Abstract

The aim of this study is to compare the influences of lingual appliances of different dimensions on sound performance, oral comfort and patients’ acceptance before and after the insertion of two types of lingual brackets (STb – 7^th G). Forty-six patients, with Class 2 division 1 malocclusion, were distributed randomly into two groups. 23 patients in group A (26 females +20 males) were treated with STb lingual brackets (Ormco, Glendora, CA, USA), whereas 23 patients in group B (14 female +9 males) were treated with 7^th G lingual brackets (Ormco, Glendora, CA, USA). Speech performance was tested using spectrographic analysis of fricative /s/ sound and standardized questionnaires two weeks before extraction and application support device (T0) directly before the placement of lingual brackets (T1), within 24 hours thereafter (T2), 1 month after (T3), and 3 months after (T4) bracket placement. patients′ acceptance was assessed using standardized questionnaires. Data were analyzed by (Minitab® v15). As a result, all lingual appliances investigated in this study led to significant impairments in sound performance and oral comfort, but with interappliance differences in the degree of impairment. The 7^th G lingual bracket is more problematic than the STb one in terms of speech articulation. Although patients with both brackets suffered from different degrees of oral impairment, patients with 7^th G brackets had more untoward effects, particularly during the first month of treatment.