biodata and works of william clark

1. WILLIAM J. CLARK
-MANOJ PRATHAP .C
III YR POST GRADUATE

2. INTRODUCTION
• Dr. William J. Clark is a Scottish Orthodontist
• He has completed his B.D.S., D.D.O., D.D.Sc.,F.D.S.R.C.S.(Eng)
• In 2010 he completed a thesis on “New Horizons in Orthodontics & Dentofacial
Orthopaedics” for a D.D.Sc. Degree from Dundee University, and has received an
honorary fellowship award (F.D.S.) from the Royal College of Surgeons (England).
• His recent researches are on skeletal and dental correction of Class II and III
malocclusion

3. Dr Clark is the first recipient of an award of distinction from the British
Orthodontic Society for an outstanding contribution to the specialty of
orthodontics. In 2008 he received the first award from the International
Functional Association (IFUNA) for personal outstanding international
service to functionalism and orthodontics
In 1990 he presented the first teleconference in clinical dentistry in a
live course in Chicago, transmitted by satellite to 25 cities in the USA
and Canada. This launched his techniques and for the past 30 years he
has travelled worldwide to deliver courses and lectures in over 40
countries

4. Dr Clark has 50 years experience in orthodontic practice and continues to
develop innovative appliances in orthodontic and orthopedics techniques. The
Twin Block was developed in 1977 in his orthodontic practice in Scotland. The
technique is the most widely used functional technique throughout the world,
and is illustrated in "Twin Block Functional Therapy - Applications in Dentofacial
Orthopaedics", published by Mosby in 2002
In (2005) cooperation with Ortho Organizers Dr. Clark designed TransForce
Lingual Appliances for arch development and he has recently developed Fixed
Twin Blocks, the next logical advance in functional orthopaedic therapy.

5. He has Invented two appliances which has revolutionized the
field of functional appliance
-Twin Block (1977)
-Transforce (2005) & Transforce 2 (2010)

6. History on Functional Orthopaedic appliances-
• The Term Dentofacial Orthopaedics was suggested by late
Sir Norman Bennett
• 1879 –Norman W Kingsley Was the first person to suggest
forward positioning of mandible during orthodontic
treatment (Removable plate with molar clasp-Jumping of
the Bite)
• The Early 1900’s Forerunner of Functional Appliances –
Monobloc, Pierre Robin (1902)
• Early 1900’s was the controversies between the USA and
Europeans on the Design of the Functional Appliances
• Edward Angle used interlocking springs to opposing
Molar bands to reposition the mandible

7. • Early 1900’s George Crozat came up with the first Precious Metal
Appliance called –Crozat Appliance
• Martin Scwartz developed the split plate and he introduced the
schwartz clasp
• Philip Adams in Belfast Later modified this clasp and called it adams crib
which is now commonly used in all functional appliances
• Alfred P Rogers Father of Myofunctional Therapy
• Wilhelm Roux (wolff’s law)1883 – Karl Haupl was interested in the
activity of orofacial Muscles and bone changes
• Viggo Anderesem 1908 –Activator- Benno Lischer”when sucking habits
with a finger can casuse open bite and narrow arches could not the
same muscles be used to correct these ?”
Activator-Biomechanical working Retainer
He had given it to his daughter
• Norwegian system came into play, They published
A textbook called Funktionskieferorthopadie

8. • Emil Herbst, Herbst Appliance 1905 – Retentionscharnier
• Hans Peter Bimler, Bimler Appliance- (Elastic Bite Former) World war 2 victim with a gonial fracture a
splint was given
• Double Plate (1956) Schwarz-similar to twin block without the increased vertical block it was a split of the
activator
• 1944 – Tooth Positioner, Harvold D Kesling
• Late 1940’s –Nuk Sauger appliance, Adolph Mueller a pacifier

9. • 1960 –Wilhelm Balter Bionator
• 1967- Rolf Frankel , Frankel Regulators
• 1977 – Twin Block
The twin block was developed by William Clark for the treatment of Class II
malocclusions. It was based on the same theory as the monobloc and Frankel
appliance. The appliance consists of maxillary and mandibular bite blocks
designed to use the forces of occlusion as the functional mechanism. As the
appliance was formed of two separate pieces, it could be worn full time and was
more comfortable for the patient

10. Twin Block
The First Twin Block was Fitted by William Clark In the year 1977 on
7th to a young patient who was a son of a dental colleague who fell down and had
luxated the upper incisors

11. Twin Block Consists of-
Base plates
Bite block
Wire components- Delta ,Ball end clasp,
Labial Bow if Needed
Skeletal Changes with Twin Block
Forward Growth/Repositioning of Mancible
Increase in SNB angle, Slight change in SNA due to maxillary
Restraint
Changes in ANB ,Increase in Lower Anterior Facial Height
Dental Changes with Twin Block
Overjet Reduction
Retroclination of the upper incisors
Proclination of the lower incisors
Lower molar eruption anterior and superiorly

12. Bite Registration – Roccabado rule –TMJ movement at 70% of the total joint displacement,
Upto 10 mm overjet Edge to edge bite with 2mm inter incisal clearance, more than 12 mm
Stage wise advancement
George bite gauge has a millimetre gauge to accurately state the amount of activation
Vertical Dimension
2mm-Anterior region
4-5mm –Premolar Region (More than Freeway Space)
2-3mm – Molar Region
Stages OF Twin Block
- Active Phase (6-9 months)
- Support Phase (4-6 months)
- Retention Phase (8-9 months)
Relative Contraindications
• Class II Skeletal by Maxillary Prognathism alone
• Labial Tipped Lower Incisors ( Compensatory Effect)
• Severe Crowding

13. Modifications of Twin Block
• Transverse Development blocks
• Saggital Developmental Blocks
• Saggital and Transverse Developmental blocks
• Close anterior open bite-palatal spinner
tongue crib, second molar stops
• Lip pads
• Magnetic blocks – Attractive and Repulsive blocks
• TMJ therapy
• Twin Blocks With TPA & Lingual Arch, Hyrax
• Designer Twin Blocks

14. Biofinisher in Twin block- Extruding Lower Molars By Vertical
Traction to Stabilize TMJ

16. Advantages Dis-advantages
• Comfort
• Asthetics
• Function
• Patient Compliance
• Facial Improvement at
start of the treatment
• Less speech difficulties
• Arch development
• Mandibular incisor
demineralization and
caries in capped twin
blocks
• Tipping of lower
anterior

17. TRANS FORCE

18. Transverse Expander
Molar area- on Activation 8mm
Canine area- On activation 8mm
Molar – Canine length variations -19mm,
20mm,21mm,22mm.
Saggital Expander
Incisor to molar is measured and required amount of
expansion is planned
Molar area- On Activation 2mm (transverse
expansion)
Canine area- on Activation 6mm ( saggital)

24. CASE 2 -TRANSVERSE EXPANSION

26. CASE 3 – ADULT

28. “Dr Clark has been happily married for 52 years and
although he would like to have more time to spend with
his wife and family and to develop his other interests, such
as playing the saxophone and clarinet, he is not ready to
retire quite yet”- O.P. Karbanda

29. NEWER ADVANCEMENTS
-Fixed Twin Block
-Transforce 3

31. Summary
• 1879 –Norman W Kingsley- Bite Jumping Appliance
• Monobloc, Pierre Robin (1902)
• Early 1900’s George Crozat- Crozat Appliance
• Martin Scwartz-Scwartz clasp and plate
• Alfred P Rogers Father of Myofunctional Therapy
• Viggo Anderesem 1908 –Activator
• Emil Herbst, Herbst Appliance 1905 – Retentionscharnier
• Hans Peter Bimler, Bimler Appliance
• Double Plate (1956) Schwarz
• 1944 – Tooth Positioner, Harvold D Kesling
• Late 1940’s –Nuk Sauger appliance, Adolph Mueller
• 1960 –Wilhelm Balter Bionator
• 1967- Rolf Frankel , Frankel Regulators
• 1977 – Twin Block
• 2005 – Transforce