A comparison between two lingual orthodontic brackets in terms of speech performance and patients' acceptance in correcting Class II, Division 1 malocclusion: a randomized controlled trial

OBJECTIVE: To compare speech performance and levels of oral impairment between two types of lingual brackets. METHODS: A parallel-group randomized controlled trial was carried out on patients with Class II, Division 1 malocclusion treated at the University of Hama School of Dentistry in Hama, Syria. A total of 46 participants (mean age: 22.3 ± 2.3 years) with maxillary dentoalveolar protrusion were randomly distributed into two groups with 23 patients each (1:1 allocation ratio). Either STb (Ormco) or 7(th) Generation (Ormco) lingual brackets were applied. Fricative sound/s/ spectrograms were analyzed directly before intervention (T(0)), one week following premolar extraction prior to bracket placement (T(1)), within 24 hours of bracket bonding (T(2)), one month after (T(3)), and three months after (T(4)) bracket placement. Patients′ acceptance was assessed by means of standardized questionnaires. RESULTS: After bracket placement, significant deterioration in articulation was recorded at all assessment times in the 7(th) Generation group, and up to T(3) in the STb group. Significant intergroup differences were detected at T(2) and T(3). No statistically significant differences were found between the two groups in reported tongue irritation levels, whereas chewing difficulty was significantly higher in the 7(th) Generation group one month after bracket placement. CONCLUSIONS: 7(th) Generation brackets have more interaction with sound production than STb ones. Although patients in both groups complained of some degree of oral impairment, STb appliances appeared to be more comfortable than the 7(th) Generation ones, particularly within the first month of treatment.