Art-3-Tsolaki
ORTHODONTICS www.stomaeduj.com
MANDIBULAR INCISOR INCLINATION IN PATIENTS
Original Articles
WITH CLASS II MALOCCLUSION: COMPARISON
OF TREATMENT EFFECTS THROUGH TIME
Anastasia Tsolaki1a , Maria Tsami2b , Athina Chatzigianni3c , Moschos A. Papadopoulos3d*
1Health Professions Division, Department of Orthodontics, College of Dental Medicine, Nova Southeastern University, FL, USA
2Private practice, Larissa, Greece
3Department of Orthodontics, School of Health Scieces, Faculty of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
a
Postgraduate Student; e-mail: anastasia.tsolaki96@gmail.com; ORCIDiD: https://orcid.org/0009-0005-9856-8140
b
Dentist; e-mail: mlilly@hotmail.com; ORCIDiD: https://orcid.org/0009-0001-8481-0128
c
Assistant Professor; e-mail: achatzigianni@dent.auth.gr; ORCIDiD: https://orcid.org/0000-0001-7114-689X
d
Professor and Head; e-mail: mikepap@dent.auth.gr; ORCIDiD: https://orcid.org/0000-0002-7630-7258
ABSTRACT https://doi.org/10.25241/stomaeduj.2022.9(3-4).art.3
Introduction The aim of this study was to evaluate the effect of different treatments on lower incisor (L1)
inclination in patients with Class II malocclusion.
Methodology 73 patients (39 females, 34 males) with Class II malocclusion were retrospectively collected
from the postgraduate orthodontic clinic. All patients were treated at least with multibracket appliance (MBA)
and Class II elastics (CLII) alone (control group), or in combination with the removable-functional appliance
(RFA), fixed-functional appliance (FFA), or lingual arch (LA). Pre- and post-treatment L1-NB (mm), L1-GoGn
(°) and L1-NB (°) values were analyzed. The analysis of the treatment effect in relation to the outcomes and
time were done by the Propensity Score Matching (PSM) method using Cox regression and Survival analysis.
Results Regarding L1-NB distance, patients treated only with CLII elastics have lower risk of incisor
proclination, however, the risk may occur from the beginning of the treatment. FFA, RFA and LA present
higher risk of incisor proclination, but this occurs later in time (hazard ratio HR= 0.4 RFA/0.22 FFA and LA).
Concerning L1-GoGn angle, all treatments have high risk of proclination. However, RFA reduces the rate of
risk (p=0.003) (HR=0.22), while FFA increases the rate of risk (HR=0.35).
Conclusion Multibracket orthodontic treatment with CLII elastics alone produces unfavorable labial incisor
inclination rapidly. Combination treatment of RFA with CLII elastics delays the occurrence of proclination,
while FFA highly increases the risk of proclination. The use of the lingual arch retains the position of the
dentition for longer time, however once the lower incisor proclination occurs, it deteriorates fast.
KEYWORDS
Mandibular Incisor; Inclination; Class II Malocclusion
1. INTRODUCTION is achieved with a variety of extraction and non-
extraction approaches, maxillary expansion, use of
From the early steps in orthodontic science, the headgears, functional appliances, fixed-functional
position and inclination of the lower incisor has appliances, Class II elastics, with or without skeletal
been considered essential in diagnosis, treatment anchorage and other [5].
planning and retention. In 1941 Holly Broadbent Systematic reviews (SRs) and meta-analyses (MAs)
correlated normal dentofacial growth with incisor in Class II malocclusion patients treated with
mandibular plane angle and set the basis for removable functional appliances revealed minor
cephalometric analysis [1]. In 1943 Margolis was the skeletal changes, while the effects of the treatment
first to correlate lower incisor inclination with chin were mostly dentoalveolar, such as increased
position [2]. Tweed advocated that the mandibular inclination of lower incisors and uprighting of the
incisors must always be positioned upright on the maxillary incisors [6-7]. Because the lack of success
alveolar process in order to achieve harmony in the of functional appliances has been attributed under
lower facial third [3]. some circumstances to the lack of patient compliance
Class II malocclusion is present in approximately regarding appliance wear, the treatment effects of
one-third of the patients seeking orthodontic fixed functional appliances (FFAs) were examined
treatment [4]. Correction of Class II discrepancies as well in other SRs or/and MAs and presented with
OPEN ACCESS This is an Open Access article under the CC BY-NC 4.0 license.
Peer-Reviewed Article
Citation: Tsolaki A, Tsami M, Chatzigianni A, Papadopoulos AM. Mandibular incisor inclination in patients with class II malocclusion: comparison of
treatment effects through time. Stoma Edu J. 2022;9(3-4):95-102.
Received: January 02, 2022; Revised: March 17, 2022; Accepted: March 28, 2022; Published: March 30, 2022.
*Corresponding author: Prof. Moschos A. Papadopoulos; Department of Orthodontics, School of Health Sciences, Faculty of Dentistry,
Aristotle University of Thessaloniki, Thessaloniki, Greece; Tel./Fax: +302310999556; e-mail: mikepap@dent.auth.gr
Copyright: © 2022 the Editorial Council for the Stomatology Edu Journal.
Stoma Edu J. 2022;9(3-4):95-102 pISSN 2360-2406; eISSN 2502-0285 95
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similar results as far as the inclination of the lower line (L1-GoGn°) and the distance between L1 and
Original Articles
incisors is concerned. Nasion-B point line (L1-NB mm) were examined. The
Further, the application of Class II elastics apart from total treatment time and also the treatment time
the side effects that produces, such as extrusion of each appliance was available from the patients’
of the lower first molars and of the upper incisors, records. More specifically, the date of application
their use is highly associated with proclination of of the MB, CLII, RFA, FFA or LA and the total active
the lower incisors and retroclination of the upper treatment of each appliance were retrieved. Also,
incisors [8]. crowding was evident in 35 patients (47,9%), while 38
A direct comparison of the effect of different patients (52,1%) had no crowding (Tab. 2).
therapeutic methods on lower incisor inclination Table 2. Descriptive statistics of the sample regarding the presence of
seems not to have been examined thoroughly. Thus, crowding in the lower arch in the different treatment groups.
the aim of this study was to evaluate the effect of MBA+CLII No other + FFA + RFA + LA Total
different orthodontic treatment approaches taking treatment
also into consideration the possible influence of
treatment time on the lower incisor inclination of Yes 23 3 2 7 35
Crowdin
patients presenting Class II discrepancy. No 16 7 15 0 38
Total 39 10 17 7 73
2. METHODOLOGY
An analysis of the treatment effect in relation to the
A study sample of 73 patients (39 females and 34 outcomes and the implementation of time was done
males; mean age 13.2±4.1 years) was retrospectively by the propensity score matching (PSM) method
collected in consecutive order from the Postgraduate using Cox regression and Survival analysis [9]. In
Orthodontic Clinic. The patients’ inclusion criterion randomized clinical trials (RCTs) treatment groups
was the Class II malocclusion with at least half cusp and/or control groups are balanced for the baseline
to full Class II canine and molar relationship and Class characteristics of participants between groups with
II treatment approach, such as functional appliance, no systematically difference between them. With
Class II elastics and other. Patients with extractions, the use of PSM the differences between groups can
stripping, surgical intervention or craniofacial be estimated and the distribution of the baseline
anomalies were excluded. All patients were treated at characteristics can be balanced to be similar between
least with the multibracket appliance (MBA) (Straight the groups [10]. In the orthodontic field, orthodontic
wire, Roth prescription) in both dental arches and treatments are not static with a direct treatment
Class II elastics, with or without another treatment, effect. Instead, different types of treatments,
which preceded or followed, such as removable- appliances or methods are used during a long period
functional appliance (RFA), fixed-functional appliance of time and usually there are differences between a
(FFA), or lingual arch (LA). specific treatment effect and the time of application
The descriptive statistics of the sample are shown of the corresponding treatment. The treatment effect
in Tab. 1. Pre-treatment and post-treatment lateral is affected by the time period of the treatment. The
cephalograms were analyzed with the use of the involvement of time in the orthodontic treatment
Viewbox 4 software (dHal Software, Athens, Greece) effect can be studied and analyzed using two
to measure the inclination and position of the lower statistical tools, which are very common in medical
incisors at the beginning and at the end of the science; the Survival analysis and the Cox regression
treatment. The angles between the lower incisor analysis. Survival analysis is a statistical technique to
(L1) and the Nasion-B point line (L1-NB°), the Go-Gn analyze a “time to event outcome variable”, where the
Table 1. Descriptive statistics of the sample. CLII Tx time: Time of Class II elastics wear during treatment; Total Tx Time: Total treatment duration;
L1-NB (mm): distance between the lower incisor (L1) and Nasion-B point line; L1-GoGn°: angle between L1 and the Nasion-B point line; L1-GoGn°: angle
between L1 and the Go-Gn line.
Variable N Age Sex CLII Total L1-NB L1-NB L1-GoGN
Treatment Mean Male Tx Time Tx Time (mm) (°) (°)
(±SD) % Mean Mean Mean Mean Mean
(±SD) (±SD) (±SD) (±SD) (±SD)
MBA + CLII 39 14.1 46.15% 13 37.6 2.73 25.5 98.3
(±5.18) (±8.2) (±16.3) (±1.58) (±6.44) (±6.40)
MBA + CLII + FFA 10 13.8 60% 11 34.4 4 30.8 107
(±1.93) (±10.9) (±8) (±2.43) (±8.36) (±8.44)
MBA + CLII + RFA 17 11.4 47.06% 16.4 48.6 3.93 28.3 102
(±1.46) (±10.7) (±16.1) (±2.35) (±6.03) (±5.02)
MBA + CLII + LA 7 11.1 71.42% 11.2 47.7 2.70 26.8 99.7
(±1.07) (±13.4) (±19.9) (±1.63) (±8.15) (±9.08)
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outcome variable are the treatments that have been value. Tab. 3 and Figs. 1, 2, 3 show the results of the
Original Articles
used in a study and the event is the goal achievement Cox regression analysis.
of the treatment. The Cox (Proportional Hazards) Table 3. Prognostic performance of different treatments on the lower
regression is a statistical method for studying the incisor inclination for the accepted outcome (post-treatment normal
effect of multiple variables upon the time an event incisor inclination) after adjusting with ATT Propensity Score.
takes to happen. Treatments/ L1-NB L1-NB L1-GoGN
An important limitation of observational studies Outcomes (mm) (°) (°)
in relation to non-randomized study designs is the
treatment selection bias. Due to that limitation, the Coef -1.15 -1.48 -1.12
baseline characteristics of the study population Hazard
could dramatically differ for each treatment group FFA Ratio 0.31 (0.07-1.41) 0.23 (0.02-2.07) 0.32 (0.04-2.46)
[10-13]. Direct estimations about the treatment (CI)
effect without considering these sources of p value 0. 1312 0.36 0. 276
heterogeneity can lead to bias estimations about Coef -3.39 -2.71 -0.98
the treatment effects [14]. Propensity score can be Hazard
estimated by a logistic regression model that predicts RFA Ratio 0.03 (0.003-0.33) 0.07 (0.01-0.31) 0.37 (0.05-2.69)
the treatment assignment given the observed (CI)
baseline characteristics. This method gives the
p value 0.00371** 0.000618*** 0.260
opportunity to evaluate the treatments through
relatively homogeneous population groups. It is Coef -1.37 1.77 -1.62
worth mentioning that the considerable amount Hazard
of differences in the sample size of the groups of LA Ratio 0.25 (0.05-1.29) 0.17 (0.01-2.88) 0.2 (0.01-3.32)
this study is balanced with the use of PSM, which (CI)
takes this inequality into account. For example, p value 0.09813 0.22 0.12
crowding differences between patient groups were *p<0.05, **p<0.01
balanced with the use of different statistical weights
among groups. Randomized clinical trials are the
goal standard for estimating casual effectiveness by
assigning treatments independently from covariates.
The process of propensity score simulates the process
of RCTs with the limitation that the unobserved
confounders have no way to be adjusted [15].
3. RESULTS
AFirst the Propensity Score of the 73 patients was
computed with the Average Treatment Effect
(ATE) method to compare outcomes among the Figure 1. Reverse Kaplan-Meier is presented for the cumulative
treatments. Treatment outcomes were categorized probability of Lower Incisor NB (mm) for the endpoint with normal
into “accepted” or “not accepted” according to the inclination.
value of the outcome and the relationship with the
physiological mean values. More specific, the value
of outcome is referred to the post-treatment value
of the lower incisor inclination. Accepted outcomes
had a post-treatment incisor inclination value within
the mean ± Standard Deviation (SD) value of each
measurement, while not accepted outcomes lay
beyond the SD values and exceeded the mean value.
The ATE method was also used to compute Propensity
Scores for the population and a Cox proportional
hazard model was implemented to assess the impact
of the treatments on the above outcomes. The group Figure 2. Reverse Kaplan-Meier is presented for the cumulative
of patients treated with MBA/Class II elastics and no probability of Lower Incisor-GoGN angle for the endpoint with normal
inclination.
other treatment were used as reference group to
estimate the effect of the other treatments. For the The analysis showed that RFA treatment results in
above method we had two groups of patients, those a statistically significant achieve effect of L1-NB
who had an accepted outcome (normal lower incisor (mm) and the L1-NB (°) (p=0.00371 and 0.000618
inclination) and those who had a non-accepted respectively). The negative sign of the regression
outcome (lower incisor proclination), according to coefficient (coef ) in the tables shows that the
the post-treatment incisor inclination value. probability of each additional treatment to reach the
desired accepted result for every outcome reduces
3.1 Patients with an accepted outcome the effect of Class II elastics. For example, regarding
Patients with an accepted outcome presented an the L1-NB (mm) value, the RFA treatment decreases
accepted post-treatment lower incisor inclination the cumulative probability of producing an accepted
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outcome by a hazard ratio of only 0.03, while the FFA Regarding the L1-GoGn (°) measurement, according
Original Articles decreases the probability by 0.31 and the LA by 0.25. to the Kaplan-Meier graph (Fig. 5) patients treated
with CLII, RFA, FFA and LA have all high risk of
producing lower incisor proclination.
Likewise, for CLII alone treatment the risk may
occur from the beginning, during the first weeks of
application of the Class II elastics. In contrast, RFA,
FFA, and LA have the probability to produce the
occurrence of proclination later in time than the CLII.
Figure 3. Reverse Kaplan-Meier is presented for the cumulative
probability of Lower Incisor-NB angle for the endpoint with normal
inclination.
3.2 Patients with a non-accepted outcome
Patients with a non-accepted outcome presented
a non-accepted post-treatment lower incisor Figure 5. Kaplan-Meier curve is presented for patients with Lower
inclination value. Further analysis was conducted Incisor-GoGN angle with proclined endpoint.
in this group of patients and these were the most
important results. Specifically, the Average Treatment
Effect on the Treated (ATT) Propensity Score was Especially the RFA treatment reduces the rate of risk
computed for the group who exceeded the accepted with a statistical significance of p=0.00269 compared
values and presented incisor proclination. Survival to the other treatments, with a hazard ratio of 0.22.
analysis was conducted to examine the risk of labial On the other hand, FFA has an increased rate of risk
incisor inclination among the different treatments. for proclination with a hazard ratio of 0.35.
Regarding the L1-NB (mm) measurement, according Lastly, regarding the L1-NB (°) measurement,
to the Kaplan-Meier graph (Fig. 4) patients treated according to the Kaplan-Meier graph (Fig. 6) patients
only with CLII have lower risk of exceeding the L1-NB
treated with CLII, RFA, FFA and LA have all again high
(mm) value.
risk of producing lower incisor proclination.
Figure 4. Kaplan-Meier curve is presented for patients with Lower
Incisor-NB (mm) for the proclined endpoint. Figure 6. Kaplan-Meier curve is presented for patients with Lower
Incisor-NB angle with proclined endpoint.
The risk for labial inclination is the same as for L1-
However, this risk may occur from the beginning, GoGn (°) measurement. RFA reduces the rate of risk
during the first weeks of application of the Class II with a statistical significance of p=0.0465 compared
elastics. On the other hand, RFA, FFA, and LA present to the other treatments, with a hazard ratio of 0.3.
a higher risk of producing a not accepted outcome FFA on the other hand has an increased rate of risk
of the L1-NB (mm) value compared to CLII alone for increasing lower incisor inclination with a hazard
during the treatment, but this happens later in time ratio of 0.5.
than the CLII. Moreover, RFA causes a not accepted As above, only the combination of CLII with FFA
L1-NB (mm) value in a later time compared to all the
increases the probability of proclination, while the
other treatments.
combination with RFA and LA seems to reduce the
Specifically, RFA has a higher rate of increasing
the probability of lower incisor proclination with a probability of risk of proclination.
hazard ratio of 0.4 compared to FFA and LA, which As for the treatment time, CLII alone produces
have a hazard ratio of 0.22. This means that once unfavorable treatment effects more rapidly
the risk occurs, RFA can deteriorate the L1-NB (mm) compared to all combinations. Table 4 shows the
value in a shorter time period. effect sizes of survival analysis.
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Class II elastics are effective in correcting class II
Original Articles
Table 4. Prognostic performance of treatments for L1-NB (mm), L1-NB
(°), L1-GoGN (°) for the not accepted outcome (post-treatment lower incisor malocclusions and that their effects are primarily
proclination) after adjusting with ATT Propensity Score. dentoalveolar, such as flaring of mandibular incisors
Treatments/ L1-NB L1-NB L1-GoGN and loss of mandibular anchorage. In this study it
Outcomes (mm) (°) (°) was evident that multibracket appliance with Class II
Coef -1.5 -0.68 -1.06
elastics treatment is associated with the highest risk
Hazard
of lower incisor proclination compared to the other
FFA Ratio 0.22 (0.03-1.61) 0.5 (0.12-2.17) 0.35 (0.08-1.5) treatments under investigation.
(CI) To overcome the lower incisor proclination side effect,
p value 0.137 0.36 0.157 different types of appliances have been proposed
to reinforce the anchorage in the molar region and
Coef -0.9 -1.2 -1.51
thus, overcome the mandibular dental side effects.
Hazard
For example, the development of the lingual arch
RFA Ratio 0.4 (0.06-2.52) 0.3 (0.09 - 0.98) 0.22 (0.08-0.59)
is attributed to the efforts of Lloyd S. Lourie [25]
(CI)
and John V. Mershon [26]. It is considered that the
p value 0.333 0.0465 0.00269**
lingual arch can resolve lower incisor crowding by
Coef -1.5 0.87 -1.08
maintaining the arch perimeter [27]. The aim of
Hazard
including the lingual arch in the treatment of Class
LA Ratio 0.22 (0.02-3.12) 0.42 (0.11-1.56) 0.34 (0.09-1.33)
II malocclusion is mostly to enhance mandibular
(CI)
anchorage and minimize the side effects of Class II
p value 0.265 0.19 0.12
elastics, such as molar rotation and lingual tipping
*p<0.05, **p<0.01
and protrusion of mandibular incisors [28]. In this
study it was confirmed that the use of the lingual
3.3 Treatment time
arch, when used with MBA and Class II elastics can
It is worth mentioning that the treatment time of
retain the mandibular incisors for a longer period
the CLII elastics wear was studied separately for
of time compared to MBA and Class II elastics
each combination treatment, so as to determine
alone. This means that the lingual arch retains
whether the treatment time of the CLII elastics in the
the probability of risk for a longer period of time,
combined treatments with other appliances affects
the final outcome. After the statistical analysis it meaning that the lower incisors may remain stable
appeared that the treatment time of CLII elastics during treatment before reaching the not accepted
in the combination treatments does not affect proclined endpoint. However, once the risk with the
statistically significant the outcome (p-values of use of LA occurs, then the incisors may deteriorate
0.765, 0.907, 0.498 for lower incisor NB, lower incisor fast. Concluding, there is a timepoint after which the
NB (mm) and lower incisor GoGn respectively). lower incisor inclination may deteriorate very fast
and abruptly when lingual arch and Class II elastics
4. DISCUSSION are used.
A lot of studies have been conducted in order
TAs already known, studies comparing dentoskeletal to evaluate the skeletal and dental changes that
alterations in treated Class II patients with those account for the Class II correction in subjects treated
of untreated subjects, revealed significant with Class II elastics compared with subjects treated
retroclination of maxillary incisors and protrusion with removable or fixed functional appliances [29-
and proclination of lower incisors [16-18]. 31]. These studies suggested that either there was
Despite the limitation of this study regarding the no statistically significant difference between the
considerable amount of differences in the sample two treatment modalities or if there was any, it did
size of the groups, the use of the PSM method, not last in the long term [32]. These results indicate
which takes into account those differences, seemed that the final outcome of the treatment of Class II
to have clearly depicted the probability of risk for malocclusion might be similar independently of the
lower incisor proclination between the investigated orthodontic device used.
treatment approaches. However, the risks of incisor proclination varied
The use of intermaxillary elastics is well documented among treatments at this study. Compared to the
in the literature, which claims that they are effective use of MB and CLII alone, only the combination of MB
in correcting the anteroposterior relationship of the and CLII with FFA increases the probability of incisor
dentition, although undesirable side effects can proclination, while the combination of MB and CLII
occur [19-22]. Most authors mention adverse results with RFA or LA seems to reduce the probability of
from the horizontal vector of force, which has been risk of proclination. This probably means that the use
shown to rotate or mesially tip the mandibular first of RFA reduces the total time of Class II elastics wear,
molars, procline the mandibular anterior teeth, leading to more favorable results.
and displace the entire lower dental arch anteriorly Systematic reviews and meta-analysis concluded
[19,21,23,24]. Systematic reviews revealed that that the treatment of Class II malocclusion with FFAs
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was associated with more pronounced soft tissue 6. ABBREVIATIONS
Original Articles
and dentoalveolar changes, including significant
proclination and protrusion of mandibular incisors CLII: Class II elastics
[16]. RFA: Removable functional appliance
This is in accordance with our study and moreover, it FFA: Fixed functional appliance
was evident that FFA treatment has the highest risk LA: Lingual arch
of producing mandibular incisor proclination among MBA: Multibracket appliance
HR: Hazard ratio
all treatments under investigation.
PSM: Propensity score matching
RCT: Randomized clinical trial
5. CONCLUSION
Tx: Treatment
ATE: Average treatment effect
Multibracket appliance (MBA) orthodontic treatment
SD: Standard deviation
with Class II elastics alone is associated with the
high risk of producing unfavorable mandibular CONFLICT OF INTEREST
incisor proclination, which takes place more rapidly None to declare.
when compared to the combination treatment of
Class II elastics with the other appliances under FUNDING
investigation. This research did not receive any specific grant from funding
Removable appliance treatment in combination agencies in the public, commercial, or not-for-profit sectors..
with MBA and Class II elastics reduces the risk and
AUTHOR CONTRIBUTIONS
delays the occurrence of proclination,
AT, MT: Data collection and interpretation, manuscript writing; AC:
• Fixed functional appliance treatment in combina- Conceptualization, methodology, manuscript writing, reviewing
tion with MBA and Class II elastics highly increases and editing; MAP: Conceptualization, methodology, supervision,
the risk of proclination. reviewing and editing.
• The use of the lingual arch in combination with MBA
and Class II elastics retains the probability of risk at AKNOWLEDGEMENTS
the early stages of treatment, however a high risk of The authors acknowledge Mr. Evaggelos Akrivos for the statistical
incisor proclination occurs abruptly later in time. analysis of the data.
REFERENCES
1. Broadbent BH. Ontogenic development of occlusion. Angle 10. Austin PC, Laupacis A. A tutorial on methods to estimating
Orthod. 1941 Oct;11(4):223-241. clinically and policy-meaningful measures of treatment effects
Google Scholar in prospective observational studies: a review. Int J Biostat.
2. Margolis HI. The axial inclination of the mandibular incisors. 2011;7(1):6. doi: 10.2202/1557-4679.1285. Epub 2011 Jan 6.
Am J Orthod Oral Surg. 1943 Oct 1;29(10):571-594. PMID: 22848188; PMCID: PMC3404554.
Google Scholar Full text links CrossRef PubMed Google Scholar Scopus WoS
3. Tweed CH. The Frankfort-mandibular plane angle in orthodon- 11. Laupacis A, Sackett DL, Roberts RS. An assessment of
tic diagnosis, classification, treatment planning and prognosis. clinically useful measures of the consequences of treatment.
Am J Orthod Oral Surg. 1946 Apr;32:175-230. doi: 10.1016/0096- N Engl J Med. 1988 Jun 30;318(26):1728-1733. doi: 10.1056/
6347(46)90001-4. PMID: 21022281. NEJM198806303182605. PMID: 3374545.
CrossRef PubMed Google Scholar Full text links CrossRef PubMed Google Scholar Scopus WoS
4. Melsen B, Allais D. Factors of importance for the development 12. Cook RJ, Sackett DL. The number needed to treat: a
of dehiscences during labial movement of mandibular incisors: clinically useful measure of treatment effect. BMJ. 1995 Feb
a retrospective study of adult orthodontic patients. Am J Orthod 18;310(6977):452-454. doi: 10.1136/bmj.310.6977.452. Erratum
Dentofacial Orthop. 2005 May;127(5):552-561; quiz 625. doi: in: BMJ 1995 Apr 22;310(6986):1056. PMID: 7873954; PMCID:
10.1016/j.ajodo.2003.12.026. PMID: 15877035.2005;127:552-561. PMC2548824.
Full text links CrossRef PubMed Google Scholar Scopus WoS CrossRef Google Scholar Scopus WoS
5. Gungor AY, Turkkahraman H, Yilmaz HH, Yariktas M. Cepha- 13. Jaeschke R, Guyatt G, Shannon H, et al. Basic statistics for
lometric comparison of obstructive sleep apnea patients and clinicians: 3. Assessing the effects of treatment: measures of
healthy controls. Eur J Dent. 2013 Jan;7(1):48-54. PMID: 23408768; association. Can Med Assoc J. 1995 Feb 1;152(3):351-357. Erratum
PMCID: PMC3571509.2013;7:48-54. in: Can Med Assoc J 1995 Mar 15;152(6):813. PMID: 7828099;
Full text links CrossRef PubMed Google Scholar Scopus PMCID: PMC1337533.357.
6. Faria PT, de Oliveira Ruellas AC, Matsumoto MA, et al. Full text links PubMed Google Scholar Scopus WoS
95-102
Dentofacial morphology of mouth breathing children. Braz Dent 14. Rosenbaum PR, Rubin DB. The central role of the propensity
J. 2002;13(2):129-132. doi: 10.1590/s0103-64402002000200010. score in observational studies for causal effects. Biometrika. 1983
PMID: 12238804.2002;13:129-132. Apr 1;70(1):41-55.
CrossRef PubMed Google Scholar Google Scholar Scopus WoS
7. Proffit WR, Fields HW Jr, Moray LJ. Prevalence of malocclusion 15. Schmoor C, Gall C, Stampf S, Graf E. Correction of confoun-
and orthodontic treatment need in the United States: estimates ding bias in non-randomized studies by appropriate weighting.
from the NHANES III survey. Int J Adult Orthodon Orthognath Surg. Biom J. 2011 Mar;53(2):369-387. doi: 10.1002/bimj.201000154.
1998;13(2):97-106. PMID: 9743642. Epub 2011 Feb 10. PMID: 21308726.
PubMed Google Scholar Scopus Full text links CrossRef PubMed Google Scholar Scopus WoS
8. Janson G, Sathler R, Fernandes TMF, et al. Correction of Class II 16. Zymperdikas VF, Koretsi V, Papageorgiou SN, Papadopoulos
malocclusion with Class II elastics: a systematic review. Am J MA. Treatment effects of fixed functional appliances in patients
Orthod Dentofacial Orthop. 2013 Mar;143(3):383-392. doi: with Class II malocclusion: a systematic review and meta-analysis.
10.1016/j.ajodo.2012.10.015. PMID: 23452973. Eur J Orthod. 2016 Apr;38(2):113-126. doi: 10.1093/ejo/cjv034.
Full text links PubMed Google Scholar Scopus WoS Epub 2015 May 19. PMID: 25995359; PMCID: PMC4914762.
9. Schulz KF, Altman DG, Moher D. Consort 2010 Statement: Full text links CrossRef PubMed Google Scholar Scopus WoS
updated guidelines for reporting parallel group randomized 17. Pangrazio-Kulbersh V, Berger JL, Chermak DS, et al. Treatment
trials. Br Med Journal. 2010;340:c332. doi:10.1136/bmj.c332. effects of the mandibular anterior repositioning appliance on
Full text links PubMed Google Scholar Scopus patients with Class II malocclusion. Am J Orthod Dentofacial
100 Stoma Edu J. 2022;9(3-4): 95-102 pISSN 2360-2406; eISSN 2502-0285
Mandibular incisor inclination in Class II malocclusion
www.stomaeduj.com
Orthop. 2003 Mar;123(3):286-295. doi: 10.1067/mod.2003.8. 26. Mershon JV. The removable lingual arch as an appliance for
Original Articles
PMID: 12637901. the treatment of malocclusion of the teeth. Int J Orthodontia.
Full text links CrossRef PubMed Google Scholar Scopus WoS 1918 Nov 1;4(11):578-587.
18. Pancherz H, Bjerklin K. Mandibular incisor inclination, Google Scholar
tooth irregularity, and gingival recessions after Herbst therapy: 27. Chen CY, Hsu KC, Marghalani AA, et al. Systematic review and
a 32-year follow-up study. Am J Orthod Dentofacial Orthop. 2014 meta-analysis of passive lower lingual arch for resolving man-
Sep;146(3):310-318. doi: 10.1016/j.ajodo.2014.02.009. PMID: dibular incisor crowding and effects on arch dimension. Pediatr
25172253. Dent. 2019 Jan 15;41(1):9-22. PMID: 30803471.2019;41:9-19.
Full text links CrossRef PubMed Google Scholar Scopus WoS Full text links PubMed Google Scholar Scopus WoS
19. Wein SL. The lingual arch as a source of anchorage in Class II 28. Viglianisi A. Effects of lingual arch used as space maintainer
treatment. Am J Orthod. 1959 Jan 1;45(1):32-49. on mandibular arch dimension: a systematic review. Am J Orthod
Google Scholar Dentofacial Orthop. 2010 Oct;138(4):382.e1-382.e4. doi: 10.1016/j.
20. Kanter F. Mandibular anchorage and extraoral force. Am J ajodo.2010.02.026. PMID: 20889031.
Orthod. 1956 Mar 1;42(3):194-208. Full text links CrossRef PubMed Google Scholar Scopus WoS
21. Proffit WR, Fields HW Jr. Contemporary orthodontics. 2nd 29. Nelson B, Hansen K, Hägg U. Class II correction in patients
edition. St. Louis: Mosby, 1993, p. 495-515. treated with class II elastics and with fixed functional appliances:
Google Scholar a comparative study. Am J Orthod Dentofacial Orthop. 2000
22. Graber TM. Combined extraoral and functional appliances. In: Aug;118(2):142-149. doi: 10.1067/mod.2000.104489. PMID:
Graber TM (ed). Dentofacial orthopedics with functional 10935954.
appliances. 2nd edition. St. Louis: Mosby; 1997, p. 383-84. Full text links CrossRef PubMed Google Scholar Scopus WoS
Google Scholar 30. Jayachandran S, Wiltshire WA, Hayasaki SM, Pinheiro FH.
23. Meikle MC. The dentomaxillary complex and overjet Comparison of AdvanSync and intermaxillary elastics in the
correction in Class II, Division 1 malocclusion: objectives of correction of Class II malocclusions: a retrospective clinical study.
skeletal and alveolar remodeling. Am J Orthod. 1980 Am J Orthod Dentofacial Orthop. 2016 Dec;150(6):979-988. doi:
Feb;77(2):184-197. doi: 10.1016/0002-9416(80)90006-8. PMID: 10.1016/j.ajodo.2016.05.008. PMID: 27894547.
6928346. Full text links CrossRef PubMed Google Scholar Scopus WoS
CrossRef PubMed Google Scholar Scopus 31. Uzel A, Uzel I, Toroglu MS. Two different applications of Class II
24. Ellen EK, Schneider BJ, Sellke T. A comparative study of elastics with nonextraction segmental techniques. Angle
anchorage in bioprogressive versus standard edgewise Orthod. 2007 Jul;77(4):694-700. doi: 10.2319/071006-283. PMID:
treatment in Class II correction with intermaxillary elastic force. 17605495.
Am J Orthod Dentofacial Orthop. 1998 Oct;114(4):430-436. doi: Full text links CrossRef PubMed Google Scholar Scopus WoS
10.1016/s0889-5406(98)70189-1. PMID: 9790328. 32. Nelson B, Hägg U, Hansen K, Bendeus M. A long-term
Full text links CrossRef PubMed Google Scholar Scopus WoS follow-up study of Class II malocclusion correction after treat-
25. Dewey M. The use of the lingual arch in the treatment of ment with Class II elastics or fixed functional appliances. Am J
malocclusion as used by Dr. Lloyd S. Lourie. Int J Orthodontia. Orthod Dentofacial Orthop. 2007 Oct;132(4):499-503. doi:
1916 Nov 1;2(11):648-661. 10.1016/j.ajodo.2005.10.027. PMID: 17920503.
Google Scholar CrossRef Google Scholar Scopus
Anastasia TSOLAKI
DDS, Postgraduate Student
Health Professions Division
Department of Orthodontics
College of Dental Medicine
Nova Southeastern University, FL, USA
CV
Anastasia Tsolaki, DDS, is a postgraduate student in Orthodontics at the Department of Orthodontics, College of Dental Medicine,
Health Professions Division, Nova Southwestern University in Florida, USA since 2021. She received her Doctor of Dental Surgery
degree from the Aristotle University of Thessaloniki, Greece in 2019. She has participated in a number of congresses and
conferences in the dental and orthodontic field with poster or oral presentation. She has professional experience in dental and
orthodontic practices since 2020. Her skills include knowledge of 3 foreign languages.
Stoma Edu J. 2022;9(3-4):95-102 pISSN 2360-2406; eISSN 2502-0285 101
Tsolaki A, et al.
www.stomaeduj.com
Questions
Original Articles
1. There is a higher risk of mandibular incisor proclination when:
qa. Fixed functional appliances are combined with multibracket appliance treatment;
qb. Removable appliances are combined with multibracket treatment and Class II elastics;
qc. Removable appliance alone are used;
qd. Lingual arch is used.
2. Which appliance retains the inclination of the lower incisors at the early stages of
treatment?
qa. The multibracket appliance;
qb. The fixed functional appliance;
qc. The removable appliance;
qd. The lingual arch.
3. When does the risk of mandibular incisor proclination increase during treatment?
qa. At the early stages of multibracket appliance treatment;
qb. At the later stages of multibracket and Class II treatment, where lingual arch is used;
qc. At the early stages of treatment, where lingual arch is used;
qd. At the early stages of fixed functional treatment.
4. Which combination treatment delays the occurrence of lower incisor proclination?
qa. The combination of fixed functional appliance and multibracket appliance;
qb. The combination of Class II elastics with multibracket appliance;
qc. The combination of removable appliance, followed by multibracket appliance and Class II elastics;
qd. The combination of fixed functional appliance, multibracket appliance and Class II elastics.
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102 Stoma Edu J. 2022;9(3-4):95-102 pISSN 2360-2406; eISSN 2502-0285