Measurement of cheek/tooth forces during speech production

This paper deals with the "in vivo" evaluation of the forces exerted by perioral muscles on dental arches and describes the relationship between these loads and the acoustic emission, during speech production. To carry out the research two miniaturised load cells were placed on the upper incisors' vestibular surface of 12 patients (6 male, 6 female age ranging from 19 to 25 years) to monitor the contact forces generated during the pronunciation of three phonemes containing labio-dental sounds. The acoustic pressure was gathered by means of a capacitive microphone. From the obtained results it is shown that some values of the force applied during speaking are of significance in corrective orthodontics; in fact, the maxima of the recorded values were approximately 2.7N and 1.0N for female and male subjects, respectively. Also a tendency was observed for a logarithmic dependence between the loads exerted by perioral muscles on teeth and the acoustic pressure level due to the voice; in fact, the correlation coefficients R were, for some of the examined patients, >0.9, even if values of 0.4 also were observed.