ORTHODONTICS

1. INTERCEPTIVE
ORTHODONTICS
UNDER THE GUIDANCE OF
DR. MRIDULA TREHAN
PROFESSOR AND HEAD
(DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPEDICS)
PRINCIPAL/ DEAN
NIMS DENTAL COLLEGE AND HOSPITAL

2. CONTENTS
 Introduction
 Procedure
 Serial extraction
 Developing anterior crossbite
 Interception of habits
 Space regaining
 Muscles exercises
 Interception of skeletal malrelation

3.  Removable of soft tissues and bony
structure

4. LEARNING OBJECTIVES
The student should acquire the following
knowledge:
 Interceptive orthodontics procedures
 Serial extraction
 Space regaining
 Muscles exercises
 Interception of skeletal malrelations

5. DEFINITION
 That phase of the science and art of
orthodontics employed to recognize and
eliminate potential irregularities and
malpositions of the developing dentofacial
complex.

6. PROCEDURES
1. Serial extraction
2. Correction of developing crossbite
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

7. SERIAL EXTRACTION
DEFINITION:
 It is a process of extracting teeth in a
predetermined definite order in cases
which show signs of persistent
irregularities of teeth due to insufficient
space in the arch to accommodate the
present amount of tooth substance.

8.  HISTORY
 Kjellgren (1929): Used the term serial extraction
 Nance (1940’s):Popularized technique in USA .
Father of serial extraction.
Planned and progressive extraction.
 Hotz(1970):Active supervision of teeth by
extraction

9.  RATIONALE: 2 principles:
1)Arch length-tooth material discrepancy
2)Physiologic tooth movement

10.  INDICATIONS:
1) Cl. I malocclusion showing harmony between
skeletal and muscular systems
2) Arch length deficiency: indicated by:
a) Absence of physiologic spacing
b) Premature loss of deciduous canines
c) Lingual eruption of L.I.’s
d) U and L anterior crowding
e) Localized gingival recession in lower anteriors.

11. f) Ectopic eruption of teeth
g) Mesial migration of buccal segment.
h) Abnormal eruption pattern and sequence.
i) Lower anterior flaring.
j) Ankylosis of teeth.
3) Where growth is not enough to overcome
discrepancy between tooth material and basal
bone.
4) Patients with straight profile and pleasing
appearance.

12.  CONTRA-INDICATIONS:
1) Cl. II & III malocclusion with skeletal
abnormalities.
2) Spaced dentition.
3) Anodontia or oligodontia.
4) Open bite and deep bite.

13. 5) Midline diastema.
6) Cl. I malocclusion with minimum space
discrepancy.
7) Unerupted malformed teeth eg. Dilaceration
8) Extensive caries or heavily filled first permanent
molars.
9) Mild disproportion between tooth material and
arch length that can be treated by
reproximation.

14.  ADVANTAGES:
1) Treatment is more physiologic.
2) Psychological trauma can be avoided
3) Eliminates or reduces duration of fixed t.t.
4) Better oral hygiene is possible reducing risk of
caries.
5) Health of investing tissues is preserved.
6) Lesser retention period at completion of t.t.
7) More stable results.

15.  DISADVANTAGES:
1) Requires clinical judgement. No single
approach can be applied to all patients.
2) Treatment time is prolonged
3) Patient cooperation is required.
4) Patient has a tendency of developing
tongue thrust.

16. 5) Deepening of bite
6) Risk of arch length reducing by mesial
migration of buccal segment
7) Space can exist between canine and
second premolar
8) Fixed treatment is required for correction
of axial inclination of teeth

17.  DIAGONOSTIC PROCEDURE:-
 Arch length deficiency of not less than 5-7
mm.
 Carey’s analysis in the lower arch and arch
perimeter analysis in the upper arch.
 Eruption status of dentition from O.P.G.
 Skeletal tissue assessment from
Cephalometric radiographs.

18.  PROCEDURE:-
1. Dewel’s method
2. Tweed’s method
3. Nance method

19.  DEWEL’S METHOD :-
 Three steps:-
1. Removal of deciduous canines:-8-9 Years
 To create space for alignment of Incisors.
2. Extraction of deciduous first molars:-
 After 1 year
 To accelerate eruption of first premolars.
3. Extraction of erupting first premolars:-
 To permit permanent canines to erupt in their
place.

21.  MODIFIED DEWEL’S TECHNIQUE:
 First premolars are enucleated at the time
of extraction of deciduous first molars
especially in the mandibular arch where 3
erupts before 4.

22.  TWEED’S METHOD:-
 Extraction of D around 8 years of age.
 Followed by extraction of 4 and C.
 NANCE METHOD:- D 4 C
 Similar to Tweed’s method.
 POST SERIAL EXTRACTION FIXED THERAPY
 For correction of axial inclination and detailing of
occlusion.

23. DEVELOPING ANTERIOR
CROSSBITE
 Should be intercepted and treated at an early
stage because:
1)It is self-perpetuating
2)Have the potential of growing into skeletal
malocclusion.
 Classified as:
1)Dento-alveolar
2)Skeletal
3)Functional

24.  DENTO-ALVEOLAR ANTERIOR CROSSBITE
 1 or more maxillary anterior teeth are in
lingual relation to mandibular anteriors.
 Usually single tooth crossbite due to over-
retained deciduous teeth.
 Treated with tongue blade, Catalan’s
appliance and double cantilever springs
with posterior bite plate.

28.  FUNCTIONAL ANTERIOR CROSSBITE:
 Pseudo Cl.III malocclusion
 Due to occlusal prematurities
 Treated by eliminating occlusal
prematurities.

29.  SKELETAL ANTERIOR CROSSBITE:
 Due to skeletal maxillary retrognathism or
mandibular prognathism.
 Treated during growth by growth
modification procedures by use of
myofunctional or orthopaedic appliances.

30. INTERCEPTION OF HABITS
 THUMB SUCKING
 TONGUE THRUST
 MOUTH BREATHING

32. SPACE REGAINING
 Done by distal movement of the first
molar before eruption of the second molar
 SPACE REGAINERS:
1)GERBER SPACE REGAINER
2)SPACE REGAINERS USING JACK SCREWS
3)SPACE REGAINING USING CANTILEVER
SPRING

35. MUSCLE EXERCISES
 EXERCISE FOR THE MASSETER MUSCLE
 Clench teeth while counting to 10.
 Repeat this for some duration of time.
 EXERCISE FOR THE LIPS(CIRCUM-ORAL
MUSCLES)
a) Hold a piece of paper between lips.
b) Stretch upper lip in a downward direction
c) Holding and pumping of water back and forth
behind the lips.

36. d) Massaging of lips.
e) Button pull exercise
f) Tug of war exercise
 EXERCISES FOR THE TONGUE
1) One elastic swallow
2) Tongue hold exercise
3) Two elastic swallow
4) The hold pull exercise

38. INTERCEPTION OF SKELETAL
MALRELATIONS
 INTERCEPTION OF CLASS II
MALOCCLUSIONS
 Excessive maxillary growth: Face bow with
headgear
 Deficient mandibular growth:
Myofunctional appliances

40.  INTERCEPTION OF CLASS III
MALOCCLUSIONS:
 Mandibular prognathism:Chin cup with
headgear

41. Maxillary deficiency: FR III or face mask therapy.

42. REMOVAL OF SOFT TISSUE AND
BONY BARRIERS
 Eruption of permanent tooth is stimulated
by surgically exposing the crown.
 Excision of soft tissue and removal of any
bone overlying the crown of the
unerupted tooth.
 Opening in tissue should be slightly larger
than the greatest dimension of tooth.
 Surgical wound given a cement dressing
for 2 weeks.

43. BIBILIOGRAPHY
 Ackerman JL, Profitt WR: Preventive and
interceptive orthodontics: Strong theory
weak in practice. Angle Orthod 1980; 50:
75-86
 Dewel : Prerequisites in serial extraction.
Am J Orthod 1969; 87-93
 Dewel :Serial extraction in orthodontics.
Indications, objective and treatment
procedures. Am J Orthod 1954; 906-926

44.  Edwards JG: The diastema, The frenum,
The frenectomy: Clinical study. Am J
Orthod 1977; 71: 489-508
 Graber TM : Orthodontics : Principles and
practice. WB Saunders, 1988
 Profitt WR: Contemporary Orthodontics, St
Louis, CV Mosby, 1986
 Norton A, Wickwire NA, Gellin ME : Space
management in mixed dentition. J Dent
Child 1975; 42: 112-118