The document discusses the Twin Block functional appliance used in orthodontic treatment. It begins with an introduction to Twin Blocks and their development. It then covers topics like appliance designs, the mode of action, treatment techniques, controversies and various clinical applications for treating different malocclusions. Case studies and references from literature on the effects of Twin Block therapy are also summarized. The document provides an overview of the versatile Twin Block appliance and how knowledge of its modifications and clinical applications can help achieve successful orthodontic results.
5. NECESSITY IS THE MOTHER OF INVENTION
First twin block app
: 1977, to 8ys old patient.
First patient
: Colin Gove.
First fabricated
: Jim Watt.
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9. BITE REGISTRATION
It is a crucial factor in design & construction.
It determines the degree of activation built in to the
appliance.
The degree of activation should stretch the muscles of
mastication sufficiently to provide the possitive
propriocepive response.
Consideration is given to facial growth pattern.
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10. BITE REGISTRATION
STEP WISE ADVANCEMENT Vs SINGLE STEP ADVANCEMENT
A study was done to identify the pattern of bone formation
in tmj in response to the step wise mandibular advancement
compared to single step advancement with fixed functional
appliances .
They concluded that step wise advancement produces more
skeletal effects than single advancement and more
prominent effect with step wise advancement was found
in the glenoid fossa compared with the condyle.
( Semin Orthod 2003:9:41-46)
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11. BITE REGISTRATION IN TWIN BLOCK TECH
VERTICAL ACTIVATION.
AND
CONTROL OF VERTICAL DIMENSION.
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14. OCCLUSAL INCLINED PLANE
Active component of twin block .
Occlusal forces are in the range of 400 – 500gms
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15. STAGE I
: ACTIVE PHASE ( 6-9 MONTHS)
STAGE II
: SUPPORTIVE PHASE ( 3-6 MONTHS)
RETENTION : UPPER ANT INCLINED PLAN ( 9MONTHS)
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16. STAGE I : ACTIVE PHASE ( 6-9 MONTHS)
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17. STAGE II : SUPPORTIVE PHASE ( 3-6 MONTHS)
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18. It can be done by cold cure acrylic or preformed
heat cure block.
No acrylic is added to the lower inclined plan.
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19. Central control of adaptive response &Neuromuscular &
skeletal adaptations.
( McNamara , 1980 )
Adaptation of bone growth in response to functional
stimulus.
( Wood side et al , 1987 )
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20. A comparison of twin block response with animal
experiments.
(Harvold)
A review of paradigm of genetic control
( Petrovic et al , 1981 )
Improved clinical use of twin block & herbst
as a result of radiating viscoelastic tissue
forces on the condyle & fossa in treatment &
long term retention : growth relativity.
( Voudouris et al :ajo do:2000:117:247-66.)
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21. 1.TREATMENT OF CLASS I DIV I WITH DEEP BITE.
EXACTO BITE
A. BITE REGISTRATION.
PROJET BITE GUAGE
B. TEMPORARY FIXATION OF TWIN BLOCK
C. COMFORT ZONE
D. MANAGEMENT OF DEEP OVERBITE.
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23. 3.COMBINATION THERAPY IN PERM DENTITION
INTEGRATION OF TWIN BLOCK WITH FIXED APPLIANCES
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24. 4. TWIN BLOCK TRACTION TECH
In the treatment of severe maxillary protrusion.
To control vertical growth pattern.
To intrude upper posterior teeth.
In adult treatment where mandibular growth
cannot assist correction of severe malocclusion.
CONCORDE FACEBOW
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25. 5.TREATMENT OF ANT OPEN BITE
Etiology.
C / F of ant open bite.
Appliance modifications.
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26. 6. TREATMENT OF CLASS II DIV II MALOCCLUSION
C/F.
Bite registration.
Appliance design.
Sagittal appliance
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27. 7. TREATMENT OF CLASS III MALOCCLUSION
Reverse twin blocks
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28. 9. MANAGEMENT OF CROWDING &
EXTRACTION THERAPY
Extraction & Functional therapy are contra indicatory terms.
Indications in certain cases.
a. Severe crowding.
b. Vertical growth pattern with crowding.
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29. 10. TREATMENT OF FACIAL ASYMMETRY
SAGITTAL TWIN BLOCK IS THE APPLIANCE OF CHOICE.
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30. 11.MAGNETIC TWIN BLOCKS
To accelerate correction of arch relationship.
To encourage increased occlusal contacts on the bite blocks
& to maximise favourable forces applied to correct
malocclusion.
Attracting magnets : Samarium cobalt & Neodynium
boron.
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31. 11.MAGNETIC TWIN BLOCKS
Author has used magnets in FIVE different clinical situations
1.
2.
3.
4.
5.
Cl II div 1 with large overjet.
Mild Cl II buccal segment relationship.
Mild Cl II div 1 with overjet 7mm.
Unilateral Cl II adult patient with TMD.
Skeletal Cl III with persistent cross bite failed to resolve with
conventional mechanics.
6. Treatment of facial asymmetry.
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32. 12.TWIN BLOCK IN TMJ THERAPY
C / F.
Diagnosis.
Goals of TMJ therapy.
Appliance design.
Stages of treatment : 1.Sagittal development
2.Functional Repositioning
3.Vertical development
Biofinisher.
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34. 13. FIXED TWIN BLOCKS
Advantages of fixed appliances
Esthetic appliance design.
Stages of treatment.
1. Interceptive treatment & arch development by the Wilsons
modular appliance system.
2. Orthopaedic treatment by fixed twin blocks.
3. Detailed orthodontic correction by fixed appliance.
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35. Twin Block is versatile removable functional appliance
used to treat various types of malocclusions.
Having knowledge about the Twin Block and its various
modifications with proper case and appliance selection
successful results can be obtained.
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36. 1. Twin Block Functional Therapy,
by William J Clark.
2. Orthodontics & Dentofacial Orthopedics
by McNamara & Brudon.
3. Dentofacial Orthopedics with Functional Appliances
by Graber , Rakosi & Petrovic.
4. Orthodontics Current Principles & Techniques
by Graber , Vanarsdall.
5. Removable Orthodontic Appliances
by Graber & Neumann.
6. Am J Orthod Dentofacial Orthop :2000:117:247-66.
7. Semin Orthod : 2003:9: 41-46.
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