Dr. William J. Clark is a Scottish
orthodontist known for developing
Twin Block Appliance A twin block is an orthodontic appliance developed by William J. Clark whose purpose is to lengthen the lower jaw by posturing it forward. If the jaw is growing during treatment, it naturally grows at a faster rate; otherwise the appliance is use ...
in Orthodontics. This appliance was developed by Dr. Clark in 1977 in Scotland and since then this appliance has been used in correction of Class 2 malocclusions with
retrognathic mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
. He also developed invisible TransForce Appliance in 2004.
Orthodontics
Clark is the recipient of the first award for distinction in Orthodontics by
British Orthodontic Society. The International Functional Association awarded Clark in 2008 for his contributions to Orthodontics. He published a textbook in 2002 called ''Twin Block Functional Therapy - Applications in Dentofacial Orthopaedics''. Dr. Clark is credited to be the first person part of a
teleconference at a dental course in Chicago in 1990 which was eventually transmitted to 25 different cities via satellite.
Twin-Block Appliance
Twin-block appliances are used to correct Class II
malocclusions
In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855-1930), ...
with a deficient mandible. The appliance is removable in nature and involves more patient compliance than fixed functional appliances such as
Herbst, Forsus or MARA which are attached to teeth. As the patient bites together, they bite with their mandible forward. Clark recommended the appliance to be worn for at least one year in order to see any growth changes happening. The actual growth of mandible is still a question and literature shows that a Twin-Block appliance is as effective as a Herbst appliance.
References
{{DEFAULTSORT:Clark, William J.
American dentists
Orthodontists