The accompanying illustration shows an apparatus for the control of thumb sucking in infants, the mechanism of which is as follows:
This splint is made of aluminum wire, 3/16 inch (0.48 cm.) in diameter, according to measurements of the infant's arm, the circumference at the axilla and at the wrist and the length of the arm from the axilla to the wrist. The large loop fits the arm at the axilla. The distal end is fastened around the wrist with a ball and socket chain, such as is used on electric pull chains. The apparatus is cool and durable and can be easily sterilized. The ball and socket chain cannot be easily unfastened by an infant. This is a modification of an apparatus for the control of thumb sucking described in the American Journal of Diseases of Children1 some time ago.
478 Peachtree Street.
ANDERSON WW. THUMB SUCKING APPARATUS. Am J Dis Child. 1933;46(1):90. doi:10.1001/archpedi.1933.01960010100009