Differential changes in the adenoids and tonsils in Japanese children and teenagers: a cross-sectional study.

When adenoids (Ad) and tonsils (Tn) become hypertrophied, craniofacial and general body growth is affected. However, there are no objective explicit criteria for evaluating the size of the Ad and Tn, and their respective growth patterns remain unclear. This study determined the average proportions of the Ad and Tn sizes to the upper airway area at various developmental stages in Japanese individuals. Lateral cephalometric radiographs were obtained from 300 Japanese children and teenagers (150 boys and 150 girls, aged 6-20 years), and the respective proportions of Ad to the nasopharynx (Ad/Np) and Tn to the oropharynx (Tn/Op) in the upper airway were determined. Average and standard deviation (SD) were calculated for each of the 5 age groups: lower primary school, upper primary school, junior high school, senior high school, and young adults. We investigated the correlation between age and growth patterns of Ad and Tn, and determined the average Ad/Np and Tn/Op. There was an age-related decrease in Ad and Tn size, and a significant positive correlation between Ad/Np and Tn/Op values in the upper primary school group. Both Ad/Np and Tn/Op decrease as individuals approach adulthood. However, the growth patterns of the Ad/Np and Tn/Op differ from each other.