A comparison of tonsillar size and oropharyngeal dimensions in children with obstructive adenotonsillar hypertrophy

Abstract

Hypertrophy of the tonsils and adenoids is the most common cause of obstructive sleep apnea in children. There is relatively little known about the occurrence of subclinical variations in the dimensions of the oropharynx which may predispose to the development of obstructive sleep apnea in children without obvious craniofacial abnormalities. Fifty-one children (3–10 years) were divided into two groups: the first group consisted of 18 patients with small tonsils and no history of snoring who underwent tonsillectomy for chronic tonsillitis. They were compared to a second group of 33 patients with large tonsils who underwent tonsillectomy and adenoidectomy for symptoms of obstructive sleep apnea. Age, height, weight, body surface area and tonsil weight were correlated to the dimensions of the oropharynx obtained by direct measurement intraoperatively including the length of the soft palate, anterior-posterior depth of the nasopharynx and the distances between the medial tonsillar surfaces, anterior tonslliar pillars and lateral pharyngeal walls at mid-tonsil level. Increased patient height, weight and surface area correlated positively to increased distance between the lateral pharyngeal walls and to the length of the soft palate in the patients with small tonsils. No such correlation existed in the patients with obstructive adenotonsillar hypertrophy. In addition, the distance between the lateral pharyngeal walls was significantly decreased in the group with large, obstructing tonsils as compared to those with small tonsils and no history of obstruction ( P < 0.01). However, the patients with small tonsils and no obstruction had significantly longer soft plates ( P < 0.01) and less depth to the nasopharynx ( P < 0.01). As expected, tonsil weight was significantly greater in obstructed patients ( P < 0.01). Diminished oropharyngeal size in addition to adenotonsillar hypertrophy may contribute to the development of obstructive sleep apnea in otherwise normal children. Previous observations that excessive soft palate length and shallow nasopharyngeal depth predispose to the development of obstructive symptoms were not confirmed by this study.