George W. Burnett

The effect of x-ray irradiation on the oral tissues of the Macacus rhesus monkey.

Abstract Studies were made of x-ray irradiation of 4,000 r., 5,000 r., and 6,000 r. upon the oral tissues of 3-year-old Macacus rhesus monkeys. This treatment produced lesions in the cheek and tongue which varied in severity with the intensity of the irradiation which they received. These lesions healed within four to six weeks after irradiation. Two distinct types of reactions occurred in the mandible and maxilla following irradiation, but the time of onset of the lesion was not necessarily correlated with the intensity of the irradiation. The most severe reaction, to which the term radioosteitis is applied, is characterized by necrosis of bone and gross infection and sloughing of gingiva and bone of the affected area. The less severe reaction, to which the term radioosteonecrosis is applied, is characterized by necrosis of bone which is not infected. While the response of the monkey and the human being to irradiation may not be identical, these studies have indicated that data concerning the clinical course of the effect of irradiation can be studied in Macacus rhesus monkeys and that the reactions produced are similar to those which have been observed in human beings.

The effect of x-ray irradiation on the incisors of the syrian hamster

Abstract With the exception of the odontogenic epithelium, the reaction of the tissues of the continually growing incisors of Syrian hamsters was essentially the same as that previously reported in the literature for similar tissues of white rats exposed to similar doses of irradiation. The odontogenic epithelium of the hamster that continued to grow after irradiation was reduced to a thin strand of cuboidal or squamous cells. Local proliferation of the distorted strands of displaced epithelium resulted in several knoblike areas. The earliest stage of cellular proliferation resulted in an enlarged strand of tissue without keratinization. In an intermediate stage, as the cellular structure continued to proliferate, keratin was deposited. In the latest stage of development observed, an enlarged cyst filled with keratin had formed. The odontogenic epithelium of the hamster did not resume its usual function of forming normal tooth tissues within the period in which the animals were observed.