patient.
CONCLUSIONS
Minor or no relapse in short-term follow-up (1 year)
was noted in the maxillary front after correction of
irregularity and a 2- to 4-year period of bonded re-
tention.
There was a significant positive correlation between
the amount of correction of incisor rotation and the
magnitude of relapse.
No significant relation was found between the
amount of correction of CPD and magnitude of re-
lapse.
There was no difference in the relapse pattern be-
tween rotational displacements and labiolingual dis-
placement.
84% of the overcorrected CPDs returned to a de-
sired position.
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... Rotational or displacement relapse may occur in a different direction to the original condition 43 and over correction may not improve final tooth position. 233 Yet, overcorrection in an attempt to enhance stability has been advocated for rotated maxillary 124,234 and mandibular 195 incisors, some proffering early in treatment. 5,23,195 When undertaken early (with tooth position normalised later) and combined with IPR, good mandibular incisor stability was recorded 195 but maxillary incisor rotational relapse averaged about 30%. ...
... 5,23,195 When undertaken early (with tooth position normalised later) and combined with IPR, good mandibular incisor stability was recorded 195 but maxillary incisor rotational relapse averaged about 30%. 124,234 Even with selective root torque for overcorrection of bodily displaced teeth, some relapse tendency remained 234 and similarly with overcorrection of maxillary expansion. 150 Overcorrection has also been advocated for Class II malocclusion, 150 increased overbite 44 and open bite 66 treatment to try to minimise relapse, but it is not eliminated. ...
... 5,23,195 When undertaken early (with tooth position normalised later) and combined with IPR, good mandibular incisor stability was recorded 195 but maxillary incisor rotational relapse averaged about 30%. 124,234 Even with selective root torque for overcorrection of bodily displaced teeth, some relapse tendency remained 234 and similarly with overcorrection of maxillary expansion. 150 Overcorrection has also been advocated for Class II malocclusion, 150 increased overbite 44 and open bite 66 treatment to try to minimise relapse, but it is not eliminated. ...
Article
Retaining teeth in their corrected positions following orthodontic treatment is one of the most challenging aspects of orthodontic practice. Despite much research, the rationale for retention is not entirely clear. Teeth tend to revert to their pre-treatment positions due to periodontal and gingival, soft tissue, occlusal and growth factors. Changes may also follow normal dentofacial ageing and are unpredictable with great variability. In this overview, each of these factors are discussed with their implications for retention, along with adjunctive procedures to minimise relapse. The state of current knowledge, methods used to assess relapse, factors regarded as predictive of or associated with stability as well as overcorrection are outlined. Potential areas requiring further investigation are suggested. The way in which the clinician may manage current retention practice, with a need for individualised retention plans and selective retainer wear, is also considered.
... Tratamentul ortodontic poate îmbunătăţi estetica facială în cazul înghesuirilor dentare, dar stabilitatea pe termen lung a dinților aliniaţi este foarte variabilă și imprevizibilă. O variabilitate largă privind rezultatele pe termen lung ale acestor proceduri terapeutice poate fi corelată cu gradul iniţi al de înghesuire, cu planul de tratament, cu vârsta pacientului și cooperarea lui în timpul și după finalizarea tratamentului (4). ...
... Referitor la alinierea dinților frontali maxilari, relațiile de contact dintre incisivul lateral şi incisivul central par a fi cele mai critice. Contactele proximale mici în suprafață ar putea creşte şansele de recidivă de-a lungul timpului (3,4). ...
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Purpose: To emphasize the esthetic result of bringing anterior teeth into alignment with orthodontic treatment, as a mean of smile makeover. Material and method: Clinical and imagistic evaluations were performed in 4 patients with chief complaints related to poor dental esthetics. An interdisciplinary approach integrating orthodontics, oral surgery and prosthetics into oral treatment planning was performed. The patients underwent orthodontic treatment. Teeth extraction in the laterally maxilla were performed for space management. Results and discussions: Initial situations and final results were clinically and imagistically compared. Considerable esthetic improvement was noticed in all cases and all patients were satisfied with the final results. Conclusions: Orthodontic therapy is the first choice in cases with crowding in the anterior maxilla and complex treatment needs. The esthetic results of orthodontic therapy are unique.
... [1][2][3] Additionally, it is observed that the more severe the initial rotation, the greater the tendency for relapse. 4 Various methods have been utilized to minimize rotational relapse, such as early correction, overrotation, and long-term retention, but supracrestal fibrotomy is considered most efficacious. 5 This procedure, where the gingival fibers are severed with a surgical blade, was introduced by Edwards 6 , and Crum and Andreasen. ...
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Objective To evaluate the effectiveness of a diode laser (810 nm) for circumferential supracrestal fiberotomy compared with conventional surgical circumferential supracrestal fiberotomy in preventing rotational relapse in orthodontically treated cases. Methods Seventy-six patients (age range from 18-25 years) with mandibular crowding ranging between 5-8 mm and rotation >10˚ (from the individualized arch form) treated non-extraction with a straight wire appliance (McLaughlin, Bennet, Trevisi; 0.022 inch) prescription were selected for the study. The patients were randomly allocated into 3 groups of 22 patients each: Group 1 (Control group-No circumferential supracrestal fiberotomy), Group 2 (Conventional circumferential supracrestal fiberotomy), and Group 3 (diode laser circumferential supracrestal fiberotomy). After leveling and alignment up to “0.019x0.025” stainless steel wire, the arch wire was removed for a period of 1 month. Impressions were made and the poured casts were scanned. The 3D models (.STL files) were evaluated for changes in the irregularity index and rotational relapse. Results One-way ANOVA and post-hoc Tukey’s test were used for data analysis. Group 1 (Control group) showed greater relapse in both irregularity index and rotation angulations in comparison with Groups 2 and 3, which was statistically significant (p<0.001). There was no statistically significant difference in irregularity index and rotational relapse between Group 2 and Group 3 (p=0.35 for irregularity index, and p=0.41 for rotational relapse). Conclusion The control group showed significantly more relapse than both circumferential supracrestal fiberotomy groups. Both conventional and diode laser circumferential supracrestal fiberotomy decreased the relapse tendency.
... The disadvantages are that the retainers frequently suffer from composite breakage or wire fractures. In addition, bonded retainers may also create difficulties in cleaning approximal sites, increasing plaque accumulation and gingival bleeding (3)(4)(5)(6)(7). However, this might not affect periodontal health (6). ...
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Background: Maxillary bonded and removable retainers maintain teeth in correct positions following orthodontic treatment. There is insufficient evidence regarding the capacity of the retention methods to stabilize the maxillary teeth both during and after retention. Objective: To evaluate retention capacity and 1-year post-retention changes in the irregularity of maxillary anterior teeth and single anterior tooth contact point discrepancy (CPD) of two bonded and one removable retention method. Trial design: Three-arm parallel group single-centre randomized controlled trial. Methods: Ninety adolescent patients treated with fixed orthodontic appliances were enrolled. After gaining informed consent, the patients were randomized in blocks of 30 by an independent person into one of three groups: A) bonded retainer 13-23; B) bonded retainer 12-22; and C) removable vacuum-formed retainer. The primary outcomes were changes in Little's irregularity index (LII) and single CPD measured on digitalized casts before retention (T1), after 2 years of retention (T2), and 1-year post-retention (T3). Blinding: The digital casts were blinded for the outcome assessor. Results: Data on all 90 patients were analysed according to intention-to-treat principles. Changes in LII during retention were 0.3 mm in group A, 0.6 mm in group B, and 1.0 mm in group C. No significant differences between the groups were seen (P > 0.05). Changes during post-retention were 1.1 mm in group A, 0.5 mm in group B, and 0.4 mm in group C. Group A showed more significant changes than groups B and C (P = 0.003). During the whole post-treatment period, no significant differences were shown between the groups (P > 0.05). CPD did not differ significantly between the groups at any point. Harms: Three patients showed changes of LII over 3 mm or CPD over 2 mm during the post-retention period, and two accepted to be realigned. Limitations: The trial was a single-centre study evaluating 1-year post-retention changes. Conclusions: The changes were clinically insignificant during and after the retention period. Thus, all three methods showed equal retention capacity. Trial registration: www.clinicaltrials.com (NCT04616755).
... Some orthodontists claim that depending on the facial pattern using cephalometry, an individual position of the mandibular incisors needs to be defined to achieve longterm stability [4]. Others suggest an overcorrection of the present malocclusion or of tooth rotations [5]. In contrast, Reitan et al. advocated a concept of severing periodontal fibers to effectively prevent posttreatment displacement of teeth [1,2,6,7]. ...
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Objectives New opportunities have arisen to manufacture three-dimensional computer-aided design/computer-aided manufacturing (3D CAD/CAM) retainers from titanium blocks by digital cutting technology. These novel technologies need to fulfill requirements regarding digital planning and position accuracy. The aim of the present study was to investigate the digital construction, the CAD/CAM production and the intraoral positioning accuracy of custom-manufactured novel 3D CAD/CAM titanium retainers. Materials and methods A total of 37 prime4me® RETAIN3R (Dentaurum, Ispringen, Germany) retainers were inserted to stabilize the upper anterior front teeth. Following insertion, an intraoral scan was used to record the position. The intraoral position was compared to the virtual setup using 3D superimposition software. Measurement points were evaluated in all three dimensions (horizontal, sagittal and vertical planes). Data were analyzed using Kruskal–Wallis test followed by Dunn’s multiple comparison test. Results A total of 185 measurements were performed. The horizontal plane and the sagittal plane demonstrated a high level of positioning accuracy between the planned and the intraoral position. Statistically significant deviations between the preceding virtual setup and the intraoral situation were observed in the vertical dimension. Within the retainer, the intraoral positioning accuracy decreased for the measurement points in the direction of the distal retainer segment. Conclusion Based on the results, the present study shows a high level of congruence between the 3D virtually planning and the final intraoral position of the fabricated novel 3D CAD/CAM titanium retainers.
... In this case, it had a high risk of relapse due to over-stretched supra alveolar and transeptal fibres indicating fixed retainer (Littlewood et al., 2017). In agreement, previous studies investigating relapse tendency after orthodontic correction of anterior teeth reported that it was reduced after retained with fixed retainer (Naraghi et al., 2006;O'Rourke et al., 2016). In addition, there are reports of occasional, severe and unwanted tooth movement and relapse caused by failed fixed retainers as a result of bonding or wire fatigue (Shaughnessy et al., 2016;Littlewood et al., 2017). ...
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Background: Crowding, rotation and impaction of teeth are some of the complications of supernumeraries. This article aims to discuss the orthodontic treatment of a severely rotated upper left central incisor (UL1) secondary to an erupted mesiodens. An 18-year old Malay male presented with Class I malocclusion with severely crowded upper arch, presence of erupted mesiodens, severely rotated upper left central incisor, displaced upper left lateral incisor and upper left canine and centreline discrepancy. Methods: He had a combination of segmented arch and couple force mechanics to correct severely rotated central incisors. Following anchorage reinforcement, the upper mesiodens and the upper right first premolar was extracted. Subsequently, treatment was continued with conventional straight wire mechanics. Results: The severely rotated upper left central incisor was successfully corrected, and the upper arch crowding was resolved. The fixed appliances were debonded and he was provided with upper dual retention. He had gingival recession Type 1 at UL2 due to the bony defect. Conclusion: Severe crowding can be managed with segmented arch mechanics without any detrimental effects using low forces and good planning. Further periodontal consultation and management were required for the treatment of UL2.
... There are different retention strategies to maintain the position of the teeth in the maxilla. The strategies commonly include a bonded retainer between the maxillary canines (6,7). Also removable vacuum-formed retainers (VFRs) are widely used, and VFRs have been reported to produce stability as good as that produced by fixed retainers (8). ...
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Background: There has been an increased interest in conducting healthcare economic evaluations. Also, orthodontic treatments have gathered focus from an economic point of view, however orthodontic research seldom examines both clinical and economic outcomes. Objective: To evaluate and compare the costs of three retention methods: a bonded retainer to the maxillary four incisors, a bonded retainer to the maxillary four incisors and canines, and a removable vacuum-formed retainer (VFR) in the maxilla. The null hypothesis was that there was no difference in costs for the three types of retention methods. Trial design: Three-arm, parallel group, single-centre, randomized controlled trial. Materials and methods: Ninety adolescent patients, 54 girls and 36 boys, treated with fixed or removable retainers in the maxilla, were recruited to the study. The patients were randomized in blocks of 30, by an independent person, to one of three groups: bonded multistranded PentaOne (Masel Orthodontics) retainer 13-23, bonded multistranded PentaOne (Masel Orthodontics) retainer 12-22, and removable VFR. A cost analysis was made regarding chair time costs based on the costs per hour for the specialist in orthodontics, and material costs plus any eventual costs for repairs of the appliance. Changes in Little's irregularity index and in single contact point discrepancies (CPDs) were measured on digitalized three-dimensional study casts. Data were evaluated on an intention-to-treat basis. The analysis was performed at 2 years of retention. Results: No statistically significant difference in costs between the maxillary fixed retainers and the VFRs was found, however, the material and emergency costs were significantly higher for the VFR compared with the bonded retainers. All three retention methods showed equally effective retention capacity, and no statistically significant differences in irregularity or CPDs of the maxillary anterior teeth in the three groups was detected. Limitations: It was a single-centre trial, and hence less generalizable. Costs depended on local factors, and consequently, cannot be directly transferred to other settings. Conclusions: All three retention methods can be recommended when considering costs and retention capacity. Trial registration: NCT04616755.
... Some degree of relapse appeared on upper right central incisor after five years. However, this corresponded with what Al-Jasser et al. [29]; Naraghi et al. [30] found, as they mentioned, that minor relapse in short-term follow-up (1 year) was noted in the maxillary anterior teeth after correction of irregularities compared to a 2 to 4-year period of bonded retention. This result could be attributed to failures that may occur during the retention period without any follow-up checkup of the patient. ...
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It is undeniable that the advent of extra-alveolar mini-implants for anchorage purposes has revolutionized the field of Orthodontics. This case report sheds light on an innovative anchorage plan using TADs, to carry out treatment for a 15-year-old female patient. The patient reported to the clinic with a chief complaint of rotated second premolars, crowding, and a deep bite. On examination, it was seen that the patient had a Class I skeletal pattern, Class II subdivision molar relationship, 90-degree maxillary second premolar rotations, crowding in both the arches, and a deep bite. In this case, the clinicians decided to use TADs for premolar derotation as it not only provides a pure rotational couple without any deleterious effects on the adjacent teeth but also helps shorten the overall treatment time. The total treatment time for this case was 10 months.
... Bonded lingual retainers are easily accepted by patients and are nondependent of patient cooperation . 10,11 In general; abnormal frenal attachment may require removal either before orthodontic treatment or at the end of active treatment. The advantage of excision prior to orthodontic treatment is the ease of surgical access. ...
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Maxillary midline diastema is a common esthetic problem requiring treatment. This case presentation shows the treatment of a patient with a midline diastema using combination of both fixed orthodontic mechanotherapy and frenectomy procedure. A 16-year-old male patient, whose chief complaint was a small diastema between upper central incisors, had a symmetric face and competent lips. Intraoral examination showed class 1 molar relationship buccal segments relationship with normal overjet and overbite. For the closure of midline diastema, here we use frenectomy with fixed orthodontic appliances. Citation: Mandal M. Closure of midline diastema through combined periodontal Surgery and fixed orthodontic approach.
Article
The results of 264 consecutively treated orthodontic cases were evaluated. According to the defined criteria, optimal treatment objectives were only achieved in 43.2% of the cases. Some of the treatment problems and reasons for failure are identified and discussed. In 16% of cases co-operation problems were the main obstacle to successful treatment. Significant root resorption was observed in 14% of cases. The overall probability for elimination of increased overjet was found to be 71%. Myo-functional problems were an obstacle to treatment in several cases. 1.8% of patients were dissatisfied with the treatment result for aesthetic reasons. It is concluded that close study of treatment problems and failures must be undertaken on an individual basis but 'failure rate' or 'score of success' should be taken into consideration more frequently in clinical orthodontics.
Article
The experience obtained in clinical evaluation of forty-three direct-bonded mandibular canine-to-canine retainers after a minimum observation period of 1 year (range, 1 to 2.5 years) is summarized. Results indicate that the bonded retainer has all the advantages of a fixed soldered retainer, in addition to being invisible. Patient acceptance was excellent, and the failure rate in terms of loose retainers was low. Also, for a number of other retention problems, direct bonding with different types of lingual wire seems to open up a range of promising new possibilities.
Article
A quantitative method of assessing mandibular anterior irregularity is proposed. The technique involves measurement directly from the mandibular cast with a caliper (calibrated to at least tenths of a millimeter) held parallel to the occlusal plane. The linear displacement of the adjacent anatomic contact points of the mandibular incisors is determined, the sum of the five measurements representing the Irregularity Index value of the case. Reliability and validity of the method were tested, with favorable results. At the University of Washington, several clinical studies have been and are continuing to be performed, using this technique as one of several methods of assessing pretreatment status and posttreatment change. It is hoped that this article will aid the reader in understanding the rationale and utility of a simple quantitative tool which could be used in malocclusion assessment.
Article
Information about the individual perception of a patient's own occlusion is considered of importance in orthodontics. One hundred thirty young adults (mean age, 18.1 years) were clinically examined and interviewed with the purpose of relating self-awareness and satisfaction to the actual occlusal status and determining whether dissatisfaction is based on realistically perceived anomalies. From study casts taken at the time of examination, six anterior traits were recorded as either malocclusion, minor deviation, or near-ideal occlusion according to two sets of criteria. Self-awareness was assessed by analyzing agreement between the subjects' reports on the presence of the six traits and the corresponding recordings. Satisfaction was evaluated from three questions with fixed alternative answers. The majority of the young adults (63%) were characterized as having near-ideal occlusion or only minor deviations. Only mild and moderate malocclusions were present in the sample since severe malocclusions are routinely treated during childhood. The subjects were generally aware of anterior traits. Almost all the subjects (98%) with near-ideal occlusion or minor deviations expressed satisfaction. Malocclusion was present in 14 of the 16 subjects who were dissatisfied, and dissatisfaction was based on realistically perceived anomalies. However, traits rated as malocclusion were present in 30% of the satisfied subjects, which may in part be explained by the mild degree of malocclusion in the sample. Awareness of occlusal traits varied among the satisfied subjects.
Article
In a further study of serially treated cases from a Welsh town, the results achieved for crowding, tooth alignment, residual spacing, tooth rotation, arch dimension, and centre line discrepancy are examined. The initial stability of the treatment change in these variables is also presented.
Article
The purpose of this study was to compare the effect of overjet and overbite correction in non-extraction and extraction therapy in a sample of Class II malocclusions treated with the Edgewise appliance. The subjects were 20 children treated without extraction and 20 children treated with extraction of the four first premolars. During the post-treatment period a relapse of overjet and overbite occurred in both groups. However, there was a beneficial net effect of overjet and overbite correction in both groups with no significant difference between the two groups. The study showed that mandibular intercanine width, space conditions in the lower jaw and mandibular incisor position were important factors in treatment planning.
Article
Pretreatment, end of treatment, 10-year postretention, and 20-year postretention records of 31 four premolar extraction cases were assessed to evaluate stability and relapse of mandibular anterior alignment. Crowding continued to increase during the 10- to 20-year postretention phase but to a lesser degree than from the end of retention to 10 years postretention. Only 10% of the cases were judged to have clinically acceptable mandibular alignment at the last stage of diagnostic records. Cases responded in a diverse unpredictable manner with no apparent predictors of future success when considering pretreatment records or the treated results.