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Formants frequency and dispersion in relation to the length and projection of the upper and lower jaws
Anthony T Macari1, Ingrid A Karam1, Dollen Tabri2
1Division of Orthodontics and Dentofacial Orthopedics, Department of Otolaryngology-Head & Neck Surgery, American University of Beirut Medical Center, Beirut, Lebanon.
Objective:
Investigate the association between formants frequencies and length and sagittal projection of the maxilla and mandible.
Study Design:
Cross-sectional study.
Method:
A total of 47 consecutive patients were recruited. Craniofacial measures included; maxillary length (ANS-PNS), mandibular length (Co-Gn), relationship between maxilla and mandible in the sagittal plane (ANB), the sagittal projection of the maxilla (SNA), and mandible (SNB). Subjects were asked to phonate vowels /a/, /i/, /o/, and /u/. Measurements were made in real-time and formant frequencies across F1, F2, F3, and F4 were determined.
Results:
There was a significant negative association between the length of the maxilla and F4 for all the vowels, and a significant negative association between the length of the mandible and F4 for vowels /o/ and /u/. The length of maxilla and mandible also negatively associated with F3 for vowels /a/, /i/, /o/, and vowels /i/, /o/, and /u/ respectively. For the first two formants, the negative association was less pronounced.
Conclusion:
There was a significant negative association between the formant frequencies F3, F4, and the length of the mandible and maxilla for vowels /a/, /i/, /o/, and /u/.
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