The change in speech pattern while undergoing Invisalign treatment is minor, temporary or more frequently may not occur at all. However, in few cases, there will be slight change in the speech for a day or two and when your tongue adapts to the aligners these slight changes shall disappear
When Invisalign is worn for the first time, you might experience a certain lisp. This lisp might be only noticeable to you. During the treatment process, if Invisalign causes any defect in speech, its highly recommended that you pronounce the words using the aligners on. As your tongue gets adapted to the aligners, slowly, the lisp shall disappear.