Development of the nasopharynx: A radiological study of children

Abstract

The relation between pharyngeal tonsil and the bony nasopharynx determines the nasopharyngeal airway patency. Despite its importance, an anatomical study utilizing advanced imaging has not been conducted. The aim of the study was to evaluate the pharyngeal tonsil and bony nasopharynx depth and their ratio (adenoid‐nasopharyngeal ratio [ANR]) with relation to sex and age in the general pediatric population. After excluding reported history of adenoidectomy, acute upper airway illness, allergy, and poor quality, 200 randomly selected head computed tomographies (CTs) of children were evaluated. CTs were divided into five age groups (0–5, 5.1–8, 8.1–11, 11.1–14, and 14.1–17 years). For each CT scan, the pharyngeal tonsil, bony nasopharynx and ANR values were calculated. A significant difference was found in the bony nasopharynx and pharyngeal tonsil depth between the five age subgroups (P < 0.001). Both bony nasopharynx and pharyngeal tonsil depth significantly increased between the age groups of 0–5 years to 5.1–8 years (4.17 mm increase, P < 0.001 and 3.47 mm increase, P < 0.009, respectively). The pharyngeal tonsil depth gradually decreases following the age of 8 years. No difference was found between age groups beyond age of eight for both the pharyngeal tonsil tissue and the bony nasopharynx. The ANR has an upward trend in the age group of 5.1–8 years. No sexual predilection was found. The bony nasopharynx and the pharyngeal tonsil tissue both grow during childhood. Different growth rates result in the narrowest airway in the age group of 5.1–8 years (ANR peak). These growth curves should be taken under consideration when treating pediatric pharyngeal tonsil hypertrophy. Clin. Anat., 33:1019–1024, 2020. © 2019 Wiley Periodicals, Inc.

Development patterns of adenoids in Chinese children without sleep-disordered breathing: a retrospective magnetic resonance imaging study with consecutive age groups

“…Second, we created balanced age and sex groups in this study and strict inclusion criteria using a validated sleep questionnaire, which may benefit our results as being more representative. Cohen et al [ 6 ] and our previous studies [ 4 , 5 ] reported that the bony nasopharynx grew rapidly under 5 years and slightly increased between 5 and 8 years. This may explain this A/N ratio peak where adenoids grow faster than the bony nasopharynx, resulting in an increase in the A/N ratio at 6 years.…”

“…Two previous studies evaluated the age-associated changes in the size of the adenoid and reported results in agreement with our findings. Cohen et al [ 6 ] reported that adenoids have a unique pattern with a developmental peak in children from 5 to 8 years, followed by an involution based on CT data. Papaioannou et al [ 3 ] reported that adenoids reach their maximum size at the age of 7 years (linear measurements) and subsequently become smaller, based on MRI data from 149 children without snoring.…”

“…No consensus exists on the A/N ratio in the general pediatric population. Papaioannou et al [ 3 ] and Cohen et al [ 6 ] reported that the A/N ratio increased to 8 years, with maximal value at the age group of 5 to 8 years, followed by a gradual decrease. However, a study showed a constant ratio of adenoid linear dimension to pharyngeal lumen diameter irrespective of age in children without snoring.…”

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

“…The evaluation modalities for upper airway and lymphoid tissue morphology include three-dimensional computed tomography (CT), cone-beam CT, and magnetic resonance imaging (MRI) other than cephalometric radiographs [10][11][12][13]. Although accurate 3-dimensional images are obtained when using 3-dimensional CT and cone-beam CT, these techniques have disadvantages such as high radiation exposure and high cost.…”

Antrochoanal Polyp: Updated Clinical Approach, Histology Characteristics, Diagnosis and Treatment

“…In cases of limited physical examination, imaging may contribute to the diagnosis. One should keep in mind that adenoid to nasopharynx ratio decreases with age (especially in children >8 years) due to a change in nasopharynx width [13]. Therefore, children older than 8 years must undergo complete nasal flexible endoscopy to rule out nasal polyp (Table 1).…”