Abstract
Some patients attending orthodontic departments present with oral habits. There are many reports on the relationship between malocclusion, particularly open bite, and oral habits.
In the present study, we using acoustic features that can be evaluated by listening(i.e.zero-crossing rates and mel-frequency cepstrum coefficients [MFCCs]). We evaluated the presence of tongue thrust during speech, both before and upon completion of MFT. We also explored the relationship between therapeutic efficacy and maxillofacial morphology.
Comparison between T1 and T2 time-points revealed significant differences in MFCC-8 values within the same speaker; thus, it is likely that speech underwent acoustic changes due to recovery from tongue thrust. Additionally, when MFCC-8 values at T2 time-points in the tongue-habit group were compared to the control group, no differences were found,even when normal swallowing was achieved after MFT. This suggests that MFCC-8 values are markers of the acoustic properties of patients with tongue thrust when swallowing, and enable identification of tongue thrust in acoustic analysis.
MFT leads to recovery from tongue thrust when swallowing, along with associated changes in pronunciation. The presence or absence of tongue thrust during swallowing or speech can be evaluated using MFCC-8. Subjects who retain tongue thrust when speaking,even after MFT, tend to have certain skeletal characteristics, including a long face and shallow overjet.
