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Orthod Craniofac Res. 2017;20:237–244.
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237
© 2017 John Wiley & Sons A/S.
Published by John Wiley & Sons Ltd
Accepted: 5 September 2017
DOI: 10.1111/ocr.12206
ORIGINAL ARTICLE
Ankyloglossia as a risk factor for maxillary hypoplasia and soft
palate elongation: A functional – morphological study
A. J. Yoon1 | S. Zaghi2,3 | S. Ha4 | C. S. Law1 | C. Guilleminault5 | S. Y. Liu2
1Sections of Pediatric Dentistry and
Orthodontics, Division of Growth and
Development, UCLA School of Dentistry,
Los Angeles, CA, USA
2Division of Sleep Surgery, Department of
Otolaryngology, School of Medicine, Stanford
University, Stanford, CA, USA
3UCLA Health, Santa Monica, CA, USA
4UCLA School of Dentistry, Los Angeles, CA,
USA
5Sleep Medicine Division, Stanford Outpatient
Medical Center, Redwood City, CA, USA
Correspondence
A. J. Yoon, Section of Pediatric Dentistry
and Orthodontics, Division of Growth and
Development, UCLA School of Dentistry,
Los Angeles, CA, USA.
Email: jungdds@gmail.com
Structured Abstract
Objectives: To characterize associations between restricted tongue mobility and max-
illofacial development.
Setting and Sample Population: Cross- sectional cohort study of 302 consecutive sub-
jects from an orthodontic practice.
Material and Methods: Tongue mobility (measured with tongue range of motion ratio
[TRMR] and Kotlow free tongue measurement) was correlated with measurements of
the maxillofacial skeleton obtained from dental casts and cephalometric radiographs.
Results: Tongue range of motion ratio and Kotlow measures of restricted tongue mo-
bility were associated with (i) ratio of maxillary intercanine width to canine arch length,
(ii) ratio of maxillary intermolar width to canine arch length and (iii) soft palate length.
Restricted tongue mobility was not associated with hyoid bone position or Angle’s
skeletal classification.
Conclusions: Restricted tongue mobility was associated with narrowing of the maxil-
lary arch and elongation of the soft palate in this study. These findings suggest that
variations in tongue mobility may affect maxillofacial development.
KEYWORDS
ankyloglossia, frenulum, maxillofacial development, myofunctional dysfunction
1 | INTRODUCTION
The tongue may play a role in developmental of the maxillofacial skel-
eton.1,2 During development, the tongue maintains a balance of forces
between the soft tissue structures and the growing maxillofacial skel-
eton.3,4 When tongue mobility is impaired by congenital or develop-
mental conditions (eg microglossia, aglossia, tongue hemiatrophy, cleft
tongue, bifid tongue,5 oromotor dystonia of cerebral palsy,6 oromotor
dyspraxia of William’s syndrome7), there are developmental conse-
quences for the maxillofacial skeleton.8,4 The most common congen-
ital disorder affecting tongue mobility is lingual frenulum restriction
resulting in ankyloglossia, with an incidence of approximately 4.8% in
the newborn.9
Tongue mobility is influenced by the length and thickness of the
lingual frenulum, which extends from the ventral surface of the tongue
to the floor of the mouth.10 During deglutition, the tongue pushes
onto the palate,11 and the lingual frenulum determines the extent to
which the tongue can elevate.3 Upward pressure of the dorsum of
the tongue against the palate during swallowing helps form the width
and shape of the hard palate. A short- lingual frenulum limits upward
movement such that during deglutition the tongue thrusts anteriorly
instead of upward against the hard palate. This has been clinically
associated with reduced palatal width.3 The palatal bones form the
roof of the oral cavity and the floor of the nasal cavity. Thus, maxil-
lary constriction is also accompanied by narrowing of the nasal cavity,
resulting in nasal obstruction, mouth breathing and sleep- disordered
breathing.12
Studies have explored the influence of the tongue and lingual fren-
ulum on anomalies such as mandibular prognathism, maxillary protru-
sion and anterior open bite.3,13,1,14 However, there remains the need
for investigator- blinded, controlled studies examining the association
of lingual frenulum and tongue posture on development of the maxilla,
as it defines the dimension and patency of the nasal and oropharyn-
geal airway. This study is a functional- morphological investigation of
238
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YOON et al.
the association between tongue mobility and maxillofacial develop-
ment in a large cohort.
2 | MATERIALS AND METHODS
This was a cross- sectional cohort study of 302 consecutive subjects
evaluated in a private orthodontic practice (AY, Los Angeles, CA, USA)
from July to September 2016. Subjects aged six and over were invited
to participate. Exclusion criteria were as follows: history of frenec-
tomy, orthodontia, maxillary expansion, maxillofacial surgery, missing
or ectopic eruption of canines or first molars and functional trismus.
The study involved three main components: (i) functional measure-
ment of tongue mobility, (ii) anatomical measurement of the maxil-
lary and mandibular arches using dental casts and (iii) radiographic
measurement using lateral cephalometric radiographs. The following
demographic data were collected the following: age, gender, height
(cm), weight (kg) and BMI (kg/m2). Subjects who participated in the
study provided written informed consent for their examination find-
ings, dental casts, radiologic studies and personal health information
to be used for research purposes. The study protocol was approved
by the institutional review board (IRB) of University of California, Los
Angeles (IRB#16- 001286).
2.1 | Tongue mobility measurements
Assessment of the lingual frenulum and tongue mobility was per-
formed by two measures: (i) Tongue Range of Motion Ratio (TRMR)
and (ii) Kotlow free tongue measurement. A single rater performed
all measurements, and the average of three consecutive measure-
ments was obtained. TRMR is calculated as the mouth opening with
tongue tip to maxillary incisive papillae (MOTTIP) divided by maxi-
mal interincisal mouth opening (MIO). Our methods of measuring
MIO and MOTTIP have previously been published (Figure 1). Briefly,
functional TRMR as related to MIO grading scale is rated as follows:
Grade 1 = >80% (complete tongue mobility), Grade 2 = 50%- 80%
(average to mildly restricted tongue mobility), Grade 3 = <50%
(moderately restricted tongue mobility), Grade 4 = < 25% (severely
restricted tongue mobility)15 (Figure 2). Kotlow free tongue meas-
urement is obtained by measuring the length of the ventral surface
FIGURE1 Examples of tongue
functioning and length measurements
using the Quick Tongue Tie Assessment
Tool (QTT): Mouth opening with tongue
tip to incisive papilla (MOTTIP), maximal
interincisal mouth opening (MIO) and
Kotlow’s free tongue measurement. Tongue
range of motion ratio (TRMR) is defined as
the ratio of MOTTIP to MIO
(A) (B) (C)
FIGURE2 Examples of varying degrees of ankyloglossia categorized by tongue range of motion ratio (TRMR) grading (ratio of MOTTIP to
interincisal mouth opening [MIO])
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YOON et al.
of the tongue (while in full extension) from the insertion of the
lingual frenulum to the tongue tip.16
2.2 | Cephalometric analysis (Figure 3)
Lateral cephalogram performed with subjects in natural head po-
sition was obtained prior to initiation of orthodontic treatment.
The radiographs were analysed with Dolphin Image Software 9.0
(Chatsworth, CA, USA). The following two angular and linear pa-
rameters were measured as follows: (i) ANB: angle formed between
points A, N, and B; (ii) SN- Mn: angle formed between the SN line
and mandibular plane (mn); (iii) H- Mn (mm): perpendicular distance
from hyoid (H) to mandibular plane (Mn) which was drawn between
gonion (Go) and menton (Me); (iv) PNS- P (mm): distance between
posterior nasal spine (PNS) and tip of soft palate (P), also known as
soft palate length. Subjects were classified based on the following
ANB angle criteria: Skeletal Class I: 0° to 4°; Skeletal Class II: >4°;
Skeletal Class III: <0°. These measurements were performed by two
raters blinded to grading of tongue mobility, and the average of
three measurements was obtained.
2.3 | Orthodontic study models (Figure 4)
Stone dental casts were obtained prior to initiation of orthodon-
tic treatment. The following measurements were obtained using a
digital calliper, with the average of three consecutive measurements
recorded for each dental arch (maxillary and mandibular): interca-
nine width(C), canine arch length(A), intermolar width(M) and molar
arch length(B). The mesiolingual cusp tips of first molars were used
as the reference point for the molar measurements. In addition, for
the maxillary cast, the depth of the deepest point of palatal vault (D)
and the distance between the gingival margins of the first molars (G)
was also recorded. The following parameters, derived from the raw
measurements, were then used for analysis: (i) ratio of maxillary and
mandibular intercanine width to canine arch length; (ii) ratio of maxil-
lary and mandibular intermolar width to molar arch length; (iii) palatal
slope as calculated by the following formula:
𝜃
=tan−1
(
D
1
2
G
)
. Two
calibrated raters, blinded to grading of tongue mobility, performed the
measurements.
FIGURE3 Points and measurements for the cephalometric
analysis. Nasion (N), point A (A), sella (S), menton (Me), hyoid (H),
posterior nasal spine (PNS), tip of soft palate (P), gonion (Go), point
B (B)
FIGURE4 Measurements obtained
from maxillary and mandibular dental
casts. A- Canine arch length from line
connecting central incisors to line
connecting canine cusp tips, B- Molar arch
length from line connecting central incisors
to line connecting 1st molar ML cusps,
C- Intercanine width between canine cusp
tips, M- Intermolar width between 1st molar
ML cusps, D- Depth of deepest point of
palatal vault, G- Distance between gingival
margins of first molars, θ- Palatal slope
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YOON et al.
2.4 | Data collection
The study data were collected and managed using REDCap electronic
data capture tools hosted at the UCLA Clinical and Translational Science
Institute. REDCap (Research Electronic Data Capture) is a secure, web-
based application designed to support data capture for research stud-
ies.17 Two raters assessed cast and cephalometric measurements and
one rater assessed tongue mobility (MOTTIP), Kotlow free tongue length,
maximal interincisal mouth opening (MIO) measurements. Measurement
calibration was performed with an initial sample of 10 cases in three
repeated trials. Inter- rater (by rater) and intrarater (by trial) reliabilities
were assessed with the intraclass correlation coefficient (ICC), measure-
ment error (ME) and coefficient of variation (CV) statistics using JMP Pro
12.0 (Measurement System Analysis, EMP results, EMP Gauge R&R re-
sults).18 The results indicated measurement reliabilities between 98.0%
and 99.6% across all domains.
TABLE1 Patient demographics, dental cast measurements and cephalometric analysis by tongue range of motion ratio grade (TRMR)
TRMR Grade
P- Value
Grade 1 Grade 2 Grade 3 Grade 4
All >80% 50%- 80% <50% <25%
N Number 302 19 226 53 4
% Total 100% 6.3% 74.8% 17.5% 1.3%
Patient demographics
Gender Male 115 (38.1%) 7 (36.9%) 82 (36.3%) 23 (43.4%) 3 (75.0%) .1744
Female 187 (61.9%) 12 (63.1%) 144 (63.7%) 30 (56.6%) 1 (25.0%)
Age (y) Mean 18.1 18.3 18.0 18.9 14.5 .8103
Std dev 9.4 10.6 9.1 10.5 3.9
Weight (kg) Mean 56.3 58.9 55.7 57.9 57.5 .7474
Std dev 17.1 24.4 16.0 19.2 14.3
Height (inches) Mean 63.0 60.9 63.2 62.8 66.0 .1857
Std dev 5.2 7.9 4.9 5.1 6.3
BMI (kg/m2) Mean 21.6 23.7 21.3 22.2 20.1 .1404
Std dev 5.0 6.6 4.7 5.4 1.7
Cast measurements
Ratio Mx C
W:AL
Mean 3.5 3.6 3.6 3.1 3.0 .0015**,‡
Std dev 0.9 0.6 0.9 0.7 0.5
Ratio Mx M
W:AL
Mean 1.2 1.2 1.2 1.1 1.1 .0070**
Std dev 0.1 0.1 0.1 0.1 0.1
Ratio Mn C
W:AL
Mean 4.7 4.9 4.8 4.4 4.9 .5446
Std dev 1.5 1.2 1.6 1.2 0.8
Ratio Mn M
W:AL
Mean 1.3 1.3 1.2 1.3 1.4 .2024
Std dev 0.2 0.1 0.1 0.2 0.2
Palatal slope Mean 35.3 32.4 35.1 36.9 41.4 .0118*
Std dev 6.5 6.5 6.2 7.5 1.7
Cephalometric analysis
SN- Mn angle Mean 36.0 36.9 35.7 36.6 40.8 .2640
Std dev 6.1 7.8 5.8 6.4 7.0
H- Mn line Mean 12.7 13.4 12.4 13.3 15.7 .4038
Std dev 5.2 7.5 4.8 5.7 5.4
PNS- P line Mean 31.6 30.3 31.3 33.5 34.1 .0137*,‡
Std dev 5.0 6.2 4.6 5.6 2.8
TRMR, Tongue range of motion ratio; Mx, Maxillary; Mn, Mandibular; C, Canine; M, Molar; W:AL, Ratio of Width to Arch Length; SN- Mn angle, Angle
formed between the SN line and mandibular plane; S, sella; N, nasion; Mn plane, Line drawn between gonion (Go) and menton (Me); H- Mn (mm), perpen-
dicular distance from hyoid (H) to mandibular plane (Mn); PNS- P line, distance from posterior nasal spine (PNS) and tip of soft palate (P).
*Statistical significance with P- value <.05.
**Statistical significance with P- value <.01 on univariate analysis.
‡Statistical significance with P < .01 on multivariate analysis with a Standard Least Squares Regression Model.
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YOON et al.
2.5 | Statistical analysis
Statistical analyses were performed using JMP Pro 12 (SAS
Institute Inc., Cary, NC, USA). Continuous variables are summa-
rized as mean (M) ± standard deviation (SD). Categorical variables
are summarized as frequencies and percentages. Univariate analy-
sis with Pearson’s Chi Square or independent t test (continuous
variables) was performed to assess for nominal or continuous co-
variates of tongue measurements including age, gender, height,
weight and BMI. Due to the testing of multiple variables for each
outcome, a two- tailed P- value < .01 was selected as the cut- off for
statistical significance.
3 | RESULTS
Our study included 302 subjects with age ranging from 6 to 67 years.
Demographic factors included age: 18.1 ± 9.4 years (M ± SD); gender:
61.9% female; weight: 56.3 ± 17.1 kg; height: 63.0 ± 5.2 inches; BMI:
21.6 ± 5.0 kg/m2. Ethnicities include Asian 39.1%, Hispanic 35.8%,
TABLE2 Patient demographics, dental cast measurements and cephalometric analysis by kotlow classification
Kotlow classification
P- Value
Normal Class 1 Class 2 Class 3 Class 4
> 16 mm 12- 16 mm 8- 11 mm 3- 7 mm <3 mm
N Number 142 123 33 3 1
% Total 47.0% 40.7% 10.9% 0.99% 0.33%
Patient demographics
Gender Male 51 (35.9%) 47 (38.2%) 14 (42.4%) 2 (66.7%) 1 (100%) .3752
Female 91 (64.1%) 76 (61.8%) 19 (57.6%) 1 (33.3%) 0 (0%)
Age (y) Mean 19.2 17.3 16.9 13.0 19.0 .3454
Std dev 9.4 9.3 9.9 3.0
Weight (kg) Mean 58.3 54.6 54.0 53.0 70.9 .3383
Std dev 17.1 16.8 18.4 13.6
Height (inches) Mean 63.3 62.8 62.1 64.3 71.0 .3851
Std dev 4.9 5.2 5.8 6.5
BMI (kg/m2) Mean 22.2 21.1 21.1 19.5 21.8 .4142
Std dev 5.0 5.0 4.9 1.5
Cast measurements
Ratio Mx C W:AL Mean 3.7 3.4 3.0 2.8 3.4 .0011**,‡
Std dev 0.9 0.8 0.6 0.5
Ratio Mx M
W:AL
Mean 1.2 1.2 1.1 1.2 1.1 .0027**
Std dev 0.1 0.1 0.1 0.1
Ratio Mn C W:AL Mean 4.7 4.8 4.2 4.8 5.0 .4236
Std dev 1.4 1.6 1.3 1.0
Ratio Mn M
W:AL
Mean 1.3 1.2 1.2 1.3 1.5 .1898
Std dev 0.1 0.2 0.2 0.2
Palatal slope Mean 35.0 35.1 36.5 42.1 39.2 .2907
Std dev 6.1 6.5 8.1 1.1
Cephalometric analysis
SN- Mn angle Mean 36.4 35.5 35.1 43.8 31.5 .1061
Std dev 6.0 6.4 5.1 4.0
H- Mn line Mean 12.6 12.5 13.5 14.5 19.4 .5591
Std dev 5.1 5.1 5.5 5.8
PNS- P line Mean 30.9 31.5 34.9 33.3 36.3 .0011**,‡
Std dev 4.7 5.0 5.3 2.9
Kotlow’s free tongue length; Mx, Maxillary; Mn, Mandibular; C, Canine; M, Molar; W:AL, Ratio of Width to Arch Length; SN-Mn angle, Angle formed
between the SN line and mandibular plane; S, sella; N, nasion; Mn plane, Line drawn between gonion (Go) and menton (Me); H-Mn (mm), perpendicular
distance from hyoid (H) to mandibular plane (Mn); PNS-P line, distance from posterior nasal spine (PNS) and tip of soft palate (P).
*Statistical significance with P- value <.05.
**Statistical significance with P-value < .01 on univariate analysis.
‡Statistical significance with P < .01 on multivariate analysis with a Standard Least Squares Regression Model.
242
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YOON et al.
White 15%, Black 8%. This sample includes 47 children (ages 6- 11),
160 adolescents (age 12- 17), 71 young adults (age 18- 35), 23 adults
(age 36- 64) and 1 senior (age > 65). The average TRMR for the entire
cohort was 62.1 ± 13.8 (mean ± SD); the average Kotlow free tongue
length was 17.2 ± 5.9 mm. (Table 1 and 2).
The distribution of TRMR was as follows: Grade 1 = 6.3% (n = 19),
Grade 2 = 74.8% (n = 226), Grade 3 = 17.5% (n = 53), Grade 4 = 1.3%
(n = 4). The distribution of Kotlow classification was as follows:
Normal = 47.0% (n = 142), Class 1 = 40.7% (n = 123), Class 2 = 10.9%
(n = 33), Class 3 = 0.99% (n = 3), Class 4 = 0.33% (n = 1). There were
no significant differences in age, gender, weight, height or BMI.
Four factors achieved or approached statistical signif-
icance on univariate analysis for association with TRMR
(Table 1). Higher TRMR grade was associated with decreased
ratio of maxillary intercanine width to canine arch length
(Ratio Mx C W: AL), decreased ratio of maxillary intermolar
width to molar arch length (Ratio Mx M W:AL), increased pal-
atal slope measurements, and longer soft palate length (PNS- P
line). In the multivariate analysis with Standard Least Squares
Regression Model, two factors were found to be independently
associated with TRMR, namely, Ratio MxC W:AL and PNS- P line
0.88, PP = .0037). See Figures 5
and 6.
Similar factors achieved statistical significance on univariate
analysis for an association with ankyloglossia based on Kotlow free
tongue length measurements (Table 2). In the multivariate analysis
with Standard Least Squares Regression Model, Ratio Mx C W: AL and
PNS- P line were found to be independently associated with Kotlow
P
P = .0050). See Tables 1 and 2 for further details.
Tongue range of motion ratio and Kotlow Classification were not
associated with either dental or skeletal classification (P > .05). See
Figure 7.
4 | DISCUSSION
There are four main findings from this functional- morphological study
examining the association between tongue mobility and maxillofacial
development. First, TRMR and Kotlow measures of reduced tongue
mobility are both associated with decreased ratio of maxillary inter-
canine width to canine arch length. This is consistent with published
associations between ankyloglossia and maxillary hypoplasia. Based
on visual assessment of tongue shape and lingual frenulum in 600
individuals with Class I malocclusions in a paediatric dental practice
over 18 months, Northcutt reported that when the lingual frenulum
is short, the tongue will not generate enough upward pressure result-
ing in a narrow and underdeveloped palate.3 Defabianis illustrated the
relationship between restricted tongue mobility and maxillary con-
striction with a subject treated with lingual frenectomy, followed by
spontaneous upper arch expansion without orthodontic treatment.1
Guilleminault recently presented a case- control series of 150 pae-
diatric patients with lingual frenulum that were clinically designated
as short (n = 63) or normal (n = 87), and noted more “high and nar-
row palatal vault” among subjects in the short frenulum group.19 Our
investigator- blinded cross- sectional study with clinical, radiographic
and dental cast measurements supports the association between re-
strictions to tongue mobility and maxillary hypoplasia with objective
functional and anatomic measurements.
The second significant finding of this study is the association be-
tween soft palate length (PNS- P line) and tongue mobility. Restricted
tongue mobility (as measured by either Kotlow free tongue or TRMR)
FIGURE5 Tongue range of motion
ratio (TRMR) Grade vs Maxillary Width and
Soft Palate Length. Box and whisker plots
are displayed outlining the 95% confidence
intervals, median, interquartile ranges and
outliers for the distribution of the Ratio
Mx C W: AL and PNS- P measurements
for the entire overall sample of patients
[Colour figure can be viewed at
wileyonlinelibrary.com]
TRMR Grade vs Maxillary Width and Soft Palate Length
TRMR Grade
1234
Ratio of maxilary inter-canine
width? to arch length
1
2
3
4
5
6
7
Soft palate length (PNS-P)
10
15
20
25
30
35
40
45
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243
YOON et al.
was an independent predictor of increased soft palate length. This as-
sociation remained significant when controlling for differences in the
measurements of the maxilla, suggesting that the increased soft palate
length was not exclusively attributable to increased draping of the soft
palate tissue due to diminished tension. Prior authors have reported
that soft palate length is significantly greater in OSA patients,20 and
it is well established that increased soft palate length is a prominent
risk factor for upper airway collapsibility.21 Soft palate length has been
shown to increase progressively with ageing, weight gain and the pres-
ence of snoring, particularly among men20,22,23 We postulate that an-
kyloglossia may contribute to myofunctional dysfunction (in the form
of open mouth breathing and/or altered swallowing pattern) that in
turn promotes elongation of the soft palate.
Third, there is a lack of association between hyoid bone position
(H- MN line) and ankyloglossia. Ankyloglossia is associated with a low-
tongue posture, which has been associated with an inferiorly posi-
tioned hyoid bone.24 The hyoid bone is supported by soft tissue and is
not spatially fixed by bony articulations. Thus, the position of the hyoid
bone will vary with functional movements such as deglutition, mastica-
tion and breathing. Subjects with atypical patterns of functional move-
ments have been previously found to have alterations in the position
of the hyoid bone as compared to normal functioning controls.25 We
did not reproduce the association between position of the hyoid bone
(H- MN line) and TRMR or Kotlow measures of tongue mobility.
Finally, we did not find an association between skeletal or dental
Angle classifications with restricted tongue mobility. Two prior studies
FIGURE6 Tongue range of motion
ratio (TRMR) Grade vs Maxillary Width
and Soft Palate Length by Age Cohort.
Box and whisker plots are displayed
outlining the 95% confidence intervals,
median, interquartile ranges and outliers
for the distribution of the Ratio Mx C
W: AL and PNS- P measurements by age
cohort [Colour figure can be viewed at
wileyonlinelibrary.com]
TRMR Grade vs Maxillary Width and Soft Palate Length
By Age Cohort
Children (Age 6-11) Adolescents (Age 12-17) Young Adults (Age 18-35) Adults (Age 36-64) Senior (Age >65)
Age Cohort
TRMR Grade
Ratio of maxilary inter-canine
width? to arch length
1
2
3
4
5
6
7
Soft palate length (PNS-P)
10
15
20
25
30
35
40
45
1234 1234 1234 1234 1234
FIGURE7 Tongue range of motion
ratio (TRMR) and Kotlow measurements
by Angle Classification. There was no
significant association between TRMR
and Kotlow measurements vs. skeletal
and dental classification in this series
(P > .05) [Colour figure can be viewed at
wileyonlinelibrary.com]
244
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YOON et al.
with smaller sample sizes (n = 30)2 and (n = 150),14 however, did report
an association between ankyloglossia and skeletal Class III malocclusion.
An important limitation of the present study is the small number
of patients with extremely restricted tongue mobility. There were 53
patients with Grade 3 and only 4 patients with Grade 4 TRMR in the
study cohort. In addition, subjects who participated in the study had
presented for orthodontic treatment and may not reflect the mor-
phology of population- based controls. Future longitudinal studies
with large sample sizes from the general population would be needed
to define the impact of tongue mobility on maxillofacial development.
5 | CONCLUSIONS
The results of this cross- sectional study show an association between
restricted tongue mobility, narrowing of the maxillary dental width,
and elongation of the soft palate. The present study did not find iden-
tify associations with skeletal and dental anterior- posterior relation-
ships. Our findings suggest that variations in tongue mobility may
affect maxillofacial morphology, mainly in the form of a high- arched
palate with transverse deficiency.
ORCID
A. J. Yoon http://orcid.org/0000-0001-6807-7686
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How to cite this article:
Guilleminault C, Liu SY. Ankyloglossia as a risk factor for
maxillary hypoplasia and soft palate elongation: A functional
– morphological study. Orthod Craniofac Res. 2017;20:
237–244. https://doi.org/10.1111/ocr.12206