自孩童至年輕成人其咽呼吸道深度及舌骨位置之發育變化

Interpretation of the significance of variations in the growth and function is dependent on an understanding of the normal developmental changes. It is necessary to know the changes in the pharyngeal airway depth and hyoid bone position that occur in the normal subjects during their active growth years and beyond. Most of the previous studies emphasized the treatment effect on the pharyngeal airway size and hyoid bone position; however, the developmental changes of the pharyngeal airway and hyoid bone position seemed to receive little attention in the past. The purposes of the present study were threefold: (1) To understand the developmental changes in the pharyngeal airway depth and hyoid bone position from childhood to young adulthood in normal Taiwanese persons, (2) to identify the existence of any sexual dimorphism, and (3) to find the predictive value of selective variables for the hyoid bone position. Lateral cephalometric radiographs of 239 normal Taiwanese (132 females and 107 males; aged 7~27 years) were separated into three stages (mixed dentition stage, early permanent dentition stage, and permanent dentition stage) according to the dental age. Twenty-three linear and 20 angular measurements were taken in all subjects. Sexual dimorphism was analyzed by Student’s t-test. Analysis of variance (ANOVA) was used to compare among three stages in both genders. A stepwise regression analysis was carried out to predict the hyoid bone position. The level of significance for all analyses was set at P<0.05. Our data showed that the pharyngeal airway depth increased from the mixed dentition stage to the permanent dentition stage in both genders. There was sexual dimorphism in the lower pharyngeal airway depth. The hyoid bone position showed an obvious difference in the permanent dentition stages between genders, and the hyoid descends more obviously in males. The vertical position of the hyoid bone was associated with the ramus length and the facial angle, but the relationship in males was reversed compared to that in females.