Lip - tooth relationships during smiling and speech: an evaluation of different malocclusion types
Online veröffentlicht: 14. Dez. 2023
Seitenbereich: 153 - 159
Eingereicht: 01. Dez. 2009
Akzeptiert: 01. Juni 2010
DOI: https://doi.org/10.2478/aoj-2010-0025
© 2010 Roozbeh Rashed et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.
Background
Few studies have focused on the impact of malocclusion on lip – tooth relationships during smiling and speech.
Aim
To evaluate the impact of different malocclusions on lip – tooth relationships during smiling and speech, using video images.
Methods
One hundred and three subjects with Class I (N = 31), Class II division 1 (N = 26), Class II division 2 (N = 16) and Class III malocclusions (N = 30) were asked to repeat the same sentence and then smile in front of a video camera. Nine frames were extracted from each subject’s video clip: at rest, posed smile, unposed smile and during the pronunciation of the sounds: ‘che’, ‘fa’, ‘se’, ‘chee’, ‘tee’ and ‘mee’. On each frame, up to 10 parameters describing the lip – tooth relationships were measured.
Results
In all frames, there were no statistically significant differences in the upper central incisor display ratios among the malocclusion groups (
Conclusions
In each malocclusion the upper central incisor display ratio varied significantly among the nine frames. In each group, the buccal corridor ratio during the unposed smile was less than that during the posed smile, but only the Class II division 2 group was significantly different. The smile arc did not differ among the malocclusions.