prevention

1. A . Maheshkumar
IIInd PG
Dept of Pedodontics and Preventive Dentistry
1

2.  INTRODUCTION TO INTERCEPTIVE ORTHODONTICS
 VARIOUS INTERCEPTIVE ORTHODONTIC PROCEDURES
 SERIAL EXTRACTION
 CROSS BITE
 DIASTEMA
 SPACE REGAINING
 EXPANSION
 CONTROL OF ABNORMAL ORAL HABITS
 MYOTHERAPEUTIC EXERCISES
 INTERCEPTION OF DEVELOPING SKELETAL MALOCCLUSION
 CONCLUSION
2

3.  Involving as it does the frequent use of appliances,
orthodontic treatment is popularly regarded as ‘springs’,
‘plates’, and braces.
 There is however, much in orthodontic treatment that
depends not so much upon appliances as on interceptive
measures and therapeutic extractions, in addition to the
experience and knowledge of the operator
3

4.  The goals of orthodontic care in the primary dentition should be
aimed at either intervention in the conditions that predispose one to
develop a malocclusion in the permanent dentition or monitoring
conditions that are better treated later.
 The goal of early treatment is to correct existing or developing
skeletal, dentoalveolar and muscular imbalances to improve the
orofacial environment before the eruption of the permanent
dentition is complete.
 By initiating the orthodontic and orthopedic treatment at a younger
age the overall need for complex orthodontic treatment involving
permanent tooth extraction and orthognathic surgery persumably is
reduced
4

5.  The American Association of Orthodontists (1969)
defined interceptive orthodontics as that phase of
science and art of orthodontics employed to
recognize and eliminate the potential irregularities
and malpositions in the developing dentofacial
complex.
 Profitt and Ackermann (1980) defined as the
elimination of the existing interferences with the
key factors involved in the development of the
dentition.
5

6. The procedures that are undertaken in interceptive orthodontics
include
 Serial extraction
 Diastema
 Space regaining
 Expansion
 Control of abnormal Oral habits
 Cross bite
 Myotherapeutic exercises
 Interception of developing skeletal malrelations
6

7.  Inadequate growth of supporting bone is responsible for the
development of the procedure known as serial extraction.
 It is designed to anticipate and prevent the development of a
fully matured deformity in the permanent dentition, and it is
applied by the extraction, in the proper order, of a
predetermined series of deciduous and permanent teeth.
 Serial extraction is a series of related and correlated steps
taken in an attempt to intercept a developing malocclusion in
the mixed dentition
7

8.  French man, Robert Bunon, in 1743 .
 In 1929, Kjellgren introduced the term serial extraction.
 Hotz, Kjellgren, Dewel and Heath published their findings on
various extraction sequences.
 Holtz referred the procedure as “guidance of eruption”. This
is better title than Kjellgren’s because it implies that
knowledge of growth and development is necessary to direct
the teeth as they erupt into occlusion
8

9.  Serial extraction can be defined as the correctly timed, planned
removal of certain deciduous and permanent teeth in mixed
dentition stages with dentoalveolar disproportion in order to
alleviate crowding of incisor teeth, allow unerupted teeth to guide
themselves into improved positions and to lessen the period of
active appliance therapy or eliminate it.
 Rationale
 The rationale for serial extraction is based on several biologic facts
and processes;
1) Tooth material arch length deficiency
2) Physiologic tooth movement
3)Normal dental, skeletal, and profile development
9

10. Tooth material arch length deficiency
 Dental crowding is the result of inadequate arch size, insufficient
basal bone and/or excessive tooth material.
 It can be eliminated by making the dental arch larger by expansion
or reducing the amount of tooth material by making teeth narrower
or by extracting a tooth or teeth.
10

11. Physiologic tooth movement
 Physiologic tooth movement or drifting is dependent primarily on
the dental age at the time of extraction, spacing or crowding
conditions, eruption time, tooth position and inter digitations.
 Maxillary teeth distal to the first premolar tend to drift mesially, and
those mesial to the second premolar tend to drift distally.
 Mandibular teeth distal to the second premolar drift mesially
whereas those mesial to the permanent first molar will drift distally.
The maxillary permanent first molar uprights and rotates
mesiolingually; however, the mandibular first molars will drift
mesially less than the maxillary first molars.
11

12. Normal dental, skeletal, and profile development
 The maxillary intercanine width increases slightly more and over a
longer time. The dental arch perimeter from the distal of the
mandibular primary second molar to its antimere is less in the
permanent dentition than in the primary.
 Also the principles of leeway space, interrelationship of overjet,
overbite, axial inclinations, and mesial shift, and arch-length
analysis must be considered in determining whether to institute a
serial extraction procedure.
12

13.  Specifically the relation of the maxilla to the mandible and of both to
the cranial base must be determined to identify protrusions,
retrusions, hyperdivergences, hypodivergences, crossbites, and
asymmetries.
13

14.  To resolve differences between a known amount of tooth material
and a persistent deficiency in basal bone.
 To guide and control the eruption of teeth in arches that has no
hope of attaining their maximum size and proportion.
14

15. Intraoral radiographs :
 Complete series of periapical radiographs
/panoramic radiograph.
 Detection of congenital absence of teeth.
 Detection of supernumerary teeth.
 Evaluation of permanent teeth.
 Detection of pathologic conditions in the
early stages.
 Assessment of trauma to the teeth.
15

16. 16

17.  Detection of evidence of a true
hereditary tooth- size jaw-size
discrepancy.
 Determination of size, shape and
relative position of unerupted
permanent teeth.
 Determination of dental age of
the patient.
 Calculation of total space
analysis.
 Detection of root resorption
before ,during and after
treatment.
 Evaluation of third molars before,
during and after treatment.
 Final appraisal of the dental
health after orthodontic
treatment.
17

18. Cephalometric analysis :
 Evaluation of craniofacial relationships prior
to treatment.
 Assessment of soft tissue.
 Classification of facial pattern.
 Calculation of tooth-size jaw-size
discrepancies (total space analysis).
 Determination of mandibular rest position.
 Prediction of growth and development.
 Monitoring of skeletodental relationships
during treatment.
 Detection of pathologic conditions before
,during and after treatment.
18

19.  Evaluation of craniofacial
relationships prior to
treatment.
 Assessment of soft tissue
profile.
 Proportional facial
analysis.
 Total space analysis.
 Occlusal curve analysis.
 Monitoring of treatment
progress.
 Study of relationships.
19

20. Study models :
 Calculate total space analysis.
 Assess and record the dental anatomy.
 Assess and record the intercuspation.
 Assess and record arch form.
 Assess and record the curve of occlusion.
 Evaluate occlusion with aid of articulators.
 Measure progress during treatment.
 Detect abnormalities.
20

21.  Moyer's mixed dentition analysis
 Tanaka and Johnson analysis
21

22.  Midline shift of the mandibular central incisors due to
displaced lateral incisors
 Premature loss of primary canine
 Abnormal or asymmetric primary canine root resorption
 Ectopic eruption of the maxillary first molar
 Labial but un erupted permanent canine that are extremely
prominent
 Gingival recession on a labially displaced central incisor
 Extreme labial displacement of a mandibular incisor
 Maxillomandibular alveolar dental protrusion
 Unusual shape, size, or number of teeth
 Crowded maxillary or mandibular teeth that is excessively
inclined labially.
22

23.  Profits(1986) cites a predicted tooth size/arch size discrepancy of
10 mm or greater as an indication for serial extraction, whereas
Ringenberg(1964) cited a discrepancy of 7mm or greater.
23

24.  Class I malocclusion with lack of inter-canine width in both
maxillary and mandibular arch.
 Class I malocclusion with lack of intercanine width in
mandibular arch but adequate arch length in maxilla.
24

25. 25

26.  A number of methods of serial extraction have been described.
Three of the popular methods are;
 a. Dewel’s method
 b. Tweed’s method
 c. Nance method
26

27.  Dewel has proposed a three step extraction procedure.
 Stage 1- Premature extraction of the deciduous cuspids provides
space for the incisors to assume normal positions in an even
alignment directly over basal bone.
 Stage 2 – Subsequent extraction of deciduous first molars permits
the desirable early eruption of the first premolars.
 Stage 3 – The final extraction of the first premolars makes it
possible for the cuspids to erupt in a favourable direction into the
spaces formerly occupied by the first premolars.
 The interval between stages varies from six months to one year.
27

28.  He proposed the extraction sequence as
 At 8 years of age, all deciduous first molars are extracted. The
deciduous canines are maintained to hamper the eruption of
permanent canines.
 After the premolars are through the alveolar bone, the premolars
along with the deciduous canines are extracted.
28

29.  This method involves the extraction of
deciduous first molars followed by the
extraction of first premolars and the
deciduous canines.
29

30.  Deciding on the timing and sequencing for extracting primary and
permanent teeth is the key to success. Every serial extraction must
be individualized to accomplish the objectives for the particular
patient’s developing malocclusion.
 Class I malocclusions
 Premature loss of a mandibular primary canine.
 If the skeletal, profile, and dental patterns and the overjet, overbite,
axial inclinations, and number, size, shape, and developmental
patterns are normal and if there is 5 to 10 mm of arch length
discrepancy per arch, the remaining primary canines should be
extacted.
 If the permanent first premolars have more than half their roots
formed, the primary first molars should also be extracted; if not, the
primary first molars should be extracted when the root formation is
half completed.
 The first premolars should be extracted as they emerge.
30

31.  Bunon (1743) – primary canines, first primary
molars and first premolars
 Dewels method – C D 4
 Tweeds method – D 4 C
 Nance method – D4 C
 Most satisfactory order
 Removal of first primary molars is sometimes
advocated to promote earlier eruption of first
premolars
31

32. Anterior discrepancy : crowding
 Primary canines – to relieve incisor crowding
after eruption of lateral incisor
 Ist primary molar – performed after incisor
crowding has improved and the extn site is
reduced in size
 When the permanent canines have developed
beyond one half root length ,the Ist
premolars are extracted
32

33. 33

34. Anterior discrepancy : alveolodental protrusion
 Primary 1st molars
 Premolars have to be extracted at half root
formation in order encourage their early
eruption ahead of canines
 Next the primary canines and 1st premolars
are extracted to encourage lingual tipping of
incisors
34

35. Middle discrepancy : impacted canines
 There may already be premature exfoliation of
the primary canines
 The incisors may be splayed out due to crowding
in the apical region
 The 1st primary molars should be removed to
encourage the premolars to erupt early (at about
half root development)
 The premolars are then extracted so that the
impacted permanent max. canine will have space
to migrate away from the apices of lateral
incisors
35

36. 36

37. Tooth germ enucleation in the mandible :
 Extraction of the 1st primary molars with
subsequent enucleation of the first premolars
 Indicated when the canine appear to be
erupting before the 1st premolars
 This allows distal migration of the erupting
canines
37

38. Tooth germ enucleation in the maxilla and
mandible
 On rare occasions ,in both the max. and
mand, the permanent canines will erupt
before the premolars
 Extraction of the primary canines followed by
the first molars and enucleation of Ist
premolars
38

39. The most frequently used appliances with serial
extractions are;
a) lingual arch,
b) fixed or fixed removable head
gears,
c) removable Hawley’s appliance,
d) fixed appliance
39

40. 40

41.  Periods of sudden acceleration of growth
 This sudden increase in growth is termed as
growth spurts.
 physiological alteration in hormonal secretion
is believed to be the cause
41

42.  The following are the timing of growth
spurts –
 Just before birth
 One year after birth
 Mixed dentition growth spurt
◦ Boys: 8-11yr
◦ Girls: 7-9yr
 Adolescent growth spurts
◦ Boys: 14-16yr
◦ Girls: 11-13yr
42

43.  Pre pubescent take off stage – moderate
increment in height velocity
 Pubescent phase – very rapid growth phase
 Post pubescent phase – decelerating of height
velocity
43

44.  proposed by tweed
 According to the growth trends he divided
individuals into following groups
 Type A
 The maxilla and mandible grow together thus
the ANB angle remains unchanged. This is
accompanied with cl-l relationship and in
mixed dentition, it does not exceed 4.5˚. No
treatment is indicated in this case
44

45.  Type A subdivision
 In this condition maxilla is protruding with
the ANB angle more than 4.5˚. The treatment
is to restrict the growth of maxilla allowing
the mandible to catch up. The prognosis is
good, but at times requires the extraction of
premolars
45

46.  Type B
 The maxilla and mandible are found to grow
forward and downwards with the growth of
maxilla exceeding that of the mandible. This
type of growth trends have a poor prognosis.
Growth of the middle and lower face is
predominantly in the vertical directions. This
growth trend has poor prognosis.
46

47.  Type B subdivision
 The ANB angle is large and continuous to
grow, indicating an unfavourable growth
trend
47

48.  Type C
 The maxilla and mandible grow forwards and
downwards, with mandible growing forward
more rapidly than the maxilla. The ANB angle
seen to be decreasing , with the middle
catching up with the maxilla. Treatment is
not indicated until the eruption of canine
48

49.  Type C subdivision
 Mandible is found to be growing more
forward to compare with maxilla. With the
mandibular incisors touch the lingual surface
of maxillary incisors.
49

50.  Severe mandibular anterior crowding.
 If all the dental, skeletal, and profile considerations are
favorable and there is an arch-length deficiency in excess of
5 mm per quadrant, first extract the primary canines.
 When the permanent first premolar roots have formed half
their length, extract the primary first molars and then later
the first premolars as these teeth erupt.
50

51. 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.
51

52. 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.
52

53. 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.
53

54. 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.
54

55. Anterior midline spacing between two
maxillary central incisors.
One of the most frequently seen
malocclusion.
space present more than 0.5 mm.
easy to treat but difficult to retain.
55

56. 1) Normal developing dentition -
 Around the age of 8 years a midline diastema -commonly
seen -upper arch.
 Crown of the canine in young jaw impinges on developing
lateral incisor roots, driving the root medially and causing the
crowns to flare laterally the roots of the central incisors are
also forced together thus causing a maxillary midline diastema.
56

57. 2) Parafunctional habit –
 Flaccid lip - The upper lip is generally hypotonic while the lower
part of the face exhibit hyperactive mentalis activity a poor muscle
tone.
 Tongue thrust – May cause anterior openbite and diastema.
 Thumb/digit sucking over a prolonged period causes
proclined anterior teeth and flaring.
3)Tooth size discrepancies -
 Excessive anterior vertical overlap.
 Excessive vertical maxillary alveolar growth. Retrognathic mandible
or a prognathic mandible.
57

58. 4)Frenum attachment -
 Presence of thick & fleshy frenum.
 It prevents the two central incisors from
approximating each other due to the
fibrous connective tissue interpased
between them
5)Familial incidence -
 Heredity
6)Mesio-distal angulation of teeth
58

59. 7) Tooth anomalies -
 Microdontia
 Congenital missing teeth
 Peg laterals
 Presence of supernumerary teeth
8)Pathological-
 Soft tissue and hard tissue pathologies such as cysts, tumors and
odontomes.
 Presence of an unerupted mesiodens between the roots of the two
central incisors.
 In case of juvenile periodontitis initially loss of attachment and
alveolar bone are seen around the permanent incisors and first
molars.
59

60. 9) Trauma -
 Children are highly prone to injuries of the dento-facial region
during early year of life when the learn to crawl, walk or during play
 Most of these injuries go unnoticed and may be responsible for
Non-Vital teeth Erupting of permanent teeth into
abnormal position
60

61. Management of mid-line diastema
Treatment
according
to its cause
Active treatment Retention
Orthodontics
Treatment
Restorative
Treatment
Removable
appliance
Fixed
appliance
61

62. Treatment according to its cause –
1)Normal developing condition
 Ugly duckling stage
 Resolves by itself with the eruption of the permanent canines.
 Spontaneous closure seems to occur with less frequency in :
a) Generalized spacing
b) Initial diastema of more than 3 mm.
62

63. 2) Parafunctional habits –
 Correction of the habits has been known to spontaneously correct
the diastema within limits.
 In case of excessive diastema, correction carried out with the habit
breaking appliance.
 Habit breaking appliances for thumb sucking –

i) Removable habit breakers –
- The are passive removable appliances.
- Consist of crib which is anchored to the oral cavity by means of
clasps on the posterior teeth.
63

64. ii) Fixed habit breakers –
Heavy gauge stainless steel wire can be designed to
form a frame that is soldered to bands on the molars.
Chemical approach – Use of bitter tasting or foul
smelling preparation places on the thumb that is sucked
can make the habit distasteful.
- Habit breaking appliances for tongue thrust –
Use habit breakers as in thumb sucking.
The child is taught correct method of swallowing.
64

65. 3) Tooth size discrepancies –
Intrusion of the maxillary incisors,
Retraction of the incisors
If cephalogram indicates an excessively long lower face or a class
III growth trend.
Functional therapy
4) Frenum attachments -
Generally advocated that the diastema should be closed as far as
possible before going in for frenectomy. The reason cited is that
should the surgery be performed before the surgical scar tissue
maintains the diastema.
5) Mesio distal angulation of teeth -
The correction of the crown angulation will close the diastema.
65

66. 6) Tooth anomalies -
* Supernumerary teeth
Removal of the supernumerary followed by a closure of the
diastema.
* Peg shaped laterals
Orthodontically followed by esthetic restoration of peg shaped
laterals.
* Absence of laterals
i) The space for the missing laterals, if detected:
Early- may initially be maintained,
Later- replaced with fixed prosthesis.
ii) Orthodontically move the canines into the space of the missing
laterals, recontouring of the cuspid and the first bicuspid to simulate
the lateral and cuspid respectively.
7) Pathological
Systemic phase followed by appliance therapy.
66

67. Active treatment –
1)Orthodontically
 Done using removable appliances or fixed appliances.
* Removable appliances-
- Simple removable appliances can be used for closed
midline diastema are-
i) Finger springs ii)Split labial bow.
67

68. i) Finger springs
- most useful
- 0.5 or 0.6 mm. hard round S.S. wire is used.
- Made up of a coil or helix near the point of attachment and a free
end which moves, in a well defined arc -
1)Free end- It is the active arm 12-15 mm in length and is placed
towards the tissue.
2)The helix- It is about 3 mm in internal diameter.
3)The retentive arm- It is placed away from the tissue
and ends in a retentive tag.
68

69. Construction –
The spring is constructed such that the helix is positioned opposite
to the direction of intended tooth movement. The helix should also
be placed along the long axis at the tooth to be moved and
perpendicular to the direction of tooth movement.
Care should be taken to ensure that the cavity formed by
boxing does not become a food trap.
Activation-
Open the coil or moving the active area towards the tooth to be
moved about 3 mm of activation is considered optimum.
69

70. ii) Split labial bow-
- This is a labial bow that is split in the middle.
- Made up of 0.7 mm round S.S. wire.
- It has 2 separate short buccal arms, each with ‘U’ loop ending distal
to canine.
- It exhibits increased flexibility as compared to the conventional short
labial bows.
Modification-
- 2 buccal arms extend across the opposite central incisor and engage
onto its distal surface.
Activation-
- The split labial bow is activated by compressing the U loop 1-2 mm at
a time.
70

71. Fixed appliances-
Fixed appliances incorporating elastics or springs bring about the
most rapid correction of midline diastema. Elastics can be
stretched between the two central incisors in orders to close the
space.
Fixed appliances are –
1) Closed coil springs
2) Elastics
3) Elastic chain
4) M shaped springs
71

72. 1) Closed coil springs-
- Closed coil spring can be made of stainless steel or
nickel titanium alloys.
- They are used to close spaces once a spring is
stretched and attached at two ends.
- It tries to achieve its prefabricated length by closing the
gap between its points of attachment.
72

73. 73

74. Restorative treatment-
 Historically - construction of crowns larger than the
original teeth.
 Recent technology- composite resin material and acid etching
technology.
 Advantage-
That is nondestructive reversible and relatively inexpensive.
Disadvantage-
 Fracture and staining are possible after 5 to 10 years.
74

75. Clinical Technique-
After cleaning, shade selection and isolation
 The space to be eliminated should be carefully measured via a periodontal
probe calipers, or boley gauge.
 The entire labial surface of the tooth should be etched and
bonding agent applied.
 Composite resin should be applied, beginning at the gingival margin of the
inter proximal area.
 The entire proximal surface as well as the labial surface can be built up and
polymerized at once or incrementally.
After this build up, finish the interproximal area to the proper contour and
polish it
The second tooth is restored similarly.
75

76. 76

77. Retention
 Retention is a third phase of treatment of
mid-line diastema.
-easy to treat but difficult to retain.
-So retention is very important phase in treatment
of mid-line diastema.
Retainer use for mid-line diastema are
1. Lingual bonded retainer
2. Hawley’s retainer
77

78. Hawley’s retainer-
Hawley’s retainer, the labial bow is contoured to the
anterior teeth . The advantage is of better control over
the anterior teeth.
78

79.  Profit WR. Treatment in pre adolescent children.
Contemporary orthodontics, 4th edition.
 Graber T.M., Swain B.F. " Current Orthodontic
Concepts And Techniques".
 Aarthi Rao. Principles and Practice of Pedodontics,
 Nikhil Marwah. Comprehensive Pediatric Dentistry
79

80.  Paediatric Dentistry –by J.R . Pinkham
 Ralph E. McDonald, David R. Avery, Jeffrey A.
Dean. Dentistry for the Child and Adolescodent.
 Grabber T. M. Serial extraction: A Continous
Diagnostic and Decisional Process. Am J
Orthodontics, December 1971; 60(6): 541-575.
 Dewel B. F, Evanston. Serial Extraction:
Procedures and Limitations. Am J Orthodontics,
September 1957; 43(9): 685-687.
80

81.  Orthodontics, October 1956; 42(10): 728-739.
 Emma Laing, Paul Ashley, Farhad B. Naini, Daljit
S. Gill. Space Maintenance. International Journal
of Paediatric Dentistry 2009; (19): 155-162.
 Joseph Ghafari, Early of dental arch problems.
Space maintenance, space regaining.
Quintessence international 1986; 17(7): 423-
432.
 Warren A. Brill. The Distal Shoe Space Maintainer:
Chairside Fabrication and Clinical Performance.
Paediatric Dentistry, 2002; 24(6): 561-565.
 Bernard Lloyd Z. Serial Extraction as Treatment
Procedure. Am J
81

82. 82

83.  Maxillomandibular expansion has become perhaps the most
common nonextraction approach for treating that mild-to-
moderate tooth size arch length deficiency.
 Maxillary expansion is a well-established approach for correcting
of transverse malocclusion .
 The goal of palatal expansion is to maximize skeletal movement
and minimize dental movement, while allowing for physiologic
adjustment of the suture during separation.
83

84.  Expansion can be arbitrarily divided
orthodontic passive orthopedic
 According to rate of expansion it can be slow
or rapid expansion.
84

85.  Expansion of dental arches can be produced by a number of
orthodontic treatments including those that employ fixed
appliances, removable finger spring appliances, expansion
plate appliances or the quad helix appliance.
 Orthodontic expansion of dental arches produce lateral
movement of the posterior buccal segments, with a tendency
toward a lateral tipping of the crown and a resultant lingual
tipping of the root.
85

86.  When the forces of the buccal and labial musculature
are shielded from the occasion, a widening of the dental
arches often occurs.
 This expansion is not produced through the application
of extrinsic biomechanical forces but rather by intrinsic
forces.
 By changing the balances of forces within the orofacial
region, 4-5 mm of spontaneous arch expansion can be
obtained.
 In this type the bone deposition occurs primarily along
the lateral aspect of the alveolus, rather than in the
midpalatal suture.
 Example are lip-bumper appliance and Frankle-2
appliance.
86

87.  In true orthopedic expansion the changes are
produced primarily in the underlying skeletal
structures rather than by the movement of teeth
through alveolar bone. E.g.: Rapid maxillary
expansion (RME) appliances.
 The goal of orthopedic treatment in the mixed
dentition is to reduce the need of extraction in
permanent dentition through the elimination of
arch length discrepancies as well as the elimination
of the bony base imbalances.
87

88.  Posterior crossbites associated with real or relative
maxillary deficiencies
 Class iii malocclusion of dental or skeletal cause
 Cleft palate patients with collapsed maxillary arch
 In cases requiring face mask therapy
 Medical conditions – nasal stenosis , poor nasal
airway, recurrent nasal and ear infections
88

89.  Removable (acrylic plate , screw, clasps )
 Fixed
A. tooth borne (isaacson type, hyrax type)
B. tooth tissue borne (derichsweiler type, hass
type)
89

90.  Quad helix crozat
willams appliance
90

91.  Skeletal expansion or Surgically assisted rapid
palatal expansion is undoubtedly the best
treatment option for maxillary hypoplasia
and/or severe max. crowding. The advantages
are obvious and multiple. Indeed, there is no
segmental tilting, there is no evidence of any
orthodontic/orthopedic relapse and dental/
periodontal damage is excluded.
 Distraction Osteogenesis on the other hand is a
reliable and recognized technique for
generating callus. It readily ossifies and is
resistant to any substantial relapse.
91

92.  opening of mid palatal sutures (fan shaped ) maximum
opening in the incisor region
 Two halves rotate in both coronal and saggital plane.
 An increase in maxillary width of upto 10mm can be
achieved.
 The anchorage teeth shows buccal tipping to some
extent
 There is downward and backward rotation of mandible
following R.M.E
 Increase in intra nasal space and decrease in the air
flow resistance is seen .
92

93. 93

94.  Schedule by Timings:
 Below 15 yrs of age -90 degree rotation in morning and evening
 Above 15 yrs of age -45 degrees activation 4 times a day.
94

95.  Single tooth crossbite
 Un-cooperative patients
 After ossification of mid palatal sutures
 Skeletal asymmetry of maxilla and mandible
 Vertical growers with steep mandibular plane angle
 Patients with poor periodontal conditions
95

96.  It is also been termed as dento-alveolar expansion
 It produces more physiologic type of tissue
reaction
 Results are more stable when the arch is expanded
slowly at a rate of 0.5- 1 mm per week
 Force generated is 2-4 pounds when compared to
10-20 pounds in R.M.E.
 APPLIANCES used for slow expansion are
 Jack screw
 Coffin spring
 Quad helix
96

97. CROSS BITES
Under normal circumstances- maxillary arch
overlaps mandibular arch both labially and buccally.
But when mandibular teeth (single tooth or a
segment of teeth) overlap maxillary teeth labially or
buccally depending upon their location in the arch a
crossbite is said to exist
97

98. DEFINITION OF CROSSBITE
According to Graber:
A condition where one or more teeth may be malposed abnormally-
buccally or labially or lingually with reference to opposing tooth or teeth.
Other definition:
-A deviation of the normal faciolingual relationship of teeth of one
arch with those of opposing arch when the two dental arches are
brought into centric occlusion
OR
-Abnormal occlusion in the transverse plane
OR
-Reverse overjet of one or more teeth
98

99. CLASSIFICATION OF CROSSBITES
(1) According to the location in the arch
Anterior Posterior
(2) According to the nature of crossbite
Skeletal Dental Functional
crossbite crossbite crossbite
99

100. ETIOLOGY
Based on etiologic factors responsible for crossbite:
CROSSBITE
Dental Skeletal Functional
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101. Dental crossbites
- Generally, single tooth/segmental crossbite.
- No threat to general health of the patient
- Problems arising are – periodontal/ esthetic in nature.
- Usually result from faulty eruption pattern with no irregularity
in the basal bone.
- Once the teeth erupt – the occlusion locks them into
position and drives them even further into a crossbite
relationship.
10
1

102. 10
2

103.  1) Anomalies in tooth number i)supernumerary teeth
ii)missing teeth
 2) Anomalies in tooth size i)microdontia
ii)macrodontia
 3) Anomalies in tooth shape
 4) Premature loss of deciduous/ permanent teeth
 5) Prolonged retention of deciduous teeth
 6) Delayed eruption of permanent teeth
 7) Abnormal eruption path
 8) Ankylosis
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104.  - It results from discrepancy in structure of
maxilla and mandible or – malposition of the jaw.
 - A basic discrepancy in the width of arches is
noted.
 - A narrow maxillary arch or a wide mandibular
arch often assosciated with a buccal crossbite.
 - They cause appreciable damage to a person’s
health and
 personality.
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4

105. Etiology of skeletal crossbites
1)Retarded development of maxilla.
2) Narrow upper arch.
3)Forwardly placed mandible.
4) Unilateral hypo/hyperplastic growth of any jaw.
5) Hereditary (Class III skeletal malocclussion).
6) Congenital ( Cleft lip and palate).
7) Trauma at birth (forcep injury leading to ankylosis of TMJ.)
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106. 8)Trauma during growth (ankylosis of TMJ and retardation of
growth in traumatized bone).
9) Trauma after completion of growth (malunion of fracture
segments).
10) Habits such as prolonged thumb sucking and mouth
breathing.
Because they cause lowered tongue position ,thus tongue no
longer balances the forces exerted by the buccal group of
musculature , which leads to narrowing of upper arch leading
to posterior crossbite.
10
6

107. Functional crossbite
- An acquired muscular reflex pattern during closure of mandible
is involved in functional crossbite.
- Presence of occlusal interferences can result in deviation of
mandible during jaw closure.
- Other causes are : early loss of decidous teeth
decayed teeth
ectopically erupted teeth.
- Thus a functional crossbite results from the mandibular shifting
into an abnormal but often a more comfortable position.
10
7

108. Anterior Cross Bite
Definition:
Anterior cross bite can be defined as upper frontal
primary or individual permanent teeth lingual position in relation
to the lower incisor teeth.

109. Factors to be considered before correcting anterior cross
bite :
1. There must be sufficient room to move the inlocked tooth
mesiodistally.
2. The patient should present a normal occlusion at molar and
canine areas(class I)
3. Patient’s co-operation and parents complete consent for the
treatment.
4. The patient should be medically fit and has no other oral
abnormalities (Eg: Fetal alcohol syndrome, Apert syndrome)
since treatment is particularly difficult and requires specific
approach and methodologies

110. Treatment
For minor correction following conditions must be present:-
•There must be sufficient room mesiodistally to move the tooth
into the correct positions.
•There should be sufficient overbite to hold the tooth in its new
position in the arch, otherwise a retainer will have to be worn
indefinitely and the result of treatment will be unsatisfactory.
•The apical portion of the inlocked tooth should be in relatively
the same position as it would be if the tooth were normal
occlusion.
•The patient should have normal occlusion in the molar and
canine area.

111. TONGUE BLADE THERAPY
• It can be used successfully in a developing single tooth
anterior CROSS BITE where sufficient space is present for
bringing out of the tooth. This technique is useful when child
is co-operative and have proper encouragement and guidance
at home.

112.  A tongue blade is a flat wooden – stick similar to an ice – cream stick.
The child is instructed to place a tongue blade in such a manner that it
rests on the mandibular incisors opposing the tooth in CROSS BITE
 Either chin (Mac donald) mandibular incisors (Graber) can be used as
fulcrum.
 The patient is advised to bite with a constant pressure on the wood
incline and at the same time to exert a slight but constant pressure
with his hand on the blade so as to prevent blade displacement.
 The proper use of the tongue blade for a 1 or 2 hr/day for 10 to 14
days is usually sufficient to deflect the lingually erupting maxillary
incisor “ACROSS THE FENCE “ into a proper relationship
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113.  Indication
 Normal or excessive overbite and adequate space in the arch
to bring the incisor into correct anteroposterior relationship
with the opposing mandibular incisor used only in cases
where cross bite is due to palatally displaced maxillary incisor.
 Contraindication
 When cross bite is due to true mandibular prognathism.
 If there is an end to end over bite or an open bite (as here the
normal function of teeth can’t maintain at its same position
after treatment)
11
3

114. •Advantages
•Ease of fabrication
•Rapidity of correction, using
functional and muscles forces.
•Lack of soreness or looseness
of the teeth during
movement.
•Rarity of replase
Disadvtanges
•Patient has problems in speech during
the therapy
•Strong dietary restrictions: soft and
liquid for several days.
•If used for long time (>6 wks) lead to
open bite (anterior) and TMJ problem.
•It cant be used more than 4 wks
•Possibility of the appliance becoming
loose and requiring recementation
because of the strong occlusal
success upon it.
•Imperfect alignment of the malposed
tooth when the appliance is removed.
The dentist must rely on autonomous
adjustment for the balance for
correction.
•Difficult in maintaining oral hygiene
•Exact amount of labial movement is
unpredictable and uncontrolled
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115. Composite Inclines
 Another simple technique is to build up a composite incline
on the lower teeth directly in the patient’s mouth.
 Croll (1999) has suggested the use of a bonded compomer
slope based on the assumption that a compomer having
less strength than a composite can be easily removed when
desired.
11
5

116. Inclined Crowns:
 Stainless steel crowns for the incisor teeth are available in
various sizes. These crowns can be adapted for use as an
inclined plane.
 A metal crown which is purposely too long gingivo-incisally
is chosen for the tooth in lingual cross bite.
 The crown is fitted making sure that the “INCISIAL” margin
extends 1 to 2 mm beyond the level of the contiguous teeth.
 A double thickness of 0.006inches by 0.200inches band
material is spot welded or soldered to the lingual side of the
crown. This strip of double – thickness material is carried
over the incisal margin to form on inclined plane at about 450
to the occlusal plane.
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6

117.  The crown is placed on the malposed teeth, and the patient
closes gently in centric relation to establish the anterior
extension of the inclined plane.
 The crown is then removed, and the plane construction is
completed by making a sharp bend in the double thickness
bond material so that it turns beak towards the labial surface
of the crown. One should spot weld and solder at this point.
 The crown is tried again in the patient’s mouth The crown
labial - incisal margin of the double thickness plane may then
be reinforced by the addition of the silver solder on the inside
of the plane.
11
7

118. Hawley Type Appliance With Z Spring
 (DOUBLE CANTILEVER)
 Used to correct 1 or 2 maxillary teeth.
 Indicated only when adequate space is present .
 In case of deep bite the spring must be given along with a
posterior bite plane to help in jumping the bite. Acrylic Hawley
type appliance is made with spring pressing against lingual aspect
of the incisors.
 The spring is activated 1.5 to 2mm to provide 1 mm of tooth
movement / month.
 If the bite is deeper than normal or if correction is taking longer
than expected, then a slight opening of the bite may be desirable
by means of a bite plane.
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8

119. POSTERIOR CROSSBITE
-This refers to an abnormal transverse relationship between upper and
lower posterior teeth.
- In normal circumstances –mandibular buccal cusps occlude in the
central fossae of maxillary posterior
teeth.
- In posterior crossbite case – mandibular buccal cusp occlude
buccal to maxillary buccal cusp.
11
9

120. CLASSIFICATION OF POSTERIOR CROSSBITES
(1) According to the number of teeth involved
single tooth segmental
crossbite tooth crossbite
(2) According to existence on one/both sides of arch
unilateral bilateral
(3) According to etiologic factor
skeletal dental functional 120

121. (4) According to extent of crossbite
Simple Buccal Lingual
posterior non occlusion non
occlusion
crossbite crossbite crossbite
Buccal cusp of one/more The maxillary posteriors occlude Maxillary
posteriors
teeth occlude lingual to entirely on buccal aspect of occlude entirely on
the buccal cusp of mandibular posteriors.Also known as lingual
aspect of
mandibular teeth SCISSOR BITE mandibular
posteriors 121

122. 1) Occlusal equilibrium.
2) Coffin spring.
3) Cross elastics.
4) Soldered W –arch (Porter appliance).
5) Quad Helix.
6) Removable appliance.
7) Rapid maxillary expansion (RME).
8) Ni-Ti expanders.
9) Oral screening.
10) Fixed orthodontic appliances.
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2

123. OCCLUSAL EQUILIBRIUM
- A dental, bilateral, lingual crossbite in primary and
mixed dentition may be simply corrected by removing the
occlusal interferences usually in the cuspid area.
- may be sometimes needed to be accompanied by some
appliance.
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3

124. COFFIN SPRING
- It was designed by Walter Coffin.
- It is a removable,omega shaped wire appliance
- It produces slow and bilaterally symmetrical expansion.
- It consists of omega shaped wire of 1.25 mm diameter
placed in mid palatal region.
- Free ends of omega are embedded in an acrylic plate that covers
the slopes of the palate.
- It brings about dento alveolar expansion.
- However, it is capable of skeletal changes when used in mixed
dentition with a good retention.
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4

125. CROSS ELASTICS
- It is used to treat localized crossbites.
- Select, fit and burnish appropriate band to maxillary and
mandibular teeth.
- Solder hooks or button to the bands- - -
on palatal surface of the maxillary teeth and
on buccal surface of the mandibular teeth.
- After these bands are welded and cemented rubber elastics is
attached on the hooks
- The rubber elastics used are – heavy rubber elastics,
0.25 i.e. 3/16 inch and
6 ounce elastic
12
5

126. - The elastic should be worn full time except while eating.
- Change it atleast once per day.
- The elastics are worn until the crossbite is slightly over corrected.
- Crossbites are ususally corrected within 3-4 months (with
continuous wearing of elastics).
- Major change will be reflected in position of the maxillary molar
because of the cancellous nature of the maxillary alveolar bone
compared with denser bone around mandibular molar.
- Advantage - Usually no need of retentive appliance
- Disadvantages – Needs patient’s co operation and
is technically more difficult.
126

127. SOLDERED W – ARCH
(PORTER APPLIANCE)
- It is an efficient appliance for the correction of posterior
crossbite as well as a reminder appliance in some posterior
crossbites assosciated with thumb sucking.
- Preformed stainless steel bands are adapted to the most distal tooth involved.
- W-arch is constructed of 0.036-0.040 inch steel wire- contoured to the arch.
- Wire is made free of tissue by 1-2 mm.
- Anterior extension of the wire should touch only the teeth that must be moved
buccally.
- W-arch is expanded about 4mm wide than its passive width or so that one arm of
“W” is resting over central grooves of teeth when the other arm is in proper position.
127

128. - The appliance is cemented during active treatment.
- Activate the appliance by slightly opening the palatal loop with a
corresponding adjustment in the molar loop area.
- The appliance activation:- intra orally
or extra orally.
- Appliance expands the arch approx 1mm/side/month.
- Activated every 3-4 weeks until crossbite is slightly over
corrected.
- Retainer used for additional 3 months.
128

129. Modification : UNEQUAL W-ARCH
- Used in case of true unilateral crossbites.
- It has long and short arms.
- Short arm- touches only the teeth to be moved.
- Long arm – touches as many contralateral teeth as possible.
- The idea behind the unequal W-arch is to pit the movement of a
large number of teeth against movement of small number of teeth.
- The side with smaller number of teeth – more movement
side with larger number of teeth - less movement.
129

130. QUAD HELIX
- Introduced by Currier and Austerman, 1993.
- The quad helix is a spring that consists of 4 helices-
2 helices in the anterior palate and
2 helices near solder joint in the posterior palate.
- It is capable of dento alveolar as well as skeletal
expansion.
130

131. - Activate the appliance prior to cementation.
- Activation is done intra orally - using triple beak plier
extra orally – using hand.
- Activation is done in 2 steps :
Step 1 – Activate the posterior helical loops,
moving the free wires buccally.
Step 2 – Activate the anterior helical loops
moving the molar bands buccally.
13
1

132. - When the wire has been activated the lingual surface of molar
bands will be above the central fossa of the molars.
- The anterior portion of wires will be above the canine cusp tip.
- The appliance produces slow expansion
- Crossbite corrected in 4-6 months.
- Retain the same appliance for further 3 months.
- The quad helix can be used simultaneously with
full bonded appliance therapy.
132

133. REMOVABLE APPLIANCES
- Lateral maxillary expansion is achieved with a parallel expansion screw
housed in upper acrylic plate.
- The appliance should have excellent tissue contact and anchorage with
clasps on teeth.
- Provide acrylic relief – palatal to anterior teeth.
- The labial bow should be passive; when expansion occurs-bow becomes
activated.
- A full turn is achieved with 4 turns of a key.
- The conventional expansion schedule– ¼ turn every 3-4 days.
- Correction is dental only.
- It causes bilateral expansion.
- Relapse potential is high.
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3

134. RAPID MAXILLARY EXPANSION
- Rapid maxillary expansion is indicated for severe cases of
bilateral
crossbites where correction requires skeletal expansion.
- It involves the splitting of the mid palatal suture
- It can easily occur in a growing child (< 9 years).
- The appliance uses a mid–palatal screw (Hyrax) – soldered to
bands on the first permanent molars and primary molars.
RME screw
Banded RME Cemented RME.
134

135. - The screw is activated a quarter turn twice each day.
- Patient is monitored once a week.
- It brings about 0.2-0.5 mm/day expansion.
- The appliance produces a rapid expansion over 3-4 weeks.
- Crossbite should be over corrected and then retained for atleast
3 months with the same applaince.
135

136. NICKEL TITANIUM EXPANDERS
- They bring about slow expansion (dental changes).
- They require less adjustments than conventional stainless steel
quad helix appliances.
- Molar bands are cemented to maxillary first permanent molars
welding is done.
Ni–Ti wire shapes are attached to lingual sheath
of welded molar band.
- Various sizes are available and need to be selected depending
on :
- the amount of expansion desired
- pre treatment width of the palate
13
6

137. - Cooling the expander it gets constricted
it gets inserted into lingual tubes on the
maxillary molars.
As it warms to body temperature it becomes springy
exerts continuous force on teeth
arch expansion
137

138. HABIT
BREAKING
APPLIANCES
138

139.  Removable and fixed
appliance
◦ Palatal crib
 Breaks the suction and force on
anterior segment
 Reminder
 Makes the habit nonpleasurable
◦ Hay rakes
 Not much helpful
 Symptoms of irritability, night
tremor, day wetting
13
9

140. ORAL SCREEN/VESTIBULAR SCREEN
- Introduced by Newell in 1912.
- It is a myofunctional appliance – that takes form of a curved
acrylic shield placed in labial vestibule.
PRINCIPLE :
It works on the principle of
force application + force limitation.
i.e. to apply the forces of circumoral musculature to certain teeth
OR
to relieve those forces from teeth
therefore allowing them to move due to forces exerted by
tongue
It works on principle of “PASSIVE EXPANSION”
14
0

141. INDICATIONS :
To intercept habits – mouth breathing
thumb sucking
tongue thrusting
lip/cheek biting
To treat mild disto-occlusions.
To perform muscle exercise to help correction of hypotonic
lip and cheek muscles.
CONTRAINDICATIONS :
In children with nasal obstruction or
respiratory distress
141

142. PROCEDURE :
Take upper and lower impressions and pour working models
Casts are occluded in normal intercuspation and sealed
Extend vestibular screen into sulcus–
(where mucosal tissue reflects)
Posteriorly extend the appliance upto distal margin of
the last erupted molar.
14
2

143. MODIFICATIONS :
Hotz modification – made up of additional metal ring.
Patient with tongue thrust – additional screen placement on
lingual aspect
In Mouth breathers – vestibular screen with a number of holes
which are gradually decreased
143

144. 14
4

145. 14
5

146.  fixed or removable appliance capable of
moving a displaced permanent tooth into its
proper position in the dental arch.
 space maintainer that pushes back the teeth
that have crowded the edentulous area
14
6

147. Active space maintainer/space regainer:
This type of space maintainer as the name suggest is active and brings
about the movement of the tooth / teeth.
Types:
1. Fixed
• Open coil space regainer
• Jack screw space regainer
• Gerber space regainer
• Modified lingual arch type(‘U’ loop incorporation)
2. Removable
• Sling shot space regainer
• Spring type space regainer
• Split saddle space regainer
• Screw type space regainer
14
7

148. Sling shot type space maintainer
Also called as Hawley’s appliance with slingshot elastic
•It is so named because of its resemblance to Sling shot. Also because
the distalizing force is produced by the elastic stretched between the
two hooks.
•From the distal end of the appliance , the hooks are attached on the
buccal and lingual sides of the first permanent molar.
•An elastic band is slung between the hooks and the tension force from
the elastic band produces the distal movement of the first permanent
molar.
•The distal movement is limited to 1-2mm
14
8

149. Split saddle type space regainer/
Hawley’s appliance with split acrylic
dumb-bell spring
• This appliance is most commonly used in lower arch.
• Hawley’s appliance is constructed with a split acrylic dumb-bell spring.
2mm of space is regained
• The spring should be adjusted twice a month creating an increment of
opening in the split acrylic area of 0.5mm at a time.
• The limit of possible spring opening is at least 3mm
14
9

150. 15
0

151. Spring type space regainer /
Hawley’s with palatal spring
The active arm of the palatal spring is placed mesial to the permanent
molar to be distalized . The activation is 2mm by opening
15
1

152. Screw Type Space Regainer
An expansion screw is embedded in the resin base of a removable
appliance.
By expanding the screw , the distal movement of the molar is achieved.
The expansion of the screw is performed by the patient once a week.
The ‘6’ can be distalized by the maximum opening width of the screw, which
is about 3mm.
15
2

153. OPEN COIL SPRING
A reciprocal active fixed regainer can be used .
•Fabrication :
•Band adaptation on ‘6’
•Fix the buccal and lingual molar tubes to the band
•Impression of the band and tubes.
•Pour the cast
•Wire is bent to a U shape
•At the junction of the straight part and the curved part of the wire flow
enough solder to make a stop.
•The coil spring is slipped on the wire and wire is put in the tubes and the
band with the wire and the compressed springs is cemented on the molar.
15
3

154. 15
4

155. 15
5

156. •Gerber space regainer
•may be fabricated directly in the mouth during one relatively short
appointment
• no lab work.
•A “U” assembly which may be welded or soldered in place with silver solder
and fluoride flux is fitted in the tube, the appliance placed and wire
section extended to contact the tooth mesial to the edentulous space.
•The length of the push coil springs is established by placing the band –
tube –wire assembly in the mouth , extending the wire to the desired
length in contact with the mesial tooth and measuring the distance
between the tube stops on the wire and the end of the “U” tube.
•To this distance add the amount of space needed in the regainer , plus 1-
2mm to ensure spring activation and cut springs to this length.
•The springs are compressed enough to allow the assembly to fit the
edentulous area.
15
6

157. 15
7

158.  As early as 1960, A.P Rogers suggested that
muscle exercises be used as an adjunct to
mechanical correction of malocclusion. He
described the role of muscle imbalance in the
etiology of malocclusion and pictured the
muscle environment of the teeth as “living
orthodontic appliances”.
15
8

159.  Principles of myotherapy:
 A) Study the possible role of muscle dysfunction in the etiology and
maintenance of malocclusion.
 B) Remove, if possible, such etiologic factors as deleterious habits,
tonsils and /or adenoids.
 C) Establish early, with minimal mechanotherapy, the proper arch
form and cuspal relationship.
 D) Remove by occlusal equilibriation any interference in the primary
dentition.
 E) Begin appropriate myofunctional appliance therapy.
 F) Be certain of occlusal functional harmony during reflex activities
before ceasing appliance therapy.
15
9

160.  Specific myotherapeutic procedures:
 a) Orbicular is Oris and Circumoral Muscles:
 If the lips cannot seal because of procumbency of the incisors, it is
best not to begin exercises until the incisors are retracted
sufficiently for the lips to exert some effect against the teeth; then,
the new tooth position may prompt normal lip and swallow
activities.
 A modified oral shield (vestibular screen) which inhibits the
mentalis muscle contraction may be useful.
 Playing any brass instrument will soon produce improved lip
tonicity.
16
0

161.  b) Mandibular posture:
 Simply asking the patient to walk upright with the shoulders squared
and eyes ahead sometimes produces immediate effects in
appearance and self- image. Functional jaw orthopedic appliance
therapy may have favorable effects on mandibular posture.
16
1

162.  Patient factors such as immaturity, lack of motivation or parental
supervision, low pain threshold and poor oral hygiene could
influence the success of interceptive orthodontics. The goals and
objectives of early treatment must be established firmly in order to
prevent unnecessary, prolonged second- phase treatment later.
 Many of these are habit behaviours which affect the correct balance
of forces of occlusion. These, even though may not be the primary
factors for the etiology of malocclusion, will certainly obstruct any
tendency for self-correction.
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2

163.  Profit WR. Treatment in pre adolescent children.
Contemporary orthodontics, 4th edition.
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3

164.  Paediatric Dentistry –by J.R . Pinkham
 Ralph E. McDonald, David R. Avery, Jeffrey A.
Dean. Dentistry for the Child and Adolescodent.
 Grabber T. M. Serial extraction: A Continous
Diagnostic and Decisional Process. Am J
Orthodontics, December 1971; 60(6): 541-575.
 Dewel B. F, Evanston. Serial Extraction:
Procedures and Limitations. Am J Orthodontics,
September 1957; 43(9): 685-687.
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165.  Orthodontics, October 1956; 42(10): 728-739.
 Emma Laing, Paul Ashley, Farhad B. Naini, Daljit S.
Gill. Space Maintenance. International Journal of
Paediatric Dentistry 2009; (19): 155-162.
 Joseph Ghafari, Early of dental arch problems. Space
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