[The assessment of nasopharyngeal airway space].

In children, the nasopharyngeal airway space is provided by the size of adenoid tissue on the posterior nasopharyngeal wall and the size of nasopharynx. This airway space will be changed by the age. The objective of this study is for evaluating this airway space at the age group 7-8 years, 9-10 years, 11-12 years, 13-14 years and 15-16 years from the cephalograms by assessing is the form of adenoidal-nasopharyngeal ratio. Two hundred subjects (97 boys, 103 girls) were selected without histories of mouth breathing, or adenoidectomy or previous orthodontic treatment and cephalometrically, they are shown normal inclination of the maxilla and the mandible to cranial base, normal facial index and no anterior open-bite. They were divided into 40 subjects on each age group. From the study, the adenoidal-nasopharyngeal ratio were found 0.557, 0.487, 0.512, 0.470 and 0.415 at the age 7-8 years, 9-10 years, 11-12 years, 13-14 years and 15-16 years respectively.