Soft tissue treatment changes with fixed functional appliances and with maxillary premolar extraction in Class II division 1 malocclusion patients

Abstract

Objective:
The aim of this study was to compare the soft tissue changes and post-treatment status after complete fixed functional appliance non-extraction and maxillary premolar extraction treatment in patients with Class II division 1 malocclusion.

Materials/methods:
The sample consisted of 96 lateral cephalograms of 48 patients, divided into two groups. Group 1 consisted of 23 patients treated with fixed functional appliance associated with fixed appliances, with initial and final mean ages of 12.71 and 15.16 years, respectively, mean treatment time of 2.44 years and initial mean overjet of 6.83 mm. Group 2 comprised 25 patients treated with extraction of two maxillary premolars with initial and final mean ages of 13.05 and 15.74 years, respectively, mean treatment time of 2.67 years and initial mean overjet of 7.01 mm. t-Tests were used to compare treatment changes and the final cephalometric statuses between the groups.

Results:
According to the results, there was no inter-group difference regarding the soft tissue changes and post-treatment status.

Limitations:
The use of exclusively one type of fixed functional appliance in group 1 and performance of only one type of mechanics during space closure in group 2 were not always possible.

Conclusion:
Late pubertal patients with Class II division 1 malocclusion treated with fixed functional appliances associated with fixed appliances present similar soft tissue results as two-maxillary premolar extraction treatments.

Full text

1
© The Author 2017. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved.
For permissions, please email: journals.permissions@oup.com
Original article
Soft tissue treatment changes with fixed
functional appliances and with maxillary
premolar extraction in ClassII division 1
malocclusion patients
GuilhermeJanson, NuriaCastello Branco, AronAliaga-Del Castillo,
José Fernando CastanhaHenriques and Juliana Fernandesde Morais
Department of Orthodontics, Bauru Dental School, University of São Paulo, Brazil
Correspondence to: Guilherme Janson, Department of Orthodontics, Bauru Dental School, University of São Paulo, Alam-
eda Octávio Pinheiro Brisolla, 9-75 Bauru, São Paulo 17012–901, Brazil. E-mail: jansong@travelnet.com.br
Summary
Objective: The aim of this study was to compare the soft tissue changes and post-treatment
status after complete fixed functional appliance non-extraction and maxillary premolar extraction
treatment in patients with ClassII division 1 malocclusion.
Materials/methods: The sample consisted of 96 lateral cephalograms of 48 patients, divided into two
groups. Group1 consisted of 23 patients treated with fixed functional appliance associated with fixed
appliances, with initial and final mean ages of 12.71 and 15.16years, respectively, mean treatment
time of 2.44years and initial mean overjet of 6.83mm. Group2 comprised 25 patients treated with
extraction of two maxillary premolars with initial and final mean ages of 13.05 and 15.74years,
respectively, mean treatment time of 2.67years and initial mean overjet of 7.01mm. t-Tests were used
to compare treatment changes and the final cephalometric statuses between the groups.
Results: According to the results, there was no inter-group difference regarding the soft tissue
changes and post-treatment status.
Limitations: The use of exclusively one type of fixed functional appliance in group 1 and
performance of only one type of mechanics during space closure in group 2 were not always
possible.
Conclusion: Late pubertal patients with ClassII division 1 malocclusion treated with fixed functional
appliances associated with fixed appliances present similar soft tissue results as two-maxillary
premolar extraction treatments.
Introduction
Improvement in facial aesthetics has become an aspect of utmost
importance in contemporary society and has been recognized as one
of the major motivations for seeking orthodontic treatment (1–4).
In pursuit of esthetic excellence, professionals are often faced with
the need to predict soft tissue prole changes resulting from a vari-
ety of orthodontic devices and techniques for the correction of the
same malocclusion, especially concerning the differences between
treatment protocols with and without extractions (1–3, 5–12). This
wide variety of options tends to cause concerns as to which method
of treatment provides the most harmonious relationship among the
components of the soft tissue prole.
There is strong evidence that extractions do not cause deleterious
effects on the facial prole if a proper treatment planning, consider-
ing all patient features, is performed (1, 2, 4, 6, 8, 9). Nevertheless,
the assumption that extraction treatment can impair the facial
European Journal of Orthodontics, 2017, 1–9
doi:10.1093/ejo/cjx053

prole with excessive retrusion has discouraged this treatment pro-
tocol (3, 7, 10). This controversy also applies to the treatment of
ClassII malocclusion. The claim that treatment with two-maxillary
premolar extractions provides more upper lip retrusion makes many
professionals elect the treatment without extractions.
It has been demonstrated that treatment of Class II division 1
malocclusion without extractions and with two-maxillary premolar
extractions provide similar soft tissue results (4, 9, 12). However,
the protocol without extractions corrected the anteroposterior dis-
crepancy primarily through maxillary teeth distalization whereas the
group treated with two-maxillary premolar extractions corrected it
through retraction of the anterior maxillary segment. In patients
treated with xed functional appliances associated with xed appli-
ances, the mechanism of ClassII correction occurs not only by distal-
ization the maxillary teeth and redirection of maxillary growth, but
also by protrusion of the mandibular teeth and a relative anterior
positioning of the mandible in relation to the maxilla (13–20). For
this reason, one can speculate that treatment of ClassII division 1
malocclusion with xed functional appliances associated with xed
appliances, acting in both dental arches, might promote a different
nal facial prole, compared to a treatment protocol that acts only
in the maxillary arch. However, there is limited evidence compar-
ing these specic treatment protocols (16). Thus, the purpose of this
study was to evaluate the soft tissue changes and post-treatment sta-
tuses between ClassII division 1 malocclusion patients treated with
xed functional appliance associated with xed appliances and those
treated with two-maxillary premolar extractions.
Materials and methods
This study was approved by the Ethics in Research Committee of
Bauru Dental School, University of São Paulo, Brazil. A minimum
sample size of 23 participants per group was proposed for 80%
power at a signicance level of 0.05 to demonstrate an inter-group
post-treatment difference of 1.35 mm in the upper lip to SnPg′ line
distance (UL–SnPg′), with a previously reported standard deviation
of 1.59 (9).
The sample was retrospectively selected from the les of the
Orthodontic Department at Bauru Dental School, University of São
Paulo, Brazil. Initial and nal lateral cephalograms of 48 patients with
at least bilateral ¾ Class II molar relationship (21, 22) were divided
into two groups. Additional selection criteria included no agenesis,
supernumerary or lost teeth, maxillary arches without crowding, man-
dibular arches with slight or no crowding at pretreatment and a Class
I canine relationship at the post-treatment.
Group1 consisted of 23 patients (13 boys, 10 girls) treated with
xed functional appliances associated with xed appliances with ini-
tial and nal mean ages of 12.71 and 15.16years, respectively. The
mean treatment time of xed functional appliance was 0.72years
and the mean total treatment time was 2.44years. This group had
initial and nal mean overjets of 6.83 and 2.29 mm, respectively.
Ten patients presented with complete bilateral ClassII malocclu-
sion, seven patients presented with complete ClassII on one side and
¾ ClassII on the other and six patients presented with bilateral ¾
ClassII malocclusion. The Jasper Jumper was used in 15 patients for a
mean of 0.65years and the mean total treatment time was 2.12years.
The mandibular anterior repositioning appliance (MARA) was used
in six patients for a mean of 0.85years and the mean total treatment
time was 3.35 years. Forsus was used in two patients for a mean
of 0.33 years and the mean total treatment time was 2.15years.
The treatment sequence of the Jasper Jumper and Forsus patients
consisted of three treatment phases. Phase 1: leveling and alignment
of the maxillary and mandibular teeth ending with passive rectangu-
lar stainless steel archwires. Phase 2: placement of the xed functional
appliance that lasted until correction of the ClassII anteroposterior
discrepancy, with overcorrection of at least a quarter-cusp bilateral
ClassIII molar relationship. Phase 3: active retention with the use
of ClassII intermaxillary elastics for 18 hours a day until the end of
orthodontic treatment. The treatment sequence of MARA consisted
in the placement of the functional appliance with a transpalatal bar
and a lingual arch. Patients used the MARA appliance until overcor-
rection of at least a quarter-cusp bilateral ClassIII molar relation-
ship was obtained. MARA was removed and 0.022× 0.030-inch
slots xed edgewise appliances were placed. ClassII elastics were
also used as active retention until the end of orthodontic treatment.
Group2 consisted of 25 patients (10 boys and 15 girls) treated
with two maxillary rst premolar extractions with initial and nal
mean ages of 13.05 and 15.74years, respectively. Their mean treat-
ment time was 2.69years, and their initial and nal mean overjets
were 7.55 and 2.53 mm, respectively. Eighteen patients presented
with complete bilateral ClassII, ve patients presented with com-
plete Class II on one side and ¾ Class II on the other, and two
patients presented with bilateral ¾ Class II malocclusions. The
Figure1. Cephalometric landmarks used on lateral tracings—1: N′, soft tissue
nasion; 2: Prn, pronasal; 3: Cl, columella; 4: Sn, subnasale; 5: A′, soft tissue
Apoint; 6: UL, upper lip (most anterior point of upper lip); 7: LL, lower lip
(most anterior point of lower lip); 8: B′, soft tissue B point; 9: Pog′, soft tissue
pogonion; 10: Me′, soft tissue menton; 11: N, nasion; 12: Or, orbitale; 13:
S, sella turcica; 14: Po, porion; 15: Ptm, pterigomaxillary fissure; 16: ANS,
anterior nasal spine; 17: PNS, posterior nasal spine; 18: A, Apoint; 19: B, B
point; 20: Pg, pogonion; 21: Gn, gnathion; 22: Me, menton; 23: D, D point; 24:
Go, gonion; 25: Co, condylion; 26: Mx1MAP, most anterior point of maxillary
central incisor; 27: Mx1IE, maxillary central incisor edge; 28: Mx1IA, maxillary
central incisor apex; 29: Md1MAP, most anterior point of mandibular central
incisor; 30: Md1IE, mandibular central incisor edge; 31: Md1IA, mandibular
central incisor apex; 32: Mx6MAP, most anterior point of maxillary first molar;
33: Mx6OP, occlusal point of maxillary first molar; 34: Mx6MDP, most distal
point of maxillary first molar; 35: Md6MAP, most anterior point of mandibular
first molar; 36: Md6OP, occlusal point of mandibular first molar; 37: Md6MDP,
most distal point of mandibular first molar.
European Journal of Orthodontics, 20172

treatment sequence included extracting the two maxillary rst pre-
molars and then leveling and aligning the maxillary and mandibular
teeth, beginning with 0.016-inch nickel-titanium followed by 0.016,
0.018, and 0.020-inch stainless steel round archwires. Subsequently,
the maxillary anterior teeth were retracted on a 0.018×0.025-inch
rectangular archwire. The extraoral appliance was used to reinforce
anchorage and maintain the ClassII molar relationship. Ten patients
used extraoral headgear alone and 15 patients used extraoral head-
gear with ClassII intermaxillary elastics.
The lateral cephalograms were obtained in centric occlusion, with
the lips at rest. The initial and nal lateral headlms were digitally
traced using Dolphin Imaging Software Version 11.5 (Dolphin®
Imaging and Management Solutions, Patterson Dental Supply, Inc.,
Chatsworth, California, USA). This software also corrected the mag-
nication factors of the radiographic images that were between 6%
and 9.8%. Atotal of 37 landmarks were dened on each cephalo-
gram; 9 skeletal, 13 dental, and 10 soft tissue variables were meas-
ured (Figure1 and Table1). Skeletal maturity was assessed by using
the cervical vertebral maturation (CVM) method (23).
Errorstudy
Thirty-four cephalograms were randomly selected and remeasured by
the same examiner. The random errors were calculated according to
Dahlberg’s formula (S2=Σd2/2n) (24), and the systematic errors were
evaluated with dependent t-tests (25), at P<0.05. Intraobserver agree-
ment for the CVM method was assessed with Kappa coefcient (26).
Statistical analyses
Normal distribution was tested and conrmed with Kolmogorov–
Smirnovtests.
Comparability of the groups regarding the initial and nal ages,
treatment times, and the initial and nal overjets were evaluated
with t-tests. Mann–Whitney test was used to compare the groups
regarding the ClassII malocclusion anteroposterior occlusal severity
and the CVM indexes at the pre- and post-treatment stages. Chi-
square test evaluated the inter-group sex distribution.
t-Tests were also used to compare the initial and nal cephalometric
characteristics and the treatment changes between the groups. Results
Table1. Skeletal, dental, and soft tissue cephalometric variables.
Maxillary skeletal components
SNA SN to NA angle
Co–A Condylion to A-point distance
Mandibular skeletal components
SNB SN to NB angle
Pg–Nperp Pogonion to nasion-perpendicular distance
Co–Gn Condylion to gnathion distance
Maxillomandibular relationship
ANB NA to NB angle
NAP Angle between lines NA and AP
Growth pattern
SN.GoGn SN to GoGn angle
OP.SN SN to occlusal plane angle
Maxillary dentoalveolar components
Mx1.NA Maxillary incisor long axis to NA angle
Mx1–NA Distance between most anterior point of crown of maxillary incisor and NA line
Mx1–PP Distance between maxillary incisal edge and palatal plane
Mx6–PP Mean perpendicular distance between mesial and distal cusp of maxillary rst molar and palatal plane
Mx6–Svert Perpendicular distance between mesial of maxillary rst molar and S vertical line
Mandibular dentoalveolar components
Md1.NB Mandibular incisor long axis to NB angle
Md1–NB Distance between most anterior point of crown of mandibular incisor and NB line
IMPA Incisor mandibular plane angle
Md1–GoGn Distance between mandibular incisal edge and mandibular plane
Md6–GoGn Distance between occlusal point of mandibular rst molar and mandibular plane
Md6–Svert Perpendicular distance between mesial of mandibular rst molar and S vertical line
Dental relationship
Overjet Distance between incisal edges of maxillary and mandibular central incisors, parallel to occlusal plane
Overbite Distance between incisal edges of maxillary and mandibular central incisors, perpendicular to occlusal plane
Soft tissue prole
UL–E plane Distance from the upper lip to the esthetic plane of Ricketts
UL–S line Distance from the upper lip to Steiner’s S line (line from Pg′ to Cl)
UL–SnPg′Distance from the upper lip to the subnasale–soft tissue pogonion plane (line from Sn to Pg′)
H–Pr Distance between H line and the most anterior point on the nose
LL–E plane Distance from the lower lip to the esthetic plane of Ricketts (line from Pg′ to Pr)
LL–S line Distance from the lower lip to Steiner’s S line
LL–SnPg′Distance from the lower lip to the subnasale–soft tissue pogonion plane
Z angle Angle formed by the intersection of Frankfort horizontal plane and a line connecting the soft tissue chin (Pg′) and the
most protrusive lip point
H.NB H line (tangent to Pg′ and UL) to NB line angle
Nasolabial angle Cl.Sn.UL angle
G. Janson etal. 3

were considered statistically signicant at P < 0.05. These analyses
were performed with Statistica software (Version 7.0; StatSoft, Inc.,
Tulsa, Oklahoma, USA). Kappa coefcient was calculated using SPSS
software (Version 20; IBM SPSS, Chicago, Illinois, USA).
Results
The random errors ranged from 0.33mm (UL–S line) to 0.64 mm
(H–Pr) and from 0.87° (H.NB) to 1.46° (Nasolabial angle). Three of
the 32 variables had signicant systematic errors. Kappa coefcient
was of 0.81, indicating substantial intraobserver agreement for the
CVM method (26).
The groups were comparable regarding initial and nal ages,
treatment time, initial and nal overjet, initial malocclusion sever-
ity, sex distribution, pre- and post-treatment CVM indexes and all
the pretreatment cephalometric variables investigated (Figure2 and
Tables 2–4).
During treatment, group 1 had signicantly greater occlusal
plane clockwise rotation (OP.SN) and maxillary incisors extrusion
(Mx1–PP), smaller mesial movement of the maxillary rst molar
(Mx6-Svert), and greater labial tipping and protrusion of the man-
dibular incisors (Md1.NB, IMPA, Md1–NB) than group 2 (Table5).
At the post-treatment stage, group 1 had a signicantly greater
occlusal plane angle (OP.SN), smaller maxillary molar dentoalveolar
height (Mx6–PP) and mesial positioning (Mx6–Svert), greater man-
dibular incisors labial tipping (Md1.NB, IMPA) and overbite than
group 2 (Figure3 and Table6).
Discussion
Ideally, the sample should include only patients with full cusp
ClassII malocclusions. However, to have strictly comparable initial
morphologic characteristics between the groups, it was necessary to
include patients with bilateral ¾ cusp ClassII malocclusions because
the functional appliance group did not have enough patients that
presented with initial full cusp ClassII malocclusions (Tables 2 to
4). However, the initial overjet was similar (9, 16) or even larger (16,
27) than the samples of other studies that evaluated the effects of
ClassII malocclusion non-extraction and with maxillary premolar
extraction treatments in the soft tissue prole.
Figure 2. Superimposition of average cephalometric tracings of groups 1
and 2 at pretreatment (superimposition on SN, registered on S). The average
tracings were performed by Dolphin Imaging Software, Version 11.5.
Table2. Comparison of initial and final ages, treatment times, initial and final overjets, initial occlusal malocclusion severity and sex dis-
tribution at pre-treatment.
Variable
Group1 (xed functional
appliance)
Group2 (two-premolar
extractions)
P
n=23 n=25
Mean SD Mean SD
Initial age 12.71 1.28 13.05 0.99 0.315*
Final age 15.16 1.35 15.74 1.19 0.118*
Treatment time 2.44 0.66 2.69 0.59 0.171*
Initial overjet 7.56 2.21 7.55 1.69 0.987*
Final overjet 2.55 0.45 2.53 0.54 0.867*
Occlusal malocclusion severity
Full cusp ClassII malocclusion 10 18 0.063**
Full cusp ClassII malocclusion on one side and ¾
cusp ClassII malocclusion on the other
7 5
¾ cusp bilateral ClassII 6 2
Sex
Male 13 10 0.252***
Female 10 15
*t-Test.
**Mann–Whitney test.
***Chi-square test.
European Journal of Orthodontics, 20174

Table4. Comparison of the cephalometric variables at pre-treatment (t-test).
Group1 (xed functional
appliance)
Group2 (two premolar
extractions)
n=23 n=25
Variable Unit Mean SD Mean SD P
Maxillary skeletal components
SNA angle ° 83.01 3.46 83.90 3.69 0.395
Co–A mm 94.28 5.52 93.82 3.78 0.732
Mandibular skeletal components
SNB angle ° 77.47 2.62 77.60 3.05 0.874
Pg–Nperp mm −5.78 4.63 −5.08 5.63 0.642
Co–Gn mm 121.25 6.60 121.36 6.23 0.950
Maxillomandibular relationship
ANB angle ° 5.54 2.68 6.30 2.59 0.325
NAP ° 170.34 6.10 169.07 6.68 0.497
Growth pattern
SN.GoGn ° 29.93 3.76 31.88 5.62 0.167
OP.SN ° 13.67 4.46 14.32 4.37 0.612
Maxillary dentoalveolar components
Mx1.NA ° 24.94 8.38 22.88 7.19 0.362
Mx1–NA mm 5.27 3.34 4.50 3.36 0.427
Mx1–PP mm 30.46 2.95 30.60 3.16 0.875
Mx6–PP mm 19.22 2.42 20.25 2.36 0.141
Mx6–Svert mm 44.13 4.95 45.62 4.73 0.290
Mandibular dentoalveolar components
Md1.NB ° 27.13 5.56 28.26 5.44 0.480
Md1–NB mm 5.84 2.38 6.04 2.36 0.775
IMPA ° 97.07 6.43 96.64 6.07 0.812
Md1–GoGn mm 39.91 3.21 40.03 3.20 0.898
Md6–GoGn mm 28.41 2.66 28.58 2.38 0.819
Md6–Svert mm 41.75 5.19 42.49 4.93 0.614
Dental relationships
Overjet mm 7.56 2.21 7.55 1.69 0.987
Overbite mm 4.78 1.39 3.82 2.03 0.065
Soft tissue prole
UL–E plane mm −0.73 3.20 −0.94 2.57 0.795
UL–S plane mm 2.01 2.78 1.93 2.09 0.913
UL–SnPg′mm 5.56 2.38 5.65 1.68 0.878
H–Pr mm 1.28 5.59 1.67 4.40 0.788
LL–E plane mm 0.17 3.19 0.47 2.75 0.726
LL–S line mm 1.68 2.92 2.08 2.48 0.609
LL–SnPg′mm 3.61 2.59 4.17 2.20 0.427
Z angle ° 70.63 6.61 71.22 5.63 0.740
H.NB ° 15.04 6.07 14.78 4.41 0.863
Nasolabial angle ° 110.92 11.29 109.68 10.18 0.690
Table3. Comparison of cervical vertebral maturation index (CVM) at the pre- and post-treatment stages (Mann–Whitney tests).
CVM stages
Pre-treatment Post-treatment
Group1 (xed
functional appliances)
Group2 (two
premolar extractions)
Group1 (xed
functional appliances)
Group2 (two
premolar extractions)
n=23 n=25 p n=23 n=25 P
CS 1 2 2 0.166 1 1 0.570
CS 2 1 1 0 0
CS 3 14 8 2 0
CS 4 5 13 11 10
CS 5 1 1 4 9
CS 6 0 0 5 5
G. Janson etal. 5

The use of three different types of xed functional appliances in
group 1 should not interfere with the results, because regardless of
the device, their overall mechanisms of action and general effects are
similar (13–20). Obviously, there are small differences in the effects
of the appliances (28). However, specic treatment effect compari-
sons with the different appliances in group 1 were not the focus of
this study. The focus was only to investigate whether non-extraction
treatment with functional followed by xed appliances would pro-
duce different soft tissue changes when compared to treatment with
two-maxillary premolar extractions.
One may criticize that due to the amount of variables compared
between the groups, Bonferroni corrections (29) should have been
used. However, this procedure would decrease the probability of
detecting slight signicant differences, which are very important in
this comparison. Even without using it, no signicant differences
were detected in the primary variables under investigation. If it had
been used, similar results in these variables would be obtained.
The slightly different skeletal and dentoalveolar treatment
changes between the groups would be expected (17, 27). There is
a tendency for greater clockwise rotation of the occlusal plane dur-
ing treatment with xed functional appliances, as occurred (13, 14)
(Table 5). The maxillary incisors also tend to present greater vertical
dentoalveolar development and the mandibular incisors tend to pre-
sent labial tipping and protrusion due to the forces applied on these
teeth with functional appliances (13–15, 17, 18). On the other side,
it is also obvious that maxillary molar mesial movement would be
greater in the two-maxillary premolar extraction Group because the
molars are not subjected to distalizing forces and could even mesialize
Table5. Intergroup comparison of treatment changes (t-test).
Group1 (xed
functional appliance)
Group2 (two
premolar extractions)
P
n=23 n=25
Variable Unit Mean SD Mean SD
Maxillary skeletal components
SNA angle ° −1.25 2.93 −1.04 2.12 0.778
Co–A mm 1.86 3.54 1.04 2.55 0.364
Mandibular skeletal components
SNB angle ° 0.15 2.31 0.36 1.39 0.704
Pg–Nperp mm 1.85 4.66 0.80 2.03 0.310
Co–Gn mm 6.11 4.26 4.71 3.73 0.228
Maxillomandibular relationship
ANB angle ° −1.40 1.59 −1.41 1.66 0.972
NAP ° 1.76 3.28 3.20 3.95 0.177
Growth pattern
SN.GoGn ° 0.12 2.94 −0.62 2.52 0.354
OP.SN ° 3.57 3.97 0.18 2.78 0.001*
Maxillary dentoalveolar components
Mx1.NA ° −3.29 8.44 −0.36 7.82 0.219
Mx1–NA mm −1.20 3.39 −1.96 3.16 0.430
Mx1–PP mm 1.26 1.59 −0.36 1.74 0.001*
Mx6–PP mm 1.52 1.89 2.03 1.65 0.322
Mx6–Svert mm 0.98 3.87 4.10 2.14 0.001*
Mandibular dentoalveolar components
Md1.NB ° 6.07 4.86 2.00 5.13 0.007*
Md1–NB mm 2.18 1.59 1.16 1.35 0.020*
IMPA ° 5.69 4.70 1.92 5.56 0.015*
Md1–GoGn mm −0.36 1.98 0.56 1.74 0.093
Md6–GoGn mm 2.85 1.74 2.10 1.44 0.112
Md6–Svert mm 4.54 4.42 2.54 2.68 0.061
Dental relationships
Overjet mm −5.01 2.25 −5.02 1.69 0.978
Overbite mm −2.87 1.10 −2.40 1.77 0.275
Soft tissue prole
UL–E plane mm −2.39 1.90 −2.48 1.42 0.854
UL–S plane mm −1.98 1.68 −2.26 1.34 0.515
UL–SnPg′mm −1.43 1.52 −1.97 1.49 0.216
H–Pr mm 4.17 3.48 4.34 2.61 0.851
LL–E plane mm −0.44 1.92 −1.08 1.92 0.250
LL–S line mm −0.14 1.78 −0.91 1.82 0.146
LL–SnPg′mm 0.26 1.64 −0.67 1.77 0.065
Z angle ° 3.44 3.86 3.35 2.23 0.923
H.NB ° −2.80 2.49 −2.93 2.09 0.852
Nasolabial angle ° 2.66 7.06 6.23 9.23 0.141
*Statistically signicant at P<0.05.
European Journal of Orthodontics, 20176

in those patients that did not initially present full Class II malocclu-
sions (9, 27, 30). Besides, these teeth experience mesialization in rela-
tion to the Svert line, with normal growth (31). Nevertheless, these
subtle different skeletal and dentoalveolar changes did not produce
any signicantly different soft tissue changes between the groups.
These similar soft tissue changes would be expected (4, 7, 9, 11, 12,
27) because the changes in the anteroposterior apical base relation-
ship and overjet were similar between the groups (17, 27).
The slightly different skeletal and dentoalveolar changes in the
groups caused group 1 to present signicantly greater occlusal plane
inclination, smaller maxillary molar dentoalveolar height and mesial
positioning in relation to Svert at the post-treatment stage (Table 6).
The smaller dentoalveolar height might be consequent to the intrusive
force exerted by the functional appliance on the maxillary molars, dur-
ing treatment, which restricts their vertical development (16). Because
a distal force was applied to the molars in the functional appliance
group, the molars were more distally positioned than those of the two-
maxillary premolar extraction group, which were not subjected to dis-
talization and that could even mesialize in some patients who did not
initially present a full cusp Class II malocclusion (9, 27, 30).
At the post-treatment stage, the mandibular incisors in group 1
presented a signicantly greater labial tipping than group 2, conse-
quent to the greater labial tipping presented during treatment as pre-
viously discussed (Table 6). Although the initial overbite was similar
and there were no difference in overbite changes with treatment, the
overbite was signicantly smaller in group 2 probably because it is
usually easier to be corrected in the two-maxillary premolar extrac-
tion protocol due to the small maxillary to mandibular mesiodistal
tooth discrepancy that is created with this protocol (27, 32). Again,
these slight skeletal and dentoalveolar differences at the post-treat-
ment stage did not produce signicant differences in any soft tissue
prole variable between the groups, demonstrating that both treat-
ment protocols cause similar soft tissue results (Figure 3 and Table 6).
Similar soft tissue results had been demonstrated in the compari-
son of ClassII non-extraction treatment primarily by distalizing the
maxillary teeth with treatment with two-maxillary premolar extrac-
tions (9, 27). However, one could speculate that there could be differ-
ences when non-extraction treatment would be performed by xed
functional appliances. This study demonstrates that even in this situa-
tion, there are no differences in soft tissue changes with these different
treatment protocols. Therefore, one should not be usually concerned
in the treatment of a patient with two premolar extractions, when
the alternatives with distalization of the maxillary teeth or with the
use of xed functional appliances could be used as well. The soft
tissue changes would be similar. The results of this study differ from
a previous study (16), that found some differences when compar-
ing soft tissue changes in ClassII malocclusion patients treated with
the Forsus appliance versus two-maxillary premolar extractions and
retraction of the anterior teeth using temporary anchorage devices.
However, the mentioned study (16) only evaluated the patients dur-
ing 14months, from the insertion of the Forsus appliance or begin-
ning of en masse retractions until removal of the Forsus appliance
or completion of en masse retraction. The different results observed
could be consequent to the use of temporary anchorage devices and
to the smaller observation period of theirstudy.
One may consider that the initial ClassII malocclusion severity
between the groups was almost signicant towards a greater sever-
ity for group 2, and that this would be a limitation of the study
(Table2). Nevertheless, the general expectations would be that the
group treated with two-maxillary premolar extractions would at
least have a greater upper lip retrusion, in perfectly matched groups
regarding the Class II anteroposterior discrepancy. This would be
even more likely to happen if the occlusal ClassII anteroposterior
discrepancy was signicantly greater in group 2.However, the results
did not show any signicant difference. Therefore, this ‘almost sig-
nicant’ difference between the groups, regarding the ClassII anter-
oposterior discrepancy, reinforces that actually there is no difference
in soft tissue changes between the two treatment protocols. Besides,
the initial overjets were very similar between the groups (Table2).
Another concern that one may have in using the two-maxillary
premolar extraction protocols is regarding the smile aesthetics.
Nevertheless, it has already been demonstrated that the extraction
of two maxillary premolars does not negatively affects smile attrac-
tiveness (33–35). Additionally, a recent systematic review found that
there were no signicant differences between groups treated with
and without premolar extraction regarding the aesthethic outcomes
and that the decision of premolar extraction could be benecial in
patients having lip protrusion (36).
It can also be argued that non-extraction treatment of Class II
malocclusion prevents extraction of healthy teeth. However, preserv-
ing the maxillary premolars may result in later extraction of the third
molars (37). Furthermore, premolar extraction surgery is usually
easier and less expensive than maxillary third molar extraction (38).
The results of this study helps in the decision for one of these pro-
tocols, considering other variables than changes in the soft tissue pro-
le. Therefore, the decision between ClassII malocclusion treatment
with xed functional appliances associated with xed appliance or
two-maxillary premolar extractions should be based on variables such
as patient compliance, mandibular incisors tipping at pre-treatment,
cost-benet ratio, and orthodontist and patient treatment preferences.
One should bear in mind that these considerations are applicable to
patients with similar characteristics as the investigated groups.
Figure3. Superimposition of average cephalometric tracings of groups 1 and
2 at posttreatment (superimposition on SN, registered on S). The average
tracings were performed by Dolphin Imaging Software, Version 11.5.
G. Janson etal. 7

Limitations
This study has some limitations. Firstly, the use of three different
types of xed functional appliances in group 1. Evidently, there
are small differences in the effects of the appliances (28). Although
their overall effects are similar (13–20), the use of only one type of
xed functional appliance would be ideal. Secondly, space closure
in group 2 involved only anterior retraction or some anchorage loss
(maxillary molar mesialization) associated with anterior retrac-
tion, depending on the presence of complete ClassII or ¾ ClassII
molar relationships at pre-treatment. Despite the inclusion of some
patients with initial ¾ ClassII molar relationship would not inter-
fere with the results because the overjet was similar in the groups, it
would be ideal to include only patients with complete ClassII mal-
occlusion anteroposterior severity. Further studies with ideal sample
compositions are necessary to conrm the current results.
Conclusion
Soft tissue changes and post-treatment status of Class II division
1 malocclusion treated with xed functional appliances associated
with xed appliance and two maxillary premolars extraction are
similar in late pubertal patients.
Acknowledgement
This article is based on research submitted by Dr Nuria Castello Branco in
partial fulllment of the requirements for the PhD degree in Orthodontics at
Bauru Dental School, University of São Paulo.
Conflict of Interest
None to declare.
Table6. Comparison of the cephalometric variables at post-treatment (t-test).
Group1 (xed
functional appliance)
Group2 (two
premolar extractions)
n=23 n=25
Variable Unit Mean SD Mean SD P
Maxillary skeletal components
SNA angle ° 81.76 4.10 82.85 3.54 0.325
Co–A mm 96.14 6.03 94.86 4.80 0.418
Mandibular skeletal components
SNB angle ° 77.62 2.83 77.96 3.34 0.708
Pg–Nperp mm −3.93 7.22 −4.28 6.41 0.859
Co–Gn mm 127.36 7.11 126.07 7.20 0.534
Maxillomandibular relationship
ANB angle ° 4.15 3.03 4.89 2.13 0.328
NAP ° 172.10 5.61 172.27 5.06 0.909
Growth pattern
SN.GoGn ° 30.04 4.60 31.26 5.99 0.437
OP.SN ° 17.25 4.48 14.51 4.55 0.041*
Maxillary dentoalveolar components
Mx1.NA ° 21.66 8.32 22.51 6.59 0.693
Mx1–NA mm 4.07 3.38 2.54 2.23 0.069
Mx1–PP mm 31.72 2.91 30.24 3.44 0.115
Mx6–PP mm 20.74 2.48 22.28 2.46 0.036*
Mx6–Svert mm 45.10 5.71 49.72 5.44 0.006*
Mandibular dentoalveolar components
Md1.NB ° 33.19 5.24 30.25 4.11 0.035*
Md1–NB mm 8.02 2.65 7.20 2.01 0.227
IMPA ° 102.77 5.85 98.57 6.19 0.020*
Md1–GoGn mm 39.55 3.21 40.59 3.68 0.304
Md6–GoGn mm 31.26 3.08 30.68 3.09 0.520
Md6–Svert mm 46.29 6.14 45.03 5.82 0.469
Dental relationships
Overjet mm 2.55 0.45 2.53 0.54 0.867
Overbite mm 1.91 0.64 1.43 0.77 0.022*
Soft tissue prole
UL–E plane mm −3.11 3.43 −3.42 2.66 0.729
UL–S plane mm 0.03 2.91 −0.33 2.21 0.628
UL–SnPg′mm 4.13 2.46 3.68 1.76 0.462
H–Pr mm 5.46 6.22 6.01 4.74 0.728
LL–E plane mm −0.27 2.88 −0.61 3.23 0.701
LL–S line mm 1.54 2.58 1.17 2.93 0.648
LL–SnPg′mm 3.87 2.26 3.50 2.58 0.593
Z angle ° 74.07 7.62 74.57 6.08 0.801
H.NB ° 12.23 6.50 11.85 4.76 0.814
Nasolabial angle ° 113.58 11.82 115.91 10.31 0.469
*Statistically signicant at P<0.05.
European Journal of Orthodontics, 20178

References
1. Young, T.M. and Smith, R.J. (1993) Effects of orthodontics on the facial
prole: a comparison of changes during nonextraction and four premolar
extraction treatment. American Journal of Orthodontics and Dentofacial
Orthopedics, 103, 452–458.
2. Katsaros, C., Ripplinger, B., Högel, A. and Berg R. (1996) The inuence of
extraction versus non-extraction orthodontic treatment on the soft tissue
prole. Journal of Orofacial Orthopedics=Fortschritte der Kieferortho-
padie: Organ/ofcial journal Deutsche Gesellschaft fur Kieferorthopadie,
57, 354–365.
3. Boley, J.C., Pontier, J.P., Smith, S. and Fulbright M. (1998) Facial changes in
extraction and nonextraction patients. The Angle Orthodontist, 68, 539–546.
4. Lim, H.J., Ko, K.T. and Hwang, H.S. (2008) Esthetic impact of premolar
extraction and nonextraction treatments on Korean borderline patients.
American Journal of Orthodontics and Dentofacial Orthopedics, 133,
524–531.
5. Kocadereli, I. (2002) Changes in soft tissue prole after orthodontic treat-
ment with and without extractions. American Journal of Orthodontics
and Dentofacial Orthopedics, 122, 67–72.
6. Bishara, S.E, Cummins, D.M. and Zaher, A.R. (1997) Treatment and post-
treatment changes in patients with ClassII, division 1 malocclusion after
extraction and nonextraction treatment. American Journal of Orthodon-
tics and Dentofacial Orthopedics, 111, 18–27.
7. Zierhut, E.J., Joondeph, D.R., Artun, J. and Little, R.M. (2000) Long-term
prole changes associated with successfully treated extraction and nonextrac-
tion ClassII division 1 malocclusions. The Angle Orthodontist, 70, 208–219.
8. Erdinc, A.E., Nanda, R.S. and Dandajena, T.C. (2007) Prole changes of
patients treated with and without premolar extractions. American Journal
of Orthodontics and Dentofacial Orthopedics, 132, 324–331.
9. Janson, G, Fuziy, A, de Freitas, M.R, Castanha Henriques, J.F and de
Almeida, R.R. (2007) Soft-tissue treatment changes in ClassII division 1
malocclusion with and without extraction of maxillary premolars. American
Journal of Orthodontics and Dentofacial Orthopedics, 132, 729.e1–729.e8.
10. Scott Conley, R. and Jernigan, C. (2006) Soft tissue changes after upper
premolar extraction in ClassII camouage therapy. The Angle Orthodon-
tist, 76, 59–65.
11. Verma, S. L., Sharma, V. P., Singh, G. P. and Sachan K. (2013) Comparative
assessment of soft-tissue changes in Class II division 1 patients follow-
ing extraction and non-extraction treatment. Dental Research Journal, 10,
764–771.
12. Weyrich, C. and Lisson, J. A. (2009) The effect of premolar extractions on
incisor position and soft tissue prole in patients with ClassII, division 1
malocclusion. Journal of Orofacial Orthopedics=Fortschritte der Kiefer-
orthopadie: Organ/ofcial journal Deutsche Gesellschaft fur Kieferortho-
padie, 70, 128–138.
13. Karacay, S., Akin, E., Olmez, H., Gurton, A.U. and Sagdic, D. (2006) For-
sus Nitinol Flat Spring and Jasper Jumper corrections of ClassII division
1 malocclusions. The Angle Orthodontist, 76, 666–672.
14. Pangrazio, M.N., Pangrazio-Kulbersh, V., Berger, J.L., Bayirli, B. and
Movahhedian A. (2012) Treatment effects of the mandibular anterior
repositioning appliance in patients with Class II skeletal malocclusions.
The Angle Orthodontist, 82, 971–977.
15. Chiqueto, K., Henriques, J.F., Barros, S.E. and Janson, G. (2013) Angle
ClassII correction with MARA appliance. Dental Press Journal of Ortho-
dontics, 18, 35–44.
16. Upadhyay, M., Yadav, S., Nagaraj, K., Uribe, F. and Nanda, R. (2012)
Mini-implants vs xed functional appliances for treatment of young adult
ClassII female patients. The Angle Orthodontist, 82, 294–303.
17. Lima, K.J, Henriques, J.F., Janson, G., Pereira, S.C., Neves, L.S. and Can-
çado, R.H. (2013) Dentoskeletal changes induced by the Jasper jumper
and the activator-headgear combination appliances followed by xed
orthodontic treatment. American Journal of Orthodontics and Dentofa-
cial Orthopedics, 143, 684–694.
18. Giuntini, V., Vangelisti, A., Masucci, C., Defraia, E., McNamara, J. A. Jr.
and Franchi, L. (2015) Treatment effects produced by the Twin-block
appliance vs the Forsus Fatigue Resistant Device in growing Class II
patients. The Angle Orthodontist, 85, 784–789.
19. Perinetti, G., Primožič, J., Furlani, G., Franchi, L. and Contardo, L. (2015)
Treatment effects of xed functional appliances alone or in combination
with multibracket appliances: a systematic review and meta-analysis. The
Angle Orthodontist, 85, 480–492.
20. Siara-Olds, N.J., Pangrazio-Kulbersh, V., Berger, J. and Bayirli, B. (2010)
Long-term dentoskeletal changes with the Bionator, Herbst, Twin Block,
and MARA functional appliances. The Angle Orthodontist, 80, 18–29.
21. Andrews, L.F. (1975) The Straight Wire Appliance. Syllabus of Philosophy
and Techniques. 2nd edn. Larry F.Andrews Foundation of Orthodontic
Education and Research, San Diego.
22. Wheeler, T.T., McGorray, S.P., Dolce, C., Taylor, M.G. and King, G.J.
(2002) Effectiveness of early treatment of ClassII malocclusion. American
Journal of Orthodontics and Dentofacial Orthopedics, 121, 9–17.
23. Baccetti, T., Franchi, L. and McNamara, J.A. (2005) The cervical vertebral
maturation (CVM) method for the assessment of optimal treatment timing
in dentofacial orthopedics. Seminars in Orthodontics, 11, 119–129.
24. Dahlberg, G. (1940) Statistical Methods for Medical and Biological Stu-
dents. Interscience Publications, New York.
25. Houston, W.J. (1983) The analysis of errors in orthodontic measurements.
American Journal of Orthodontics, 83, 382–390.
26. Blackman, N.J. and Koval, J.J. (2000) Interval estimation for Cohen’s
kappa as a measure of agreement. Statistics in Medicine, 19, 723–741.
27. de Almeida-Pedrin, R.R., Henriques, J.F., de Almeida, R.R., de Almeida,
M.R. and McNamara, J.A. Jr. (2009) Effects of the pendulum appliance,
cervical headgear, and 2 premolar extractions followed by xed appliances
in patients with ClassII malocclusion. American Journal of Orthodontics
and Dentofacial Orthopedics, 136, 833–842.
28. Zymperdikas, V.F., Koretsi, V., Papageorgiou, S. N. and Papadopoulos,
M.A. (2016) Treatment effects of xed functional appliances in patients
with ClassII malocclusion: a systematic review and meta-analysis. Euro-
pean Journal of Orthodontics, 38, 113–126.
29. Armstrong, R.A. (2014) When to use the Bonferroni correction. Ophthal-
mic and Physiological Optics, 34, 502–508.
30. Nangia, A. and Darendeliler, M. A. (2001) Finishing occlusion in ClassII
or ClassIII molar relation: therapeutic ClassII and III. Australian Ortho-
dontic Journal, 17, 89–94.
31. Ngantung, V., Nanda, R.S. and Bowman, S.J. (2001) Posttreatment evalu-
ation of the distal jet appliance. American Journal of Orthodontics and
Dentofacial Orthopedics, 120, 178–185.
32. Janson, G., Barros, S.E., de Freitas, M.R., Henriques, J.F. and Pinzan, A.
(2007) ClassII treatment efciency in maxillary premolar extraction and
nonextraction protocols. American Journal of Orthodontics and Dentofa-
cial Orthopedics, 132, 490–498.
33. Isiksal, E., Hazar, S. and Akyalcin, S. (2006) Smile esthetics: perception
and comparison of treated and untreated smiles. American Journal of
Orthodontics and Dentofacial Orthopedics, 129, 8–16.
34. Janson, G., Branco, N.C., Morais, J.F. and Freitas, M.R. (2014) Smile
attractiveness in patients with Class II division 1 subdivision malocclu-
sions treated with different tooth extraction protocols. European Journal
of Orthodontics, 36, 1–8.
35. Meyer, A.H., Woods, M.G. and Manton, D.J. (2014) Maxillary arch width
and buccal corridor changes with orthodontic treatment. Part 2: attrac-
tiveness of the frontal facial smile in extraction and nonextraction out-
comes. American Journal of Orthodontics and Dentofacial Orthopedics,
145, 296–304.
36. Iared, W., Koga da Silva, E.M., Iared, W. and Runo Macedo, C. (2017)
Esthetic perception of changes in facial prole resulting from orthodontic
treatment with extraction of premolars: a systematic review. Journal of the
American Dental Association (1939), 148, 9–16.
37. Janson, G., Putrick, L.M., Henriques, J.F, de Freitas, M.R. and Henriques,
R.P. (2006) Maxillary third molar position in ClassII malocclusions: the
effect of treatment with and without maxillary premolar extractions.
European Journal of Orthodontics, 28, 573–579.
38. Kim, T.W., Artun, J., Behbehani, F. and Artese, F. (2003) Prevalence of third
molar impaction in orthodontic patients treated nonextraction and with
extraction of 4 premolars. American Journal of Orthodontics and Dentof-
acial Orthopedics, 123, 138–145.
G. Janson etal. 9