Download dental medicine 1153 cephalometric features of class iii malocclusion

Rev. Med. Chir. Soc. Med. Nat., Iaşi – 2015 – vol. 119, no. 4
DENTAL MEDICINE
ORIGINAL PAPERS
CEPHALOMETRIC FEATURES OF CLASS III MALOCCLUSION
Georgeta Zegan 1, Cristina Gena Dascălu 2*, R. B. Mavru 1, Daniela Anistoroaei 1
University of Medicine and Pharmacy “Grigore T. Popa” - Iasi
Faculty of Dental Medicine
1. Department of Surgery
Faculty of Medicine
2. Department of Preventive Medicine and Interdisciplinarity
* Corresponding author: E-mail: [email protected]
CEPHALOMETRIC FEATURES OF CLASS III MALOCCLUSION (Abstract): Aim: The
study aimed to identify quantitative and relational characteristics of bone, dental and soft ti ssue structures for Class III malocclusion, according to gender and age range. Material and
methods: 60 conventional lateral cephalograms were divided into two groups according to
ANB angle: the group of cases with skeletal Class III (n=36) and a control group with skel etal Class I (n=24). There were performed 53 digital cephalometric measurements according
to Steiner, Tweed and Jarabak analyzes. The Kolmogorov-Smirnov, t-student and Levene
tests were used to find the characteristics of Class III, using SPSS 16.0 for Windows. Results: We found 14 parameters that distinguished the two classes disorders (the angles SNB,
SND, FMA, IMPA, MeGoOcP, Mand 1-MeGo, NSAr, ArGoMe, NGoMe and SNPog; the
distances Ao-Bo and 1u-NPog; Holdaway and AFH ratios) and 3 parameters for the Class III
age ranges (NGoAr angle, Ls-NsPog' distance and S-Ar:Ar-Go ratio) (p≤0.05). There were
found no significant differences between genders for skeletal Class III. Conclusion: Emphasizing the cephalometric characteristics of Class III malocclusion, with the overall growth
together with dental and occlusion development, requires early orthodontic therapy. Keywords: CONVENTIONAL LATERAL CEPHALOMETRIC RADIOGRAPHY, CLASS III
MALOCCLUSION, DIGITAL CEPHALOMETRIC MEASUREMENTS.
Class III malocclusion is characterized
by a mesial relation of the mandible compared to the maxillary, the cause beeing
skeletal and its origin is usually hereditary
(1). This anomaly shows a low prevalence
at the white population (1-2%) and with an
increased frequency in Asian countries like
Japan (4-13%) (2).
Bourdet (cit by 3) was the first researcher who described the 1737 skeletal Class III
pattern in children with mandibular prognathia. In such cases, lateral cephalometric
radiography is essential in establishing the
skeletal, dental and facial diagnosis in order
to appropriately apply orthodontic or surgical treatment (4). Sagittal discrepancies are
mainly due to excessive growth of the mandible with hyperdivergence growth pattern,
resulting mandibular prognathia. Most studies of skeletal Class III malocclusion were
performed on Eastern Asian populations (59). Diversity of opinion on parameters values of cephalometric characteristics of
skeletal Class III are supposed to be the
expression of the ethnic composition of the
groups studied (10-12).
1153
Georgeta Zegan et al.
Our research was conducted in order to
investigate the cephalometric characteristics of skeletal Class III malocclusion on a
sample of patients without orthodontic
treatment from the northeastern region of
Romania. The aim of the study was to
compare the cephalometric parameters of
Class III with the skeletal Class I, to identify quantitative and relational differences of
bone, dental and soft tissues structures, by
gender and age range.
MATERIAL AND METHODS
This retrospective and case-control
study was conducted for 60 conventional
lateral cephalograms, from the Orthodontics Clinic at the Ambulatory Clinic of the
"St. Spiridon" University Emergency Hospital, Iasi, Romania, during January 2006
and December 2014. The cephalograms’
selection criterion was their good technical
quality. All radiographs were performed
with the same X-ray device, the STRATOX Orthopantomograph with magnification
factor of 11.8%.
The lateral cephalograms provided from
patients from northeastern Romania, (28 47% males and 32 - 53% females), with
ages
between
7–26
years
(mean
14.33±5.758 years), without previous orthodontic treatment. The patients cephalograms were divided in two groups, by skeletal class (ANB angle): cases group=36
(60%) patients with skeletal class III
(ANB<2°), which were 17 (42%) males
and 19 (53%) females, 26 (72%) with age
<14 years and 10 (28%) with age >14
years; control group=24 (40%) patients
with skeletal class I (ANB≤4°), witch are
11 (46%) males and 13 (54%) females. The
patients with craniofacial dysostosis, craniofacial synostosis, endocrine and genetic
syndromes were excluded. The informed
consent was acquired from all subjects or
1154
the patients’ parents. The study was conducted in accordance with the Helsinki
Declaration of 1975, as revised in 2000.
The anatomical outlines of the lateral
cephalograms were drafted on tracing paper
with a 0.5mm diameter pencil. The tracing
paper was scanned (MFD Canon Pixma
MP280) in digital format (JPG File), after
which it was stored on a computer (Asus
Eee PC 1015BX) (13). The digital cephalometric analysis was performed with Onyx
CephTM (Onyx CEPH 2.7.18 (174) Image
Instruments GmbH, Chemnitz, Germany).
The landmarks were located with the
mouse pointer directly on the digital paper
image on the computer display (fig. 1).
Fig. 1. Cephalometric landmarks:
sella (S), nasion (N), E-point (E), L-point (L),
porion (Po), condylion posterior (ppCond), articulare (Ar), orbitale (Or), gonion (Go), menton
(Me), gnathion (Gn), pogonion (Pog), D-point
(D), anterior nasal spine (ANS), A-point (A), Apoint acc. to Jarabak (AJ), prosthion (Pr), infradentale (Id), B-point (B), upper incisor apex
(Ap1u), upper incisor crown tip (1u), incision
superior (I1u), incision inferior (I1l), lower incisor crown tip (1l), lower incisor apex (Ap1l),
anterior point for the occlusal plane (AOcP),
posterior point for the occlusal plane (POcP),
pronasale (Pn), labrale superior (Ls), labrale
inferior (Li) and pogonion soft tissue (Pog')
Cephalometric features of class III malocclusion
For each imagines there were measured
28 angles (°), 21 linear dimensions (mm)
and 4 bone ratios (%), dental and soft
tissues (n=53 measurements), using Steiner (14), Tweed (15) and Jarabak (16)
analyses (fig. 2). Every single scanned
paper was digitally measured under identical calibration conditions for the size of
the cephalometric images. All data obtained were extracted and stored in the
electronic format (Microsoft Office Excel
97-2003 Worksheet). The protocol included a quantitative evaluation of the skull
basis, maxillary, mandible, and the relations between them, as well as with the
dental and soft tissues.
Fig. 2. Cephalometric parameters
(a) acc. Steiner: SNA, SNB, ANB, SND, II, SN-OcP, SN-GoGn, Max1-NA, Max1-SN, Mand1NB, 1u-NA, 1l-NB, Pog-NB, Holdaway ratio, S-L and S-E. (b) acc. Tweed: FMIA, FMA, IMPA, Wits, PoOr-OcP, Z, PFH, AFH and AFH:PFH. (c) acc. Jarabak: MeGo-OcP, Mand1-MeGo,
1u-NPog, 1l-NPog, Ls-PnPog', Li-PnPog', NSAr, SArGo, ArGoMe, Sum, N-S, S-Ar, NGoAr,
NGoMe, Ar-Go, S-Ar:Ar-Go, Go-Me, SN-GoMe, GoMe:NS, N-Go, S-Me, NSGn, S-Go, N-Me,
SGo:NMe, SNPog and NAPog.
Statistical analysis was made with program SPSS 16.0 (SPSS Inc., Chicago, IL),
for Windows. The numerical values were
calculated according to the parameters of
descriptive statistics (mean value, standard
deviation (SD), error of standard deviation
(SEM), minimum and maximum value). To
compare the measured values of the two
skeletal classes, sexes and age intervals, the
Kolmogorov-Smirnov, t-Student and Levene
tests for the equality of variances were applied, with p≤0.05 value, corresponding to
the 95% confidence interval, beeing considered statistically significant.
RESULTS
There were measured the angles and
distances between the bone structures,
dental and soft tissues for each lateral
cephalometric radiograph, using the three
cephalometric analyses. The measurement
mean values were compared between the
two skeletal classes.
For the Steiner (14) analysis there were
found statistically significant differences
between skeletal classes for the sagittal
position of the mandible to the anterior
cranial base plane (SNB angle), sagittal
position of symphysis mentalis to the ante-
1155
Georgeta Zegan et al.
rior plane of the cranial base (SND angle)
and for Holdaway ratio (tab. I).
For the Tweed (15) analysis there were
found statistically significant differences
between skeletal classes for the mandibles’
growth direction (FMA angle), sagittal
position of the lower central incisor to the
mandibular plane (IMPA angle), sagittal
relation of maxillary-mandible (Wits or
distance Ao-Bo) and for skeletal anterior
height (AFH) (tab. II).
For the Jarabak (16) analysis there were
found statistically significant differences
between skeletal classes for inclination of
the occlusal plane to mandibular basis
(MeGoOcP angle), sagittal position of the
lower central incisor to mandibular basis
(Mand 1-MeGo angle), sagittal position of
the upper central incisor to the Downs
facial plane (distance 1u-NPog), temporomandibular joint and glenoid Fossae posi-
tion (NSAr angle), type of condylar growth
(ArGoMe angle), type of mandibular
growth (NGoMe angle) and sagittal position of mandibular basis to the anterior
cranial base plane (SNPog angle) (tab. III).
Other differences of angular, linear and
ratios measured mean values were not significant.
The mean values of the digital measurements of skeletal Class III were compared between the two sexes and no statistically significant differences were found.
The mean values of the digital measurements of skeletal Class III were compared for two intervals of age <14 years
and >14 years and there were found statistically significant differences for the type
of mandibular growth (NGoAr), sagittal
position of the upper lip (Ls-NsPog') and
for the cranial base length and mandibular
ramus height ratio (S-Ar:Ar-Go) (tab IV).
TABLE I
Descriptive statistics and differences between groups for cephalometric measur ements of Steiner analysis
Parameters
SNA
SNB
ANB
SND
II
SN-OcP
SN-GoGn
Max1-NA
Max1-SN
Mand1-NB
1u-NA
1l-NB
Pog-NB
Holdaway ratio
S-L
S-E
Cases with skeletal class III
Control with skeletal class I
(n=36)
(n=24)
Mean
SD
SEM
Mean
SD
SEM
Angular (°)
79.7217
5.43376
0.90563
80.7038
3.09720
0.63221
80.4567
5.47972
0.91329
77.7275
3.17859
0.64883
-0.7344
2.35933
0.39322
2.9758
0.65558
0.13382
78.1900
5.22631
0.87105
75.7771
3.05570
0.62374
131.8017
11.17348
1.86225
131.9329
11.09934
2.26564
15.5447
5.47329
0.91222
16.2433
5.03722
1.02822
30.3708
6.66255
1.11042
28.7871
5.03722
1.02822
28.4169
7.19123
28.4169
24.6783
7.37017
1.50443
108.1381
7.52379
1.25396
105.3813
7.91621
1.61589
20.5164
7.80400
1.30067
20.4154
6.85486
1.39924
Linear (mm)
6.4519
2.75272
0.45879
5.5350
2.13288
0.43537
4.3242
2.26633
0.37772
3.6167
1.37529
0.28073
2.4647
1.65978
0.27663
2.9592
1.59626
0.32584
3.2861
2.14431
0.35738
2.0646
1.48163
0.30244
56.6764
12.57102
2.09517
53.1608
5.57675
1.13835
19.5053
4.77858
0.79643
20.2213
2.87271
0.58639
p value
0.426
0.032*
0.000****
0.046*
0.965
0.619
0.332
0.056
0.179
0.959
0.174
0.176
0.256
0.018*
0.204
0.513
p>0.05 – no statistically significant differences; *p<0.05 – statistically significant differences; ****p<0.0001 – extremely statistically
significant differences.
1156
Cephalometric features of class III malocclusion
TABLE II
Descriptive statistics and differences between groups for cephalometric measur ements of Tweed analysis
Parameters
FMIA
FMA
IMPA
SNA (°)
SNB (°)
ANB (°)
Wits (Ao-Bo) (mm)
POr-OcP (°)
Z (°)
PFH (mm)
AFH (mm)
AFH/PFH (%)
Cases with skeletal class III
Control with skeletal class I
(n=36)
(n=24)
Mean
SD
SEM
Mean
SD
SEM
Triangle (°)
66.0664
8.20082
1.36680
64.9429
6.79298
1.38661
26.8550
6.57577
1.09596
22.4987
5.35326
1.09273
87.0789
8.14199
1.35700
92.5571
7.37926
1.50628
Further measurements
79.7217
5.43376
0.90563
80.7038
3.09720
0.63221
80.4567
5.47972
0.91329
77.7275
3.17859
0.64883
-0.7344
2.35933
0.39322
2.9758
0.65558
0.13382
-5.1500
4.75349
0.79225
-0.3163
3.73168
0.76173
9.4183
5.07064
0.84511
8.6367
5.72637
1.16889
77.2153
10.15696
1.69283
75.6438
7.68934
1.56958
50.8775
9.17578
1.52930
49.7838
5.77117
1.17804
66.8661
10.86013
1.81002
61.6392
5.37680
1.09753
76.4650
9.69464
1.61577
80.9875
8.93843
1.82455
p value
0.581
0.009**
0.010**
0.426
0.032*
0.000****
0.000****
0.581
0.522
0.606
0.033*
0.073
p>0.05 – no statistically significant differences; *p<0.05 – statistically significant differences; **p<0.01 – highly statistically significant
differences; ****p<0.0001 – extremely statistically significant differences.
TABLE III
Descriptive statistics and differences between groups for cephalometric measur ements of Jarabak analysis
MeGoOcP (°)
Cases with skeletal class III
Control with skeletal class I
(n=36)
(n=24)
Mean
SD
SEM
Mean
SD
SEM
Dental analysis
17.4908
3.75773
0.62629
13.8633
3.85878
0.78767
II (°)
131.6975
11.06530
1.84422
131.9329
11.09934
2.26564
0.936
Max1-SN (°)
108.3031
7.44283
1.24047
105.3813
7.91621
1.61589
0.152
Mand1-MeGo (°)
87.0583
8.18432
1.36405
92.5779
7.38995
1.50847
0.010**
1u-NPog (mm)
3.3825
4.08578
0.68096
6.0708
2.51376
0.51312
0.006**
1l-NPog (mm)
1.6036
3.50999
0.58500
0.4429
2.72691
0.55663
0.177
Ls-NsPog' (mm)
-5.6833
2.80010
0.46668
-4.2250
2.93086
0.59826
0.057
Li-NsPog' (mm)
-2.8067
3.19658
2.94068
0.60026
0.859
NSAr (°)
121.4239
5.57444
4.79078
0.97791
0.004**
SArGo (°)
142.3531
6.31661
1.05277
141.7117
6.72933
1.37362
0.709
ArGoMe (°)
129.1639
7.70221
1.28370
122.7921
5.41522
1.10538
0.001***
Sum (°)
392.9414
7.07147
1.17858
390.1100
5.17420
1.05618
0.098
N-S (mm)
70.9967
10.02414
1.67069
71.3171
5.34401
1.09084
0.887
S-Ar (mm)
35.6836
5.92013
0.98669
34.6004
2.98528
0.60937
0.411
NGoAr (°)
53.3419
3.67529
0.61255
52.0700
4.22530
0.86249
0.221
NGoMe (°)
75.8211
6.60669
1.10111
70.7229
4.60316
0.93962
0.002**
Parameters
0.53276
-2.6613
Skeletal analysis
0.92907
125.6046
p value
0.001***
1157
Georgeta Zegan et al.
Ar-Go (mm)
Cases with skeletal class III
(n=36)
Mean
SD
SEM
50.8775
9.17578
1.52930
Control with skeletal class I
(n=24)
Mean
SD
SEM
49.7838
5.77117
1.17804
S-Ar:Ar-Go (%)
71.2353
12.67297
2.11216
70.3342
9.95383
2.03182
0.771
Go-Me (mm)
68.1181
12.47722
2.07954
66.8333
7.90436
1.61347
0.656
Go-Me:N-S (%)
95.9083
10.18379
1.69730
93.9050
10.62951
2.16974
0.466
SNA (°)
79.7217
5.43376
0.90563
80.7038
3.09720
0.63221
0.426
SNB (°)
80.4567
5.47972
0.91329
77.7275
3.17859
0.64883
0.032*
ANB (°)
-0.7344
2.35933
0.39322
2.9758
0.65558
0.13382
0.000****
SNGoMe (°)
32.9414
7.07147
1.17858
30.1100
5.17420
1.05618
0.098
N-Go (mm)
114.3119
16.68898
2.78150
115.9513
8.56687
1.74871
0.659
S-Me (mm)
133.3447
19.64042
3.27340
126.0708
7.73846
1.57961
0.090
NSG (°)
66.2544
4.50370
0.75062
66.7404
3.09286
0.63133
0.647
S-Go (mm)
81.3564
12.09777
2.01629
79.3687
5.92924
1.21030
0.459
N-Me (mm)
118.7572
18.61302
3.10217
114.0229
8.46308
1.72752
0.248
S-Go:N-Me (%)
68.7256
5.66855
0.94476
69.7362
4.44223
0.90677
0.465
SNPog (°)
81.5817
5.24116
0.87353
79.2075
3.07573
0.62783
0.050*
NAPog (°)
175.2058
4.63133
0.77189
176.7813
1.97550
0.40325
0.122
Parameters
p value
0.606
p>0.05 – no statistically significant differences; *p<0.05 – statistically significant differences; **p<0.01 – highly statistically significant
differences; ***p<0.001 – very highly statistically significant differences; **** p<0.0001 – extremely statistically significant differences.
TABEL IV
Descriptive statistics and significant differences between intervals of age for ceph alometric measurements of the skeletal class III
Parameters
NGoAr (°)
Ls-NsPog' (mm)
S-Ar:Ar-Go (%)
Cases with skeletal class III (n=36)
Age <14 years (n=26)
Age >14 years (n=10)
Mean
SD
SEM
Mean
SD
SEM
54.3362
3.49701
0.68582
50.7570
2.87759
0.90997
-4.9931
2.79605
0.54835
-7.4780
1.95437
0.61803
73.8815
13.52723
2.65291
64.3550
6.59167
2.08447
p value
0.007**
0.015*
0.008**
*p<0.05 – statistically significant differences; **p<0.01 – highly statistically significant differences.
DISCUSSION
Our research has focused on the comparison of cephalometric measurements
between skeletal Class III and Class I in
order to identify the quantitative characteristics and bone structures relations, dental
and soft tissues of Class III malocclusion,
according to gender and age range. The
skeletal Class was identified using the
ANB angle value, beeing recognized by
many authors as the skeletal discrepancies
indicator (11, 13, 17, 18). We used three
1158
cephalometric analyzes used by orthodontists, in order to identify three aspects
(skeletal, dental and soft tissues) characteristic to the Class III malocclusion. We
chose efficient cephalometric analysis
software for precision measurements.
Using statistical tests allowed us to find
significant differences between skeletal
Classes, which represented the defining
parameters of skeletal Class III malocclusion for the studied population. Thus, we
found 14 statistically significant measure-
Cephalometric features of class III malocclusion
ments (10 angular, 2 linear and 2 of percentage), that characterized the skeletal
Class III: mandibular prognatia by the anterior sagittal position of the mandible to the
anterior cranial base plane (increased SNB
angle and decreased Ao-Bo distance);
progeny by the anterior sagittal position of
symphysis mentalis to the anterior cranial
base plane (increased SND and SNPog
angles and Holdaway ratio); mandible’s
hyperdivergent growth (increased FMA and
NgoMe angles); lower dental retroclination
(decreased IMPA and Mand 1-MeGo angles and 1u-Npog distance); occlusal plane
tilting towards the mandible basis (increased Me GoOcP angle); anterior position of temporomandibular joint (decreased
NSAr angle); posterior condylar growth,
with the opening of the mandibular angle
(increased ArGoMe angle); facial anterior
height growth (increased AFH ratio).
Previous comparative studies (of Class I
and Class III) reported similar parameters
as prognathia, posterior mandibular rotation, forward position of the mandible and
lower central incisor retroclination (3, 6-9,
19-22), as well as different parameters as
cranial base shortening, underdeveloped
maxillary, upper central incisor proclination and facial deficiency of the zygomatic
region (11, 12, 23, 24). Results are still
controversial and some authors argue that
the cranial morphology in subjects with
Class III does not differ from those with
Class I (8, 25). Contradictions in existing
trials results are due to the heterogeneity of
ethnic, race and age diversity of studied
groups and research methods.
In our study, the digital measurement
values of skeletal Class III were compared
between sexes and we did not find statistically significant differences. The literature
reports significant differences between the
sexes regarding the position of the upper
lip (26).
In the present study, statistically significant differences between the two age ranges, prepubertal (<14 years) and pubertalpostpubertar (>14 years) of skeletal Class
III, showed emphasis of several characteristics together with the growth dentalmaxillofacial complex, at the studied population. Thus, we found 3 parameters that
showed the emphasis of the vertical growth
of the mandible (decreased NGoAr angle),
mandible prognathia (decreased S-Ar:ArGo ratio) retrusion of the upper lip (decreased Ls-NsPog' distance). Previous studies show that specific Class III parameters
are established from an early age and are
maintained throughout the skeletal growth
(6, 27), and puberty is of significant importance on the mandibular length growth,
the maximum pubertal beeing extended in
subjects with class III (10, 28).
Our study presents anthropometric importance in the population studied and has
clinical-diagnostic value for a correct specialized orthodontic or surgical therapy (4).
CONCLUSIONS
The present study demonstrates that the
Class III malocclusion shows a distinct pathology, characterized by a series of specific
cephalometric parameters which set the diagnosis and indicate the morphological dentalmaxillofacial segment that should be orthodontically corrected as early as possible.
Our study has particular importance for
practitioners and suggests the necessity in
their involvement in identifying at an early
age these serious skeletal discrepancies.
Future similar studies may extend to other
types of skeletal malocclusion affecting
facial esthetics and dental health of our
young population.
1159
Georgeta Zegan et al.
REFERENCES
1. Jacobson A, Evans WG, Preston CB, Sodowsky PL. Mandibular prognathism. Am J Orthod 1974;
66:140-171.
2. Ishii H, Morita S, Takeuchi Y, Nakamura S. Treatment effect of combined maxillary protraction and
chin cap appliance in severe skeletal class III cases. Am J Orthod Dentofacial Orthop 1987; 92:304-312.
3. Sara M. Wolfe EA. Craniofacial growth of class III subjects six to sixteen years of age. Angle Orthod
2011; 81(2):211-216.
4. Balcoş C, Dănilă I, Săveanu I. Orthodontic treatment need of the students of the Faculty of Dental
Medicine from Iasi. Rev Med Chir Soc Med Nat, Iaşi 2011; 115(1): 37-39.
5. Chang H, Kinoshita Z, Kawamoto T. Craniofacial pattern of class III deciduous dentition. Angle
Orthod 1992; 62:139-144.
6. Chen F; Terada K. Longitudinal evaluation of the intermaxillary relationship in class III malocclusions. Angle Orthod 2006; 76(6):747-753.
7. Choi HJ; Kim JY. Cephalometric characteristics of Korean children with class III malocclusion in the
deciduous dentition. Angle Orthod 2010; 80(1):86-90.
8. Chung CJ; Jung S. Morphological characteristics of the symphyseal region in adult skeletal class III
crossbite and openbite malocclusions. Angle Orthod 2008; 78(1):28-43.
9. Jeong M, Hwang CJ. Semi-longitudinal study on growth development of children aged 6 to 16. Korean J Orthod 1999; 29:51-72.
10. Reyes BC, Baccetti T, McNamara JJr. An estimate of craniofacial growth in class III malocclusion.
Angle Orthod 2005; 76(4):577-584.
11. Proff P, Will F. Cranial base features in skeletal class III patients. Angle Orthod 2008; 78(3):433-439.
12. Mouakeh M. Cephalometric evaluation of craniofacial pattern of Syrian children with class III malocclusion. Am J Orthod Dentofacial Orthop 2001; 119:640-649.
13. Chen SK, Chen YJ, Yao CCJ, Chang HF. Enhanced speed and precision of measurement in a computer-assisted digital cephalometric analysis system. Angle Orthod 2004: 74(4):501-507.
14. Steiner CC. Cephalometrics for you and me. Am J Orthod 1953; 39:729-755.
15. Tweed CH. The Frankfort mandibular incisor angle (FMIA) in orthodontic diagnosis, treatment planning and prognosis. Angle Orthod 1954; 24:121-169.
16. Jarabak J, Fizzel J. Technique and treatment with light wire edgewise appliances. St Louis, Mo: Mosby; 1972.
17. Panagiotidis G, Witt E. Der individualisierte ANB-Winkel. Fortschr Kieferorthop 1977; 38:406-416.
18. Iwasaki H, Ishikawa H, Chowdhury L, Nakamura S, Ilida J. Properties of the ANB angle and the Wits
appraisal in the skeletal estimation of Angle’s class III patients. Eur J Orthod 2002; 24:477-483.
19. Mitani H. Prepubertal growth of mandibular prognathism. Am J Orthod.1981; 80:546-553.
20. Guyer EC, Ellis IE, McNamara JAJr, Behrents RG. Components of class III malocclusion in juveniles
and adolescents. Angle Orthod 1986; 56:7-30.
21. Mitani H, Sato K, Sugawara J. Growth of mandibular prognathism after pubertal growth peak. Am J
Orthod Dentofacial Orthop 1993; 104:330-336.
22. Miyajima K, McNamara JAJr, Kimura T, Murata S, Iizuka T. An estimation of craniofacial growth in the
untreated class III female with anterior crossbite. Am J Orthod Dentofacial Orthop 1997; 112:425-434.
23. Sanborn RT. Differences between the facial skeletal patterns of class III malocclusion and normal
occlusion. Angle Orthod 1955; 25:208-222.
24. Galão C. Estudo de algumas medidas cefalométricas da classe III. Ortodontia 1980; 13:166-174.
25. Ellis E, McNamara JAJr. Components of adult class III malocclusion. J Oral Maxillofac Surg 1984;
42:295-305.
26. Anderson D, Popovich F. Relation of cranial base flexure to cranial form and mandibular position.
Am J Phys Anthropol 1983; 61:181-187.
27. Graber TM, Vanarsdall RL. Orthodontics currents principles and techniques. 2nd ed. Philadelphia:
Mosby-Year Book; 1994.
28. Kuc-Michalska M; Baccetti T. Duration of the pubertal peak in skeletal class I and class III subjects.
Angle Orthod 2010; 80(1):54-57.
1160