This document discusses the Twin Block functional appliance, including its development, designs, mode of action, and treatment techniques. It introduces the Twin Block, developed in 1977 to treat a young patient. Key features and benefits are outlined, along with bite registration procedures, component designs, and treatment stages. Modifications for treating various malocclusions are described, along with integration with fixed appliances. The versatility of the Twin Block for treating different malocclusions is emphasized.

1. PROF (Dr.) SAIBEL FARISHTA

2.  INTRODUCTON
 DEVELOPMENT OF TWIN BLOCKS
 APPLIANCE DESIGNS & CONSTRUCTIONS
 TWIN BLOCK TECHNIQUE
 MODE OF ACTION
 TREATMENT BY TWIN BLOCK TECH
 CONCLUSION
 REFERENCES

4. “NECESSITY IS THE MOTHER OF INVENTIO
 First twin block app : 1977, to 8ys old patient.
 First patient : Colin Gove.
 First fabricated : Jim Watt.

5. Comfort
Esthetic
Function
Patient compliance
Facial appearance
Speech
Clinical management

6. Arch development
Mandibular repositioning
Vertical control
Facial asymmetry
Safety & efficiency
Integration with fixed appliance
Treatment of TMJ dysfunction

7. BITE REGISTRATION
STANDARD TWIN BLOCK
OCCLUSAL INCLINED PLANES

8. 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.

9. BITE REGISTRATION
STEP WISE ADVANCEMENT Vs SINGLE STEPADVANCEMENT
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)

10. BITE REGISTRATION IN TWIN BLOCK TECH
VERTICAL ACTIVATION.
AND
CONTROL OF VERTICAL DIMENSION.

11. BASIC COMPONENTS
CONTROVERSIES REGARDING LABIAL BOW

12. DELTA CLASP
BALL END CLASP &BASE PLATE

13. OCCLUSAL INCLINED PLANE
 Active component of twin block .
 Occlusal forces are in the range of 400 – 500gms

14. STAGE I : ACTIVE PHASE ( 6-9 MONTHS)
STAGE II : SUPPORTIVE PHASE ( 3-6 MONTHS)
RETENTION : UPPER ANT INCLINED PLAN ( 9MONTHS)

15. STAGE I : ACTIVE PHASE ( 6-9 MONTHS)

16. STAGE II : SUPPORTIVE PHASE ( 3-6 MONTHS)

17.  It can be done by cold cure acrylic or preformed
heat cure block.
 No acrylic is added to the lower inclined plan.

18.  Central control of adaptive response &Neuromuscular &
skeletal adaptations.
( McNamara , 1980 )
 Adaptation of bone growth in response to functional
stimulus.
( Wood side et al , 1987 )

19.  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.)

20. 1.TREATMENT OF CLASS I DIV I WITH DEEP BITE.
D. MANAGEMENT OF DEEP OVERBITE.
A. BITE REGISTRATION.
EXACTO BITE
PROJET BITE GUAGE
B. TEMPORARY FIXATION OF TWIN BLOCK
C. COMFORT ZONE

21. 2. TREATMENT IN MIXED DENTITION

22. 3.COMBINATION THERAPY IN PERM DENTITION
INTEGRATION OF TWIN BLOCK WITH FIXED APPLIANCES

23. 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

24. 5.TREATMENT OF ANT OPEN BITE
 Etiology.
 C / F of ant open bite.
 Appliance modifications.

25. 6. TREATMENT OF CLASS II DIV II MALOCCLUSION
 C / F .
 Bite registration.
 Appliance design.
Sagittal appliance

26. 7. TREATMENT OF CLASS III MALOCCLUSION
Reverse twin blocks

27. 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.

28. 10. TREATMENT OF FACIAL ASYMMETRY
SAGITTAL TWIN BLOCK IS THE APPLIANCE OF CHOICE.

29. 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.

30. 11.MAGNETIC TWIN BLOCKS
Author has used magnets in FIVE different clinical situations
1. Cl II div 1 with large overjet.
2. Mild Cl II buccal segment relationship.
3. Mild Cl II div 1 with overjet 7mm.
4. Unilateral Cl II adult patient with TMD.
5. Skeletal Cl III with persistent cross bite failed to resolve with
conventional mechanics.
6. Treatment of facial asymmetry.

31. 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.

32. 13. FIXED TWIN BLOCKS

33. 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.

34. 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.

35. 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.