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

Abstract

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 7th Generation (Ormco) lingual brackets were applied. Fricative sound/s/ spectrograms were analyzed directly before intervention (T0), one week following premolar extraction prior to bracket placement (T1), within 24 hours of bracket bonding (T2), one month after (T3), and three months after (T4) 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 7th Generation group, and up to T3 in the STb group. Significant intergroup differences were detected at T2 and T3. No statistically significant differences were found between the two groups in reported tongue irritation levels, whereas chewing difficulty was significantly higher in the 7th Generation group one month after bracket placement. Conclusions: 7th 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 7th Generation ones, particularly within the first month of treatment.

Evaluation of the C-lingual Retractor and the Conventional Lingual Orthodontic Brackets in Terms of Speech Performance and Oral Discomfort: A Randomized Controlled Trial

“…The target words were then sampled into a computer and the frequency of the /s/ sound was measured using SpectraPLUS® software (SpectraPLUS®-sc, version 5.0.26.21, Pioneer Hill Software LLC, Poulsbo, WA, USA). The upper boundary frequency of the fricative /s/ sound was analyzed using the spectrogram [ 8 - 10 ]. The maximum grayness of the spectrogram represented the maximum frequency of the bandwidth of the fricative sound (Figure 3 ).…”

“…Patients' acceptance and oral functional impairments after appliances' placements were assessed using a standardized questionnaire that consisted of six questions [ 8 , 10 ]. Patients were asked to rate their experienced speech disturbances, oral discomfort, and chewing difficulties on four-point Likert-scale possible answers at four assessment times: before appliance placement (T0), one day following appliance placement (T1), one month later (±3 days) (T2), and three months later (±1 week) (T3).…”

“…Despite its esthetic superiority, lingual brackets cause considerable impairments of speech and other oral functions. Several studies have reported the distortion of articulation after lingual brackets application; some of these studies have employed auditive analysis [ 8 - 10 ], others have assessed speech alteration semi-objectively and/or subjectively [ 8 - 12 ]. The levels of oral discomfort after lingual bracket placement have been investigated as well [ 8 - 17 ].…”

“…Important concerns regarding the effects of lingual appliance thickness on oral impairments have arisen; some papers have compared the levels of oral discomfort between different lingual appliance systems [ 12 , 14 ], and one paper has tested the effect of lingual bracket size on patients' acceptance [ 10 ]. There was a consensus that patients with larger dimensions of the lingual appliance were most commonly affected regarding speech disturbance and oral discomfort.…”

Evaluation of the Oral Health-Related Quality of Life (OHRQoL) in Patients Undergoing Lingual Versus Labial Fixed Orthodontic Appliances: A Randomized Controlled Clinical Trial

“…Lingual brackets cause speech disturbances, tongue irritation, and difficulty in chewing, with more social embarrassment than labial brackets [ 17 , 18 ]. Several studies have investigated the OHRQoL during orthodontic treatment with fixed labial appliances [ 19 - 21 ].…”