Interceptive Orthodontics
Introduction:-A malocclusion, if detected as
soon as possible, can be eliminated or
made less severe, by initiation of
interceptive orthodontic procedures.
An interceptive procedure
undertaken at the right time can, therefore
, either eliminate developing malocclusion
or make it less severe, so as to allow
corrective orthodontics to deliver a stable
& conservative result.
• Defined : Interceptive orthodontics as that
phase of the science and art of
orthodontics employed to recognize and
eliminate potential irregularities and
malpositions in the developing dentofacial
complex.
The procedures undertaken in interceptive
orthodontics include:1. Serial extraction.
2. Space regaining.
3. Correction of developing cross bite.
4. Oral habit elimination.
5. Muscle exercises.
6. Interception of developing skeletal
malocclusion.
7. Removal of soft tissue or bony barrier to
enable eruption of teeth.
1) Serial extraction:
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Is an interceptive orthodontic procedure
usually initiated in early mixed dentition .
It is corrected by a procedure that include
planned extraction.
Extraction of certain deciduous teeth & later
specific permanent teeth in orderly
sequence.
Pre-determined pattern to guide the
erupting permanent teeth into amore
favorable position.
 History :
• Kjellgren in 1929 used the term serial
extraction.
• Nance during 1940 popularized this technique
in U.S.A. & termed it planned & progressive
extraction.
• Hotz in 1970 called such a procedure ‘Active
supervision of teeth by extraction’.
Rationale : is based on two basic principle
i. Arch length- tooth material discrepancy.
ii. Physiologic tooth movement.
 Indication :
1. Class-I malocclusion showing harmony
between skeletal & muscular system.
2. Arch length deficiency-following factors.
• Absence of physiologic spacing.
• Unilateral / bilateral premature loss of
deciduous canine with mid-line shift.
• Malpositioned or impacted lateral incisors that
erupt palatally out of the arch.
• Localized gingival recession in the lower
anterior region is a characteristics feature of
arch length deficiency .
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3.
Ectopic eruption of teeth.
Mesial migration of buccal segment.
Abnormal eruption pattern & sequence.
Lower anterior flaring.
Ankylosis of one or more teeth.
Growth is not enough to overcome the
discrepancy between tooth material &
basal bone.
4. Patient with straight profile & pleasing
appearance.
Contra-indication:
• Cl-II & CI-III malocclusion with skeletal
abnormalities.
• Spaced dentition.
• Anodontia / Oligodontia.
• Open bite & Deep bite.
• Middle diaestema.
• Cl-I malocclusion with minimal space
deficiency.
• Unerupted malformed teeth e.g.
dilaceration.
• Extensive caries or heavily filled first
permanent molar.
• Mild disproportion between arch length &
tooth material that can be treated by
proximal stripping.
Advantage of serial extraction :
• More physiologic treatment as teeth are
guided into normal position using
physiologic forces.
• Duration of fixed treatment is reduced.
• Health of investing tissues is preserved.
• Lesser retention period is required.
• Result are more stable.
Disadvantage :
• Good clinical judgment is required. no single
approach can be universally applied.
• Treatment time is prolonged over 2-3 years.
• Patient cooperation is very important.
• Tendency to develop tongue thrust as extraction
spaces gradually.
• Extraction of buccal teeth causes deepening of
the bite.
• Residual spaces can remain between the
canine & 2nd premolar.
Diagnostic procedure:
• Study models.
• Radiographs.
• Photographs.
Procedure: Three of the popular method
area.Dewel’s method.
b.Tweed’s method.
c.Nance method.
Dewel’s method
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3 step serial extraction procedure.
1st deciduous canines are extracted.
Deciduous 1st molar extracted a year later.
Followed by extraction of erupting 1st premolar.
Tweed’s method/Nance method
• Method involves the
extraction of deciduous 1st
molar around 8 year of
age.
• Followed by the extraction
of the 1st premolar & the
deciduous canines.
2.Space regaining:
• Primary molar is lost early & space
maintainers are not used.
• Reduction in arch length by mesial
movement.
• Preferably undertaken at an early age prior
to the eruption of 2nd molar.
Divided into two broad groups.
a. Fixed appliances.
b. Removable appliances.
a. Fixed appliances.
i. Gerber spacer regainer.
ii. Jack screw space regainer.
iii. Open coiled space regainer.
[ Herbst space regainer ]
b. Removable appliances.
• upper/ lower Hawley’s appliance with helical
spring.
• Hawley’s appliance with spilt acrylic dumb-bell
spring.
• Hawley’s appliance with slingshot elastic.
• Hawley’s appliance with palatal spring.
• Hawley’s appliance with expansion screws.
3. Correction of anterior & posterior crossbite.
• Corrected as soon as they are detected .
• Better to treat them as the permanent teeth
begin to erupt.
• Easier to bring about changes in the mixed
dentition stage.
• Unilateral / bilateral.
• True / functional or combination of two.
• Could lead to a skeletal malocclusion.
• Which would require corrective orthodontic
treatment later on.
• Common appliances used in the correction
of crossbite are –
-Tongue blade therapy
-Inclined planes
-Composite inclines
-Hawley’s appliance with Z spring
-Quad helix appliance .
TONGUE BLADE THERAPY
4. Control of abnormal habit:
• Habit in the orthodontic sense refer to certain
actions involving the teeth & other oral or
perioral structures .
• Which are repeated often enough by some
patients to have profound & deleterious effect
on position of teeth & occlusion.
• Habit that can affect the oral structures are,
thumb sucking, tongue thrusting , mouth
breathing, etc.
Thumb sucking:
• Presence of this habit upto 21/2-3years is
consider quite normal.
• Beyond 31/2-4years of age can have a
damaging influence on the dentoalveolar
structure.
• Tongue thrust: Is defined as a condition in
which the tongue makes contact with any
teeth anterior to the molar during swallowing.
• Present with open bite & anterior proclination.
• Intercepted by using habit breaker.
• Trained & educated on the correct technique
of swallowing.
 Mouth breathing :
• Can be obstructive or habitual in nature.
• Nasal obstructive such as nasal polyps ,nasal tumors,
chronic nasal inflammatory conditions & deviated
nasal septum.
• Persistence of habitual oral breathing is an indication
to use a vestibular screen to intercept the habit.
5.Muscle exercise :
a. Exercise for the masseter muscle:
• To strengthen the masseter muscle .
• Clenching of teeth by the patient while counting to ten.
• Repeat the exercise for some duration of time.
b. Exercise for the lip [circum oral muscles]
i.
Upper lip is stretched in the posteroinferior direction by
overlapping the lower lip .such muscular lip allow the
hypotonic lips to form oral seal labially.
ii. Hypotonic lips can also be exercised by holding a piece
of paper between the lips.
iii. Parent can stretch the lips of the child in the
posteroinferior direction at regular interval.
iv. Swashing of water between the lips until they get tired .
v. Massaging of the lips.
vi. Use of oral screen with a holder-to exercise the lips.
vii. Button pull exercise.
viii. Tug of war exercise.
c. Exercise for the tongue:
i. One elastic swallow.
ii. Two elastic swallow.
iii. Tongue hold exercise.
iv. The hold pull exercise.
6.Removal of soft tissue & bony barriers:
• Supernumeary teeth , over-retained &
ankylosed primary teeth are other
possible causes of non eruption.
7. Interception of skeletal malrelations
 Interception of Cl-II malocclusions.
• Excessive maxillary growth, deficiency in
mandibular growth or a combination of
both.
• Maxillary growth can be restricted by use
of face bow with head gear.
• Mandibular growth is usually treated by
myo-functional appliances.
Interception of Cl-III malocclusions.
• Mandibular prognathism, maxillary
retrognathism & combination of both.
• Chin cup with head gear helps in
restriction of mandibular growth .
• FR III or face mask therapy is used for
cases of maxillary deficiency.