detailed overview on interceptive orthodontics, with treatment plan for variable cases

1. Interceptive orthodontics
Dr. Rafia shah
BDS, M.Phil., MSc (Orthodontic trainee).
Lecturer at LUMHS Jamshoro Pakistan

2. What is Interceptive orthodontics
Branch of orthodontics undertaken to;
• Eliminate the developing problem at the right time.
• Prevent severity of malocclusion.
• Allows corrective orthodontics to
deliver desired stable results.
• Ensure that abnormal oral habits aren’t fixed, they may be
eliminated with appliances.
• Shorten treatment time in order to prevent discomfort to
patient.

3. Definition of interceptive orthodontics according to
American association of Orthodontics:
That phase of the science and art of orthodontics
employed to recognize and eliminate potential
irregularities and malposition in the developing
dentofacial complex.

4. Steps taken during interceptive orthodontics
1. Space regaining
2. Correction of anterior and posterior cross bite
3. Elimination of abnormal oral habits
4. Muscle exercise
5. Removal of soft and hard tissue barrier at the path of
eruption of a tooth
6. Resolution of crowding
7. Interception of developing skeletal
malocclusion.

5. Space Regaining

6. Space Regaining
Premature loss of any deciduous tooth
may lead to loss of space for the
succedaneous tooth, which result due to
mesial tipping / drifting of adjacent into
the empty space.
Causes of mesial tipping/ drifting:
1. Extensive carious lesions
2. Ectopic eruption
3. premature extraction of deciduous 1st
molar without any space maintainer.

7. Procedure of gaining space
Mixed dentition analysis

8. 1. Moyers mixed dentition analysis
The purpose of analysis is to;
• Evaluate space in the arch for succeeding permanent teeth.
• Evaluate space for necessary occlusal adjustments.
Strategy of analysis:
 Estimate the size of un erupted permanent canine and premolars from
radiographic image
 Estimate the size of canine and premolars from the permanent teeth already
erupted in the arch
 Mandibular incisors are chosen to estimate the size of un erupted teeth
because they erupt early in the arch.
Maxillary incisors show much variability so their correlation with other teeth is

9. Procedure in the mandibular arch
1. Measure the mesiodistal width of all
four mandibular incisors via tooth
measuring /pointed Boley’s gauge
2. Determine the space required for the
alignment of incisors;
Determine width by placing one point of the
gauge at the midline of central incisors and
other point along the line of dental arch on
the distal side of left lateral incisor. Same
process shall be repeated for the right side.

10. 3. Compute the amount of space available after
incisor alignment.
Mark the point in the arch at the distal surface of
lateral incisor and the mesial surface of 1st
permanent molar.
Take the measurement on both sides in the similar
way.
4. Predict the combined width of cupid and two
bicuspids from the value given in
the chart.
The value at 75% correspond to
the sum of the width of mandibular
four incisors will be said to be the
most practical for clinical standpoint.

11. Procedure in the maxillary arch
• Same as for the mandibular arch.
• Only different probability values will be used to predict sum for cuspid and
two bicuspids.
• Allowance for overjet correction must be made while aligning incisors.
It shall be noted that sum of the width of lower incisors is used to predict the
space required for maxillary cuspids and bi cuspids

15. 2. Tanaka and Johnson analysis
• They simplified Moyers 75% of
prediction into a formula.
• Doesn’t require radiograph and
prediction table.
• It is a correlational-statistical method.

16. Prediction for maxillary cupid and bi cuspids
𝑚𝑒𝑠𝑖𝑜𝑑𝑖𝑠𝑡𝑎𝑙 𝑤𝑖𝑑𝑡ℎ 𝑜𝑓 𝑓𝑜𝑢𝑟 𝑙𝑜𝑤𝑒𝑟 𝑖𝑛𝑐𝑖𝑠𝑜𝑟𝑠
2
+ 11
= estimated width of canine and premolars of one quadrant
Prediction for mandibular cupid and bi cuspids
𝑚𝑒𝑠𝑖𝑜𝑑𝑖𝑠𝑡𝑎𝑙 𝑤𝑖𝑑𝑡ℎ 𝑜𝑓 𝑓𝑜𝑢𝑟 𝑙𝑜𝑤𝑒𝑟 𝑖𝑛𝑐𝑖𝑠𝑜𝑟𝑠
2
+ 10.5
= estimated width of canine and premolars of one quadrant

17. Timing of 1st permanent molar distalization
The timing of molar distalization is important;
• Before age of 9 the roots of molar are not complete,
so it is easier to carry tipping or bodily movement.
• Delayed treatment will make it difficult to be
distalized because erupting adjacent 2nd permanent
molar will not allow it….to do so extra oral anchorage
will be required .
• Best age to get results is 7-10 years.
Space may be regained by distalization with;
Fixed appliances
Removable appliances

18. Fixed Appliances
1. Open coil space re-gainers
(Herbst space re-gainer)
2. Jackscrew space re-gainer
3. Gerber space re-gainer

19. Open coil space re-gainers (Herbst space re-gainer)
• Band is adapted on the 1st permanent molar which
need to be distalized.
• Buccal tube are spot welded to the lingual and buccal side of the band.
• Tubes are 0.25 inch long, they carry flanges for spot welding.
• Both the tubes shall be placed parallel to each other in all planes.
• The lumen of the tube should be aimed at the junction of crown
and gingival of 1st premolar.
• Impression will be taken after the band placed over the 1st molar, the holes of the
tube will be covered with carding wax at this time.
• Once the impression is achieved with the band placed, then it
will be poured to make model.

20. • Stainless steel 0.7 mm wire is then U shaped,
which then be seated in both the tubes passively.
• The anterior part of the U shape will be given
reverse bend, that will contact the distal end of first
premolar below its greatest convexity.
In case of rectangular tubes, the rectangular wire of
0.0125*0.025 will be used, but this will be harder to
bend.
• At both the curve ends of wire (buccally & lingually)
enough solder shall be flown to make a stop.
• Then enough space open coil spring that extend
from the stop till the point (2mm distal) to the
anterior limit of tube on the molar band.

21. • Band is removed by heating the stone present inside
the band and by cutting the softened residue.
• The coil spring is slipped over the wire, then the
wire is placed in both the tube
• Band is cemented on the tooth along with the
compressed spring.
• The compressed spring will behave passively and
exert reciprocal pressure mesially to the premolar
and distally to the permanent molar.
• Seating pressure is applied on buccal side of band in
mandibular molar, whereas for maxillary molar band
placement pressure is applied on palatal and buccal
side.

22. Jackscrew Space Regainer
• To recover the loss of space caused by tooth drift
into an edentulous space.
• It uses 2 banded adjacent teeth.
• It use threaded shaft with a screw and a locknut.
• It is activated regularly to exert consistent force
against the banded teeth.
• A bilateral version of this appliance consist of a
coiled loaded lingual arch that passes through
tubes soldered lingually to molar band.
• Appliance produce rapid result.

23. • Band is place on the molar tooth and the impression is
taken along with the band placed.
• Cast is poured.
• 0.036 inch tubes is soldered or welded on the band
buccally.
• Tube shall be positioned on middle 1/3rd of the band and
shall be aligned with other banded abutment tooth.
• Manufacturer provide the jackscrew with an a
adjustment nut and a lock nut on the threaded shaft.
• Properly alignment of shaft b/w both the abutment
teeth shall be kept under consideration.

24. • The mesial end of the shaft shall
be trimmed and contoured to the
premolar band surface.
• Distal end of the shaft shall be left
2mm from the tube o the molar
band.
• a liberal amount of flux is applied
and soldered onto the premolar
band.
• Finally the appliance is cemented
into the oral cavity.

25. Gerber Space Regainer
• It may be fabricated directly in the mouth.
• Doesn’t require laboratory procedure.
• U shaped assembly with U shaped wire is used to
make appliance.
• This in turn is soldered onto the mesial aspect of
the band .
• Later a coil spring is fitted onto the U shaped wire
• Which then be fitted into the U shaped assembly.
• Finally it will be cemented on the molar tooth.

26. Removable Appliances
1. Upper and lower Hawley's appliance
with helical spring.
2. Hawley's appliance with Split
Acrylic Dumb-bell spring.
3. Hawley's appliance with Slingshot
Elastic
4. Hawley's appliance with palatal
spring.
5. Hawley's appliance with expansion
screw.

27. 1. Upper / lower Hawley's appliance with helical spring
Used for both mandibular and maxillary
molars.
It consists of:
• Short labial bow gives more anchorage.
• Adams clasp on contralateral molar.
• 0.6mm wire helical spring with the active arm towards the
tissue.
Helical spring used can be single or double,
depending upon expertise of a dentist.

28. Helical spring
• Double helical spring require more time to bend .
• Its kinder to periodontium of a tooth to be
positioned.
• To increase retention, an active arm of the
spring shall be placed in the undercut.
Note:
Application of excessive pressure in attempt to
lessen treatment time may produce necrosis.
Improperly positioned spring may displace itself and
the appliance too.

29. Activation of Helical Spring
During the 1st week of treatment:
Helical spring should be adjusted with distally directed little or no
pressure.
At the 2nd week of treatment and there after at 2 week interval:
Spring should be adjusted with slight distally directed pressure
against the permanent 1st molar tooth.
• The child’s arch shall be measured constantly with
modified Boley's gauge in order to assure distalization.
• Normally 2mm distalization is obtained in 2-4 months.

30. 2. Hawley's appliance with Split Acrylic Dumb-bell
spring.
• Constructed on mandibular arch.
• Used to regain up to 2mm of lost space.
• Space is gained by distal tipping of molar.
• Dumb-bel spring allow easy adjustment.
Activation of dumb-bell spring
• Should be adjusted twice a month.
• Opening of spring should create 0.5mm increment
of opening at split area of acrylic plate
• Spring can be possibly opened up to 3mm.
Note : large adjustment may not allow proper seating
of a plate into the area mesial to molar, which needs distalization.

31. Hawley's appliance with Slingshot Elastic
• Here wire elastic holder with hook is used to
transmit force, instead of a wire spring.
• it is also called sling shot appliance.
• The force exerted id via elastic stretched between 2 hooks.
• One hook is place at lingual surface of a
molar to be distalized.
• Other hook placed on buccal surface of the
same molar.

32. Hawley's appliance with palatal spring.
• Spring is made up of 0.5 mm stainless steel wire.
• Active arm is placed on the mesial surface of the
molar to be distalized.
• Active arm shouldn’t be too long.
• Helix diameter shall be 0.2mm.
Activation of a spring:
Opening of a spring by 2mm.

33. Hawley's appliance with expansion screw.
Over view of expansion screws
Expansion screws are first introduced by Schwartz.
These are basically of 2 types:
 Encased type
 Skeleton type
According to Fisher’s the screws are;
 One point
 Two point
Other kinds of screws are
 RME ( Rapid Maxillary Expanders)
 Micro screws
 Special
 eccentric

34. Encased type of screws:
• They are sturdy so resist stress.
• Spiral part of it may some time turn back.
• May be incorporated with springs.
Skeleton type of screws:
• Superior and most preferred type.
• Its spiral part is embedded in the acrylic.
• Available in various sizes.
• Broader is used in maxillary and narrower is used for mandibular arch.
• Small size is also effective for molar distalization.
• 1 full turn of the screw bring 0.4-0.8 mm expansion.
Note: 1/4th turn of Fischer screw would bring 0.1/0.25mm expansion.

35. Correction of anterior and
posterior cross bite

36. Cross bite
• Could be anterior or posterior.
• Should be corrected as soon as detected.
• May be treated during mixed dentition period at time the permanent
teeth begin to erupt.
• May be unilateral/bilateral or may be true /functional
• If not treated in time, them may lead to skeletal malocclusion, which
may require corrective orthodontics treatment.
Appliances used to treat cross bites:
1. Tongue blade therapy 2. Inclined planes 3. Composite inclines
4. Quad helix 5. Hawley’s appliance with z spring
6. Medium, mini and micro screws embedded in acrylic appliance

37. Elimination of abnormal
oral habits

38. Oral habits
Thumb sucking/ digit sucking, mouth breathing ,lip sucking,
tongue thrusting :
• tend to cause class II malocclusion
• Lead to an imbalance in the forces acting on the teeth.
• If untreated may lead to skeletal malocclusion.
• Lead towards abnormal positioning of tongue,
aberrant lip and perioral musculature.
• Develop unfavourable V shaped arch with high
palatal arch.

39. Muscle exercise
• For normal occlusion it is important to have a proper balance
of surrounding musculature, any aberration of surrounding
musculature may lead to development of malocclusion.
• Muscle exercise allows clinicians to bring such aberrant muscle
function into normal functioning, in order to achieve normal
growth and development of malocclusion.
Uses of exercise:
1. To guide the development of occlusion.
2. To allow optimal growth pattern.
3. To provide retention and stability in post-corrective
(mechanical)orthodontic cases

40. Types of exercise
1. Exercise of orbicularis and circumoral group
of muscle.
2. Exercise of tongue muscles.
3. Exercise of masseter muscle.
4. Exercise of pterygoid muscle.

41. Exercise of orbicularis and circumoral group of
muscle.
• Upper lip is stretched posterio-inferiorly by overlapping the
lower lip. this exercise allows hypotonic muscle to make a
lip seal.
• By holding piece of paper between lips.
• Swishing of water between lips until they get tired.
• Massaging of lips.
• Playing a reed musical instrument.
• Placement of scotch tape over the lips to train lip seal.
• Use of oral screen with holder.
• Button pull exercise.
• Tug of war exercise.

42. • Button pull exercise:
A thread is passed from1
1
2
inch diameter button.
Button is kept in behind the lips with the thread
projecting outward. Patient is asked to seal lips to resist button and pull the
thread to force it outward.
• Tug of war exercise:
Here to buttons are threaded in the same string
at both the ends.1 button is placed behind lips and
other is left outward. Another person is asked to pull the thread while patient
tries to resist it with the lips.

43. Exercise of tongue muscles
• One elastic swallow:
An orthodontic elastic usually 5/16th inch is placed on
the tip of tongue. Patient is asked to elevate tongue to
touch rugae and swallow.
• Two elastic swallow:
Two 5/16th inch elastic are used.
1 is placed on the tip of tongue and other at the
dorsum in the middle, then patient is asked to
swallow.

44. • Tongue hold exercise:
A 5/16th inch elastic is used.
A spot is designated and patient is asked to place elastic
over there for definite period with closed lips.
Then pt. is asked to swallow with elastic in position and
lips apart
• Hold pull exercise:
The tip of tongue is made to contact palate in the
midline.
The mandible is gradually opened.
This helps stretching of frenum to relive a mild tongue
tie.

45. Exercise of masseter muscles
• Patient is asked to clench
teeth.
• Count up to 10 in mind
• Then relax
• Repeat the same till gets tired.

46. Exercise of pterygoid muscles
• In case if the disto-occlusion is present.
• Patient is asked to stretch mandible as
much as possible and then retracted.
• Repeat the exercise until the muscle
get tired.
• The ability to keep the mandible in
correct position gradually improves.

47. Limitation of muscle exerciser
• Exercise are not known to drastically alter any bone
growth pattern.
• They are not a substitute for corrective orthodontic
treatment.
• Patient compliance is extremely important.
• If not done correctly, can be counter productive.

48. Removal of soft and hard tissue
barrier at the path of eruption of
a tooth

49. Clinical conditions where hard/ soft tissue barriers impede eruption
of teeth:
1. Retained deciduous tooth/ teeth:
• Occur due to use of soft detergent diet.
• Generally observed in the mandibular anterior
region where permanent teeth erupt lingually.
• In maxillary region permanent teeth
erupt buccally/ labially.
• Unilateral presence of retained teeth may cause midline shift thus
leading to arch space deficiency.
Management:
Extraction of retained deciduous teeth

50. 2. Supernumerary teeth and mesioden:
There presence may impede eruption of
permanent teeth.
Management:
Timely extraction may intercept development of malocclusion.
3. Fibrous/bony obstruction of the erupting tooth bud:
If the contralateral tooth doesn’t erupt within 3 months, then radiographic
assessment shall be done in order to plan
excision of soft tissue/ removal of
overlying bony.
Management:
Maximum removal shall be done over the
crown of unerupted tooth.
Post surgical zinc oxide eugenol dressing shall be for 2 weeks

51. Resolution of crowding

52. Crowding:
• Is present at different satges of dentition.
• Variable severity is seen during mixed dentition stage.
• In anterior region incisal liability plays an active role to solve it.
• In posterior region leeway space of Nance help
resolution. 0.9mm in maxilla/quadrant
1.7mm in mandible/quadrant
Incisal liability occur:
• In anterior region due to requirement of greater mesiodistal
dimension by permanent as compared to deciduous teeth.
• Due to non- spaced dentition, where primate space is absent.

53. Manifestations of crowding:
Maxillary lateral incisors erupt more palatally/
labially and mandibular teeth erupt more lingually.
Note: deciduous -permanent tooth size difference is average 6-7mm.
Mechanism which resolve incisal liability by growth and
development of occlusion.
Interdental spacing.
Intercanine arch growth
Labial positioning of the incisors

54. Interdental spacing.
• Presence of space during deciduous
and mixed dentition helps
accommodate the erupting large
permanent incisors (Leighton).
• Primate space is generally 2-3mm.
• In the mandible eruption of
permanent lateral incisor causes
lateral shift of deciduous canine, thus
help reliving crowding further.

55. Intercanine arch growth
• Intercanine width provide 3-4mm
space.
• It is greater in maxilla
• Help accommodate crowding during
growth.
• Premature loss of deciduous canine
may lead to development of deep bite
and loss of Intercanine arch width.

56. Labial positioning of the incisors
• Labial placement of incisors
provide 1-2mm of spacing.
• Helps to correct incisors
alignment.

57. Ways to manage crowding
1. Observation
• Proper observation during deciduous
dentition may resolve up to 50% of
crowding in permanent dentition.
• Normal physiological space is between
2-3mm.
• If such space is greater than 6mm and
crowded incisors require only 2mm
space then no interception shall be
done.

58. 2. Disking of primary teeth
• Disking is done when anterior teeth
crowding require not greater than 4mm
space.
• Disking is done from mesial surface of
deciduous canine to distal surface of it.
• In case of more space requirement
mesial surface of 1st deciduous molar
shall be disked.
• Topical fluoride application shall be
given to prevent senility after disking.

59. 3. Extraction and serial extraction
• Deciduous may be extracted if
radiographic position of permanent
tooth near eruption.
• Retained deciduous tooth may be
extracted.

60. 4. Corrective orthodontic referral
• Some of the mixed dentition cases
may require fixed orthodontic
treatment,
• Intervention hall be of short duration
in mixed dentition.
• Selective cases are preferred for fixed
appliances.
• Retention appliance must be followed
after removal of fixed treatment.

61. Serial extraction /Guidance eruption
Definition
• Planned and sequential removal of primary
and permanent teeth to intercept and
reduce dental crowding problem. Tweed
• The correctly timed, planned removal of
certain deciduous and permanent teeth in
mixed dentition cases with dentoalveolar
disproportion. Tandon

62. Rationale of Serial extraction /Guidance
eruption
In case of arch length tooth material
discrepancy:
When the tooth material is more than arch
length, then selective extraction of teeth help
guiding teeth to normal.
Physiological tooth movement:
The normal tendency of human teeth to move
towards extraction space can be prevented by
planned and selective removal of teeth

63. Serial extraction
• Term was coined by kjellgren.
• Procedure was popularized by Nance.
• Preferred by Holtz as guidance of eruption
• Initiated at the early mixed dentition stage.
• Help to resolve potential anticipated irregularities of dento facial
complex.
• It includes planned extraction of deciduous followed by some
permanent teeth.
• Done to guide eruption pathway to the permanent teeth.
• If done carefully may reduce patient’s time, cost and treatment
discomfort

64. Indications of serial extraction
1. Class I malocclusion
with normal skeletal and muscular pattern.
With arch length- tooth material discrepancy of 5mm or more/ quadrant
2. Arch length deficiency
It could be unilateral or bilateral.
Pathological or non pathological
Pathological conditions causing Arch length deficiency includes:
• Extensive proximal caries leading to mesial migration of teeth.
• Premature loss of deciduous troth with lack of space maintainer.
• Deleterious oral habits.
• Improper proximal restoration
• Tooth ankylosis

65. Non-pathological conditions causing Arch length deficiency
includes:
• Midline shift mandibular incisors due to displaced lateral
incisors.
• Premature loss of deciduous canine.
• Abnormal canine root resorption.
• canine being blocked out labially.
• Bimaxillary protrusion.
• Gingival recession of mandibular anterior labially.
• Ectopic eruption.
• Lower anterior flaring

66. Contraindications of serial extraction
• Class II and class III malocclusion with
skeletal abnormalities.
• Mild to moderate crowding with arch length-tooth material
discrepancy < 5mm/quadrant.
• Spaced dentition.
• Congenital absence of tooth-------anodontia/oligodontia.
• Extensive caries where 1st permanent molar cant be conserved.
• Open bite cases.
• Deep bite cases.
• Midline diastema.
• Un erupted teeth eg: dilacerations.

67. Diagnostic steps for serial extraction
1. Clinical examination:
Done to find malocclusion and find need for investigation
2. Study models: provide information to;
Asses dental anatomy of teeth.
Assess intercuspation of the teeth.
Assess arch form and curve of occlusion.
Evaluate occlusion.
Undertake different model analysis ------Carey’s, arch perimeter and
mixed dentition analysis .
Between and post treatment assessment.

68. 3. Radiographs:
Types of recommended radiographs are;
Intra oral periapical
Lateral cephalometric
Orthopantomogram (OPG)
They provide information about;
Congenitally missing teeth, supernumerary teeth.
Bony pathosis.
Stage of root development and Possible eruption pattern.
Radiographic mixed dentition analysis to be undertaken.
Dental age of patient.
Different relations b/w craniofacial structures using
cephalometry.
Soft tissue matrix.
Facial pattern.
Mid and post treatment relationship.
Treatment progress

69. 4. Photographs
Intraoral and extraoral photographs are
used to have following information:
Pre-med & post evaluation of self assessment.
Progression in treatment & patients motivation.
Any change in facial profile (Rt. Lateral, Lt. lateral
mid and post treatment).
Muscular hypo and hyperactivity.

70. Tweeds method

71. Procedure for serial extraction
Different authors have given different sequence for guidance of
tooth eruption.
Tweeds method
Proposed extraction sequence is DC4
1st deciduous molar is extracted at the age of 8.
Deciduous canine are maintained to slow down eruption of
permanent canine.
As soon as 1st premolar is eruptive with the
crown above alveolar level (radiographically),
the deciduous canine along with 1st pre molar is extracted.
Mnemonic
Tweed…do count four to eight

72. Dewel's method

73. Dewel's method
Proposed extraction sequence is CD4.
Deciduous canines are is extracted at the age
of 8 ½ years to allow space for crowded anterior.
At 9 ½ years as the crowding get resolved the1st
deciduous molars are extracted by viewing half level
root development of 1st premolar (radiographically),
in order to allow premature eruption of 1st premolar.
Once 1st premolars are erupted, they are extracted
to allow canines to get in their place to provide
alignment.
Mnemonic
Dewel….climbed door for
safety at 8.5

74. Modified Dewel's method
If radiographic evaluation shows permanent
canine at higher level than the 1st premolar.
Then enucleation of the developing crown of 1st premolar will be
done at the time of extraction of deciduous 1st molar.
Another modification is;
Extract the 2nd deciduous molar instead of 1st premolar enucleation
after placing arch hold in order to allow distal eruption of 1st
premolar.
On eruption of permanent canine the 1st
premolar are extracted.

75. Nance method

76. Nance method
Proposed extraction sequence is D4C.
Its basically modified Tweeds method.
Extraction of deciduous 1st molar is done at the age
of 8 years.
Followed by extraction of the 1st premolar and deciduous
canine
Mnemonic:
Nance learnt dance
from chorographer

77. Grewe’s method

78. Grewe’s method
He has described the sequence of extraction on the basis of clinical
condition
1. Class I malocclusion with premature
loss of mandibular deciduous canine.
2. Class I malocclusion with severe
mandibular anterior crowding.
3. Class I malocclusion where mandibular
anterior crowding is 6-10 mm arch deficiency.
4. Dental class II with normal overjet.
5. Dental or skeletal class II with slight but minimal overjet.

79. Class I malocclusion with premature loss of mandibular deciduous
canine
Scenario:
Appears with midline shift to the affected side.
Extraction sequence:
• Deciduous canine of the opposite side shall be
extracted if the arch length discrepancy is 5-10mm.
• Next the extraction of 1st deciduous molar shall be done (in case if the roots
of 1st premolar developed more than half).
Note: if the roots of 1st premolar are not developed more than half then
extraction of deciduous 1st molar shall be delayed.
• 1st premolar shall be extracted as it erupt.
Note in case of any asymmetry on either of the side and either of the jaw then
serial extraction would be difficult to achieve.

80. Class I malocclusion with severe mandibular anterior
crowding
Scenario:
In case of arch length deficiency of more than5mm/quadrant.
Extraction sequence :
• Deciduous canines shall be extracted.
• Next the 1st deciduous molar shall be extracted
(in case if the 1st premolar has at least half of the roots extracted).
• As the 1st premolars erupt in the oral cavity then they shall be extracted.

81. Class I malocclusion where mandibular anterior crowding is
6-10 mm arch deficiency.
• Such problem arise when there is crowding in
canine-premolar region.
• Arise when there is bi maxillary protrusion.
Objective:
Remove 1st premolar as early as possible.
Extraction sequence
• Extraction of 1st deciduous molar shall be done (in case if the roots of 1st
premolar developed more than half to allow early eruption of premolar).
• Extract 1st premolars as they erupt.
• Extract deciduous canines.
Note: In case if canine erupts before premolar…then the deciduous canine
shall be extracted first, followed by 1st deciduous molar and enucleation of 1st
premolar.

82. Dental class II with normal overjet.
Scenario:
• No crowding in lower arch, only there is crowding
in upper arch.
Extraction sequence:
• Proposed sequence is CD4.
• Extraction of deciduous canines.
• Extraction of deciduous 1st molar.
• Followed by extraction of 1st premolar.
Note: deciduous 2nd molars are kept under review to be extracted to
allow buccal interdigitation.

83. Dental or skeletal class II with slight but minimal overjet.
Scenario:
crowding in both lower arch, and upper arch.
Extraction sequence :
• Extraction of maxillary 1st deciduous molar and
mandibular deciduous 2nd molar.
• Followed by enucleation of mandibular 2nd premolar.
• Maxillary 1st premolar and maxillary deciduous canine
are extracted (when maxillary 1st premolar emerge
into the oral cavity).
Note: some corrective orthodontic intervention may be needed.

84. Advantages of Grewe’s method
• More physiological as teeth are guided into
normal position by using physiological forces.
• Duration of fixed treatment is reduced.
• Health of investing tissue is preserved.
• Lesser retention period is required.
• More stable results

85. Disadvantages of Grewe’s method
• Good clinical judgement is required.
• No single approach can be applied universally.
• Treatment time is about 2-3 years.
• Patients cooperation is required.
• Tendency to develop tongue thrust as extraction
space closes gradually.
• Extraction of buccal teeth may lead to deepening of bite.
• Residual space may be left between canine and 2nd premolar.
• Some amount of fixed appliance therapy is needed
at the end of treatment.

86. Interception of developing skeletal
malocclusion.
• Detection of developing malocclusion at an early stage
may result in normal occlusion.
• Such changes are brought about by myofunctional
therapy.
• Myofunctional therapy is also called Functional Jaw
Orthopaedics.
Classification of myofunctional appliances:
Tooth-borne passive
Tooth-borne active
Tissue-borne

87. Interception of Class II Malocclusion.
Reasons of class II malocclusion:
• Increased maxillary growth.
• Decreased mandibular growth.
• Combination of both.
Treatment by myofunctional appliances:
For excessive maxillary growth face bow along
with head gear.
For decreased mandibular growth myofunctional
appliances.

88. Interception of Class III Malocclusion
Reasons of class III malocclusion:
• Decreased maxillary growth.
• Increased mandibular growth.
• Combination of both.
Treatment by myofunctional appliances:
For decreased maxillary growth Frankel’s III
appliance
Increased mandibular growth chin cup

89. Note:
Myofunctional appliances are not usually
accepted by patients because the are; bulky,
hard and stiff.
In recent time softer appliances are used,
which are product of CAD/CAM technique.
Such appliances are soft, flexible and less
bulky.