Serial extraction in orthodontic

Prof. Maher A. FoudaProf. Maher A. Fouda
Prepared by:- Bilal A.M.Prepared by:- Bilal A.M.
Faculty of dentistry-MansouraFaculty of dentistry-Mansoura
university - Egyptuniversity - Egypt

A 13-year-old girl
who did not have
the benefit of serial
extraction and early
treatment

A 13-year-old girl
who had the benefit
of serial extraction
and early treatment.

SERIAL EXTRACTION
The combination of preventive therapy
and orthodontics, is essential during
development and the guidance of the
child's dentition towards an adult
occlusion of good quality. It is for this
reason that child dental care and
orthodontics form an entity.
Only with such basic thinking in mind
is it possible to guide development
towards an optimal form and function
of the dentition.

So, the question of serial extraction arises
when the first permanent tooth erupts and,
if it is to be considered, it is during the
period of six to twelve years of age.
Serial extraction is an interceptive procedure
designed to assist in the correction of hereditary
tooth-size Jaw-size discrepancies. It improves the
alignment of the teeth when they emerge into the
oral cavity.

It does not replace mechanotherapy but if it
done properly in carefully selected patients,
it reduces treatment time, the cost of
treatment, discomfort of the patient at the
sensitive teenage period and time lost by
the patient and parents.

Both Hotz and Kjellgren stated that the goal of
serial extraction is to create a modified occlusion
with less than the normal complement of teeth in
order to assure better function,improved aesthetics
and stability throughout life.
(Brouwer, 1986)
The principle of early treatment, associated with the
extraction of primary teeth followed by the removal of
permenant teeth firstly described by Robert Bunon in
1743. Kjellgren's term " Serial extraction" which he
introduced in 1929, is somewhat dangerous because it
tends to create a misconception of simplicity. It is , in
fact, misleading . It implies that there is nothing more
involved than the more extraction of teeth. So, Hotz's
term (1947) "Guidance of Occlusion" is better.

CRITERIA FOR SERIALEXTRACTION
(lndications)
1. Class I malocclusions are ideal for serial
extraction because the dentition is basically in a
favorable relationship and successful treatment is
possible with a minimum of mechanotherapy.
2. A true,relatively severe, hereditary tooth-size
jaw-size discrepancy. (10 mm or more).
3. A mesial step mixed dentition developing into a
class I permenant relationship.
4. A minimal overjet relationship of the incisor
teeth.
5. A minimal overbite of incisors.

6. A Facial pattern that is class I maxillary
mandibular alveolodental protrusion.
7. A Facial pattern that is class II maxillary
alveolodental protrusion (with extraction of the two
maxillary first premolars).
8. Class I maxillary mandibular prognathism with
severe crowding.
9. Class II maxillary prognathism.(Serial extraction
in class II malocclusions aids in the correction of
tooth-size jaw-size discrepancy but not necessarily
in the correction of a class II relationship).

10. In high angle cases (steep mandibular plane),
associated with
severe crowding.
11. Premature loss of anterior teeth B,C.
12. Lingual eruption of anterior teeth.
13. Unilateral deciduous canine loss and shift to
the same side.
14. Ectopic eruption.
15. Ankylosis.
16. Abnormal resorption.

CONTRA INDICATIONS OF SERIAL EXTRACTION
1. Class III malocclusions are not suitable for serial
extraction.
2. A Facial pattern that is class I maxillary
mandibular alveolodental retrusion.
3. A Facial pattern with Class II mandibular
alveolodental retrusion.
4. Class I maxillary mandibular retrognathism.
5. Class II mandibular retrognathism.
6. In low angle cases (low mandibular plan angle).
7. Class I malocclusion cases where the lack of
space is slight and the teeth are only slightly
crowded.

8. When there are teeth missing from the dental
arch.
9. Deep overbite cases.
10. Anterior openbite cases.
11. When fixed appliance cannot be used to avoid
arch collapse.

OBJECTIVES OF SERIALEXTRACTION
1- Serial extraction allows teeth to become aligned
when they emerge into the oral cavity rather than
to stay in a crowded unfavorable condition for
several years.
2- It makes the treatment easier and the
mechanotherapy less complicated.
3- It makes the treatment less extensive and
shorter in time(especially during the teenage
period).
4- To avoid loss of labial alveolar bone.

5- To reduce malposition of individual teeth.
6- It encourages eruption of permenant teeth in
favorable direction.
7- To minimize unfavorable sequalea as root
resorption ,decalcification and soft tissue
proliferation that so ofen accompany protracted
period of appliance therapy.
8- It reduces the cost of treatment.

EXAMINATION AND EVALUATION
Serial extraction should never be initiated without
a comprehensive diangosis, which is established
by a thorough examination and evaluation of the
diagnostic records.

I-Clinical Analysis
The hereditary tooth-size jaw-size discrepancies
must be differentiated from crowded dentitions
resulting from factors that are more enviromental
in nature. It is quite likely that true hereditary
crowding will be treated with the aid of
extractions and, if discovered early , with serial
extraction. On the other hand, crowding resulting
from enviromental factors may be treated without
extractions.

A-Hereditary crowding
The signs of a true hereditary tooth-size jaw-size
discrepancy may be outlined as follows:
1. Maxillary mandibular alveolodental protrusion
without interproximal spacing.
2. Crowded mandibular incisor teeth.
3. A midline displacement of the permanent
mandibular incisors, resulting in the premature
exfoliation of the primary canine on the crowded
side.
4. A midline displacement of the permanent
mandibular incisors with the lateral incisors on
the crowded side blocked out, usually lingually
but occasionally labially .

5. A crescent area of external resorption on the
mesial aspect of the roots of the primary
canines , caused by crowded permanent lateral
incisors.
6. Bilateral primary mandibular canine exfoliation,
resulting in an uprighting of the permanent
mandibular incisors ; this, in turn, increases the
overjet and/or the overbite .
7. A splaying out of the permanent maxillary or
mandibular incisor teeth due to the crowded
position of the unerupted canines.
8. Gingival recession on the labial surface of the
prominent mandibular incisor.
9. A prominent bulging in the maxilla or mandible
due to the crowding of the canines in the

10. A discrepancy in the size of the primary and
permanent teeth, reducing the leeway space .
11. Ectopic eruption of the permanent maxillay
first molars, resulting in the premature exfoliation
of the primary second molars ; this indicates a
lack of development in the tuberosity area.
12. A vertical palisading of the permanent
maxillary first, second, and third molars in the
tuberosity area, again indicating a lack of jaw
development.
13. Impaction of the permanent mandibular
second molars in the absence of treatment.

B- Enviromental crowding :
It may result under thefollowing condition :
1. Trauma.
2. Iatrogenic treatment.
3. A discrepancy in the size of individual
teeth.
4. A discrepancy between mandibular tooth
size and maxillary
tooth size and maxillary tooth size.
5. An aberration in the shape of teeth.

6. An aberration in the eruptive pattern of the
permanent teeth.
7. Transposition of teeth.
8. Uneven resorption of primary teeth.
9. Rotation of teeth.
10. Suppression of primary teeth.
11. Premature loss of primary teeth resulting in
the reduction of arch length due to subsequent
drifting of permanent teeth .
12. A reduction of arch length due to interproximal
caries in the primary teeth.
13. Emergence sequence.
14. Exfoliation sequence of primary teeth.
15. Prolonged retention of primary teeth.

II Diagnostic records :
A complete set of diagnostic records is required
including , intaoral radiographs , cephalometric
radiographs , facial photographs , study models
and intraoral slides of the dentition.
1- Intraoral radiograph
A complete series of periapical radiographs or a
panoramic radiographs must be taken for the
following:
1. Protection of the patient and the orthodontist.
2. Detection of congenital absences of teeth .
3. Detection of supernumerary teeth.
4. Evaluation of the dental health of the
permanent teeth,
especially the first molars.

5. Detection of pathologic conditions in the early
stages.
6. Assessment of trauma to the teeth after an
injury.
7. Detection of evidence of a true hereditary
tooth-size jawsize discrepancy such as the
resorptive pattern on the mesial of the roots of
the primary canines.
8. Determination of the size, shape, and relative
position of unerupted permanent teeth.
9. Evaluation of the eruptive patterns of
unerupted permanent teeth.
10. Calculation of the total space analysis .

11. Detection of root resorption before, during,
and after treatment.
12. Evaluation of third molars before, during, and
after treatment.
13. Final appraisal of the dental health after
orthodontic treatment.
14. Determination of dental age of the patient by
assessing the length of the roots of permanent
unerupted teeth and the amount of resorption of
primary teeth.

Dental Age Analysis
Dental age is determined by two ways ; tooth
eruption and root formation. Dental age, assessed
particularly by root length, is an essential
requirement in the decision of a serial extraction
program. Serial extraction too early in the primary
dentition can delay the eruption of permenant
teeth. In case of early extraction of the primary
molars, fanning reported an initial spurt in eruption
of premolars. This leveled off and the tooth then
remained stationary erupting later than its
antimare with a normally shedded primary tooth.

If serial extraction is initiated with extraction of the
primary canines, the length of the roots of the
premolars is not an important consideration. If,
however, one is contemplating initiating serial
extraction by the removal of the primary first
molars, then the length of the root of the premolar
is an important consideration and guide the
commencement of the procedure.
The relative eruptive rates of the permenant
canines and first premolars influence the decision
as to which primary teeth one should extract.

If an examining periapical radiographs one
observes the mandibular first premolar crown
ahead of the permenant mandibular canine crown,
the premolar with less than half its root formed,
and the madibular incisors crowded, then the
primary canine should be extracted to relieve the
crowding. The primary molar should be left until
the first premolar has attained half its root length.
If on examining the radiographs one observers
the premolar crown even with the canine crown,
the premolar with half its root formed, and an
alveodental protrusion, then the primary first molar
should be extracted to encourage the emergence
of its successor.

2- Cephalometric radiographs :
Sound orthodontic treatment, including
serial extraction, is based on the intelligent
use of cephalometric radiographs and
analysis. They are utilized for the following :
1. Evaluation of craniofaciodental
relationships prior to treatment.
2. Assessment of the soft tissue matrix.
3. Calculation of tooth-size jaw-size
discrepancies.
4. Determination of mandibular rest
position.
5. Prediction of growth and development.

6. Monitoring of skeletodental relationships
during treatment.
7. Detection of pathologic conditions before,
during, and after treatment.
8. Assessment of trauma after facial injuries.
9. Study of relationships prior to ,
immediately following, and several years
after treatment for the purpose of long-range
improvement in treatment planning.
10. Classification of facial patterns.

proportional facial analysis
The proportional facial analysis is basically a
classification of facial patterns based on the
Steiner and the Merrifield and Tweed
cephalometric analysis , and
especially on the counterpart
analysis of Enlow .
It includes an evaluation of the
following relationships:
Anterior cranial base (1,2).
Posterior cranial base (2,3).

Cranial base angle (1,2,3).
Ramus of the mandible (3,4).
Corpus of the mandible (4,5).
Gonial angle (3,4,5).
Nasomaxillary complex
(6,7,8,9).
Maxillary dentition (10,11).
Mandibular dentition (12,13).

To determine the relationship between the
facial structures and the cranium, between
the maxilla and the mandible, between the
maxilla and the maxillary dentition, between
the mandible and the mandibular dentition,
between the maxillary dentition and the
mandibular dentition, and between the soft
tissue profile and the underlying hard tissue
structures.

3- facial photographs :
Ortial , (1995) stated that; the vertical skeletal pattern is
afactor that makes malocclusions with the same tooth
arrangment very different.
Facial patterns play an extremely important role in serial
extraction in the following :

1. Evaluation of craniofacial relationships prior to
treatment.
2. Assessment of soft tissue profile.
3. Proportional facial analysis.
4. Total space analysis.
5. Occlusal curves analysis.
6. Monitoring of treatment progress.
7. Study of relationships prior to , immediately following ,
and several years after treatment to improve treatment
planning.

American Board of Orthodontics requirements for facial photographs.
(From American Board of Orthodontics:
Specific instructions for candidates, St Louis, 1998, The Board.)
Requirements:
-Quality, standardized facial photographic prints either in black and
white or color
-Patient's head oriented accurately in all three planes of space and in
the Frankfort horizontal
plane
-One lateral view; facing to the right; serious expression; lips closed
lightly to reveal muscle
imbalance and disharmony

-One anterior view; serious expression
-Optional: One lateral view and/or one anterior view with
lips apart
-Optional: One anterior view, smiling
-Background free of distractions
-Quality lighting revealing facial contours, with no shadows
in the background.
-Ears exposed for purpose of orientation
-Eyes open and looking straight ahead; glasses removed

4- Intraoral p h o t o g r a p h s :
Treatment could be performed without the use of
color
transparencies of the dentition. However, they are
extremely valuable for one reason: to record, for
future reference, the structure of the enamel. This is
particularly important when bands or brackets are
removed.

It is quite possible that the orthodontist
could be accused of producing decalcification,
or an imperfection in the enamel, that was
already present before treatment was begun.
Intraoral photographs add the dimension of
color to the records, which aids in assessing and
recording the health or disease of the teeth and
soft tissue structures.

5- Study models:
Study models provide a three- dimensional record
of the dentition and are essential for many
reasons. They are used to :
1. Claculate total space analysis.
2. Assess and record the dental anatomy.
3. Assess and record the intercuspation.
4. Assess and record arch form.
5. Assess and record the curves of occlusion
(occlusal curves analysis).

6. Evaluate occlusion, with the aid of articulators .
7. Measure progress during treatment.
8. Detect abnormalities .
9. Provide a record before , immediately after,
and several years following treatment for the
purpose of studying treatment procedures.
10. Assess in detetmination of 3 , 4 , 5 by mixed
dentition analysis .

Mixed dentition analysis
This analysis aids in determination of cases
indicated for serial extraction. The purpose of
this analysis is to evaluate acurately as possible,
future crowding in the permenant dentition using
a prediction of mesiodistal width of the
permenant canines and premolars. The value
obtained is added to the already known
measurement of the permenant incisors . This
represents space required . The resulting
calculation is subtracted from the arch
circumference of space available. If the result is
significantly negative, future crowding can be
predicted.

Many methods of mixed dentition analysis have
been suggested. They are :
1-Nance Analysis (1947) :
He found that the combined width of the primary
canine and primary molars averages l .7mm
more in the mandibular arch and 0.9mm more in
the maxillary arch, than the combined widths of
their successors measure.
2-Moyers Analysis (1963) :
He found that the approximated size of the
canines and premolars is calculated by
measuring the mesiodistal width of erupted
permenant incisors. Prediction is done on the
propability charts.

3- Sim's Analysis (1972) :
He pointed out that various tooth size charts
indicated that the mesiodistal width of a first
premolar is nearly one third of the combined
mesiodistal widths of the cuspid and bicuspids
in a quadrant. This hold true for the maxillary
and mandibular arches.
N.B : The width of the first premolar determined
radiographically using the long cone parallel
techinque.

4- Johnson-Tanaka- A n a l y s i s (1974) :
They found that half the mesiodistal width
of the mandibular incisors measured on
the cast plus 11 mm. For the maxillary
arch and 10.5mm. for the mandibular arch
equal to the mesiodistal width of unerupted
cuspid and bicuspids.

5 - A b o u l - A z m - F o u d a ' s A n a l y s i s
(1989):-
It is a new equation for predicting the combined
mesiodistal width of unerupted cuspid and
bicuspids.
- For the upper arch :
mesiodistal dimension of cuspid and bicuspids
=(buccolingual dimension of first permenant
molar X 2) - 1 .
- For the lower arch :
mesiodistal dimension of cuspid and bicuspids
=buccolingual dimension of first - permenant
molar X 2.

Categories Of Serial Extraction
The best results can be achieved when
disturbing factors are minimal. Flexibility in
thinking is necessary, diagnosing every case
individually, and each time the patient is seen it
needs to be carefully assessed.

There are three categories which are:
1. A period of interceptive guidance.
Extending approximately 5years, from age
7.5 to 12.5 . This consists entirely of the
guidance of occlusion, including serial
extraction, and is the most ideal service
that one can provide. The results are
achieved without multibanded
mechanotherapy.

2. An initial period of interceptive guidance,
extending approximately 4 years , from age
7.5 to 11.5 , plus a second period of
multibanded treatment extending
approximately lyear(from 11.5 to 12.5).
3- An initial period of interceptive treatment,
extending approximately 1 year, from 8.5 to
9.5 plus a period of interceptive guidance
extending approximately 2 years,from 9.5 to
11.5, and a second period of multibanded
treatment extending approximately 1.5 years,
from 11.5 to 13.

GENERIAL TECHNIQUES FOR SERIAL EXTRACTION
1-Hotz Method:
It is the basic procedures for serial extraction :
1.Extraction of deciduous canines. This is generally
followed by spontaneous correction of the position
of the permanent incisors.
2. Extraction of deciduous first molars, to encourage
early eruption of first premolars.
3. Extraction of first premolars.
This method proposed by Hotz, (1947).
(Brouwer, 1986)

2- Nance Method:
Nance showed that the difference of leeway space
may vary from 0 to 4 mm. Between the deciduous
and permenant teeth in the mixed dentition.
When we see that there is a significant crowding ,
we begin our planned program of guided
extraction in three stages :
1. Removal of deciduous canines at 8 - 9
years:
The immediate purpose is to permit the eruption
and optimal allignment of the lateral incisors,
prevention of the eruption of the maxillary lateral
incisors in lingual cross-bite or the mandibular
incisors in lingual malposition.

But this improvement is gained at the expence of
space for the permenant canines vitally important
is the fact that the correct lateral incisor position
prevent the mesial migration of the canines into
severe malposition that will
require treatment with mechanotherapy later.
2- Removal of the first diciduous molars at 9-
10 years:
This is done to accelerate the eruption of the first
premolars ahead of the canines. Generally
speaking the first deciduous molars are removed
12 months after the deciduous canines. Thus,
first deciduous molars removal would be when
the roots of the first premolars have half root
calcification.

Sometimes the removal is done earlier in the
mandibe than in the maxilla to enhance the early
eruption of first premolars.
3- Removal of the erupting first premolars :
The purpose of this step is to permit the canine to
drop distally into the space created by the
extraction. The extraction of first premolar
happens more frequently in the maxillary arch
than in the mandibular arch.

The reason is the eruption sequence, which upper
first premolar eruption is ahead of lower one.
Sometimes, while removing first deciduous molars
we enucleate the unerupted first premolars (usually
in the lower arch).Sometimes , it becomes
necessary to remove the mandibular second
deciduous molars to permit the first premolars to
erupt.

3 - Tweed's orthodontic guidance:
When diagnosis shows that a discrepancy
between tooth and jaw-size, and the age of the
patient is between 7 - and 8 - years ,
serial extraction is performed as following :
1- At age 8 years; all 4 deciduous first molars
are extracted. If the permenant incisors are not
severely crowded, the deciduous canines
mantained in position so that the eruption
of the permenant canines will not be hastened.

2. When the first premolars erupt to about the
level of the crest of the alveolar mucosa they are
extracted. The deciduous canines are also
extracted at this time. If the first premolars are
extracted 4 to 6 months prior to the eruption of the
permenant canines, the permenant canines
usually shift posteriorly and erupt in the space left
by the extracted first premolars.
The second deciduous molars should be
maintained in the arch to avoid mesial shifting of
first permenant molars.

CLASS 1 TREATMENT
The classic procedure of serial extraction
has been the elimination of the primary
canines, primary first molars, and permanent
first premolars.This has been the most
popular and widely used procedure.

serial extraction in treatment of different cases
of class I :
A- CASES WITH ANTERIOR DISCREPANCY :
CROWDING
- Treatment Procedure:
1. Extraction of the primary canines:

If we found severe crowding, a developing Class I
malocclusion, a favorable overjet overbite relation
of the incisor teeth, and an ideal orthognathic
facial pattern. On examining the one radiographs,
can note a crescent pattern of resorption on the
mesial of the primary canine roots.

This is an indication of a true hereditary tooth-
size jaw-size discrepancy. It signifies that the
first premolars are emerging favorably, ahead
of the permanent canines. None of the
unerupted permanent teeth have reached one
half root length. Because of this, we would not
extract the primary first molars. The primary
canines should be extracted to relieve the
incisor crowding.

2. Extraction of the primary first molars :
The incisor crowding has improved ; the overbite
has increased, and the extraction site is reduced
in size. The radiographs reveal that the first
premolars have reached one half root length. It is
now time to extract the primary first molars to
encourage the eruption of the first premolar teeth.

3. Extraction of the first premolars :
Since the permanent canines have developed
beyond one half root length, indicating that they
are prepared to accelerate their eruption, the
premolars are extracted.

4. Multibanded treatment:
To treat the typical result of serial extraction, a
relatively deep overbite with a distoaxialinclination
of the canines, a mesioaxial inclination of the
second premolars, a Class I molar relationship, an
improved alignment of the incisors ; and residual
spaces at the extraction sites.

5. Retention :
When multibanded mechanotherapy is completed.

A, Lateral view. B, Anterior view. C, Occlusal view of
mandibular dentition 18 years after treatment.

B. CASES WITH ANTERIOR DISCREPANCY ;
ALVEOLODENTAL PROTRUSION:
- Treatment Procedure :
1. Extraction of the primary first molars:

When we found a minor irregularity of the incisor teeth ,
the crowns of the first premolars and canines are at the
same level, the canines are beyond one half root length
and are erupting faster than the premolars, the first
premolars have one half their root length developed, the
primary first molars should be extracted toaccelerate
eruption of the first premolars.

2. Extraction of primary canines and first
premolars:
When the first premolars have emerged
sufficiently, they areextracted along with whatever
primary canines remain. No effort
is made to prevent lingual tipping of the incisor
teeth since the objective is to reduce the
alveolodental protrusion.

3. Multibanded treatment:
The dentition is aligning itself. Very little
mechanical treatment will be required.

4. Retention :
Retention in the mandible is less crucial since
there was minimal irregularity before treatment.

C. CASES WITH MIDDLE DISCREPANCY :
IMPACTED CANINES :
When the tooth-size jaw-size discrepancy is
severe , causing premature exfoliation of the
primary canines and the radiograph will reveal
that the first premolars are ahead of the canines

in eruption and have attained one half their root
length, we must begin with extraction of the primary
first molars. The impacted permanent maxillary
canines may cause severe splaying of the maxillary
incisors to such an extent that the lateral incisors do
not contact the primary canines .

In this situation extract the primary first
molars to encourage the first premolars to
emerge as early as possible. The canines
will then have space to migrate away from
the apices of the incisors and begin their
eruption into the oral cavity. In this
instance we should be concerned more
with incisor irregularity.

2. Extraction of the first premolar:
Since the permanent canines have developed
beyond one half root length, indicating that they
are prepared to accelerate their eruption, the

D- CASES NEED PREMOLAR ENUCLEATION:
Advantages:
1- Enucleation of premolars can be used to
minimize the severity of crowding in arch-length
deficiency cases.
2- It can minimize the severity of the malocclusion
simplifying appliance therapy if proper diagnosis
and good surgical technique are employed.
3- The mandible tends to rotate in a
counterclockwise manner following enucleation of
four first premolars without appliance therapy.

4- Enucleation offers autonomous adjustment of
the mandibular incisors and root positioning of
mandibular cuspids.
5- Enucleation cases usually require fewer
traumatic surgical procedures and less
supervision by the orthodontist.
(Ingram, W76)

I. CASES NEED ENUCLEATION IN THE
MANDIBLE :
l. Extraction of the primary first molars and
enucleation of the mandibular first premolars :

If it is evident that the canines will emerge into the
oral cavity ahead of the first premolars, we can
extract the primary first molars and enucleate the
first premolars. This will encourage distal
migration of the canines as they erupt.

2. Extraction of the primary maxillary
canines and maxillary first premolars:
In the maxilla the first premolars usually emerge
before the canines. Therefore enucleation is
less likely to be indicated.

I I . CASES NEED ENUCLEATION IN THE
MAXILLA AND MANDIBLE
1. Extraction of primary canines and primary first
molars and enucleation of the first premolars:
On occasion the canines in both the maxilla and
the mandible will erupt prior to the first premolars.
We must extract the primary canines and first
molars and enucleate the first premolars.

E. CASES IN WHICH ENUCLEATION IS AVOIDED :
When the permanent canines are erupting ahead
of the first premolars and if there is an opportunity
to place multibanded appliances at the completion
of serial extraction, enucleation of the premolars
should be avoided.

When the first premolars have attained
one half their root length, the primary first
molars should be extracted.

2. Extraction of the primary maxillary canines,
maxillary firs premolars, and primary
mandibular second molars:
Some 6 to 9 months later , when the emerging
mandibular first premolar appears to be obstructed
by the mesial contour of the primary second molar,
we should extract the offending tooth. However,
this sequence is usually not necessary in the
maxillary dentition.

3. Extraction of the mandibular first premolars:
When these teeth emerge sufficiently, they are
extracted.

CLASS II TREATMENT PLAN
Serial extraction can be an important part of
Class II treatment , it must be stressed that ,
serial extraction does not replace
mechanotherapy.

TREATMENT PLAN
1. Initial period of interceptive treatment:
During this period, which may extend 1 to 1.5
years, the primary first molars and maxillary
first premolars are extracted as early as
possible. This provides space for retraction of
the permanent maxillary anterior teeth. Bands
are placed on the premanent maxillary incisors
and first molars and on the primary second
molars. With a maxillary edgewise arch and an
anterior high pull headgear, the maxillary
incisors are retracted, intruded, and torqued.
This reduces the overjet and overbite.

The primary objective of the initial period of
interceptive treatment is to decrease the
vulnerability of and possible injury to the maxillary
incisors. In the mandible the primary canines are
extracted to relieve the permenant incisor
crowding. Later the primary first molars and
premolars are extracted . To prevent collapse of
the mandibular incisors and accentuation of the
curve of occulsion, bands are placed on the
permanent incisors and first molars and on the
primary second molars. Progress is made from
round leveling arches to ideal edgewise arches.

2. Period of interceptive guidance:
During this period retention appliances are worn
and serial extraction is continued. The parents are
informed that appointments will be required every
3 months for assessment of growth and
development with the aid of diagnostic records
and that teeth will be extracted periodically as
indicated.
3. Second period of active treatment:
When all the permanent teeth have emerged, a
multibanded appliance is placed and the Class II
is corrected.

Serial extraction in treatment of defferent cases of
class II :-
A. CASES WITH ANTERIOR DISCREPANCY:
MAXILLARY PROTRUSION
1. Extraction of primary maxillary first molars:
In this instance the patient has a maxillary
alveolodental protrusion with everything else
normal. The objective is to retract the maxillary
incisor teeth and relieve the anterior discrepancy
as early as possible.

To do this, space must be created in the first
premolar area. To encourage the early
eruption of the premolars, the primary first
molars are extracted. In the maxilla we can
get away with this when the root is nearly one
half its length, but not in the mandible. While ,
if there is mandibular incisor crowding,
we must extract the primary mandibular first
molars.
(Dugoni, 1992).

2. Extraction of the primary maxillary canines
and maxillary first premolars:
The primary canines may interfere with the final
emergence of the first premolars. This is
especially true when a directional force high pull
headgear has been utilized to begin the retraction
of the maxillary incisors. Therefore , canines
should be extracted as well as the premolars.
Space is now provided for complete retraction of
the maxillary incisors with the high pull headgear.
Because there is no lack of space in the
mandibular dentition, development is progressing
in a normal manner.

3. Extraction of the primary second molars:
Treatment time may be accelerated somewhat by
extraction of the primary second molars when the
second premolars have reached at least one half
root length. This step is not always necessary.
In both the maxillary and the mandibular
dentition, when the second premolars begin their
emergence and the permanent second molars
are about to emerge, the second period of
multibanded edgewise mechanotherapy is
initiated.
5. Retention.

B. CASES WITH MIDDLE DISCREPANCY •
IMPACTED MAXILLARY CANINES:
1. Extraction of primary maxillary first molars :
The primary first molars are extracted to allow
early eruption of the first premolars. This , in turn,
creates space for the permanent canines to move
away from the roots of the permanent lateral
incisors.
2. Extraction of the maxillary first premolars.
By mechanotherapy.
4. Retention.

C. CASES WITH POSTERIOR DISCREPANCY :
ECTOPIC ERUPTION IN THE MAXILLA :
1. Extraction of the primary maxillary second
molars:
A lack of development in the tuberosity area will
create the posterior discrepancy that causes the
permanent first molars to erupt ectopically in a
forward position leading to premature exfoliation
or , at least , resorption of the primary maxillary
second molars. If the primary molars have not
exfoliated, they should be extracted at this time.
This will create a Class II relationship of the
permanent first molars. The mandibular
dentition is relatively normal.

2. Extraction of the primary maxillary first
molars:
To encourage early emergence of the first
premolars, the primary maxillary first molars
should be extracted.
canines if still present and the maxillary
first premolars.
4. Multibanded edgewise appliance.
5. Retention.

D. CASES WITH ANTERIOR DISCREPANCY :
MAXILLARY PROTRUSION &MANDIBULAR
INCISOR CROWDING .-
molars and primary mandibular canines:
The purpose of these extractions is to
encourage early emergence of the first
premolars and to promote favorable alignment
of the mandibular incisors. This in aggrement
with Dugoni, (1995).

canines, maxillary first premolars, and
primary mandibular first molars:
With extraction of the maxillary first premolars,
space has now been provided for retraction of
the maxillary incisors by the directional force,
high pull, J hook headgear .

3. Extraction of the mandibular first premolars:
It is possible that the primary mandibular second
molars will have to be extracted to allow for
emergence of the first premolars. Then the first
4. Second period of active treatment,
multibanded edgewise appliance.
5. Retention

E. CASES WITH MIDDLE DISCREPANCY:
MAXILLARY AND MANDIBULAR CANINE AND
PREMOLAR CROWDING :
molars:
The purpose of this extraction is to encourage
eruption of the first premolars and relieve the
middle discrepancy. Because of root length
development it may not be wise to extract the
primary first molars in the mandible at this time.

2. Extraction of the primary maxillary canines,
maxillary first premolars , and primary
mandibular first molars.
3. Extraction of the primary maxillary second
molars and mandibular second premolars :
The purpose of extracting the mandibular
premolars is to relieve the middle discrepancy
and allow for the mesial migration of the
permanent first molars.
4. A. Second period of active treatment,
multibanded edgewise appliance.
5. Retention.

THE TREATMENT OBJECTIVES AFTER
SERIAL EXTRACTION
They are:
1. Closure of residual extraction spaces.
2. Improvement of the axial inclination of
individual teeth.
3. Correction of rotations.
4. Correction of midline discrepancy.
5. Correction of a residual overbite.

6. Correction of a residual overjet.
7. Correction of crossbites.
8. Refinement of the intercuspation of individual
teeth.
9. Improvement and coordination of arch form.
10. Correction of the Class II relationship in
some Class II patients. When the serial
extraction phase has been completed, the
multibanded appliance is placed and treatment
is initiated utilizing the traditional concepts of
the orthodontic treatment.

PROPABLE OBSTACLES
1. Sometimes removal of premolars does not
stimulate the distal migration of canines. In this
case, surgical exposure and retraction of canines
is indicated.
2. Large restorations or caries in second
premolars may indicate their extraction instead of
first premolars.
3. Congenital missing of one or more premolar
may create a problem and require a change in
the convential serial extraction procedure.
4. The removal of premolars in the mandibular
arch may enhance the overbite tendency. This
will need holding arch or bite-plate.

5. The ultimate status of third molars should be
considered. Sometimes extraction of premolars
will enhance normal eruption of the third molars.
6. The timing of tooth removal: It is not always
possible to see the patient at the optimal time for
teeth removal.
7. It is much difficult to close spaces in the
mandibular arch in the premolar area than in the
maxillary arch , so, some orthodontists are
willing to accept minor irrigularties of the lower
incisors and remove only the maxillary first
premolars.

REFERENCES
Ingram A.H. "Premolar Enucleation" Angle Orthod. 1976.
Joondeph D.R., et al. " Second Premolar Serial Extraction".
Am. J. Orthod., 1976.
Wagers L.E. " Preorthodontic Guidance And The Corrective
Mixed Dentition Treatment Concept". Am. J. Orthod., 1976.
Graber T.M., Swain B.F. " Current Orthodontic Concepts
And Techniques". W.B. Saunders Company 1984.
Brouwer H. "Child Dental Care And Serial Extraction"
British J. Orthod. 1986 Me.
Little R.M., et al. "Serial Extraction Of First Premolars -
Postretention Evaluation Of Stability And Relapse". Angle
Orthod. 199).

Dugoni, S.A. "Mixed Dentition Treatment" Am. J. Orthod. 1992 June.
Reading JF. " Dento-Alveolar Disproportion" Aust. Orthod. J., 1993
Mar.
Proffit W.R., Fields H.W. "Contenporary Orthodontics“ 1994. (Mosby
Year Book).
Dugoni , S.A. , "Mixed Dentition Case Report" Am. J. Orthod. 1995
March.
Ortial JP. "Vertical Dimension And Therapeutic Choices". Am. J.
Orthod. Dentofacial Orthop., 1995 Oct.

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