Discomfort caused by bonded lingual orthodontic appliances in adult patients as examined by retrospective questionnaire.

A retrospective questionnaire survey of 111 retention-period adult patients was performed to examine discomfort that may be caused by bonded lingual orthodontic appliances. Despite instructions to avoid or relieve the discomfort, 57% to 76% of patients complained of tongue soreness, difficulty in chewing fibrous food, difficulty in pronouncing the s and t sounds, and difficulty in tooth brushing after the bonding of lingual appliances; the levels were significantly higher than those undergoing edgewise labial treatment. Twenty percent to 44% of patients experienced high levels of the aforementioned discomfort. Although this discomfort decreased gradually with time, 20% to 46% of patients felt discomfort until after the removal of the lingual appliances. The ratio of tongue soreness and speech difficulty caused by upper lingual bracket application to lower lingual bracket application was almost equal. Rank correlation analyses revealed two things: the deeper the bite, the greater the level of tongue soreness, teeth pain and difficulty in chewing tough food; and the larger the overjet, the greater the level of tongue soreness.