Speech Effect Of Fixed Labial Orthodontic Appliance In Patient With Class III Incisor Relationship

Objective: To evaluate the pre-existing speech distortion and long-term speech effect of the fixed labial orthodontic appliance in Class III incisor relationship (Class III) subjects. Methods: Speech performance of selected fricative consonants was analyzed with PRAAT software inClass I incisor relationship (Class I control) subjects as the baseline as well as in Class III subjects at six different time-points. Results: Class III subjects took shorter voicing duration to utter all sounds at T0 compared to Class I control subjects. At T1, Class III subjects took longer voicing duration to utter the sounds compared to T0. No significant difference was found between T4 and T0. At T5, no significant difference was found between Class III subjects and Class I control subjects. Conclusions: Class III subjects had significant pre-existing speech distortion and further deterioration in the speech quality was reported immediately after bracket placement which self-resolved after 6 months. Orthodontic treatment improved the pre-existing speech distortion in Class III subjects after a year.