Effects of retainers on the articulation of speech.

Articulation abilities of 15 patients were evaluated at the end of orthodontic treatment with the initiation of removable upper and lower retainer wear. A test of articulation, based on consonants and vowels (cv), (vcv), (vc), (cvc) nonsense syllables, was used to evaluate the articulatory distortions with no retainers and with maxillary and mandibular retainers worn respectively and together. The test was performed (a) on the first day, (b) 24 hours later, and (c) 1 week later. Statistically significant articulatory distortions with the /t/ and /d/ sounds on the first day with upper retainer only and with both retainers worn together were noted. Also significant distortion of the /k/ sound with both retainers worn was observed. These distortions, due to the wearing of retainers, decreased to an insignificant level or disappeared completely on the seventh day showing the ability of tongue adaptation in a very short period of time.