W. C., aged 13 years and 7 months, undersized and underweight, came to me for the first time Aug. 9, 1913, with a limited motion of the mandible permitting of but ¼ inch separation of the incisors and no lateral motion. At the age of 4 years and 2 months, while swinging, he fell 8 feet and struck his chin on the hard wood floor. As the child suffered intense pain and was unable to move the mandible, a physician was summoned. Palliative treatment was instituted, and the child fed through a tube for a period of two months. No attempt was made to use the mandible, and it ankylosed in the position I found it. Roentgenoscopy disclosed the condition to be a previous fracture of the ramus, the line of fracture running into the joint, and a mass of callous substance filling the joint. Ether was administered and the