Singing Voice Quality: The Effects of Maxillary Dental Arch and Singing Style

Introduction: In classical singing techniques, it is common to manipulate the vocal tract to channel airflow to increase voice quality and volume. Technique varies according to the style of the music, the voice type, and range of a given singer. Although these practices are intentional, fixed physiological aspects of a singer's vocal instrument also play an extremely impactful role in determining voice quality. Objectives: In the present study, the relationship between the dimensions of the maxillary dental arch and voice quality were examined in professional singers. Methods: The dimensions of the palate were measured from the maxillary dental casts of 14 female singers. Audio recordings were made for the same participants while singing a sustained /a/ singing vowel, a glissando, the song "Are You Sleeping", and a selected song from their personal repertoire. The dimensions of the palate were measured from maxillary dental casts. From the recordings, two parameters were calculated: (1) the Singing Power Ratio (SPR) and (2) A₂ A₁ ratio. Higher SPR values indicate a stronger ring in the voice, typical of operatic singing style, while higher A₂ A₁ ratio values are associated with the belting singing style. Results: Singers with larger frontal palate depth, smaller posterior palate depth, larger frontal palate width, and smaller posterior palate width seem to be more suitable for an operatic singing style. Singers who had larger overall depth and width of the palate measurements produced an increased second harmonic, typical of the belting style. Conclusions: When considering a singer's ability to produce vocalizations successfully, physiological structure is an increasingly important factor. The present study discovered that palate depth and width are associated with statistically significant differences in SPR and A₂/A₁ parameters. These parameters correlate with two styles of singing, operatic, and belting respectively.