The need for extraction in orthodontics
Choice of teeth for extraction
Maxillary Incisors . indication , contraindication , case report
mandibular incisors . Indication , contraindication , case report + vid
Canines. indication , contraindication , case report
First premolars . indication , contraindication , case report +vid
Second premolars . indication , contraindication , case report +vid
Maxillary First molar . indication , contraindication , case report
Maxillary second molar. indication , contraindication , case report
mandibular First molar. indication , contraindication , case report
mandibular second molar. indication, contraindication , case report +vid
mandibular third molar. indication , contraindication , case report
Extraction teeth for gaining space in orthodontics
Painless removal of teeth from its socket is
termed as extraction.
Extraction in orthodontics is a therapeutic
method to gain space for relieving crowding.
Extractions in orthodontics remains a relatively
controversial area. It is not possible to treat all
malocclusions without taking out any teeth.
Extractions in orthodontics may be carried
out as an -interceptive procedure during the
mixed dentition as
And as therapeutic extractions carried
out as treatment procedure for
THE NEED FOR EXTRACTION
Extraction of teeth may be required in the following
Arch Length-Tooth Material Discrepancy .
Correction of Sagittal Inter arch Relationship .
Extraction for the Relief of crowding : must be
A-Condition of the teeth
B-Position of the crowding
C-Position of the teeth
Arch Length-Tooth Material
Ideally the arch length and tooth
material should be in harmony with each
If the dentition is too large to fit in the
dental arch without irregularity, it may
be necessary to reduce the dentition size
by the extraction of teeth. It is not
normally acceptable to increase the
dental arch size, because the increased
dental arch dimension would not be
tolerated by the oral musculature.
Arch Length-Tooth Material Discrepancy
Angle believed that all 32 teeth could be
accommodated in the jaws, in an ideal occlusion with
the first molars in a Class I occlusion, with the
mesiobuccal cusp of the upper first molar occluding in
the buccal groove of the lower first molar.
Correction of Sagittal Interarch Relationship
Abnormal sagittal malrelationship such as Class II /Ill
malocclusion may require extraction to achieve a normal interarch
Correction of Sagittal Interarch Relationship
In a Class I malocclusion
it is preferable to extract in both the arches
because it is not advisable to discourage the
development of only one arch more than the
In most Class II cases with abnormal
of the lower teeth and where a point is
upper proclination, normal alignment
abnormally forward relative to the B point,
Class III cases are usually treated by
extracting teeth only in the lower arch
Extraction for the Relief of Crowding
Extraction for the relief of crowding will be governed by:
Condition of the teeth
Grossly carious teeth, root canal treated
teeth and teeth with large restorations are
preferred for extraction over healthy teeth.
Position of the crowding
Crowding in one part of the arch is more readily corrected if extractions
are done in that part rather than a remote area of the arch. However,
incisor crowding is usually relieved by premolar extraction as it gives a
more pleasing appearance and occlusal balance than with incisor
extraction.The first premolar, positioned in the
center of each quadrant, is usually near the area
of crowding whether in the anterior or buccal
CHOICE OF TEETH FOR EXTRACTION
Choice of teeth to be extracted depends un local
conditions which include:
Direction and amount of jaw growth
Discrepancy between size of dental arches and basal
State of soundness, position and eruption of teeth
Degree of dentoalveolar prognathism
Age of patient
State of dentition as a whole
The maxillary central incisors, are rarely extracted as a part of
Indications for maxillary incisor extraction
Unfavorably impacted maxillary incisors.
Buccally or Lingually blocked out lateral incisor with good
contact between central incisor and canines.
If a lateral incisor is crowded in linguo-occlusion with its apex
palatally displaced and if the canine is erupting in a forward
position and is upright or distally inclined, lateral incisor
extraction is indicated (Fig. 21,9A).
Grossly carious incisor that cannot be restored.
Trauma/irreparable damage to incisors by fracture.
Case report central incisors
Extraction of upper central incisors is not common in
orthodontics. However, malformed central incisors with poor
prognosis could be candidates for extraction
Based on clinical and radiographic findings, together with poor
prognosis of upper central incisors and the appropriate size of
lateral incisors with long roots, extraction of the upper central
incisors plus substitution of the lateral incisors was determined as
a suitable treatment
Once the maxillary lateral incisors had been situated in the central incisor
and the maxillary canines in the lateral incisor positions, rectangular
stainless steel arch wires were ligated in place to correct the torque in
both arches and uprighting of the incisors roots.
The active orthodontic treatment was completed in 16 visits over the
course of 19 months. At the completion of orthodontic treatment, the
smile was consonant and the palatally lateral incisors were corrected.
Further aims of treatment including preservation of class I molar
relationships and creation of normal overjet and overbite were also
achieved (Figures 4 and 5).
By the completion of orthodontic treatment brackets were removed and
the patient was referred for prosthodontic alteration of the shape of teeth.
The maxillary lateral incisors were built up with Z100-3M resin
composite to resemble central incisors.
The cusps of canines were grinded.
The distal and labial surfaces were flattened
and reshaped to mimic lateral incisors
and also meet the patient’s esthetic requirements
Indications lower incisor extraction
Angle Class I malocclusion with severe anterior
tooth size discrepancy (greater than 4.5 mm
lower anterior crowding with lack of space for
approximately one mandibular incisor
Dental Class I malocclusions with anterior cross bite due to
crowding and protrusion of the lower incisors.
Malocclusions that tend towards a Class III malocclusion
Moderate Class III malocclusions with anterior cross bite, or
incisors with edge-to-edge relationship, showing a tendency
towards anterior open bite.
Indications lower incisor extraction
Class II Division 1 skeletal and dental malocclusions with
maxillary protrusion and crowding or protrusion of the lower
Cases in which one wishes to avoid increasing intercanine width
in certain malocclusions
As a non-surgical alternative in Class III treatments.
Extraction of lower incisors may be appropriate:
When one incisor is completely excluded from the arch and
there are satisfactory approximal contacts between other
incisors (Figs 21,9B and 21,9C).
Poor prognosis as in case of trauma, caries, bone loss, etc.
Severely malpositioned incisor.
Lower canines are severely inclined distally and lower incisors
are fanned-it is very difficult to correct this condition by
extractions further back
All cases requiring extractions in both arches with severe
overbite and horizontal growth pattern, bimaxillary
crowding, no tooth size discrepancy in the anterior teeth
Deep bite cases with horizontal growth pattern.
All cases which require upper first premolar
extraction while canines arc in a Class I relationship.
Bimaxillary crowding cases with no tooth size
discrepancy in the incisor area.
Cases having anterior discrepancy due to either
sma11 lower incisors or large upper incisors.
A female patient 16 years old reported with a chief
complaint of crowding in lower anterior teeth and
forwardly placed upper anterior teeth. She had a mild
convex pleasing facial profile with competent lips
intra-oral clinical examination showed severe crowding with
mandibular anteriors and mild crowding with maxillary
anteriors and angles Class I molar relation bilaterally. Due to
lower anterior crowding, mandibular left canine was
displaced buccally [Figure 2] Model analysis showed Boltons
ratio, mandibular anterior and overall excess of 5.6 mm and
1.4 mm respectively
The main objective of treatment plan was aimed at relieving
lower and upper anterior crowding without much disturbing
her facial profile. Extraction of mandibular left lateral incisor,
to facilitate proper aligning of 33 was planned which would
gain space enough to relieve lower anterior crowding
The orthodontic treatment was started using PAE 0.022 slot
brackets. 0.014 inch NiTi preformed arch wire was used as initial
wire as to exert very light forces.4 Alignment and levelling was
achieved with subsequent wire sequence (Table 1). After levelling,
using 0.019 x 0.025 SS arch wire space closure was started with
very light forces using tie backs.
Extraction of one incisor in cases of moderate to severe crowding
may even satisfy the requirement of maintaining the arch form and
width without expansion of the inter-canine width
Selecting the best treatment option is often difficult and not all
factors can be achieved, but a proper case selection and proper
decision on which tooth to extract can prove extraction of
mandibular incisor a therapeutic extraction option in severe lower
anterior crowded cases. A systematic treatment approach with
simple mechanics and torque control can aid in achieving a stable
occlusion that is esthetic and in functional harmony
The permanent canines are important teeth and are not
frequently extracted as a part of orthodontic treatment .
Their extraction causes flattening of the face, altered facial
balance and change in facial expression .
When the lower canine is crowded, it is sometimes tempting to
extract this tooth .
However, this is avoided because the approximal contact
between the lateral incisor and first premolars rarely
Mandibular canine may be extracted when it is likely to be
very difficult to align, e.g. when it is excluded from the arch
and the apex is severely malpositioned or when it is
Maxillary canines develop far away from their final
location and have a long path of eruption from their
development site to their final position in the oral cavity.
Therefore, they are not uncommonly impacted or ectopic
and their alignment is difficult, even impossible. Extraction
may be required in such cases.
When maxillary canine is completely excluded from the
arch and approximal contact between lateral incisor
and first premolar is good, extraction of the canine may be
37-year-old female patient with Class II malocclusion and
severe maxillary crowding, including palatally displaced
upper left lateral incisor and buccally displaced upper left
canine (which was
completely blocked out
of the arch), The upper
left canine showed severe
gingival recession and
bone loss. The upper
and lower midlines
were shifted to the left
by 4mm and 2mm,
Case report (1) canine
After extraction of both upper canines, a passive self-ligating
appliance (Damon 3*) was bonded in the upper arch from
second molar to second molar, and an .014" superelastic nickel
titanium archwire was placed for initial alignment and
correction of the lateral incisor crossbite (Fig. 2A).
Two months later, the mandibular arch was bonded from second
premolar to second premolar. After initial lower alignment, an .017" ×
.025" superelastic nickel titanium wire was placed in the upper arch and
an .018" superelastic nickel titanium wire in the lower, and Class III
elastics were prescribed to improve the overjet (Fig. 2B)
Upper .019" × .025" stainless steel posted and lower .018"
stainless steel archwires were placed for finishing, with
bilateral maxillary tiebacks and interarch elastics used to
resolve the remaining lateral open bite (Fig. 2C
After 12 months of treatment, the patient had a bilateral Class II molar
relationship with the upper first premolars in the canine positions (Fig.
3). The treatment achieved the objectives of crossbite correction and
improvement of the patient’s smile and facial esthetics
Case report (2) canine
This 1 3 -year-old female presented to my office with the chief
complaint of crooked teeth (Fig. 1 ) . Her health history was
Analysis of the case showed a Class I dental pattern,
moderate maxillary and mandibular crowding, ectopic maxillary
canines, which were erupting into the mouth from the buccal side,
and a retained primary canine tooth.
The panoramic radiograph ( Fig. 2 ) shows a transmigrated
mandibular canine with its incisal tip resting at the apex of # 2 2
in the mandibular symphysis
Remove the severely impacted tooth and retained primary
canine. Substitute for the missing canine with the ﬁrst premolar.
After the ﬁve treatment options were presented, the decision
was made to remove the transmigrated canine and to substitute for
the loss of the canines with lower ﬁrst premolars.
With a plan for substitution, after removing the impacted
canine and retained primary this case can now be seen as a
straight forward Class II subdivision case. The PowerScope Class
II Corrector (Fig. 3) was planned to provide the force to the lower
anterior for protracting the right premolars and molars into the
substituted position. This is a wire to wire attached Class II cor-
rector. When fully activated, it will consistently provide 260g of
force for the protraction of the right buccal segment.
The Power Scope Class II Corrector
The Power-Scope has several advantages over Class II
elastics for this situation. The compressed NiTi spring will
provide a predominantly horizontal and only slightly
intrusive push-type force mesial to the maxillary molar and
distal to the lower canine position.
lt is the tooth most commonly extracted as part of orthodontic
therapy especially for the relief of crowding because:
• It is positioned near the center of each quadrant of the arch
and is therefore near the site of crowding, i.e. the space gained
by their extraction can be utilized for correction both in the
anterior and posterior region.
• First premolar extraction is the least likely to upset molar
occlusion and is the best alternative to maintain vertical
• The contact between the canine and second premolar is
• First premolar extraction leaves behind a posterior segment
that offers adequate anchorage for retraction of the 6 anterior
1. Tooth of choice for extraction to relieve moderate to severe
anterior crowding in both the arches. In lower arch crowding,
where canines are mesially inclined, spontaneous
improvement in incisor alignment will follow.
2. Correction of moderate to severe anterior proclination
as in Class lJ div 1 or Class I bimaxillary protrusion.
3. In high anchorage cases, first premolar takes precedence
over second premolar as the teeth to be extracted.
4. As a part of serial extraction
Timing of Extraction
The first premolars should not be extracted until all premolars,
permanent incisors and canines have erupted sufficiently for
brackets to be placed on them .
The only exception to this rule is when second premolars cannot
erupt because they are impacted.
The four first premolars shouId not be extracted more than three
weeks before starting active treatment to avoid mesial migration
of posterior teeth and therefore leaving insufficient space for
A 28-year-old male presented with a severe arch-length
discrepancy that had produced severe upper and lower
crowding and labially blocked-out canines .
He had a Class I molar relationship, with the upper and lower
left first molars in crossbite. Cephalometric analysis showed a
Class I, straight skeletal profile and normal incisor
A diagnostic cast setup was performed with the four first
premolars removed to evaluate the projected alignment of the
treated case, assuming that the teeth distal to the extraction
sites would not move forward
The computer-generated Clin Check setup, showing the type
and placement of attachments, was reviewed, modified, and
accepted (3). Because the canines were mesially angulated,
the Clin Check technician was instructed to maintain their root
angles throughout the retraction phase and not to upright the
virtual images as the extraction spaces were closed. The case
required 50 upper and 49 lower aligners; interproximal
reduction was not indicated until the middle and later stages
(21 and 48).
Indications for Extraction
1. When second premolar is completely excluded from the arch following
forwards drift of first molar after early loss of deciduous second molar.
2. Second premolar extraction is preferred in mild anterior crowding
cases as space closure and vertical control is easier after anterior alignment.
The presence of first premolar anterior to extraction site strengthens the
anterior anchorage, thereby facilitating closure from behind.
3. Second premolar extraction is preferred when one wishes to maintain
soft tissue profile and esthetics.
4. Unfavorably impacted second premolars.
5. Grossly carious or periodontally compromised second premolar (Fig.
6. In open bite cases second premolar is preferred for extraction as it
encourages deepening of the bite.
This case report describes the management of 18-year old
female patient with moderate crowding which was
treated with second bicuspid extraction. At the end of
treatment, patient had pleasing profile, good
intercuspation, ideal overjet, and overbite.
The patient had a mild convex profile and symmetric
chief complaint of unesthetic appearance of her smile
Intra orally the patient had a Super Class I molar (SI 11)
relationship and Class I canine on both sides with an overjet of
3 mm and an overbite of 2 mm with mild anterior crowding
and proclination. Her lower right canine and upper right lateral
incisor were in cross bite.
Cephalometric analysis indicated a skeletal Class I relationship
with average growth pattern. The maxillary and mandibular
incisors were mildly proclined with the normal nasolabial
The treatment objectives were:
To correct proclination in both the arches
To correct canine cross bite on the right side
To relieve the crowding
To correct the dental midline
To establish a Class I molar relationship and to maintain a Class I
To obtain ideal overjet and overbite
Orthodontic tooth movement is initiated with 0.022 slot MBT
bracket system in both the arches. 0.016 NiTi was the initial wire,
followed 0.017 × 0.025 NiTi, 0.019 × 0.025 NiTi, 0.019 × 0.025
SS. In the maxillary arch premolars and canines retracted
separate followed by upper anterior retraction. In the mandibular
arch, en masse retraction was carried out.
Extraction of First molars are regarded as the cornerstones of
dental arches and are considered to play a key role in the
establishment of occlusion by Angle. They are usually not
extracted unless otherwise indicated
Extraction of first molars is avoided because:
• It does not give adequate space to relieve anterior crowding.
• Deepening of bite
• Poor a proximal contact between second premolar and second molar
• Second premolar and second molar may tip into extraction space
• Mastication is affected
1. Minimum space requirement for
correction of anterior crowding or mild
2. Grossly decayed/periodontally
compromised molar with poor prognosis
3. Impacted molar-rarely seen.
4. First molars are extracted when they are
grossly decayed or heavily filled. First
permanent molars are highly susceptible to
dental caries, especially during childhood,
immediately after their eruption.
5. Extraction of first molars may be
advantageous in open bite cases as this
may lead to deepening of the bite.
Case report :first molar extraction in four quadrents
A 12-year-old female who presented with a Class I malocclusion on
a Skeletal I base, having an average maxillary–mandibular planes
angle and slightly increased lower facial height.
She had moderate upper and lower crowding, and her first molars
had suffered previous caries.
Treatment was carried out using fixed appliances with reinforced
anchorage and first molars were extracted in all four quadrants.
Oral hygiene and dietary advice. Upper palatal arch to upper second
molars with anterior Nance button.
Extraction of the upper and lower first molars left and right . Upper
and lower fixed appliances using pre-adjusted Edgewise system.
Upper removable wrap around retainer. Lower bonded retainer .
The 4 first molars were extracted to relieve the upper and lower
Three of these teeth were heavily restored and had a poor long-term
Because of this the first molars were chosen instead of first premolars,
which would normally have been the extraction choice, being nearer to
the site of crowding.
Nance button was fitted to bands on the fully erupted second
This would maintain sufficient upper first molar space for
correction of the malocclusion.
The 4 first molars were extracted, the lower second molars banded
and all the remaining teeth were bonded with brackets of
0.022x0.028-inch slot size, Andrew’s prescription
Initial alignment was carried out with upper and lower 0.016-inch
nickel- titanium wires, using stainless Steel tubing to protect the
wires in the extraction sites and lace-backs in all 4 quadrants.
Space was created for the lower lateral incisors by the use of a NiTi
coil spring on a lower 0.018-inch stainless steel round wire.
Subsequently, a 0.012-inch nickel-titanium piggy-back arch wire
was used to align the lateral incisors to the base arch wire.
After full expression of the round nickel titanium wires,
0.018x0.025-inch rectangular nickel titanium wires were placed,
and followed by upper and lower 0.019x0.025-inch stainless steel
working wires to allow final space closure.
Intra-arch nickel-titanium closed-coil springs in all four quadrants
were used for space closure after removal of the upper palatal arch
dead ligatures were used to maintain space closure, whilst upper
and lower 0.014-inch stainless steel wires were placed with minor
bends to allow final tooth positioning.
No inter-arch elastics were used as this
might have reduced the overbite.nickel-
titanium closed-coil springs in all four
Following debond, an upper removable
wraparound retainer was provided for 3
months full-time wear,
6 months night time wear and a lower 0.0175-
inch annealed twistflex retainer was bonded
lingually to the lower incisors and canines.
Case reports extraction first lower molar
The patient, male, 13 years and four months old,
presented for initial examination with the chief
complaint of maxillary incisor protrusion .
He had no sucking or postural habits and had normal
swallowing and speech. Regarding oral health,
His mandibular first molar crowns were significantly
The mandibular second molars and maxillary first
molars showed carious lesions on the occlusal surface
and the presence of dental calculi and gingivitis was
The treatment plan provided for extraction of the
mandibular first molars given their crown destruction,
and need of endodontic treatment and prosthetic
rehabilitation, which would be convenient to avoid in such
a young patient.
In order to maintain mechanics symmetry while not
depending heavily on patient compliance, maxillary first
molar extractions were also planned.
The planned retention consisted of a removable maxillary
retainer and an canine to canine bonded lingual retainer in
the mandibular arch.
Extraction Mandibular second molars
Mandibular second molar is positioned at the end of the dental
arch and therefore is away from the site of crowding. Its
extraction does not help in relieving the crowding, however,
extraction may be indicated in the following cases:
second molar extraction allows distal movement of the first
permanent molar. This provides enough space for premolar
To relieve impaction of mandibular third molar: Since the
position of eruption of third molar is variable, extraction of
second molar is not usually indicated to relieve third molar
To prevent lower incisor crowding: evidence shows that patients
with lower second molar extraction suffered less lower arch
To correct mild to moderate arch length deficiencies
existing with good facial profiles .
Severely carious, ectopically erupted or severely rotated
second molar .
Open bite cases, extraction may help in correcting the
anterior open bite .
Mechanism of extraction of lower second molars
in correction of skeletal Class III malocclusion
To correct anterior crossbites and normalize molar relationship, the
upper arch should move forward and the lower arch backward.
Therefore, extractions in the upper arch may be undesirable.
Extraction of lower teeth mesial to the first molars might aid
correction of the anterior crossbite, but it might also be unfavorable
to the correction of molar relationship. Furthermore, occlusal
interlocking of all eight premolars might increase stability after
orthodontic therapy, which is crucial to treatment of Class III
Extraction of the lower second molars may be a useful treatment
option in the management of severe Class III malocclusion.
However, such treatment should be carried out after detailed
evaluation of third molar position, etc. Although extraction of
lower second molars provides enough space to move the lower
arch backward compared with the extraction of lower third
molars, it has little advantage on relieving crowding in the lower
anterior segments. Therefore, to identify the indication of
extraction of lower second molars in correction of severe Class
III malocclusion is the key for the success of the treatment.
Case Report Lower Second Molar Extraction
A 12-year-old girl presented with an anterior crossbite and a
concave profile . A concave facial profile was present, in
combination with a retrusive maxilla and a protrusive mandible
with no mandibular displacement. Surgical correction of the
skeletal deformity and facial profile was recommended, but the
patient refused the procedure and insisted on an orthodontic
The intraoral examination showed a complete Class III molar
relationship on the right side and a super Class III molar
relationship on the left side. A crossbite of left maxillary second
premolar to right maxillary
second premolar was noted .
A Tip-Edge straight-wire appliance was initiated after extraction of
the lower second molars. After 4 months of Class III elastics, the
anterior crossbite was corrected. Ten months later, a Class I molar
relationship was established. At the end of treatment, the patient
showed a straight profile, normal overbite, and overjet
The superimposition of pretreatment
and posttreatment cephalogram
tracings revealed that the
retroclination of the lower anterior
teeth had changed to a mean of 11.8
degree. A skeletal Class III tendency
remained after the treatment with an
ANB of 0.68 degree , but the facial
profile showed a significant
improvement. A follow-up panoramic
radiograph showed complete eruption
of the lower third molars.
• Success in treatment of the some severe Class III deformity in permanent
dentition could be achieved with fixed appliance and extraction of lower
second molars. • Fixed appliance in combination with extraction of lower
second molars allowed tipping movement of teeth in a larger range and
definite and limited skeletal change. • Remarkable soft-tissue change was
noted after extraction of lower second molars, and concave facial profile
changed to straight profile. • Eruption of lower third molar should be the
follow-up after extraction of lower second molar
MAXILLARY SECOND MOLARS
1. In mildly crowded cases, where less than 3-4 mm
space is required for the labial segments .
2 . To make space for crowded second premolar by
distalization of first molar .
3. When second molar is impacted against first molar
second molar extraction is preferred over extraction of
severely impacted third molar for which there is no
space in the line of occlusion.
Criteria for maxillary second molar
extraction and replacement by third molar :
• The chronologic and dental age of the patient should be past
the average time when second molars would erupt
• Size, shape and root area of third molar should be sufficient
to serve in place of second molar
• Maxillary tuberosity should be insufficient to accommodate
all 3 molars
• If second molar is in buccal occlusion and third molar is
positioned in the tuberosity
• Maxillary third molar in favorable angulation for eruption
• Second molar severely carious with questionable prognosis.
1. Maxillary third molars positioned high in the
2. Poor angulation in relation to second molar
3. Undersized crown or roots
4. Third molar bud is abseent .
Maxillary second molar should be extracted when thethird
molar has migrated sufficiently in the alveolar bone so that the
occlusal surface is approximately level with the vertical
midline of the second molar root.
Advantages of second molar extraction
• Facilitates treatment using removable appliances
• Eruption of third molar is faster
• Prevention of dished-in appearance of the face
• Few residual spaces at the end of treatment
• Good mandibular arch form
• Less chances of relapse
• Increases overbite hence, in openbite cases
• Too much tooth substance is removed in mild crowding
• Extraction site away from area of crowding.
Case report extraction upper second molar
Female patient aged 17 years and 01 month, who sought
orthodontic treatment complaining of lack of space for her
A clinical examination showed a slightly asymmetrical face; lip
asymmetry (increased muscle contraction on the left side); lip seal
at rest; a low smile line and asymmetry when raising the lips;
mesocephalic facial pattern; balanced facial thirds; and convex
Case Report extraction upper second molar
Intra oral photo
An intraoral examination revealed parabolic shaped arches; Class
II relationship of molars and canines; 4 mm overjet; 50%
overbite; teeth 25 and 34 in crossbite; light curve of Spee; lower
midline shifted 0.5 mm to the right; severe crowding in the upper
arch (-11 mm discrepancy) and crowding in the lower arch (-5
mm discrepancy .
The radiographs confirmed the presence of intraosseous third molars with
normal anatomy. The upper third molars had fully formed crowns with
two-thirds of root formation. The lower third molars were impacted.
Supernumerary teeth were also present (Fourth right and left lower molars,
and fourth right upper molar), and visible lack of space for correct
positioning of the upper canines
In order to establish a Class I molar relationship as
soon as possible and because the patient did not
exhibit any growth potential, we opted for upper
second molar extraction to facilitate distalization
of the upper first molar and class II correction.
Additionally, we also extracted the lower third
molars that were impacted and the lower
supernumerary teeth. We decided against extracting
the upper supernumerary molar given the possibility
of damage to the third molar when doing so. The
extraction of this tooth was postponed to a future,
more convenient occasion.
After extraction, the upper first molars were banded and a
cervical traction headgear was installed (350 g - 16 h / day)
for first molar distalization, which was achieved after a
period of four months.
The first upper and lower premolars were extracted to
address the severe crowding and the protrusion.
Subsequently, brackets were bonded to the lower second
premolars, canines and central incisors. Brackets were not
bonded to the upper and lower lateral incisors on account of
the crowding. We used 0.016-in Multi loop "Tweed" style
archwires to correct canine mesiobuccal inclination.
After alignment and leveling, the canines were retracted
with chain elastics. Brackets were then bonded to the lateral
incisors followed by realignment and releveling.
Any residual space was then closed by retraction of the
upper and lower incisors using rectangular archwires with
Twenty-two months after the extraction of the second
molars, third molars were erupted and ready for banding or
After treatment completion, an upper wraparound removable
appliance and a fixed lower canine-to-canine lingual arch
were installed for retention.
The patient's extraoral aspect remained as it was initially
(Fig 5), except for her profile, which had its convexity
The radiographs disclosed adequate root parallelism. Moreover,
upper third molars were found to be appropriately positioned.
At this time the removal of the supernumerary upper molar was
performed (Fig 7).
From a cephalometric standpoint, the skeletal pattern was
maintained. The most significant changes occurred in the upper
and lower incisors and lips. The upper and lower incisors were
retracted. Thus, correction of the dental double protrusion was
achieved by moving the incisors to their original position. Due to
these dental changes, the lips were retracted, reducing the
patient's profile convexity (Figs 5 and 8 and Table
Extraction of third molar during orthodontic treatment does not
yield space for de crowding or reduction of proclination.
1. The conventional timing of extraction of a third molar is when
two-thirds of its root is formed.
Extraction of third molar should not be delayed because:
• More difficult to remove when roots are completed.
• Danger of root dilacerations which may make remova I more
• Pericoronitis can develop and cause bone loss and pocket
formation may occur distal to second molar.
2. Erupting mandibular third molars have been
implicated to be the cause of late lower anterior
crowding, although the evidence is not clear
However, it is difficult to detect such a force. In
fact, late anterior crowding often develops in
individuals whose lower third molars are
3. Malformed third molars, which interfere with
normal occlusion, should be extracted.
Case report mandibular
The 13-year-old patient, in good general health. Her main
complaint was related to the presence of anterior cross bite and
ectopic eruption of tooth 13. Despite protrusion of the lower lip and
little exposure of the upper lip, facial esthetics did not seem to be a
concern to the patient .
A more detailed examination of occlusion showed the presence of
premature contact of the incisors, in a centric relation, leading to a
more anterior position of the mandible in centric occlusion. Her
mother had reported no Class III malocclusion family history, so,
the peculiarities involved in this case point to a multifactorial
The patient presented significant skeletal discrepancy with ANB
angle equal to -3°, (SNA = 82° and SNB = 85°), with good vertical
mandibular growth direction (SN-GoGn = 31°)
With regard to the tooth aspect, the patient presented Angle's Class
III malocclusions with anterior cross bite, 1 mm overjet, 50%
overbite and retroinclined mandibular and maxillary incisors. When
handling the mandible in centric relation, premature contact was
found in the incisor region which led to functional deviation in the
anterior direction that accentuated the Class III malocclusion.
Furthermore, moderate anterior-superior crowding, tooth 13 in
palato-version, and the mandibular and maxillary midlines
coinciding with each other were also found (Figs 1 and 2). When
analyzing the facial characteristics, the patient presented a
mesocephalic face with a concave profile, proportional facial
thirds, lip competence, and absence of significant asymmetries. The
lower lip was slightly more protrusive than the upper lip
panoramic radiographs (Fig 3) did not show any significant
alteration that would be contraindication to orthodontic treatment
OBJECTIVES OF THE TREATMENT
The modified Haas expander device was used in the maxillary
arch with bands on the first pre-molars and molars that were also
encapsulated in the posterior region. Standard metal brackets
were then bonded without torque or angulation using the 0.022 x
0.028-in slot edgewise system. In the mandibular arch, in
addition to the fixed appliance, a J-Hook high-pull headgear was
The Role of Mandibular Third Molars on Lower Anterior Teeth
Crowding and Relapse after Orthodontic Treatment: A Systematic
Khalid H. Zawawi and Marcello Melis ( 2014 )
They concluded that the role of the third molars in the
development of anterior tooth crowding cannot be drawn. A
high risk of bias was found in most of the trials, and the
outcomes were not consistent. However, most of the studies do
not support a cause-and-effect relationship; therefore, third
molar extraction to prevent anterior tooth crowding or
postorthodontic relapse is not justified.
Third molars and dental crowding: different opinions of orthodontists
and oral surgeons among Italian practitioners
Michela Gavazzi et al (2014) . Studied role of third molars in
causing of incisor crowding, especially in the lower arch, continues
to be controversial The aim of this work is to compare opinions of
Italian oral surgeons and orthodontists on this topic. . Italian
orthodontists and oral surgeons have the same opinion on the role
of the third molar in causing anterior crowding. The study
concluded that majority of both groups of clinicians do not
consider their preventive extraction useful in order to prevent