Formant Frequencies, Cephalometric Measures, and Pharyngeal Airway Width in Adults With Congenital, Isolated, and Untreated Growth Hormone Deficiency

Abstract

Adult subjects with isolated growth hormone deficiency (IGHD) due to a mutation in the growth hormone releasing hormone receptor gene exhibit higher values formant frequencies. In normal subjects, a significant negative association between the formant frequencies and the reduction of linear craniofacial measurements, especially of maxilla and mandible, has been reported. This suggests smaller pharyngeal width, despite low prevalence of obstructive sleep apnea syndrome. Here we evaluate their pharyngeal airway width, its correlation with vowel formant frequencies, and the correlation between them and the craniofacial measures. A two-step protocol was performed. In the first case-control experiment, aimed to assess the pharyngeal width, we compared nine adult IGHD and 36 normal statured controls. Both upper and lower pharyngeal widths were measured. The second step (assessment of pharyngeal width) was performed only in the IGHD group. Upper and lower pharyngeal widths were similar in IGHD and controls. In IGHD subjects, the lower pharyngeal width exhibited a negative correlation with F1 [a] and a positive correlation with mandibular length. There were negative correlations between F1 and F2 with linear and positive correlations with the angular measures. Pharyngeal airway width is not reduced in adults with congenital, untreated lifetime IGHD, contributing to the low prevalence of obstructive sleep apnea syndrome. The formant frequencies relate more with cephalometric measurements than with the pharyngeal airway width. These findings exemplify the consequences of lifetime IGHD on osseous and nonosseous growth.