Correlation Between the Position of the Hyoid Bone on Lateral Cephalographs and Formant Frequencies

Abstract

OBJECTIVES: The objective of this study is to examine the F1, F2, F3, and F4 during sustained vowels /a/, /i/, /o/, /u/. STUDY DESIGN: Prospective cross-sectional study. METHODS: Fifty-two consecutive patients aged between 9 years and 38 years were invited to participate in this study. Linear measurements included linear vertical distance from the hyoid bone to the sella turcica (H-S); linear vertical distance from the hyoid bone to the posterior nasal spine (H-PNS); linear measure from the hyoid bone to the most anterior point of the cervical vertebra C3 (H-C3); and linear vertical distance from the hyoid bone to the mandibular plane (H-MP). RESULTS: The results showed a moderate and statistically significant correlation between the average fundamental frequency for the vowel /a/ and H-C3, H-S, and H-PNS and another moderate negative correlation between F3 and F4, and the vertical position of the hyoid bone H-C3 and H-S. For the vowel /i/, there was a moderate negative correlation between F1, F3, and F4 and H-S and also a moderate negative correlation between F3 and F4 and H-C3. For the vowel /o/, there was a moderate negative correlation between F4 and H-S and H-PNS. For the vowel /u/, only F4 correlated significantly with H-S. CONCLUSION: There is a moderate correlation between the high formants, mostly F4, and the cephalo-caudal position of the hyoid bone.