Effect of radiotherapy on oral mucosa assessed by quantitative exfoliative cytology

The effect of radiotherapy on normal buccal mucosa was investigated using the quantitative techniques of cytomorphology (measurement of nuclear and cytoplasmic area) and DNA cytophotometry. These techniques were applied to smears obtained before, during, and after irradiation. Nuclear area and cytoplasmic area increased and DNA values were abnormal in most cases as a result of radiotherapy, returning to within normal limits one month after treatment. This contrasts strongly with the changes seen in smears from previously irradiated uterine cervices, where changes in cytomorphology may persist for several years.