Orthodontic Mechano Treatment of Ectopic Eruption of the
Permanent Mandibular Incisors of Iraqi Children (Early Mixed
Dentition) A Longitudinal Clinical Study
Wisam Wahab Sahib Al-hamadi
College of Dental Medicine, University of Babylon, Hilla, Iraq.
MJ B
Abstract
Fixed orthodontic appliances used to treat cases of bilateral distal ectopic eruption of the
permanent mandibular central incisors. A total of 27 Iraqi children at average age of 7.5-years old
selected for the study. 15 patients (9 females and 6 males) treated by extraction of the retained primary
teeth and placement of fixed appliances for alignment and repositioning of the mandibular permanent
incisors. while 7 patients (3 females and 4 males) treated by extraction of the corresponding retained
primary tooth and later alignment of the mandibular incisors, and 5 patients (2 females and 3 males)
treated by extraction of the relevant permanent lateral incisors and the corresponding retained primary
teeth.
The result of present study showed significant difference between the first method of early
mechanical orthodontic and another two methods of later mechanical orthodontic treatment regarding
time consuming, esthetic and complexity factors. No significant differences clinically between gender
groups and sides in the jaw. clinically the first method was easier and faster if compared with other
methods of later orthodontic mechanical which may need a serial extraction, expansion or other
orthodontic intervention that increase the complexity of cases treatment.
‫الخالصة‬
‫تناولت هذه الدراسة السريرية الطويلة استخدام جهاز التقويم الثابت لمعالجة حاالت متعددة من التطرف الجاابي لياغوا القوا ال الداةم اة‬
‫ ار عولجاوا بقلال‬6‫ أبثا و‬9 ‫ ماري‬15 .‫تام تقسا مهم وباار و اور‬. ‫ فل عراق أعمارهم ضامن السايل سانوات‬27.‫األمام ة السفل ة‬
‫ب نما عاول‬.. ‫األسنان اللين ة السفل ة ات العالقة واالستخدام الميكر لجهاز التقويم الثابت وعادة القوا ل السفل ة األمام ة لوضعها الصاي‬
‫أما الخمساة اخرارين‬.‫ ور) بقلل األسنان اللين ة ات العالقة بالمشكلة فقط ومن ثم إجراء العالج التقويم ف ما بعد‬4‫ إبار و‬3( ‫ منهم‬7
.‫ ور) تم عالجهم بقلل األسنان اللين ة السفل ة ات العالقة باوضافة للقوا ل السفل ة الجابي ة الداةم ة‬3‫ إبار و‬2(
‫أظهاارت النتاااة السااريرية أن هناااك ارااتالف ي اار ب ا ن المجموعااة األول ا الت ا عولجاات بالجهاااز التقااويم الثاباات ميكاارا‬
‫ ماا لام‬.‫والمجموعت ن األرري ن اللتان تم التدارل التقويم لهام ف ماا بعادن مان ح اة فتارة العاالج وتعق اده والنتااة الجمال اة لعمل اة التقويم‬
‫ساريريا ابات الطريقاة العالج اة باالساتخدام الميكار‬. ‫تسجل أية ارتالفات سريرية ب ن الجنسا ن أو الجاباا األيمان واأليسار للفاف السافل‬
‫للجهاز التقويم الثابت أسهل وأسرع وأفضل إ قوربات بنتااة الطاريقت ن األراري ن قاد تيتااج إلا متوال اة قلال منتوماة أو توسا ل الفاف‬
.‫السفل أو تدارالت عالج ة إضاف ة‬
‫ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬
tooth into a position normally occupied
by another tooth dental transposition
[3].
The prevalence of ectopic
eruption of a permanent tooth
associated with resorption of the
adjacent primary tooth varies from 2%
to 12% depending on the tooth
involved [17]. O'Meara observed in a
study of 315 cases of ectopic eruption
involving central and lateral incisors
and first permanent molars, a
Introduction
ental eruption has been defined as
the movement of a tooth from its
original position of development to its
functional position in the oral cavity
[1]. In some cases, deviations from the
normal pattern of eruption may occur
leading to a change in the final
position of the tooth, which is called
ectopic eruption [2,16]. O'Meara stated
that the most extreme case of ectopic
eruption involves the eruption of the
D
1
frequency of 12% to 52%, where 33%
of the cases corresponded to ectopic
eruption of the central incisor, without
predilection to sex or side, the right
side being more frequently involved,
mainly in the cases of the central
incisor [4].
The literature states some
etiologic factors for ectopic eruption of
lateral
incisors:
crowding,
supernumerary teeth and idiopathic
causes [2,15], as well as the premature
loss of the primary canine and the
prolonged
retention
of
the
corresponding primary teeth [5, 6].
O'Meara, who investigated ectopic
eruption of central incisors, did not
give an explanation for the etiology of
such alteration [3]. Two types of
treatments in cases of mandibular
lateral incisor ectopic eruption have
been proposed. The first involves
extraction of the relevant permanent
lateral incisor and the corresponding
retained primary teeth. In cases of
crowding, alignment of the remaining
teeth is performed later [7,14]. The
second type of treatment is extraction
of the corresponding retained primary
tooth and later alignment of the
mandibular incisors. This strategy
once performed in the initial stages of
occlusion development, could provide
enough
space for the correct
positioning
of
the
permanent
canines [4,16].
Materials and Methods
Materials
Sets
of
dental
exam
(QD\England), ray-machine (atrophy \
France),
dental
extraction
sets
(QD\England),
an
orthodontic
edgewise brackets ,arch wires(0.014
mm twist-flex ,0.014 mm round, 0.016
round) {orthomatrix \ USA}, check
and lip retractors (orthomatrix - USA),
lingual fixed retainer (Dentarium Germany), and direct bonding system
(Kerr\USA).
Samples criteria
Average of 7.5-year – old
males and females patients at the early
mixed dentition stage was diagnosed
during routine clinical exam, with
alternation in eruption pattern of the
mandibular central incisors. these teeth
erupted distally to the corresponding
primary teeth, which were
not
normally exfoliated (fig. 1) and had no
signs of physiologic resorption (fig. 2).
The molars in Angle CI I position and
mandibular primary canines in cross
bite.
Excess space was present in the
mandibular arch, and the primary
incisors were slightly flared or
proclined. The diagnosis was ectopic
eruption of permanent mandibular
incisors.
no
crowding
or
supernumerary teeth founded in all
samples.
Methods
Diagnosis done for all cases
selected, The treatment objectives
consisted of extraction of retained
primary teeth first, followed by
alignment of the permanent incisors.
Fifteen days after extraction of
primary central incisors, direct
bonding procedure done to edgewise
brackets were placed on incisors and
primary canines, but not on the
permanent lateral incisors, which was
still erupting or partially erupted.
twist-flex arch wire (0.014 mm orthomatrix) was used for the leveling
Aim of Study
The purpose of this study was
to compare between different treatment
methods in case of bilateral distal
ectopic eruption of both mandibular
permanent central incisors before the
eruption of canines and first premolars,
in order to minimize the collapse of the
dental arch in the anterior region to
avoid crowding and demand for anther
orthodontic treatment.
2
and alignment of the teeth(fig.3). After
2 weeks, it was replaced by a round
(0.014mm-orthomatrix) stainless steel
arch wire to improve alignment. After
a month, (0.016mm-orthomatrix)arch
wire was made and elastic chain were
used to close the Diastema (fig.4). The
treatment time and retention period
required for each treatment method
were as listed at table (1) and (fig. 7
and 8).
In the current cases, ectopic
eruption of the permanent central
incisors was diagnosed, but crowding
and presence of supernumerary teeth
were not present, although slight
spacing was found in the affected arch.
This may be considered an important
factors in the etiology since in the
presence of excess space, teeth may
lose their eruption guidance and could
deviate from the roots of the primary
teeth. Tylor and Hamilton's study
involving 16 cases of ectopic eruption
of the lateral incisor also observed that
in more than half of their sample, the
affected dental arch had sufficient
space to accommodate all teeth [2,15].
Sweet suggests that one of the
factors responsible for the alternation
in the eruption position of the lateral
incisors could be the premature loss of
the primary canine, leading to an
eruption pattern with a distal
orientation [5]. Tylor and Hamilton's
disagree with this suggestion, because
in their sample the canine and the
lateral primary incisor were rarely
absent. In the current cases there was
not premature exfoliation of any
primary tooth, probably due to the
irregular axial inclination of the teeth
on the anterior segment that
contributed to the positive discrepancy,
enabling the eruption of the central
incisors [2,15].
The prolonged retention of the
corresponding primary teeth was a
condition present in the current cases
of patients. Rose pointed to this factors
as the possible cause of ectopic
eruption, but Tylor and Hamilton's
consider it to be the result of the
ectopic eruption of its successor [6,11].
Bradley and bell concluded that it was
not clear whether the prolonged
retention of the primary teeth is the
result or the cause of the alternation of
eruption pattern of the permanent
successors. They state that the lack of
a correct intra osseous positioning of
Result and Discussion
Two months after beginning
treatment, a normal inclination of the
incisors and correction of the cross bite
of the primary canines were obtained
(fig. 5 and 6). After the complete
eruption of permanent lateral incisors,
the fixed appliance is completely
removed and replaced by lingual fixed
retainer. until eruption of the
permanent canines.
The permanent mandibular
incisors normally develop lingually to
the corresponding primary teeth [8,12].
Their lingual eruption usually lead to
non exfoliation of the primary teeth, a
normal situation not requiring any
intervention, since their anterior
migration will occur by the action of
the tongue musculature, concurring
with the growth and development of
the mandibular anterior segment(9,14).
in this study, this was not the pattern of
eruption found, as the incisors showed
a distal direction of eruption in relation
to their corresponding primary teeth.
This lead to the diagnosis of ectopic
eruption, which was in agreement with
study by Schaad and Thompson [10].
The etiological factors for this
eruption alternation, specifically of
lateral incisors, have been cited by
some
authors
as
crowding,
supernumerary teeth, idiopathic causes
[2,12], premature loss of the primary
canine [5], and prolonged retention of
the corresponding primary teeth [6,15].
3
the teeth would not cause adequate
pressure on the primary root to
stimulate resorption. Thus delayed
exfoliation would be a secondary
characteristic [4,13].
The treatment for this cases of
bilateral ectopic eruption of the
mandibular central incisors was the
extraction of the primary teeth with
prolonged retention
followed by
realignment and leveling of the
mandibular anterior segment as
showing in (fig. 8). This strategy is in
agreement with Bradley and Bell. The
recommended correction in the initial
stages of the malocclusion, as it
provides a better chance for the correct
positioning of the permanent canines
and first premolars, and apart from
favoring a good prognosis, also makes
faster and easier [4,13], if compared
with other methods of later mechanotherapy that may need for serial
extraction or expansion…etc, that
means increase complexity of cases.
Table (1) and (fig. 7) demonstrate the
differences in orthodontic treatment
time of three methods.
2- Taylor GS, Hamilton MC. Etopic
eruption of lower lateral incisors.ASD
J Dent Child 1971; 38: 282-284.
3- Fleming PS, Johal A, DiBiase AT.
Managing malocclusion in the mixed
dentition: six keys to success. Part 1.
Dent Update. 2008 Nov; 35(9): 60710.
4- O′Meara WF. Ectopic eruption
pattern in selected permanent teeth.J
Dent Res 1962; 41: 607-616.
5- Schopf P. Indication for and
frequency of early orthodontic therapy
or interceptive measures. J Orofac
Orthop. 2003 May; 64 (3): 186-200.
6- Bradley EJ, Bell RA. Eruptive
malpositioning
of the mandibular
permanent lateral incisors: Three case
reports.Pediatr Dent 1990; 12: 380387.
7- Keski-Nisula K, Hernesniemi R,
Heiskanen M, Keski-Nisula L, Varrela
J. Orthodontic intervention in the
early mixed dentition: a prospective,
controlled study on the effects of the
eruption guidance appliance. Am J
Orthod Dentofacial Orthop. 2008
Feb;133 (2): 254-60.
8- Bennett N. The science and practice
of dental surjery.Oxford: Oxford
university Press,1990.Apud in: Deery
E.The relashionship of crowding of
crowding to the eruptive position of
the lower permanent incisors.Br J
Orthod 1993; 20:333-337.
9- Gellin ME, Haley JV. Managing
cases of over-retention of mandibular
primary
incisors
where
their
permanent successors erupt lingually.
AsDC J Dent Child 1982;49:118-122.
10Schaad
TD,
Thompson
HE.Extreme ectopic eruption of the
lower permanent lateral incisors. Am J
Orthod 1974; 66: 280-286.
10Schaad
TD,
Thompson
HE.Extreme ectopic eruption of the
lower permanent lateral incisors. Am J
Orthod 1974; 66: 280-286.
11Russell
KA.
Orthodontic
treatment in the mixed dentition. J Can
Conclusions
a- Later mechano therapy
makes the demand for serial extraction
or expansion or any other orthodontic
intervention therapy occurring.
b- In the presence of ectopic
eruption of the mandibular central
incisors, diagnosis and intervention in
the early mixed dentition is
recommended.
cOrthodontic
treatment
performed before the eruption of the
permanent canines may reduce the
time and complexity of the procedure,
favoring an adequate of the dentition
References
1- Massler M,Schour I. Studdies in
tooth
development:Theories
of
eruption.Am J Orthod 1941; 27: 552556.
4
Dent Assoc. 1996 May; 62 (5): 41821.
12- Sweet CA.Ectopic eruption of
permanent teeth. J Am Dent Assoc
1939; 26: 574-579.
13- Steegmayer G, Komposch G.
Early orthodontic treatment of the
deciduous dentition. The therapeutic
potentials and indications. Fortschr
Kieferorthop. 1993 Aug; 54 (4): 172-8.
14- Rose JS. Atypical paths of
eruption:Some cases and effects.Dent
Pract 1958;9:69-76.
15- Shapira Y, Kuftinec MM. The
ectopically erupted mandibular lateral
incisor. Am J Orthod 1982; 82: 426429.
16- Boute S, Kleutghen J. Early
orthodontic treatment. Rev Belge Med
Dent. 1989; 44 (3): 39-53.
17- Stahl F, Grabowski R. Orthodontic
findings in the deciduous and early
mixed dentition--inferences for a
preventive strategy. J Orofac Orthop.
2003 Nov; 64 (6): 401-16.
5
Figure1 Showing the retained mandibular
deciduous teeth before treatment.
Figure 2 Periapical radiograph showing ectopic
eruption of mandibular incisors and retained
deciduous teeth
Figure 4 Placement of power chain between
mandibular incisors to close the diastema. With
arch wire 0.16 mm.
Figure 3 Direct bonding of fixed appliance after
extraction of retained deciduous teeth. With
twist-flex arch wire.
Figure 6 Final repositioning and case is ready
for retention procedure.
Figure 5 Final repositioning of mandibular
incisors excluding the permanent lateral incisor
(Still Erupting). With arch wire 0.18 mm.
6
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