ArticlePDF Available

Factors Influencing Patient Compliance during Clear Aligner Therapy: A Retrospective Cohort Study

MDPI
Journal of Clinical Medicine
Authors:

Abstract and Figures

Compliance is highly relevant during clear aligner therapy (CAT). In this retrospective cohort study, we assessed compliance and associated covariates in a large cohort of CAT patients. A comprehensive sample of 2644 patients (75.0% females, 25.0% males, age range 18–64 years, median 27 years), all receiving CAT with PlusDental (Berlin, Germany) finished in 2019, was analyzed. Covariates included demographic ones (age, gender) as well as self-reported questionnaire-obtained ones (satisfaction with ones’ smile prior treatment, the experience of previous orthodontic therapy). The primary outcome was compliance: Based on patients’ consistent use of the mobile application for self-report and aligner wear time of ≥22 h, patients were classified as fully compliant, fairly compliant, or poorly compliant. Chi-square test was used to compare compliance in different subgroups. A total of 953/2644 (36.0%) of patients showed full compliance, 1012/2644 (38.3%) fair compliance, and 679/2644 (25.7%) poor compliance. Males were significantly more compliant than females (p = 0.000014), as were patients without previous orthodontic treatment (p = 0.023). Age and self-perceived satisfaction with ones’ smile prior to treatment were not sufficiently associated with compliance (p > 0.05). Our findings could be used to guide practitioners towards limitedly compliant individuals, allowing early intervention.
Content may be subject to copyright.
J. Clin. Med. 2021, 10, 3103. https://doi.org/10.3390/jcm10143103 www.mdpi.com/journal/jcm
Article
Factors Influencing Patient Compliance during Clear Aligner
Therapy: A Retrospective Cohort Study
Lan Huong Timm
1,
*
,†
, Gasser Farrag
1,†
, Martin Baxmann
2
and Falk Schwendicke
3
1
Sunshine Smile, Windscheidstraße 18, 10627 Berlin, Germany; gassertarekf@gmail.com
2
Orthodentix, Arnoldstrasse 13 b, 47906 Kempen, Germany; martin.baxmann@orthodentix.de
3
Department of Oral Diagnostics, Digital Health and Health Services Research,
Charité—Universitätsmedizin Berlin, Aßmannshauser Straße 4-6, 14197 Berlin, Germany;
falk.schwendicke@charite.de
* Correspondence: lan.timm@plusdental.de
Contributed the same.
Abstract: Compliance is highly relevant during clear aligner therapy (CAT). In this retrospective
cohort study, we assessed compliance and associated covariates in a large cohort of CAT patients.
A comprehensive sample of 2644 patients (75.0% females, 25.0% males, age range 18–64 years,
median 27 years), all receiving CAT with PlusDental (Berlin, Germany) finished in 2019, was
analyzed. Covariates included demographic ones (age, gender) as well as self-reported
questionnaire-obtained ones (satisfaction with ones’ smile prior treatment, the experience of
previous orthodontic therapy). The primary outcome was compliance: Based on patients’ consistent
use of the mobile application for self-report and aligner wear time of ≥22 h, patients were classified
as fully compliant, fairly compliant, or poorly compliant. Chi-square test was used to compare
compliance in different subgroups. A total of 953/2644 (36.0%) of patients showed full compliance,
1012/2644 (38.3%) fair compliance, and 679/2644 (25.7%) poor compliance. Males were significantly
more compliant than females (p = 0.000014), as were patients without previous orthodontic
treatment (p = 0.023). Age and self-perceived satisfaction with ones’ smile prior to treatment were
not sufficiently associated with compliance (p > 0.05). Our findings could be used to guide
practitioners towards limitedly compliant individuals, allowing early intervention.
Keywords: orthodontics; corrective orthodontics; removable orthodontic appliance; clear aligners;
malocclusion; remote consultation; telemedicine; teledentistry; teleorthodontics; distance
counseling
1. Introduction
Technological advancements in computers, mobile phones, internet security,
telecommunications, and software allow increased options for networking, information
sharing, and consultation in medicine, facilitating remote and cost-effective (tele-
)healthcare [1–6]. In dentistry, non-contact communication between patients and dentists
has been used for various steps along the clinical workflow including initial diagnosis,
joint treatment planning, follow-up, and intermediate consultations [1–6].
The clear aligner technology (CAT) builds on clear thermoformed plastic aligners to
correct mild to moderately complex forms of malocclusion [7,8] and has gained popularity
in the past years especially for adult orthodontics [9,10]. Although there are a lot of
similarities between different CAT systems, they differ in their range of application,
methods of construction, aligner thickness, the use of bonded resin attachments, the
treatment sequence, and the application duration per aligner. While rapid technological
advances lead to a highly paced evolution of these different systems [7,8], there is often
limited evidence supporting them [7,8,11,12].
Citation: Timm, L.H.; Farrag, G.;
Baxmann, M.; Schwendicke, F.
Factors Influencing Patient
Compliance during Clear Aligner
Therapy: A Retrospective Cohort
Study. J. Clin. Med. 2021, 10, 3103.
https://doi.org/10.3390/jcm10143103
Academic Editor: Theodore Eliades
Received: 18 June 2021
Accepted: 12 July 2021
Published: 14 July 2021
Publisher’s Note: MDPI stays
neutral with regard to jurisdictional
claims in published maps and
institutional affiliations.
Copyright: © 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license
(http://creativecommons.org/licenses
/by/4.0/).
J. Clin. Med. 2021, 10, 3103 2 of 10
Like other orthodontic treatment appliances, CAT moves teeth by applying
compressive and tensile forces to the periodontium. Optimal orthodontic tooth movement
occurs when continuous forces are applied and maintained, while given that teeth are
moved, the initial forces exerted are higher than those later during each aligner step.
Hence, regular change of aligners is needed. In more recent concepts these changes are
suggested to be required after one to two weeks. Regularly changing aligners requires a
high level of patient compliance [13,14]. Such compliance is further needed as they need
to be worn near-permanently (minimum 22 h per day) [15].
Compliance for orthodontic therapy has been found to vary between males and
females [16] as well as between age groups [17], while overall data on compliance and
treatment outcomes in orthodontics are limited and ambiguous [18]. In patients with low
compliance, treatment times increase, and the outcome may be compromised [16,19].
The present study aimed to evaluate the compliance of aligner patients during
remote treatment monitoring and to assess if compliance was associated with
demographic or other covariates (e.g., previous orthodontic treatment experience,
satisfaction with their current smile). Having knowledge on determinants or indicators of
compliance may allow targeted follow-up.
2. Materials and Methods
2.1. Study Design
A retrospective cohort study was conducted using anonymized data provided by
PlusDental, a brand of the Sunshine Smile GmbH (Berlin, Germany). PlusDental is a
Berlin-based health-tech company, specializing in the digitalization of dental treatments
and operating a digital dental care platform for aesthetic orthodontic tooth corrections,
with a network of more than 200 local partner dentists. The platform integrates laboratory
manufacturing of orthodontic aligners as well as treatment monitoring elements enabling
dentists or orthodontists to monitor aligner changes of patients and aligner pressure using
a standardized questionnaire. Among other data, this information is evaluated by the
dentist or orthodontist bimonthly, and patients are provided feedback and individual
instructions on wearing duration, change interval, aligner handling, or oral hygiene by e-
mail or telephone.
Our outcome was compliance of patients with regards to usage of the self-report
(app-based) questionnaire and, within this, the daily aligner wearing time. Patients with
consistent use of the mobile application for aligner check-in and an aligner wear time of
≥22 h on ≥75% of their aligners were classified as fully compliant. Patients with
inconsistent application usage were classified as fairly or poorly compliant based on the
aligner wear time: Patients with aligner wear time of ≥22 h on 50–74.9% of their aligners
were classified as fairly compliant and patients with aligner wear time of ≥22 h on only
<50% of their aligners as poorly compliant. The study was conducted in accordance with
the World Medical Association Declaration of Helsinki and the reporting followed the
STROBE checklist [20]. The data was collected as a part of the treatment and was
anonymized for research use, which according to the Berlin State Hospital Act
(Landeskrankenhausgesetz Berlin) and the recommendations of the Datenschutz und IT-
Sicherheit im Gesundheitswesen (DIG) task force of the German Association for Medical
Informatics, Biometry, and Epidemiology (GMDS) requires neither approval from an
ethics committee nor informed consent.
2.2. Patient Selection
A comprehensive sample of patients who finished the aligner therapy successfully
with the so-called 1-1-2 CAT protocol without attachments or auxiliaries (see subsection:
Orthodontic Treatment Protocol) in 2019 were included in the study. Patients were
selected to conform to the following inclusion criteria: malocclusion in the anterior and
premolar region to be treated with CAT, adults (>18 years) with a permanent dentition,
J. Clin. Med. 2021, 10, 3103 3 of 10
absence of active periodontal disease, absence of local and/or systemic conditions that can
affect bone metabolisms, and with no extractions required for the orthodontic treatment.
These criteria coincide with the treatment scope of PlusDental (i.e., a comprehensive
sample was drawn).
2.3. Clinical Appointment
A complete clinical examination, a full set of digital photographs, and an intraoral
scan were carried out. A basic periodontal examination was performed [21,22], to rule out
periodontal diseases. Added to that, patients were asked to rate their satisfaction with
their current smile on a 10-point Likert scale (1 = very dissatisfied, 10 = very satisfied) and
report if they had previous orthodontic treatment.
2.4. Digital Treatment Planning
Virtual planning of the final desired tooth position and the required tooth
movements were carried out by a dental technician using proprietary digital planning
technology. The data resulting from this process was exported in the form of consecutive
models.
After the treatment plan was finalized and accepted by the dental practitioner, a 3-
dimensional (3D) simulation showing the steps and the virtual final position of the teeth
was sent to the patient to obtain consent on the proposed final result.
2.5. Manufacturing of Aligners
Additive manufacturing of the models was carried out by digital light processing
technology. The aligners were embossed by a patient-specific serial number indicating the
number of the step and the respective jaw to ensure ease of use by the patients. The
thermoformed aligners were trimmed 2 mm above the free gingival margin.
2.6. Orthodontic Treatment Protocol
The treatment protocol consisted of consecutive steps of aligners which might vary
according to the complexity of the case. Each aligner step was divided into three sub-steps,
each with a different foil thickness. The following wear protocol was followed, 7-day wear
time for the 0.5 mm thick and the 0.625 mm thick aligners, and 14-day wear time for the
0.75 mm thick aligners (1-1-2 protocol). Patients were instructed to wear each aligner for
a minimum of 22 h per day, except during meals, hot drinks, and oral hygiene procedures.
2.7. Treatment Follow-Up and Outcome Assessment
The patients were instructed to check-in every aligner change using the app-based
questionnaire (Figures 1 and 2) and to send a set of photos every two months for follow-
up through the PlusDental mobile application. The photos, aligner change date, the
subjective pressure exerted at the start and the end of the aligner wear, the aligner fit, the
current position of the teeth from different angles, and self-reported aligner wear duration
were assessed by a dental practitioner, who then instructed the patient to continue the
treatment, wear an aligner for a longer duration or repeat a step when necessary. Other
comments concerning the treatment, or the oral health condition of the patient were
communicated as well. At the end of the treatment process, the aligner fit, and the tooth
position compared with the virtual treatment plan as well as patients’ satisfaction were
assessed.
J. Clin. Med. 2021, 10, 3103 4 of 10
Figure 1. The PlusDental app-based questionnaire starting with the aligner check-in on the left.
Figure 2. A representation of the patient treatment execution data collected through the app-based
questionnaire.
2.8. Statistical Analysis
Descriptive statistics were carried out and two-sided Chi-square tests were used for
statistical analysis. p-values smaller than 0.05 were regarded as statistically significant. All
calculations were conducted using JASP 0.41.1 (University of Amsterdam, Amsterdam,
The Netherlands)
3. Results
3.1. Sample Characteristics
Data of all patients that finished their treatment successfully based on one intraoral
scan with the 1-1-2 system in 2019 (2644 patients) was available for analysis without
exclusion (comprehensive sample). Of these, 662 (25.0%) were male and 1982 (75.0%)
female. The median age at treatment start was 27 years (range 18–64). When categorized
by age, the largest group were young adults (18–35 years, n = 2223), followed by middle-
aged adults (ages 36–55 years, n = 406). There were only a few older adults (aged older
than 55 years, n = 15) (Table 1).
Table 1. Age group and gender distribution of the overall sample.
18- to 35- Years
Old
36- to 55- Years Old 56- to 64- Years
Old
Total
Male
563 (21.2%)
96 (3.6%)
3 (0.1%)
662 (25.0%)
Female
1660 (62.7%)
310 (11.7%)
12 (0.4%)
1982 (75.0%)
Total
2223 (84%)
406 (15.3%)
15 (0.5%)
2644 (100%)
J. Clin. Med. 2021, 10, 3103 5 of 10
The number of aligners used per patient ranged from 6 to 36 aligners. Out of all
patients, 47 (1.8%) patients were treated by 6 aligners, 434 (16.4%) patients by 9 aligners,
809 (30.6%) patients by 12 aligners, 682 (25.8%) patients by 15 aligners, 441 (16.7%) patients
by 18 aligners, 150 (5.7%) patients by 21 aligners, 72 (2.7%) patients by 24 aligners, and 9
(0.3%) patients by >24 aligners.
A total of 1333/2644 (50.4%) patients reported very strong to medium pressure at the
start of the aligner wear in 100% of their aligners, 345/2644 (13.0%) patients in 90 to 99.9%
of their aligners, 397/2644 (15.0%) patients in 80 to 89.9% of their aligners, 193/2644 (7.3%)
patients in 70 to 79.9% of their aligners, 125/2644 (7.3%) patients in 60 to 69.9% of their
aligners, 100/2644 (3.8%) patients in 50 to 59.9% of their aligners, and 151/2644 (5.7%)
patients in <50% of their aligners.
Most of the patients (2380/2644, 90.0%) reported medium to very weak pressure at
the end of their aligner wear in comparison to the pressure exerted by the aligner at the
start in 100% of their aligners, 111/2644 (4.2%) patients in 90 to 99.9% of their aligners,
95/2644 (3.6%) patients in 80 to 89.9% of their aligners, 24/2644 (0.9%) patients in 70.0 to
79.9% of their aligners, 23/2644 (0.9%) patients in 60.0 to 69.9% of their aligners, and
11/2644 (0.4%) patients in under 60% of their aligners during the treatment. Only 1 patient
reported that the aligner pressure did not change over the course of each checked-in
aligner.
Regarding their current smile aesthetics, 41.2% (577/1401 responders) indicated that
they were “very dissatisfied” to “slightly dissatisfied” (score 1–4) while 535/1401
responders (38.2%) were “neutral” (score 5–6), and 20.6% (289/1401 responders) were
“slightly satisfied” to “very satisfied” (score 7–10).
A total of 1038/2644 (39.3%) patients reported previous orthodontic treatment,
702/2644 (26.6%) reported no previous orthodontic treatment, and 904/2644 (34.2%) could
not answer the question. The patients who indicated previous orthodontic treatment had
removable appliances in 420/1038 (40.5%) cases, fixed appliances in 501/1038 (48.3%)
cases, and both removable and fixed appliances in 117/1038 (11.3%) of the cases.
Patients who had reported a previous orthodontic treatment answered in 847 (81.6%)
of the cases that they did not have any retainer anymore, 98 (9.4%) had a fixed retainer, 87
(8.4%) had removable retainers, and 6 (0.6%) had both removable and fixed retainers.
3.2. Compliance
Patients were classified according to the compliance criteria into full, fair, and poor
compliance. A total of 953/2644 (36.0%) of patients showed full compliance, 1012/2644
(38.3%) fair compliance, and 679/2644 (25.7%) poor compliance.
A total of 1203/2644 (45.5%) patients wore each aligner for 22 h per day throughout
the treatment period, 456/2644 (17.2%) patients deviated in 0.1–25% of their aligners,
306/2644 (11.6%) patients deviated in 25.1–50% of their aligners, 211/2644 (8.0%) patients
deviated in 50.1–75% of their aligners, and 468/2644 (17.7%) patients deviated in >75% of
their aligners.
Compliance was higher in males compared with females (p < 0.05). No significant
differences were found for patient group age in patient compliance (p = 0.097) (Table 2).
J. Clin. Med. 2021, 10, 3103 6 of 10
Table 2. Compliance in different age groups and by gender.
Overall
Sample
Compliance
Fair
Compliance
Poor
Compliance Chi-Square
Gender n (%)
Male
662 (25%)
277 (10.5%)
124 (4.7%)
X2 (2,
n
= 2644) =
22.34
p = 0.000014
(p < 0.05)
Female 1982 (74.9%) 692 (26.1%) 735 (27.8%) 555 (21.0%)
Age group n (%)
18- to 35-
years old
2223 (84%) 794 (30%) 852 (32.2%) 577 (21.8%)
X2 (4, n = 2644) =
7.84
p = 0.097
36- to 55-
years old
406 (15.3%) 156 (5.9%) 156 (5.9%) 94 (3.6%)
56- to 64
years
old 15 (0.5%) 3 (0.1%) 4 (0.2%) 8 (0.3%)
Total
2644 (100%)
1012 (38.3%)
679 (25.7%)
There were no significant differences in patient compliance when treatments
stretched over different time periods (p = 0.268) (Table 3).
Table 3. Comparisons of compliance by treatment duration.
Overall
Sample
Full
Compliance
Fair Compliance
Poor
Compliance
Chi-Square
Treatment duration n (%)
2 months
47 (1.7%)
20 (0.8%)
14 (0.5%)
13 (0.5%)
X2 (18, n = 2644) =
21.22
p = 0.268
3 months
434 (16.4%)
143 (5.4%)
165 (6.2%)
126 (4.8%)
4 months
809 (30.5%)
308 (11.6%)
285 (10.8%)
216 (8.2%)
5 months
682 (25.7%)
244 (9.2%)
281 (10.6%)
157 (5.9%)
6 months
441 (16.6%) 147 (5.6%) 184 (7.0%) 110 (4.2%)
7 months
150 (5.6%)
60 (2.3%)
53 (2.0%)
37 (1.4%)
8 months
72 (2.7%) 27 (1.0%) 28 (1.1%) 17 (0.6%)
9 months
7 (0.2%)
4 (0.2%)
1 (0.0%)
2 (0.1%)
10
months 1 (0.03%) 0 (0.0%) 0 (0.0%) 1 (0.03%)
12
months 1 (0.03%) 0 (0.0%) 1 (0.03%) 0 (0.0%)
Total
2644 (100%)
953 (36%)
1012 (38.3%)
679 (25.7%)
Compliance was not different for patients with different smile aesthetics satisfaction
before treatment (p = 0.110) (Table 4).
J. Clin. Med. 2021, 10, 3103 7 of 10
Table 4. Patient compliance and smile aesthetics satisfaction.
Total
Responders
Full
Compliance
Fair
Compliance
Poor
Compliance Chi-Square
Smile aesthetics satisfaction n (%)
Very satisfied to
Slightly satisfied
289 (20.6%) 96 (6.9%) 119 (7.0%) 74 (4.4%)
X2 (4, n
= 1401) =
7.54
p = 0.110
Neutral
535 (38.2%)
184 (13.1%)
201 (11.8%)
150 (8.8%)
Slightly
dissatisfied to
Very dissatisfied
577 (41.2%) 217 (15.5%) 237 (13.9%) 123 (7.2%)
Total
1401 (100%)
497 (35.5%)
557 (32.7%)
347 (20.4%)
A significant difference in patient compliance was found for patients regarding
previous orthodontic treatment. Patients without previous orthodontic treatment showed
better patient compliance (p = 0.023) (Table 5).
Table 5. Patient compliance and previous orthodontic treatment.
Total Responders
Full
Compliance
Fair
Compliance
Poor
Compliance Chi-Square
Previous orthodontic treatment n (%)
Yes
1038 (59.7%)
357 (20.5%)
391 (22.5%)
290 (16.7%)
X2 (2, n = 1740) =
7.49
p = 0.023 (p < 0.05)
No 702 (40.3%) 252 (14.5%) 294 (16.9%) 156 (9.0%)
Total
1740 (100%)
609 (35%)
685 (39.3%)
446 (25.6%)
Further analysis of patients with previous orthodontic treatment classified according
to the type of previous treatment showed that patients treated only with removable
appliances were shown to be the most compliant (p = 0.0472) (Table 6).
Table 6. Patient compliance and type of previous orthodontic treatment.
Total
Responders
Full
Compliance
Fair
Compliance
Poor
Compliance Chi-Square
Type of previous orthodontic treatment n (%)
Removable
appliance 420 (40.5%) 158 (15.2%) 165 (15.9%) 97 (9.3%) X2 (4, n
= 1038) =
9.62
p = 0.0472 (p <
0.05)
Fixed appliance
501 (48.3%)
159 (15.3%)
181 (17.4%)
161 (15.5%)
Both removable &
fixed 117 (11.3%) 40 (3.9%) 45 (4.3%) 32 (3.1%)
Total
1038 (100%)
357 (34.4%)
391 (37.7%)
290 (27.9%)
4. Discussion
CAT is increasingly popular for orthodontic corrections but relies heavily on
patients’ compliance. The present study evaluated the compliance and compliance-
associated factors in 2644 CAT patients in 2019. Based on our findings, males were slightly
more likely than females to be compliant while age and pre-treatment satisfaction with
one’s own smile was not associated with compliance. Most significantly, individuals who
had previous orthodontic treatment showed significantly lower compliance. To the
knowledge of the authors, this is the first study evaluating compliance of a large cohort of
J. Clin. Med. 2021, 10, 3103 8 of 10
clear aligner patients using a mobile application during a remote follow-up in terms of
mobile application usage and self-reported wearing hours.
Our findings require some detailed discussion. Gender has been found to be
associated with compliance for orthodontic treatment before, while the direction of any
association remains unclear. For example, Al-Abdallah et al. found female patients to be
more compliant during fixed orthodontic treatment [16], Schäfer et al. found female
patients to be more compliant during removable orthodontic treatment [23], while Crouse
found no difference between males and females [24]. The patients in these studies were
either all below 18 years of age [16,23], or partially under 18 [24], which could be the
reason for the opposite results found in our study where the youngest patients at the start
of the treatment were 18 years old (median = 27). It is possible that in adults, men are more
compliant during orthodontic treatment. This finding, however, needs to be further
confirmed in a sample with a bigger age range including adolescents and children, and
should be explored using qualitative research methods as well to better understand
reasons behind it.
Similarly, age has been ambiguously found to be associated with compliance. For
example, Barbosa et al. showed that adult patients were more compliant with fixed
appliance therapy than adolescents [17], whereas Crouse found that patients in the 14–19
and 20–39 age groups were significantly less compliant with CAT than those younger or
older. The absence of an adolescent age group in the current study could be the reason
why such effect of age on compliance could not be established, together with the small
number of patients (15/2644) in the oldest age group which was expected to be less
compliant using the mobile application. Overall, the comparison of age groups likely
suffered from limited heterogeneity and hence statistical power, as most patients were of
similar age.
The absence of a demonstrable effect of satisfaction with the current smile before
treatment and compliance during the treatment is in line with the findings of Mandall et
al. [18], where concern about the negative impact of teeth appearance was not indicative
of higher compliance during the treatment. This is somewhat counterintuitive, as one may
expect individuals unhappy with their smile to desire an aesthetic improvement more
eagerly than those less unsatisfied, who in turn may be less compliant. It is possible,
however, that all adult patients in our sample where generally relatively interested in
improving their smile aesthetics, mainly demonstrated by them paying out of pocket for
a by-large aesthetic correction.
Notably, patients who had experienced previous orthodontic treatment were shown
to be less compliant during CAT. A possible explanation is that those patients might have
been non-compliant previously, for example with their retention protocol, leading to
relapse in the first place (81.6% of the patients who had previous orthodontic treatment
reported not having retainers at the time of their clinical appointment). A significant
decrease in compliance over time regarding daily retainer wear and/or the wearing hours
is a common finding among orthodontic patients [25], especially for relatively long
orthodontic treatment processes [19]. Individuals who had experienced previous therapy
may perceive the second therapy as especially long and hence become impatient earlier,
impacting on compliance.
It is worth noting that the patients who had previous orthodontic treatment with
removable appliance were found to be more compliant than the patients who had
previous fixed orthodontic treatment. The familiarity with the removable appliances and
their mode of action might have been the reason behind the higher compliance of patients
with previous removable appliance experience during CAT.
Based on the findings in this study, the dental practitioner might be able to identify
potential low compliance CAT patients which would allow for early intervention to try to
improve compliance during remote follow-up. Among many methods, praising the
patient for compliant behavior and patient education about the consequences of poor
compliance were reported by orthodontists to be of high importance in improving
J. Clin. Med. 2021, 10, 3103 9 of 10
compliance [26]. In a remote follow-up CAT context, that could translate into delivering
praise to patients with compliant wear time and consistent application usage and
educating the patient about the consequences of poor compliance prior to treatment and
sending them reminders during treatment when deviation from compliant behavior is
observed. The efficacy of these methods needs to be further studied.
This study comes with a range of limitations. First, the absence of an under 18 years
old (children and adolescents) age group together with the small number of patients in
the oldest age group (above 56 years old) did not allow for a comprehensive
representation of the orthodontic treatment-seeking population, especially those below
the age of 18 years. Second, the aligner wearing hours and the perceived aligner pressure
were recorded using self-reports, which are susceptible to biases such as overstatement
and understatement or distortion of perception and memory [27]. This is why we
classified the patients in this study based on the consistency of mobile application usage
during remote follow-up as a more objective indicator of compliance. Third, compliance
was measured for CAT; inferences on other orthodontic therapies should not be made.
Last, the sample suffered from selection bias; only patients willing to pay a certain amount
of money out-of-pocket from mainly three countries, Germany, Switzerland, and Austria,
for one specific aligner therapy were included. Generalization to other populations should
not be attempted.
Further studies are needed to evaluate the influence of other factors on compliance
such as the type of malocclusion, the aligner thickness, the frequency of aligner breakage,
and the need for IPR.
5. Conclusions
Within the limitations of this study, gender but not age or pre-treatment satisfaction
with one own’s smile was associated with patient compliance during CAT. Most notable,
patients who had experienced previous orthodontic therapy showed significantly lower
compliance. Based on our findings, individuals at-risk should be identified in future
studies and their compliance prospectively recorded. Our findings could be used to guide
practitioners towards limitedly compliant individuals, allowing early intervention.
Author Contributions: Conceptualization, L.H.T. and F.S.; Formal analysis, L.H.T.; Writing—
original draft, L.H.T., G.F. and F.S.; Writing—review & editing, L.H.T., G.F., M.B. and F.S. All
authors have read and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: The study was conducted according to the guidelines of the
Declaration of Helsinki. The data was collected as a part of the treatment and anonymized for
research use, which according to the Berlin State Hospital Act (Landeskrankenhausgesetz Berlin)
and the recommendations of the Datenschutz und IT-Sicherheit im Gesundheitswesen (DIG) task
force of the German Association for Medical Informatics, Biometry, and Epidemiology (GMDS) does
not require approval from an ethics committee.
Informed Consent Statement: Patient consent was waived because the data was collected as a part
of the treatment and was anonymized for research use, which according to the Berlin State Hospital
Act (Landeskrankenhausgesetz Berlin) and the recommendations of the Datenschutz und IT-
Sicherheit im Gesundheitswesen (DIG) task force of the German Association for Medical
Informatics, Biometry, and Epidemiology (GMDS) does not require informed consent.
Data Availability Statement: Data available on request due to privacy restrictions.
Conflicts of Interest: Lan Huong Timm and Gasser Farrag declare gainful employment by Sunshine
Smile, the brand owner of PlusDental. Martin Baxmann and Falk Schwendicke are members of the
Scientific Board of the Sunshine Smile GmbH.
J. Clin. Med. 2021, 10, 3103 10 of 10
References
1. Favero, L.; Pavan, L.; Arreghini, A. Communication through telemedicine: Home teleassistance in orthodontics. Eur. J. Paediatr.
Dent. 2009, 10, 163–167.
2. Maspero, C.; Abate, A.; Cavagnetto, D.; El Morsi, M.; Fama, A.; Farronato, M. Available Technologies, Applications and Benefits
of Teleorthodontics. A Literature Review and Possible Applications during the COVID-19 Pandemic. J. Clin. Med. 2020, 9, 1891.
3. Jampani, N.D.; Nutalapati, R.; Dontula, B.; Boyapati, R. Applications of teledentistry: A literature review and update. J. Int. Soc.
Prev. Community Dent. 2011, 1, 37–44.
4. Park, J.H.; Rogowski, L.; Kim, J.H.; Al Shami, S.; Howell, S.E.I. Teledentistry platforms for orthodontics. J. Clin. Pediatr. Dent.
2021, 45, 48–53.
5. Dalessandri, D.; Sangalli, L.; Tonni, I.; Laffranchi, L.; Bonetti, S.; Visconti, L.; Alberto, S.; Paganelli, C. Attitude towards
Telemonitoring in Orthodontists and Orthodontic Patients. Dent. J. 2021, 9, 47.
6. Putrino, A.; Caputo, M.; Giovannoni, D.; Barbato, E.; Galluccio, G. Impact of the sars-cov2 pandemic on orthodontic therapies:
An italian experience of teleorthodontics. Pesqui Bras. Odontopediatria Clin. Integr. 2020, 20, doi:10.1590/pboci.2020.140.
7. Weir, T. Clear aligners in orthodontic treatment. Aust. Dent. J. 2017, 62, 58–62.
8. Putrino, A.; Barbato, E.; Galluccio, G. Clear aligners: Between evolution and efficiency—A scoping review. Int. J. Environ. Res.
Public Health 2021, 18, 2870.
9. Robertson, L.; Kaur, H.; Fagundes, N.C.F.; Romanyk, D.; Major, P.; Flores Mir, C. Effectiveness of clear aligner therapy for
orthodontic treatment: A systematic review. Orthod. Craniofacial Res. 2020, 23, 133–142.
10. Alansari, R.A.; Faydhi, D.A.; Ashour, B.S.; Alsaggaf, D.H.; Shuman, M.T.; Ghoneim, S.H.; Linjawi, A.I.; Marghalani, H.; Dause,
R.R. Adult perceptions of different orthodontic appliances. Patient Prefer. Adherence 2019, 13, 2119–2128.
11. Rossini, G.; Parrini, S.; Castroflorio, T.; Deregibus, A.; Debernardi, C.L. Efficacy of clear aligners in controlling orthodontic tooth
movement: A systematic review. Angle Orthod. 2015, 85, 881–889.
12. Hennessy, J.; Al-Awadhi, E.A. Clear aligners generations and orthodontic tooth movement. J. Orthod. 2016, 43, 68–76.
13. Tuncay, O.C.; Bowman, S.J.; Nicozisis, J.L.; Amy, B.D. Effectiveness of a compliance indicator for clear aligners. J. Clin. Orthod.
2009, 43, 263-8.
14. Schott, T.C.; Göz, G. Color fading of the blue compliance indicator encapsulated in removable clear Invisalign Teen ® aligners.
Angle Orthod. 2011, 81, 185–191.
15. El-Bialy, T. The effect of high-frequency vibration on tooth movement and alveolar bone in non-growing skeletal class II high
angle orthodontic patients: Case series. Dent. J. 2020, 8, 110.
16. Al-Abdallah, M.; Hamdan, M.; Dar-Odeh, N. Traditional vs digital communication channels for improving compliance with
fixed orthodontic treatment: A randomized controlled trial. Angle Orthod. 2021, 91, 227–235.
17. Barbosa, I.V.; de Ladewig, V.M.; Almeida-Pedrin, R.R.; Cardoso, M.A.; Santiago Junior, J.F.; de Conti, A.C.C.F. The association
between patient’s compliance and age with the bonding failure of orthodontic brackets: A cross-sectional study. Prog. Orthod.
2018, 19, 11.
18. Mandall, N.A.; Matthew, S.; Fox, D.; Wright, J.; Conboy, F.M.; O’Brien, K.D. Prediction of compliance and completion of
orthodontic treatment: Are quality of life measures important? Eur. J. Orthod. 2008, 30, 40–45.
19. Richter, D.D.; Nanda, R.S.; Sinha, P.K.; Smith, D.W.; Currier, G.F. Effect of behavior modification on patient compliance in
orthodontics. Angle Orthod. 1998, 68, 123–132.
20. von Elm, E.; Altman, D.G.; Egger, M.; Pocock, S.J.; Gøtzsche, P.C.; Vandenbroucke, J.P.; STROBE Initiative. The Strengthening
the Reporting of Observational Studies in Epidemiology (STROBE) statement: Guidelines for reporting observational studies.
J. Clin. Epidemiol. 2008, 61, 344–349, doi:10.1016/j.jclinepi.2007.11.008.
21. Corbet, E.F. Oral diagnosis and treatment planning: Part 3. Periodontal disease and assessment of risk. Br. Dent. J. 2012, 213,
111–121, doi:10.1038/sj.bdj.2012.666.
22. Dietrich, T.; Periodontology, O.B.O.T.B.S.O.; Ower, P.; Tank, M.; West, N.X.; Walter, C.; Needleman, I.; Hughes, F.J.; Wadia, R.;
Milward, M.R.; et al. Periodontal diagnosis in the context of the 2017 classification system of periodontal diseases and
conditions—Implementation in clinical practice. Br. Dent. J. 2019, 226, 16–22, doi:10.1038/sj.bdj.2019.3.
23. Schäfer, K.; Ludwig, B.; Meyer-Gutknecht, H.; Schott, T.C. Quantifying patient adherence during active orthodontic treatment
with removable appliances using microelectronic wear-time documentation. Eur. J. Orthod. 2015, 37, 73–80.
24. Crouse, J.M. Removable Clear Aligner Therapy. J. Clin. Orthod. 2018, 52, 710–713.
25. Kacer, K.A.; Valiathan, M.; Narendran, S.; Hans, M.G. Retainer wear and compliance in the first 2 years after active orthodontic
treatment. Am. J. Orthod. Dentofac. Orthop. 2010, 138, 592–598, doi:10.1016/j.ajodo.2008.12.027.
26. Mehra, T.; Nanda, R.S.; Sinha, P.K. Orthodontists’ assessment and management of patient compliance. Angle Orthod. 1998, 68,
115–122.
27. Sahm, G.; Bartsch, A.; Witt, E. Reliability of patient reports on compliance. Eur. J. Orthod. 1990, 12, 438–446.
... Many studies have explored the factors influencing compliance, including age, gender, employment status, and socioeconomic background [8,9]. Research consistently shows that personality traits also play a role in compliance across various fields [10,11]. ...
... p ≤ 0.05). This result, in line with Timm et al. [8], underscores the necessity of gender-specific strategies to enhance adherence in orthodontics. It highlights the importance of considering gender differences in treatment planning. ...
... Patients undergoing CA therapy for over a year showed significantly lower adherence than those being treated for one year or less (p ≤ 0.05). This is consistent with other studies [8,19], reflecting treatment fatigue as patients lose motivation over time. Developing strategies to maintain engagement throughout extended treatment may help mitigate this decline. ...
Article
Full-text available
Introduction: Patient compliance is crucial for achieving optimal outcomes in clear aligner (CA) therapy. Compliance may be influenced by various factors, including demographics, level of education, doctor-patient interaction, and personality traits based on the Big Five Inventory (BFI), which assesses openness, conscientiousness, extraversion, agreeableness, and neuroticism. This study investigates the relationship between personality traits and compliance among CA patients. Methods: A cross-sectional study was conducted with 67 participants aged 12-60 undergoing CA treatment in Jeddah, Saudi Arabia. Patients completed an online questionnaire that assessed compliance behavior and personality traits using the BFI-10 tool. Data were statistically analyzed using SPSS software, version 26 (IBM Corp., Armonk, NY), to examine correlations between personality traits, demographic factors, and adherence to CA therapy. Compliance was scored based on adherence to follow-up visits and aligner wear time. Result: The study revealed that 34 participants (50.75%) demonstrated high adherence to the prescribed regimen. Males showed significantly higher compliance than females (p ≤ 0.05). Participants aged 12-34 exhibited the highest adherence rates (p ≤ 0.05), and those undergoing treatment for one year or less were also more compliant (p ≤ 0.05). Notably, satisfaction with one's smile did not significantly correlate with adherence (p > 0.05), contradicting the assumption that dissatisfaction with appearance drives better compliance. Furthermore, no significant association was identified between personality traits across any BFI domain and adherence. Conclusion: Despite the hypothesis that personality traits influence patient compliance, this study did not find a significant correlation. These findings suggest that factors other than personality traits may be more critical to adhering to CA treatment. The results highlight the need for further research to explore additional variables that may impact patient compliance in orthodontic therapy.
... During the last two decades, optically transparent aligner therapy has become more and more popular, although orthodontic treatments still often rely on metal brackets [1,2]. This development is in large part because optically transparent aligners are perceived as an appealing option due to esthetics and, more importantly, the possibility of removal for chewing food and tooth cleaning [3]. Furthermore, compared to traditional brackets, clear aligners provide a more stable course of treatment [4]. ...
... The surface representations in Figures 6 and 7 show the displacement of the crown to be considered from the therapy start in dark blue to the situation after nine-week aligner treatment in dark red. The translation and rotation in time steps of one week, using colors from blue to red, are visualized in three-dimensional space by cubes with a volume of (1 mm) 3 . ...
... The surface representations in Figures 6 and 7 show the displacement of the crown to be considered from the therapy start in dark blue to the situation after nine-week aligner treatment in dark red. The translation and rotation in time steps of one week, using colors from blue to red, are visualized in three-dimensional space by cubes with a volume of (1 mm) 3 . Figure 6. ...
Article
Full-text available
The effectiveness of a series of optically transparent aligners for orthodontic treatments depends on the anchoring of each tooth. In contrast with the roots, the crowns’ positions and orientations are measurable with intraoral scans, thus avoiding any X-ray dose. Exemplified by two patients, we demonstrate that three-dimensional crown movements could be determined with micrometer precision by registering weekly intraoral scans. The data show the movement and orientation changes in the individual crowns of the upper and lower jaws as a result of the forces generated by the series of aligners. During the first weeks, the canines and incisors were more affected than the premolars and molars. We detected overall tooth movement of up to about 1 mm during a nine-week active treatment. The data on these orthodontic treatments indicate the extent to which actual tooth movement lags behind the treatment plan, as represented by the aligner shapes. The proposed procedure can not only be used to quantify the clinical outcome of the therapy, but also to improve future planning of orthodontic treatments for each specific patient. This study should be treated with caution because only two cases were investigated, and the approach should be applied to a reasonably large cohort to reach strong conclusions regarding the efficiency and efficacy of this therapeutic approach.
... Several studies used only subjective measurement methods to measure patient adherence. During clear aligner treatment, studies recorded patients' self-reported daily wear time by the use of an app [50,51]. To investigate adherence to appointment-keeping, one study used a questionnaire to record self-reported levels of attendance [52]. ...
... It was reported that up to 92% of patients did not adhere to their prescribed wear time [30]. Regarding adherence to the prescribed wear time of aligners during CAT, one study found that merely 36% of patients adhere to their prescribed wear time [50]. Almost all studies investigating adherence to oral health instructions only reported key findings regarding factors to influence this adherence, but did not provide any significant findings regarding the level of oral hygiene or degree of adherence to these instructions during orthodontic treatment. ...
... The studies on the level of appointment-keeping [35][36][37] reported attendance levels ranging between 67.8% [35] and 91.7% [36]. When assessing the influence of patient demographics, conflicting results were reported about the influence of the patient's sex, with both males being reported to be more compliant to prescribed wear times of removable appliances and keeping-appointments [36,50,59] as females [37,62], to the patient's sex having no association with the level of adherence [20]. The patient's age was reported to have no association with the level of adherence [20]. ...
Article
Full-text available
Background Patient adherence is a key factor in achieving orthodontic treatment success. Despite an evolution in orthodontic healthcare, no recent comprehensive reviews are available on patient adherence in orthodontics. This scoping review provides an evidence-based overview of the literature available on multiple aspects of patient adherence in orthodontics, during both active treatment as well as during the retention phase. Knowledge gaps identified in the literature are listed. Methods The protocol for this scoping review was registered in the Open Science Framework ( https://doi.org/10.17605/OSF.IO/EC6QD ). Electronic databases and reference lists of relevant studies were searched up to 9 February 2023. The inclusion criteria were studies investigating any form of patient adherence in orthodontics published in English from 2006 onwards. The exclusion criteria were studies investigating adherence in the following patients: those with an intellectual or physical disability that could affect their ability to coincide with their therapist’s recommendations and advice, those with oral cleft and craniofacial conditions, and those treated solely for obstructive sleep apnoea. Non-peer-reviewed studies and case reports were also excluded. Results A total of 3284 articles were identified, 60 of which met the criteria for final inclusion. Conclusions There is no conclusive evidence on which factors have a significant impact on patient adherence and how patient adherence can be promoted. The degree of patient adherence is generally not compared to achieved treatment results or stability of treatment results, making it difficult to provide clear statements about the impact of the degree of adherence on desired treatment results or orthodontic stability.
... The introduction of Noxi aligners (Sweden&Martina, Due Carrare, Italy), developed by the University of Ferrara, offers a 3D-printed aligner option that can be worn for only 12 h per day, addressing the needs of patients seeking a more discreet and less demanding treatment alternative. Studies highlight that only a small percentage of patients fully adhere to traditional 22-h wear protocols [33]. This innovation aims to enhance patient compliance-one of the key factors for orthodontic treatment success-by significantly reducing the required wear time. ...
Article
Full-text available
Background: Retention is a critical aspect of orthodontic treatment with aligners as it counteracts vertical displacing forces and ensures greater predictability of tooth movement. The aim of this study is to evaluate and compare the retention effectiveness of 3D-printed aligners and thermoformed aligners, analyzing how margin design and thickness gradients affect retention under different occlusal conditions. Methods: Tensile tests were conducted using a Sauter TVO-A01 machine, recording the force required to displace each aligner from the models. Quantitative data on the retention force of each aligner were collected based on malocclusion type and design specifics. Results: Scalloped thermoformed aligners demonstrated significantly lower retention values (p = 0.029) compared to 3D-printed aligners with high margins with horizontal and vertical gradients. Scalloped margin aligners exhibited significantly lower retention values (p = 0.008) compared to straight margin aligners. Additionally, 3D-printed aligners with uniform thickness gradients had significantly lower retention values (p = 0.040) compared to thermoformed aligners. Conclusions: The 3D printing production process enables customizable designs tailored to the unique characteristics of each patient. High-margin 3d-printed aligners with horizontal and vertical gradients provide superior retention, particularly in complex clinical situations such as dental crowding.
... Should the mechanical design of an aligner effectively address the critical criteria of comfort, stability, and the ability to visualize treatment progress, it is likely to substantially enhance patient adherence, thereby facilitating improved clinical results. At present, the majority of researches concerning patient compliance with clear aligners predominantly emphasized the correlations between compliance and various factors, alongside elements of remote monitoring [123][124][125]. There exists a notable scarcity of literature that rigorously investigates, from a biomechanical perspective, how patient comfort and compliance fluctuate across diverse clinical cases and treatment scenarios. ...
Article
Full-text available
Introduction Although with increasing popularity due to aesthetic appeal and comfort, clear aligners (CAs) are facing challenges in efficacy and predictability. Advancement in the underlying biomechanical field is crucial to addressing these challenges. This paper endeavors to provide a comprehensive framework for understanding the biomechanics of CA and enlightening biomechanics-based improvements on treatment strategies. Methods A thorough review of the English-language literature accessible through PubMed and Google Scholar, without any publication year restrictions, was undertaken to unravel the biomechanical aspects of CA. Results This review presented an up-to-date understanding of aligner biomechanics arranged by the framework of the material-dependent mechanical characteristics of CA, the geometric characteristics-dependent force transmission of the CA system, methods for studying the biomechanics of CA, and the biomechanical analyses for different types of tooth movement. Conclusions Biomechanics should be the fundamental concern for concepts, methods and adjuncts attempting to enhance the accuracy and predictability of tooth movement induced by CA. Improvement on material properties and alteration of geometric design of CA are two main approaches to develop biomechanically optimized force system. Exploration of real-world force sensing and monitoring system would make substantial progresses in aligner biomechanics.
... However, patient compliance shows a significant difference, with 98% of orthodontists and 90% of general dentists agreeing on its importance. This suggests a universal recognition of compliance's role, but general dentists may need to emphasize it more in patient education as emphasized in previous studies conducted on the compliance of patients in clear aligner therapy (18)(19)(20). ...
Article
Full-text available
Clear aligners, a modern orthodontic solution for malocclusions, have gained widespread popularity due to their aesthetic appeal, convenience, and technological advancements. Understanding the perceptions and attitudes of orthodontists and general dentists toward clear aligners is essential to enhance their adoption and effectiveness in orthodontic care. Objective: To assess orthodontists' and general dentists' awareness, attitudes, and confidence levels toward using clear aligners in orthodontic practice. Methods: A descriptive cross-sectional study was conducted using a 10-item questionnaire distributed via Google Forms. The sample consisted of 200 participants: 100 orthodontists and 100 general dentists. The responses were rated on a 5-point Likert scale, and the data were analyzed using SPSS version 23. Chi-square tests and t-tests were applied to assess differences between the two groups, with a significance level set at p<0.05. Results: The response rate was 85%. Orthodontists demonstrated significantly higher confidence in using clear aligners than general dentists (p<0.001). Orthodontists were also more likely to view aligners as the future of orthodontics and reported fewer challenges, such as patient compliance and accessibility. In contrast, general dentists expressed lower confidence in achieving precise outcomes with aligners and faced more difficulties during treatment. Conclusion: Orthodontists show greater confidence and a more positive outlook on using clear aligners than general dentists. Addressing the differences in experience and perceptions between these groups could lead to improved implementation of clear aligner therapy in dental practice, ultimately benefiting patient outcomes.
... only 36% showed full compliance, while 38.3% demonstrated fair compliance, and the other 25.7%, poor compliance. 6 Although patients may be more likely to comply with shorter required wear times, such reduced wear could affect treatment outcomes, since the duration of force application influences osteoclast recruitment in the periodontal ligament and thus affects tooth movement. 7 In animal models, however, intermittent force application has produced almost as much tooth movement as has fulltime force application. ...
Article
Objectives To investigate maxillary canine movement accuracy and anchorage during space closure in first premolar extraction cases (maximum anchorage) using In‐House Clear Aligners (IHCAs). Materials and Methods A randomised controlled trial with a split‐mouth design recruited 16 adults in university setting. Each patient was randomly assigned by side for canine retraction using 12 IHCAs to both the experimental palatal power arm (Pa) and non‐Pa control (C). Accuracy was assessed using GOM Inspect by superimposing the virtual and actual digital models between pretreatment and 12th IHCA. Paired t‐test or Wilcoxon signed‐rank test was used to compare virtual‐power arm (VPa) versus actual‐power arm (APa) and virtual‐control (VC) versus actual‐control (AC). Root mean square error (RMSE) was calculated. Results Pa displayed a significant difference in preliminary canine distalisation (VPa 2.0 mm vs. APa 2.4 mm), while the control did not differ. Both Pa and control exhibited significantly greater actual distal crown tipping than virtual movement (VPa 4.4° vs. APa −6.3°/VC 4.4° vs. AC −4.3°). AC achieved more canine rotation than VC. RMSE was slightly greater in Pa than control for canine distalisation (Pa 0.6 vs. C 0.55 mm) and distal crown tipping (Pa 10.9° vs. C 8.99°). Conversely, Pa displayed better accuracy in canine rotation. For anchorage, Pa and control exhibited significantly greater actual mesialisation and mesial tipping than virtual. RMSE for anchorage mesialisation and mesial tipping were comparable between Pa and control. Conclusions Preliminary canine retraction using Pa may result in greater error in distal crown tipping but less rotation than control. Trial Registration ISRCTN 14020146 by the International Standard Randomised Controlled Trial Registry
Article
Full-text available
The palatal anchorage device (PAD) is commonly used in fixed appliance for anchorage, but the biomechanics of PAD in patients treated with clear aligners(CAs)remains poorly understood, especially in its elastic mode and force magnitude. This study aimed to assess the biomechanical effects of using PAD for retraction during clear aligner treatment (CAT) with the extraction of two maxillary first premolars. Four finite element models were created: (1) Incisors retraction (IR) with active contraction of the clear aligner only; (2) IR with PAD using different forces (50,75,100 g) or not; (3) PAD without IR (forces of 50,75,100 g), and (4) Different elastic directions (D1, D2, D3) from aligner to PAD without IR. IR caused lingual tipping and extrusion of the central incisors, as well as mesial and buccal tipping of the first molar. PAD during IR provided strong anchorage for the first molar, with elastics slightly increasing the lingual tipping and extrusion of the central incisors. Elastics applied to the U-shaped arch led to central incisor intrusion and reduced lingual retraction. The highest stress was observed on the mesial attachment of the canine. PAD effectively reinforced posterior anchorage in CAT, while anterior positioning facilitated anterior teeth intrusion. The biomechanical importance of the canine’s mesial attachments in maxillary teeth treatment planning was highlighted.
Article
Full-text available
Introduction The purpose of this study was to compare the mechanical changes of clear aligners manufactured using either the direct method (Graphy Tc-85) or the indirect method (CA Pro or Invisalign) following an exposure to different liquids. Material and Method The clear aligners were produced using a single patient’s digital maxillary model. CA Pro aligners were produced indirectly using the Ministar S device, while Graphy Tc-85 resin aligners were produced directly using a three-dimensional printer (Ackuretta, Taipei, Taiwan). Invisalign appliances were produced by Align Technology, Inc. The appliances were randomly divided into seven groups: a control group and six experimental groups. The control group appliances were not immersed in any liquid. The appliances in the experimental groups were immersed in six different liquids (orange juice, soy sauce, cola, red wine, tea, and coffee) for 24 hr at 37°C. Following immersion, the upper right first molar section of each appliance was separated using an abrasive disc and embedded in a 2 mm thick acrylic layer. A cyclic loading test was conducted using a specialised mechanism (a combination of a dynamometer and a deformation depth measuring instrument) and each sample was subjected to varying cyclical forces until a deformation depth of 1 mm was reached. The force magnitude required to achieve the 1 mm material deformation at the 1st, 5th, 10th, and 50th cycles of loading was recorded for each sample. Results As a result of repeated loads, the indenting force values decreased in the three sample groups, regardless of the liquid in which the appliances had been stored. However, soy sauce and orange juice had a greater detrimental effect on the mechanical properties of the aligners compared to the other liquids. On comparing the force values required for the material to reach a 1 mm depth during the 1st and 50th loadings, the decreases were recorded as 0.4% for Graphy Tc-85, 26.3% for CA Pro, and 42.1% for Invisalign. Conclusions Of the tested aligners, Graphy Tc-85 was the most resistant to repetitive loads, while Invisalign was the least resistant. It is inherently difficult to predict how different liquids will affect aligners made of different materials.
Article
Full-text available
The purpose of this study was to analyze the attitude of dentists and patients towards the use of Dental MonitoringTM (DM), an orthodontic telemonitoring software. Thus, two different specially prepared specific questionnaires were administered to 80 dentists (40 were general dentists and 40 orthodontists) and 80 orthodontic patients. All dentists judged positively telemonitoring, as 96.25% of them considered telemonitoring indicative of high tech and high-quality treatment; 100% considered it a way to reduce the number of in-office visits; 17.5% agreed on a weekly telemonitoring frequency, 40% on a biweekly, and 42.5% on a lower frequency. Further, 97.5% of patients judged positively telemonitoring; 81.25% of them considered telemonitoring indicative of high-tech treatment; 81.25% declared to be interested in reducing the number of in-office visits through telemonitoring; 27.5% agreed on taking self-picture every week, 57.5% every two weeks, and 15% on a lower frequency. Both patients and dentists positively judged telemonitoring, considering it a technologically advanced tool increasing the perception of quality and accuracy of the treatment. Both groups were interested in reducing the number of in-office visits, although not all of them revealed to be ready to invest more money and time in it.
Article
Full-text available
In recent years, clear aligners have diversified and evolved in their primary characteristics (material, gingival margin design, attachments, divots, auxiliaries), increasing their indications and efficiency. We overviewed the brands of aligners used in Italy and reviewed the literature on the evolution of clear aligners based on their characteristics mentioned above by consulting the main scientific databases (PubMed, Scopus, Lilacs, Google Scholar, Cochrane Library). Inclusion and exclusion criteria were established. The data were collected on a purpose-made data collection form and analyzed descriptively. From the initial 580 records, 527 were excluded because they were not related to the subject of the review or because they did not meet the eligibility criteria. The remaining 31 studies were deemed comprehensive for the purpose of the review, although the "gingival margin design" feature and "auxiliaries" tool are not well represented in the more recent literature. Current knowledge on invisible aligners allows us to have a much clearer idea of the basic characteristics of aligner systems. There remains a need to deepen the use of systems other than In-visalign™ to give greater evidence to aligners that are very different based on the characteristics analyzed here and that are very widespread on the market.
Article
Full-text available
This study presents a novel technique utilizing high-frequency vibration to shorten treatment time and preserve alveolar bone in challenging orthodontic cases that have been treated with Invisalign® clear aligners. Four non-growing orthodontic patients (age range 14-47 years old) with Class II skeletal patterns (convex profiles with retrognathic mandibles) who sought correction of their crowded teeth and non-surgical correction of their convex profiles were included in this study. These patients were treated using Invisalign clear aligners together with high-frequency vibration (HFV) devices (120 Hz) (VPro5™) that were used by all patients for five minutes per day during active orthodontic treatment. Vertical control and forward rotation of the mandible for each patient was achieved through pre-programming the Invisalign to produce posterior teeth intrusion. Successful forward rotation of the mandibles achieved in all patients led to improvement of their facial convex profiles (apical base relationship (ANB) improved 2.1 ± 0.5 degrees; FMA (Frankfurt mandibular plane angle) improved 1.2 + 1.1 degrees). Dental decompensation was achieved by lingual tipping of the lower incisors and palatal root torque of upper incisors. The use of HFV together with Invisalign facilitated achieving these results within a 12 ± 6 months period. In addition, more bone labial to the lower incisors after their lingual movement was noted. In conclusion, the use of HFV concurrent with SmartTrack Invisalign aligners allowed complex tooth movement and forward mandibular projection without surgery in non-growing patients with skeletal Class II relationships. The clinical impact and implications of this case series are: (1) the use of HFV facilitates complex orthodontic tooth movement including posterior teeth intrusion and incisor decompensation; (2) forward mandibular projection of the mandible and increased bone formation labial to lower incisors can be achieved in non-growing patients that may minimize the need for surgical intervention in similar cases or gum recession due to lower incisors labial inclination.
Article
Full-text available
Objective: To assess the possibility of controlling patients at a distance according to principles of teleorthodontics to understand its possible usefulness in the future routine activity and the impact pandemic may have had on different types of orthodontic treatments. Material and Methods: One hundred orthodontic patients (57 F, 43 M, age 7-46) during quarantine were checked through videocalls and photos sent by patients following proper instructions. Three groups have been distinguished based on the type of therapy: A-fixed appliances; B-removable appliances; C-clear aligners. Relevant events about dental and gingival health, integrity of appliances, orthodontic therapies related symptoms and overall progress of treatments were recorded. Results: A and B groups reported higher percentages of gingival inflammation (27 and 22%), dental plaque (16 and 13%), deciduous tooth loss (8 and 16%). Bracket and attachment detachment were the most frequent events in A and C groups (22 and 23%). Pain and discomfort were reported in A and B groups (35 and 32%). Therapies continued to progress better in C (51% improved dental alignment) and B (31% improved malocclusions) groups. Conclusion: Orthodontics is safe and allows during emergencies to postpone checks. Everyday mobile-technology is useful in managing orthodontic patients unable to carry out in-person control. When their effectiveness equals other systems, treatments with clear aligners without attachments should be preferred in patients unavailable for regular checks.
Article
Full-text available
Background: COVID-2019 spread rapidly throughout the world from China. This infection is highly contagiousness, has a high morbidity, and is capable of evolving into a potentially lethal form of interstitial pneumonia. Numerous countries shut-down various activities that were considered "not essential." Dental treatment was in this category and, at the time of writing, only non-deferrable emergencies are still allowed in many countries. Therefore, follow-up visits of ongoing active therapies (e.g., orthodontic treatment) must be handled taking special precautions. This literature review aims at reducing in-office appointments by providing an overview of the technologies available and their reliability in the long-distance monitoring of patients, i.e., teledentistry. Methods: A literature review was made according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines. Randomized clinical trials, cross sectional, observational, and case-control studies were evaluated with the Mixed Methods Appraisal Tool for quality assessment and study limitations. Results: A primary search found 80 articles, 69/80 were excluded as non-relevant on the basis of: the abstract, title, study design, bias, and/or lack of relevance. Twelve articles were included in the qualitative analysis. Conclusions: Teleorthodontics can manage most emergencies, reassuring and following patients remotely. The aim set by dental teleassistance was met as it reduced patients' office visits whilst maintaining regular monitoring, without compromising the results. Although our preliminary findings should be further investigated to objectively evaluate the efficacy, cost-effectiveness, and long-term results, we are confident that teleassistance in orthodontics will have a role to play in the near future.
Article
Full-text available
Introduction Pursuing an esthetically-pleasing orthodontic outcome, orthodontic patients must consider and choose from the different available options of orthodontic appliance. Practitioners need to be better informed of their customers’ preferences to make better practice management decisions and satisfy their patients’ needs. Purpose To explore adult laypeople’s perceptions of the attractiveness, acceptability, preference and economic value of different orthodontic appliances when they consider these appliances for themselves and for their children. Patients and methods This cross-sectional survey included 199 adults (110 females). The average age of participants was 27.7 years. Participants answered a questionnaire evaluating and comparing multiple smiling images of an adult wearing different orthodontic appliances. Participants rated each appliance for: (1) attractiveness on a Likert scale; (2) acceptability of having the appliance placed for themselves and their children (with a yes/no response); (3) preference (by ranking all appliances in order); and (4) economic value (by providing the additional amount they are willing to pay for each appliance for themselves and their children). Results We found a statistically significant difference in the attractiveness scores between the different orthodontic appliances (p< 0.0001). The most attractive appliances were clear aligners and lingual brackets. The least attractive appliances were colored o-tied-brackets followed by shaped-brackets. Clear aligners were the most acceptable appliances among our participants to have placed on themselves (86.9%) and their children (84.9%). Shaped brackets were the least acceptable appliances among our participants to have placed on themselves (24.1%) and their children (36.2%). The most preferred appliances were lingual brackets (39.2%), followed by clear aligners (34.17%). The least preferred appliances were colored o-tied-brackets (4%). Participants varied with regards to how much more they were willing to pay for each of the different orthodontic appliances. The majority were willing to pay more for clear aligners and lingual brackets to have them placed on themselves but not to have them placed on their children. Conclusion Adults preferred more innovative esthetic appliances over traditional ones and were willing to pay more to have them placed on themselves but not on their children.
Article
Technology has transformed almost every aspect of our lives. Smartphones enable patients to request, receive, and transmit information irrespective of the time and place. The global pandemic has forced healthcare providers to employ technology to aid in 'flattening the curve. The Novel Coronavirus, which is responsible for COVID-19, is transmitted primarily through person-to-person contact but may also be spread through aerosol generating procedures, so many clinics have severely limited interpersonal interactions. 1 The purpose of this article is to provide helpful information for those orthodontists considering some form of remote practice. Various HIPAA-compliant telecommunication or teledentistry systems that can be used for orthodontic treatment are introduced and discussed. Detailed information about each platform that can potentially be used for orthodontics is provided in Figure 1. The authors do not endorse any of the products listed and the included software is not all inclusive but instead is a glimpse into the options available.
Article
ABSTRACT Objectives: To compare the efficacy of traditional and digital communication strategies in improving compliance with fixed orthodontic therapy and to investigate the effect of gender, baseline oral hygiene habits, socioeconomics, and parents’ education on orthodontic compliance. Materials and Methods: Orthodontic patients were randomly allocated to three groups. Group 1 received traditional communication including verbal and written instructions, whereas group 2 and group 3 received, in addition to traditional communication, weekly text messages or e-mails with audiovisual links, respectively. Baseline demographics (age, gender, baseline oral hygiene habits, socioeconomics, and parents’ education) as well as compliance indicators (treatment duration, failed appointments, incidence and total number of appliance breakages) were recorded. For statistical analysis, Pearson chi-square, independent t-test, and one-way analysis of variance were used (P , .05). Results: Of 120 patients (aged 12 to 18 years) recruited, 108 completed the trial (G1¼37, G2¼35, G3 ¼ 36). Weekly text messages failed to improve patient compliance. On the other hand, sending weekly e-mails with audiovisual links significantly (P ¼ .014) reduced the incidence of appliance breakage as compared with the control group. Females had a significantly lower incidence of breakage (P ¼ .041) and a fewer total number of breakages (P ¼ .021). Patients from households with high income had significantly better compliance (P , .05). A higher level of parents’ education was significantly associated with a lower incidence and total number of breakages (P , .01). Conclusions: Communication with patients using link-rich e-mails and reminders could improve patient compliance with fixed orthodontic treatment. Female patients, high household income, and high parent education are associated with better compliance with fixed orthodontic treatment.
Preprint
This study presents a novel technique utilizing high frequency vibration to shorten treatment time and preserve alveolar bone in challenging orthodontic cases treated with Invisalign® clear aligners. Four non-growing orthodontic patients (age range 14-47 years old) with Class II skeletal patterns (convex profiles with retrognathic mandibles) who sought correction of their crowded teeth and non-surgical correction of their convex profiles were included in this study. These patients were treated using Invisalign clear aligners together with high frequency vibration (HFV) devices (120 Hz) (VPro5™) that were used by all patients for five minutes per day during active orthodontic treatment. Vertical control and forward rotation of the mandible for each patient was achieved through pre-programming the Invisalign to produce posterior teeth intrusion. Successful forward rotation of the mandibles achieved in all patients led to improvement of their facial convex profiles (ANB improved 2.1 + 0.5 degrees; FMA improved 1.2 +1.1 degrees). Dental decompensation was achieved by lingual tipping of the lower incisors and palatal root torque of upper incisors. The use of HFV together with Invisalign facilitated achieving these results within a 12+6 month period. In addition, more bone labial to the lower incisors after their lingual movement was noted. In conclusion, the use of HFV concurrent with SmartTrack Invisalign aligners allowed complex tooth movement and forward projection without surgery in non-growing patients with skeletal Class II relationships. The clinical impact and implications of this case series is that the use of HFV facilitates complex orthodontic tooth movement including posterior teeth intrusion and incisor decompensation in addition to increased bone formation labial to lower incisors that may minimize future gum recession due to their labial inclination.
Article
Objective: To analyse through a systematic review the effectiveness of clear aligners by assessing: (a) predictability of clear aligners and (b) treatment outcome comparison of clear aligner therapy with fixed appliance therapy. Methods: An electronic search was made from January 2014 to April 2019 using MEDLINE, Embase, Web of Science and LILACS databases without any limitations on language. Three reviewers independently assessed the articles. Quality assessment of observational studies and randomized control trial was done by using the ROBINS tool and Cochrane risk of bias tool, respectively. GRADE instrument was used to assess certainty level for each identified outcome. Results: Seven eligible articles (one randomized controlled trial and six retrospective cohort) were included in our systematic review. Most of the studies (six out of seven) had a moderate risk of bias and one had a high risk of bias. Conclusions: 'Low to moderate level' of certainty in regard to specific clear aligner therapy tooth movements' efficiency was identified. Clear aligners may produce clinically acceptable outcomes that could be comparable to fixed appliance therapy for buccolingual inclination of upper and lower incisors in mild to moderate malocclusions. However, not all potential clinical scenarios have been assessed in the included studies. Most of the tooth movements may not be predictable enough to be accomplished with only one set of trays with clear aligners despite the recent advances in technology.