2. Interceptive orthodontics has been defined as
that phase of the science and art of orthodontics
employed to recognize and eliminate potential
irregularities and malpositions of the developing
dento-facial complex.
Unlike preventive orthodontics procedures that are
aimed at elimination of the factors that may lead to
malocclusion,
Interceptive orthodontics is undertaken at a time when
the malocclusion has already developed or developing.
2
3. 3
Procedures undertaken in interceptive
orthodontics
1. Serial extraction
2. Correction of developing overbite
3. Control of abnormal habits
4. Space regaining
5. Muscle exercises
6. Interception of skeletal malrelation
7. Removal of soft tissue or bony barrier to enable
eruption of teeth
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SERIAL EXTRACTION
Usually initiated in the early mixed dentition when one
can recognize & anticipate potential irregularities in the
dento-facial complex & is corrected by a procedure that
includes the planned extraction of certain deciduous
teeth & later specific permanent teeth in an orderly
sequence & pre-determined pattern to guide the erupting
permanent teeth into a more favorable position.
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HISTORY
Kjellgren (1929) – used the term ‘serial extraction’ first
to describe a procedure where some deciduous teeth
followed by permanent teeth were extracted to guide the
rest of teeth into normal occlusion.
Nance (1940’s) – popularized the technique in USA &
called it “planned & progressive extraction”
Hotz (1970) – called it ‘active supervision of teeth by
extraction’
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RATIONALE
2 Basic principles
Arch length-tooth material discrepancy :
Whenever there is an excess of tooth material as
compared to arch length, it is advisable to reduce the
tooth material in order to achieve stable results.
Physiologic tooth movement :
Human dentition shows tendency to move towards an
extraction space.
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INDICATIONS
1. Class I malocclusion showing harmony between skeletal
& muscular system.
2. Arch length deficiency as compared to the tooth
material. It is indicated by the foll. Features
a)Absence of physiologic spacing
b)Unilateral or bilateral premature loss of deciduous
canines with midline shift
c) Malpositioned or impacted lateral incisors
d)Markedly irregular or crowded upper & lower anteriors
e)Localized gingival recession in the lower anterior region
is a characteristic feature of arch length deficiency
f) Ectopic eruption
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g) Mesial migration of buccal segment
h) Abnormal eruption pattern or sequence
i) Ankylosis of one or more teeth
3. Where growth is not enough to overcome the
discrepancy between tooth material and basal bone
4. Patients with straight profile and pleasing appearance
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CONTRA-INDICATIONS
1.Class II & III malocclusion with skeletal
abnormalities
2.Spaced dentition
3.Anodontia / oligodontia
4.Open bite & deep bite
5.Midline diastema
6.Class I malocclusions with minimal space
deficiency
7.Unerupted malformed teeth e.g. dilaceration
8.Extensive caries
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ADVANTAGES
1. Treatment is more physiologic as it uses physiologic
forces to guide the tooth into normal positions
2.Physiological trauma associated with malocclusion can
be avoided
3.It eliminates or reduces the duration of multibanded
fixed treatment
4.Better oral hygiene is possible
5. Health of investing tissues is preserved
6.Lesser retention period is indicated at the completion
of treatment
7. More stable results obtained as the tooth material &
arch length are in harmony
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DISADVANTAGES
1. Serial extraction requires clinical judgment
2.Treatment time is prolonged as the treatment is
carried out in stages spread over 2-3 years
3.It requires the patient to visit the dentist often. Pt. co-
operation is needed.
4.As extraction spaces are created that close gradually,
the patient has tendency of developing tongue thrust
5. Extraction of buccal teeth can result in deepening of
the bite
6.Ditching or space can exist between the canine &
second premolar
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DIAGNOSTIC PROCEDURE
• Should involve assessment of the dental, skeletal & soft
tissues.
• An arch length deficiency of not less than 5 – 7 mm
should exist to undertake this procedure.
• Study model analysis should be carried out to
determine the arch length discrepancy
• Carey’s analysis in the lower arch & arch perimeter
analysis in the upper arch.
• Eruption status of dentition evaluated from an OPG
• Skeletal tissue assessment involves comprehensive
cephalometric examination.
• Soft tissue assessment by clinical exam &
Cephalograms
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Step 1- extraction of deciduous
canines to create space for alignment
of incisors
Step 2- extraction of deciduous 1st molars
to accelerate eruption of 1st premolars
Step 3- extraction of erupting 1st
premolars to permit permanent canines
to erupt
Serial extraction completed
DEWEL’S METHOD
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TWEED’S METHOD
Step 1- extraction of deciduous 1st
molar
Step 2- extraction of deciduous canine
and 1st premolars
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NANCE METHOD
Similar to Tweed’s technique & involves
extraction of deciduous 1st molars followed by the
extraction of the 1st premolars and the deciduous
canines
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DEVELOPING ANTERIOR CROSSBITE
Anterior crossbite is a condition characterized by reverse
overjet where in one or more maxillary anterior teeth are
in lingual relation to the mandibular arch
It should be treated for the following reasons :
1. This type of malocclusion is self-perpetuating i.e. if the
crossbite is present in deciduous dentition, it may
manifest in the permanent dentition as well.
2.Simple anterior crossbites that are not treated early
have the potential of growing into skeletal
malocclusion that later need complicated orthodontic
treatment.
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CLASSIFICATION
1. DENTO-ALVEOLAR ANTERIOR CROSSBITE : Anterior
crossbite in which one or more maxillary teeth are in lingual
relation to mandibular anteriors is termed as dento-alveolar
anterior crossbite. Usually occurs due to over-retained
deciduous teeth that deflect the erupting permanent teeth into a
palatal position.
• Treated by using tongue blades, Catalan's appliance & double
cantilever springs with posterior bite plate
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2. FUNCTIONAL ANTERIOR CROSSBITE : It is so called
pseudo Class III malocclusion where the mandible is
compelled to close in a position forward of its true
centric relation. Occurs as a result occlusal prematurities
that cause a deflection of mandible into a forward
position during closure.
• Treated by eliminating occlusal prematurities.
3. SKELETAL ANTERIOR CROSSBITE : Occur usually as a
result of skeletal discrepancies in growth of maxilla or
mandible. Also can be a result of maxillary skeletal
retrognathism or hypoplasia or mandibular
prognathism.
• Treated best during growth by growth modification
procedures by use of myofunctional appliances or
orthopedic appliances
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INTERCEPTION OF HABITS
Some habits that affect the oral structures are thumb sucking,
tongue thrusting and mouth breathing.
THUMB SUCKING
• Most frequently practiced by children & is capable of producing
damaging effects on the dento-alveolar structures.
• Presence of habit till 21/2 – 3 years is considered normal.
• Persistence of habit beyond 31/2 – 4 years can have damaging
influence.
• It is intercepted by use of habit breakers that could be of
removable type or one that is fixed.
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TONGUE THRUST
It is defined as a condition in which the tongue makes contact
with any teeth anterior to the molars during swallowing.
It is a deleterious habit that can clinically present with open bite
and anterior proclination.
Can be intercepted by using habit breakers.
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MOUTH BREATHING
Mouth breathing can be obstructive or habitual in
nature,
Obstructive mouth breathing can be a result of nasal
obstructions such as nasal polyps, nasal tumors, chronic
nasal inflammatory conditions and deviated nasal
septum.
Habitual mouth breathing is where oral breathing
persists as a habit after the removal of nasal obstruction.
It affects oro-facial equilibrium due to lowered
mandibular & tongue posture & can produce
malocclusion.
Interceptive procedures should involve identification &
removal of the cause.
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SPACE REGAINING
If a primary molar is lost early and space maintainers are not
used, a reduction in arch length by mesial movement of the first
molar can be expected.
Space regainers are used preferably at an early age prior to the
eruption of the second molars.
Some commonly used space regainers
GERBER SPACE REGAINER
•A seamless orthodontic band or a crown is selected for
the tooth to be distalized.
•This space regainer consists of a ‘U’ shaped hollow
tubing and a ‘U’ shaped rod that enters the tubing.
•The tube is soldered or welded on the mesial aspect of
the first molar to be moved distally.
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•The ‘U’ shaped wire or rod is fitted into the tube, in such a way
that the base of the ‘U’ rod contacts the mesial to the edentulous
area.
•Open coil springs of adequate length are placed around the free
ends of the ‘U’ shaped rod & inserted into the tubing assembly.
•The forces generated by the compressed open coil springs bring
about a distal movement of the first molar.
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SPACE REGAINERS USING JACK SCREWS
•The appliance consists of a split acrylic plate with a jack
screw in relation to the edentulous space & is retained
using Adams clasps
•Space regaining can be brought about using jackscrews
placed in such a way that an increase in arch length is
obtained by distalization of the molar.
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SPACE REGAINING USING CANTILEVER SPRING
The molar can be distalized to regain space by using
removable appliances that incorporate simple finger
springs.
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MUSCLE EXERCISES
Muscle exercises help in involving aberrant muscle function
Types of muscle exercises include :
EXERCISE FOR THE MASSETER MUSCLE
•Involves clenching of teeth by the pt. while counting till ten.
EXERCISE FOR THE LIPS (CIRCUM-ORAL MUSCLES)
•Stretching of the upper lip to maintain lipseal is done for pts with
short hypotonic lips.
•Pts are asked to stretch the upper lip in downward direction
towards the chin.
•Holding & pumping of water back & forth behind the lips
•Massaging of the lips
•Button Pull exercise
•Tug of war exercise
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EXERCISES FOR THE TONGUE
• One elastic swallow
• Tongue hold exercise
• Two elastic swallow
• The hold pull exercise
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REMOVAL OF SOFT TISSUE AND BONY
BARRIERS
Whenever a permanent tooth fails to erupt at the appropriate
time, its eruption may be stimulated by surgically exposing the
crown.
Surgical procedure involves excision of the soft tissue & removal of
any bone overlying the crown of the unerupted tooth.
Surgically created opening in the tissue is slightly larger than the
greatest dimension of the tooth.
The surgical wound is given a cement dressing for a period of 2
weeks.
