Longitudinal Morphological Changes in the Adenoids and Tonsils in Japanese School Children

Abstract

The adenoid (Ad) and tonsil (Ts), located in the upper airway, play an important role in immunological protection. These lymphoid tissues grow rapidly, reach a peak of growth at the age of 6–8 years, and decrease in their size thereafter. However, little information is available on the longitudinal growth patterns of Ad and Ts in the general population. This study aimed to evaluate the individual growth of Ad and Ts during childhood using lateral cephalograms taken longitudinally from the same individuals at the ages of 8–12 years. Our results showed that the cross-sectional areas of the Ad, nasopharynx (Np), and oropharynx (Op) significantly increased with age while small changes in the size of Ts were present throughout the study period. In addition, the values of Ad/Np and Ts/Op decreased significantly with age in the elementary school. Furthermore, there was a strong and significant correlation between the Ad/Np ratio and upper airway resistance, indicating the narrowest distance in the upper airway. In conclusion, the airway occupation in Np and Op increased with age due to the increase in the sizes of Np and Op but not the decrease in the sizes of Ad and Ts.

Effectiveness of Evaluation of Adenoid Hypertrophy in Children by Flexible Nasopharyngoscopy Examination (FNE), Proposed Schema of Frequency of Examination: Cohort Study

“…Children whose tonsil size exceeds 70% in A/C ratio should also be controlled every year. As mentioned above, there are many statements about the time of involution of the adenoid in children in the specialized literature, but there are few studies that confirm these theses [ 13 , 14 , 15 , 31 ]. Ishida performed sequential lateral cephalometric radiography in 90 children from 6 to 19 years old over a 10-year period of time.…”

“…He analyzed, in a 5-year period of time, a sample involving 99 individuals of the ages of 8–12 years. He stated that the adenoid-to-nasopharynx index decreased significantly through elementary school (in Japan, ages 6 to 12 years) [ 13 ]. However, the most interesting are the studies concerning children aged 3 to 8 years, because at these ages, adenoid symptoms seem to be the most burdensome for children.…”

“…There is prevalent opinion, often based on ENT doctors’ experience or based on the almost 100-year-old Scammon’s theory in accordance with proposed Scammon curves, that the adenoid undergoes hypertrophy during childhood and involution in adulthood [ 12 ]. To the best of our knowledge, only three longitudinal observational studies, one performed in 1976 by Handelman and two performed in Japan, published in 2018 and 2021, have assessed the sizes of the adenoid, all based on lateral cephalometric radiography [ 13 , 14 , 15 ]. Therefore, there is the need for longitudinal adenoid observations to investigate the process of adenoid involution, and to assess its influence on the reduction of adenoid symptoms in children.…”

Siblings’ Risk of Adenoid Hypertrophy: A Cohort Study in Children

“…It is commonly believed that the adenoid undergoes hypertrophy during childhood, and eventually, involution in adulthood [ 4 ]. Over the years, several longitudinal studies, Handelman and Osborne (1976), Ishida et al (2018), and Yamada et al (2021), have assessed the size of the adenoid using lateral cephalometric radiography [ 5 , 6 , 7 ]. Yamada showed that an overgrowth of adenoids occurred in preschool children, but there were no significant changes in the adenoid size from 8–12 years of age [ 7 ].…”

“…Over the years, several longitudinal studies, Handelman and Osborne (1976), Ishida et al (2018), and Yamada et al (2021), have assessed the size of the adenoid using lateral cephalometric radiography [ 5 , 6 , 7 ]. Yamada showed that an overgrowth of adenoids occurred in preschool children, but there were no significant changes in the adenoid size from 8–12 years of age [ 7 ]. A previous study based on flexible endoscopic examinations revealed that adenoid involution proceeds rather slowly; only 7.9% of preschool children (aged 3–7 years) underwent a change in the adenoid size by >15% on the adenoid to choana (A/C) ratio over one year of observation, 21.6% over a period of 2 years, and 45% over a period of 3 years [ 8 ].…”