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CEPHALOMETRIC FEATURES OF CLASS II
MALOCCLUSION
ARTICLE · SEPTEMBER 2014
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4 AUTHORS, INCLUDING:
Georgeta Zegan
Universitatea de Medicina si Farmacie Grig…
42 PUBLICATIONS 11 CITATIONS
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Loredana Golovcencu
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Available from: Georgeta Zegan
Retrieved on: 23 January 2016
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222 Volume 4 • Issue 3 July / September 2014 •
Orthodontics
CEPHALOMETRIC FEATURES OF CLASS II MALOCCLUSION
Georgeta ZEGAN1 , Cristina Gena DASCĂLU2 , Loredana GOLOVCENCU3 ,Daniela ANISTOROAEI3
1Assoc. Prof., PhD, Surgery Dept., Faculty of Medical Dentistry, “Gr. T. Popa” U.M.Ph. Iaşi2Lecturer, PhD, Preventive Medicine and Interdisciplinarity Dept., Faculty of Medicine, “Gr. T. Popa” U.M.Ph. Iaşi3Lecturer, PhD, Surgery Dept., Faculty of Medical Dentistry, “Gr. T. Popa” U.M.Ph. IaşiCorresponding author: [email protected]
Abstract
The study aimed at identifying the quantitative and
relational features of the bone, dental and soft tissuestructures, for class II malocclusion, with its divisions onsexes and intervals of age, by means of 53 digitalcephalometric measurements. 84 conventional lateralcephalometric radiographies were divided into twogroups, according to ANB angle (60=class II and 24=classI), while the divisions of class II were clinically diagnosedaccording to the overjet (24=division 1 and 36=division 2).Application of Kolmogorov-Smirnov, t-Student andLevene tests of program SPSS, version 16.0, evidencedstatistically signicant differences between the two skeletalclasses (28 characteristics), between the divisions of classII (10 characteristics), between sexes (6 measurements) andbetween the age intervals (28 measurements). The
multitude of cephalometric characteristics of thismalocclusion requires a special orthodontic therapy.
Keywords: conventional lateral cephalometric radiography,class II malocclusion, digital cephalometric measurements
1. INTRODUCTION
Class II malocclusion is characterized by askeletal difference of the maxillary bases vs thebasis of the skull, produced through maxillaryprotrusion and/or mandibular retrusion. The
molar and canine sagital relation is distalized,evidencing – according to the classication ofAngle - two clinical entities: division 1, withproclination of the upper incisors and increasedoverjet; division 2, with retroclination of theupper incisors and minimum overjet [1].
Introduction of cephalometric radiography, in1934, by Hofrath in Germany and by Broadbent,respectively, in the USA, permitted study ofmalocclusions by evidencing skeletaldiscrepancies. Several authors made known thecephalometric analyses they had performed forthe diagnosis of skeletal malocclusions, including
various angular, linear and percentualmeasurements. The literature of the eld provides
numerous cephalometric studies, developedcomparatively on skeletal classes I and II, onsexes, age, clinical divisions, dentitions anddifferent populations [2–8]. The results aredebatable, if considering the size and selectioncriteria of the experimental groups, ethnicheterogeneity, races and diversity of theinvestigation methods applied [9–11].
The present investigation aimed at establishingthe cephalometric features of class II skeletalmalocclusion, on an sample of non-orthodonticallytreated patients of north-east Romania. Thestudy intended to compare the cephalometricmeasurements of skeletal class I with those ofclass II, and to identify the quantitative andrelational differences of the bone, dental and softtissues structures between the two classes, thetwo divisions of class II, sexes and intervals ofage.
2. MATERIALS AND METHOD
The retrospective study was conducted on 84conventional lateral cephalometric radiographiestaken in the Orthodontics Clinic at “St. Spiridon”Emergency Universitary Hospital of Iassy,Romania, between January 2005 - Decembrer2013. The criterion of cephalograms selectionwas their good technical quality. All radiographieswere made on a STRATO-X orthopantomograph(11.8% magnication).
The sample of patients was formed of 33 boys
and 51 girls, with ages between 7-26 years (meanage 14.33±5.758 years), having had no orthodontic
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International Journal of Medical Dentistry 223
CEPHALOMETRIC FEATURES OF CLASS II MALOCCLUSION
treatment. The sample was divided into twogroups, according to the skeletal class (ANBangle): cases=60 patients (22 boys and 38 girls)with class II skeletal malocclusions (ANB>4°);control=24 patients (11 boys and 13 girls) with
class I skeletal malocclusions (ANB≤4°). Thedivisions of class II have been clinicallydiagnosed, on considering the incisive sagitalrelation: division 1 (n=24: boys=9 and girls=15)with increased overjet (>2mm), and division 2(n=36: boys=13 and girls=23) with minimumoverjet (<2mm). The patients affected withgenetic and endocrine syndroms have not beenaccepted. The study was conducted according tothe regulations of the Helsinki Declaration of1975, revised in 2000, and patients’ informedconsent was obtained.
The anatomic contours of the conventionallateral cephalometric radiographies were drawnon tracing paper, with a 0.5 mm in diameterpencil. The tracing paper was scanned (MFDCanon Pixma MP280) in digital format (JPG File)and introduced in the computer (Asus Eee PC1015BX) [12]. Digital cephalometric analysis wasmade on an Onyx CephTM (Onyx CEPH 2.7.18(174) Image Instruments GmbH, Chemnitz,
Germany). The radiological cephalometriclandmarks were localized directly with themouse pointer on the image of the digitalizedpaper of the screen, on using the zoom, foravoiding identication errors (g. 1). For eachimage, 53 cephalometric measurements (28angles, 21 distances and 4 percent values) weremade, according to Steiner, Tweed and Jarabak
analyses [13–15] (g. 2). Measurements wereperformed under identical calibration conditionsof the size of the cephalometric images. All dataprovided by analyses were extracted and storedin electronic format (Microsoft Ofce Excel
97-2003 Worksheet). The protocol included aquantitative evaluation of the basis of the skull,maxillary, mandible, and of the relations betweenthem, as well as with the dental and soft tissues.
Fig. 1 - Cephalometric landmarks: sella (S), nasion(N), E-point (E), L-point (L), porion (Po), condylion
posterior (ppCond), articular (Ar), orbital (Or),gonion (Go), menton (Me), gnathion (Gn), pogonion
(Pog), D-point (D), anterior nasal spine (ANS),A-point (A), A-point acc. to Jarabak (AJ), prosthion(Pr), infradental (Id), B-point (B), upper incisor apex(Ap1u), upper incisor crown tip (1u), upper incision
(I1u), lower incision (I1l), lower incisor crown tip(1l), lower incisor apex (Ap1l), anterior point of the
occlusal plane (AOcP), posterior point of the occlusalplane (POcP), pronasal (Pn), upper labral (Ls), lower
labral (Li) and pogonion soft tissue (Pog’).
Fig. 2 - Cephalometric parameters (a) acc. Steiner: 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 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.
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Statistical analysis was made with programSPSS, version 16.0 (SPSS Inc., Chicago, IL), forWindows. The numerical values were calculatedaccording to the parameters of descriptivestatistics (mean value, standard deviation (SD),
error of standard deviation (SEM), minimumand maximum value). To compare the measuredvalues of the two skeletal classes, divisions, sexesand age intervales, the Kolmogorov-Smirnov,t-Student and Levene tests for the equality ofvariances were applied, value p≤0.05,
corresponding to the 95% condence interval,being considered statistically signicant.
3. RESULTS
Table 1 evidences statistically signicantdifferences between the two skeletal classes forthe mean values of angular and linearmeasurements, and of the bone, dental and softtissues structures ratios.
Variables
Cases with skeletal class II
(n=60)
Control with skeletal class I
(n=24) p value
Mean SD SEM Mean SD SEM
Angular (°)SNA 83.1065 4.23026 0.54612 80.7038 3.09720 0.63221 0.014**
SN-GoGn 32.6233 7.65389 0.98811 28.7871 5.25848 1.07338 0.027*
FMA 27.8272 6.82642 0.88129 22.4987 5.35326 1.09273 0.001***
MeGo-OcP 17.2708 5.20074 0.67141 13.8633 3.85878 0.78767 0.005**
NSAr 122.4365 5.62944 0.72676 125.6046 4.79078 0.97791 0.017**
ArGoMe 128.8025 8.09690 1.04531 122.7921 5.41522 1.10538 0.001***
NGoMe 75.7782 5.86638 0.75735 70.7229 4.60316 0.93962 0.000***
SN-GoMe 35.0682 7.61173 0.98267 30.1100 5.17420 1.05618 0.004**
Sum 395.0682 7.61173 0.98267 390.1100 5.17420 1.05618 0.004**NSGn 68.7418 4.35942 0.56280 66.7404 3.09286 0.63133 0.044*
NAPog 168.5328 4.48051 0.57843 176.7813 1.97550 0.40325 0.000***
Max1-NA 19.7573 9.66171 1.24732 24.6783 7.37017 1.50443 0.027**
Mand1-NB 27.3725 6.00689 0.77549 20.4154 6.85486 1.39924 0.000***
FMIA 56.5245 7.10917 0.91779 64.9429 6.79298 1.38661 0.000***
Z 68.5663 10.82260 1.39719 75.6438 7.68934 1.56958 0.005**
Linear (mm)
S-L 48.5842 9.43642 1.21824 53.1608 5.57675 1.13835 0.008**
Go-Me 62.1487 6.52827 0.84280 66.8333 7.90436 1.61347 0.026**Wits 3.3862 3.23626 0.41780 -0.3163 3.73168 0.76173 0.000***
1u-NA 4.3577 2.28440 0.29491 5.5350 2.13288 0.43537 0.033*
1l-NB 5.7268 2.18188 0.28168 3.6167 1.37529 0.28073 0.000***
Holdaway 3.8662 2.60529 0.33634 2.0646 1.48163 0.30244 0.002***
1u-NPog 9.7533 4.47429 0.57763 6.0708 2.51376 0.51312 0.000***
1l-NPog 3.5032 3.23229 0.41729 0.4429 2.72691 0.55663 0.000***
Ls-PnPog’ -1.8217 3.37497 0.43571 -4.2250 2.93086 0.59826 0.003**
Li-PnPog’ -0.6248 3.47953 0.44920 -2.6613 2.94068 0.60026 0.013**
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CEPHALOMETRIC FEATURES OF CLASS II MALOCCLUSION
Ratio (%)
AFH:PFH 75.8658 10.18556 1.31495 80.9875 8.93843 1.82455 0.034*
GoMe:NS 88.6752 9.12110 1.17753 93.9050 10.62951 2.16974 0.026*
SGo:Nme 66.9525 6.22924 0.80419 69.7362 4.44223 0.90677 0.050*
Table 1 – Descriptive statistics and signicant differences between groups for cephalometric measurements(* p<0.05; ** p<0.01; *** p<0.001)
As a function of the two divisions of class II,statistical differences were observed for the mean
values of angular and linear measurements andof the bone and dental structures ratios (table 2).
VariablesDivision 1 (n=24) Division 2 (n=36) p value
Mean SD Mean SD
Angular (°)
II 120.7717 13.65901 130.0667 11.21347 0.006**
Max1-NA 23.4033 11.21191 17.3267 7.71748 0.016**
Max1-SN 106.3567 9.78103 100.5344 7.98892 0.014**
IMPA 97.9517 6.75621 94.1136 6.16053 0.027*
Mand1-MeGo 98.1308 6.69558 94.1136 6.16053 0.020*
Linear (mm)N-S 72.1029 3.59887 69.0172 5.72875 0.022*
Wits 4.8717 2.98930 2.3958 3.04318 0.003**
1u-NA 5.2590 2.08728 3.7569 2.23733 0.011**
1u-Npog 12.1196 3.98931 8.1758 4.10970 0.001***
Ratio (%)
GoMe:NS 85.3583 9.93585 90.8864 7.92434 0.020**
Table 2 – Descriptive statistics and signicant differences between division of skeletal class II forcephalometric measurements (* p<0.05; ** p<0.01; *** p<0.001)
Highly statistically signicant differenceswere observed between the two sexes of class II
divisions for the mean values of the angular
dental and linear measurements of some bonestructures (table 3).
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Variables Division 1 (n=24) Division 2 (n=36)
Male
(n=9)
Female
(n=15) p value
Male
(n=13)
Female
(n=23) p value
Mean±SD Mean±SD Mean±SD Mean±SD
Angular (°)IMPA 102.03±7.39 95.50±5.15 0.018* 94.35±4.94 93.97±6.85 0.865
Mand1-MeGo 102.03±7.39 95.79±5.17 0.023* 94.35±4.94 93.97±6.85 0.865
Linear (mm)
S-Ar 35.87±2.19 34.23±2.37 0.106 36.05±4.40 31.97±4.26 0.010*
Go-Me 64.05±7.06 59.93±6.84 0.173 65.43±6.47 60.99±5.55 0.037*
N-Go 117.23±8.23 112.13±7.19 0.125 114.90±13.10 107.78±7.57 0.046*
S-Go 79.33±7.08 78.15±6.30 0.675 80.40±13.15 73.03±7.28 0.037*
Table 3 – Descriptive statistics and signicant differences between gender division of skeletal class II forcephalometric measurements (* p<0.05)
Table 4 indicates statistical differences of theage intervals for the mean values of angularand linear measurements, and of the ratios of
bone, dental and soft tissues structures for classII divisions.
Variables Division 1 (n=24) Division 2 (n=36)Age≤14 years
(n=15)
Age>14 years
(n=9)
p value Age≤14 years
(n=23)
Age>14 years
(n=13)
p value
Mean±SD Mean±SD Mean±SD Mean±SD
Angular (°)SN-GoGn 32.98±6.32 31.66±9.88 0.691 35.45±7.00 27.85±6.73 0.003*
FMA 28.26±5.44 26.01±7.80 0.414 30.12±6.72 24.51±6.81 0.022*
MeGo-OcP 17.83±4.84 17.27±5.93 0.804 18.49±4.66 14.45±5.50 0.025*
ArGoMe 129.07±9.01 128.86±8.51 0.956 131.84±6.97 123.06±6.041 0.001*
NGoAr 53.57±5.25 53.74±4.23 0.933 54.04±4.92 50.07±3.74 0.017*
NGoMe 75.50±6.38 75.11±6.97 0.891 77.79±4.86 72.98±5.41 0.010*
SN-GoMe 34.86±6.46 34.53±9.30 0.918 37.98±6.97 30.50±7.07 0.004*
Sum 394.86±6.46 394.53±9.30 0.918 397.98±6.97 390.50±7.07 0.004*
NAPog 168.25±5.33 166.27±3.64 0.339 168.02±4.02 171.31±3.75 0.022*II 118.68±7.40 124.24±20.46 0.346 126.01±10.32 137.24±9.15 0.003*
Max1-NA 23.88±8.22 22.59±15.54 0.791 19.37±8.05 13.70±5.68 0.032*
Max1-SN 106.82±8.81 105.58±11.74 0.771 102.82±7.94 96.48±6.52 0.020*
Max1-SN 106.82±8.81 105.58±11.74 0.771 102.82±7.94 96.48±6.52 0.020*
Mand1-NB 30.68±5.11 25.61±6.89 0.051* 28.22±5.17 23.265.50 0.011*
Linear (mm)
Ar-Go 47.03±5.90 51.55±7.10 0.107 43.53±5.72 52.01±8.83 0.001*
PFH 47.03±5.90 51.55±7.10 0.107 43.53±5.72 52.01±8.83 0.001*
AFH 63.68±7.56 63.84±7.61 0.959 60.31±4.19 64.76±6.63 0.043*
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CEPHALOMETRIC FEATURES OF CLASS II MALOCCLUSION
N-Go 113.15±8.30 115.53±7.21 0.483 106.33±6.66 117.47±12.03 0.001*
S-Go 77.73±7.01 80.04±5.54 0.410 71.62±7.05 82.89±11.35 0.001*
N-Me 116.15±9.99 118.30±10.13 0.618 111.38±7.04 117.19±8.83 0.037*
Wits 4.28±2.65 5.85±3.40 0.220 1.56±3.31 3.87±1.77 0.010*
Pog-NB 2.57±0.96 2.43±1.08 0.745 1.76±1.43 3.50±2.22 0.007*1l-NPog 4.13±2.91 2.95±4.25 0.427 4.28±2.76 1.76±3.19 0.018*
Ls-NsPog’ -0.83±2.96 -1.71±4.19 0.555 -1.43±2.84 -3.72±3.70 0.045*
Li-NsPog’ 0.68±2.93 -0.70±3.43 0.302 -0.12±3.08 -2.96±3.92 0.022*
Ratio (%)
AFH:PFH 74.06±6.34 81.69±14.73 0.172 72.25±8.65 80.29±10.27 0.017*
SAr:ArGo 75.73±9.32 64.05±13.93 0.022* 75.19±11.96 68.76±8.91 0.101
SGo:NMe 66.97±3.46 68.08±7.23 0.617 64.44±6.49 70.57±6.10 0.009*
Table 4 – Descriptive statistics and signicant differences between age interval division of skeletal class IIfor cephalometric measurements (* p<0.05)
4. DISCUSSION
The present research was focused oncomparing class I and II cephalometricmeasurements, for identifying the quantitativefeatures and relations of the bone, dental and softtissues structures of class II malocclusion with
its divisions on sexes and age intervals. Theskeletal class was identied by angle ANB,accepted in literature as an index of skeletaldiscrepancies [16, 17]. Class II divisions wereclinically identied, according to the overjet, inagreement with some other studies [6,18] yet noadditional variables have been introduced, as inthe case of other works [2], for not complicatingtoo much the statistical analyses.
The results obtained on the basis of a largediversity of digital cephalometric measurements
permitted to establish the characteristics of classII malocclusion in an original manner. Thus,starting from the highly statistically signicantdifferences observed between the two skeletalclasses, class II was characterized by 28measurements (15 angular, 10 linear and 3percentual): (a) sagital angular skeletal of themaxillary and temporo-mandibular joint vs thebasis of the skull, of the growth pattern and ofthe convexity angle; (b) vertical angular skeletalof the pattern of mandibular growth and of the
occlusal plane vs the mandibular one; (c) sagitalangular dental-skeletal of the maxillary and
mandibular incisors; (d) angular of the soft tissueprole; (e) linear skeletal of skull anterior basis,of the mandible and of the A-O distance vs theocclusal plane; (f) linear dental-skeletal of themaxillary and mandibular incisors; (g) linear ofthe lips; (h) percentual of the anterior facialheight and posterior facial height and of thesizes of the mandible and of skull anterior basis.Previous studies on class II malocclusionevidenced only sagital dental-skeletal features ofthe skull basis length, position of the maxillary,mandible and upper and lower incisors, and ofthe growth patterns [3-5, 19-21].
The present study established 10 cephalometricmeasurements (5 angular, 4 linear and 1percentual), which differentiated between thetwo divisions of class II: (a) sagital angulardental-skeletal of the maxillary and mandibular
incisors; (b) linear skeletal of the anterior basisof the skull and of distance A-O vs the occlusalplane; (c) linear dental-skeletal of the maxillaryincisor; (d) percentual of the size of the mandibleand of the anterior basis of the skull. Previousstudies on class II divisions were mainly orientedon the vertical facial dental-skeletal characteristics[6, 7, 10, 11, 22]. The results obtained showed sexdifferences for class II divisions (6 measurements:2 angular dental and 4 linear manibular), as welldifferences between the age intervals (28
measurements: 14 angular, 11 linear and 3percentual). To this end, the contradictions
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observed comparatively with the conclusions ofprevious studies may be due to the ethniccharacteristics and age of the subjects underanalysis [2, 8, 23, 24].
5. CONCLUSIONS
The present study evidences the large varietyof cephalometric features of class II malocclusionand of its divisions on sexes and age intervals inthe sample studied, which calls for a specic andindividualized orthodontic therapy of eachpatients suffering from it.
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