Speech performance and oral impairments with lingual and labial orthodontic appliances in the first stage of fixed treatment

Changes in oral functions and speech when using custom-fitted mouthguards: An uncontrolled before-and-after study

BACKGROUND/AIM

Mouthguards are crucial for protecting athletes against orofacial injuries, yet concerns persist regarding their potential impact on oral functions. This study aimed to investigate the effects of sports mouthguards on oral functions and speech over time.

MATERIAL AND METHODS

Thirty national rugby players received custom-fitted mouthguards. Questionnaire responses and speech recordings were collected before mouthguard use and at various intervals after using mouthguards: immediately, 1 week, 2 month, and 6 months. Spectrographic analysis was performed to measure voice onset time (VOT) for /p, b, t, d/ phonemes. Questionnaire responses were assessed with Friedman's test, while VOT changes were examined using one-way repeated measure analysis of variance.

RESULTS

Compliance with mouthguard use improved during training and competitions, with consistent wear reported during matches. Over time, speaking difficulties and lisping decreased significantly (p < .001). The perception of nausea improved (p < .001), stabilizing after 1 month (p = .414). Sensations of bulkiness declined (p < .001). Mouth dryness reduced steadily, with no occurrences reported by all players by the end of the study. None of the participants reported bad breath, ulcers, or redness in the mouth. VOT changed immediately after wearing mouthguards (p < .001), gradually regressing toward the baseline, although not completely reaching it. Players held a favorable view of mouthguard use, with comfort and support for mandatory use increasing over time.

CONCLUSIONS

Custom-fitted mouthguards do not lead to significant long-term disruptions in oral functions. Athletes generally adapt to mouthguard use, reporting improved comfort and greater support for their use.

Impact of clear aligner therapy on speech: does clear aligner therapy cause any speech difficulty?

DATA SOURCES

Electronic search was conducted up to September 2021 in three electronic databases including Scopus, Web of Science, and EMBASE. Only studies in English language were selected.

STUDY SELECTION

Prospective and retrospective studies including cohort, cross-sectional, randomized control trials, and qualitative studies were included. Both the inclusion and exclusion criteria were reported. The search in the databases and the selection of the studies were performed independently by two reviewers. The included studies assessed the effects of clear aligner therapy on the speech difficulty.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed independently by two reviewers. The data from the relevant studies were extracted into a customized Template. The systematic review was carried out and reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Details regarding the authors, year of publication, sample size, included participants, age, groups, outcome assessment, results, and inferences were extracted from the selected studies. The quality of the selected studies was assessed based on the relevant guidelines from Cochrane Handbook for Systematic Reviews. The criteria examined sequence generation, allocation concealment, blinding, outcome data, selective reporting, and other sources of bias. Non-randomized studies were assessed using the ROBINS-I tool (Risk of Bias in Non-randomized studies). The strength of evidence was assessed by the evidence grading system developed by the GRADE collaboration as described in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

The search identified 283 results. 269 articles were excluded based on their title and abstract after evaluation against the inclusion criteria. 14 articles were assessed in full text. Finally, 7 papers were included in the qualitative analysis. The included studies were 5 cohort studies and 2 randomized clinical studies. 332 patients were examined in the included studies. There were 195 females and 137 males. 191 patients were treated using clear aligner therapy (CAT) while 122 patients were treated using labial fixed appliances and 19 patients were treated using lingual orthodontic treatment. Out of the 191 patients who were treated using CAT, 179 patients were treated using Invisalign (Santa Clara, CA, USA) while 12 patients were treated using Smile Align (Mumbai, India). All seven selected studies examined speech dysfunction. The speech difficulty was assessed through two tools - semiobjective assessment by speech pathologists and professionals and subjective evaluations by the patients themselves through a patient questionnaire that assess the effects of aligners on speech. The risk of bias assessment revealed that two studies had moderate risk of bias while five articles had serious risk of bias. Meta-analysis was not performed due to the high heterogeneity of the included studies. The level of evidence was assessed as low due to the methodological insufficiencies and risk of bias in the included studies. The results showed that both CAT and fixed appliances (FA) resulted in speech difficulties in terms of clarity and delivery of speech that include speech alteration, slurring of words, lisping, and nasality. Some patients who were treated using CAT reported impairment in the lingual space that affected their speech. Lingual FA resulted in more speech difficulty when compared to labial FA and CAT. Aligners caused errors in the articulation of /s/,/z/,/zh/,/sh/,/th/,/ch/. Acoustic analysis revealed /s/ sound appeared most affected. Aligners had an effect on speech while reading, with patients slowing down to their speed to better articulate. The above-mentioned speech difficulties were transient. The included patients normalized their speech within 7-14 days from start of treatment while few patients took 30-60 days to recover.

CONCLUSIONS

Although the likelihood of speech difficulties would be high with CAT, the current evidence states that speech difficulties shown with CAT are similar to those found with FA. However, the patients who were treated using CAT adapt quickly and speech recovers within a few weeks. Time to recovery varied greatly, ranging from a week to two months in certain cases.

Orthodontic aligners: between passion and science

INTRODUCTION

The benefits and safety of using orthodontic aligners have been reported more by clinical experience and expert opinion than by scientific evidence. Another important aspect is that aligners are constantly evolving. It is important to obtain evidence that allows for new updates in manufacturing technology, in the development of new movement planning protocols, in the incorporation and design of attachments, and in the aid of skeletal anchorage.

METHODS

Evidence retrieved from six electronic databases (CINAHL, MEDLINE, EMBASE, Psych Info, the Cochrane Library and the Joanna Briggs Library) is presented by means of questions and answers.

CONCLUSIONS

There is evidence that the aligners presented different levels of difficulty in performing each type of movement, with rotational and vertical movements being the most difficult to perform. Regarding perception of pain due to tooth movement, it seems to have less impact at the beginning of treatment; but dealing with more phonoarticulatory changes seems to require more treatment time in more complex cases. Aligners do not prevent the occurrence of root resorption, although the incidence and severity of resorption may be reduced, making oral hygiene easier and accepting the risk of white spots, caries and periodontal disease. Given the conflicting evidence, the release of bisphenol-A from the aligner cannot be denied. Solutions must be found to reduce the environmental impact of aligners disposal. There is an urgent need for well-designed randomized controlled trials.

Evaluation of the Impact of Orthodontic Treatment on Patients' Self-Esteem: A Systematic Review

Malocclusion may affect interpersonal relationships, self-esteem (SE), and psychological well-being, weakening patients' psychological and social activities. Several studies investigated the effect of orthodontic treatment on these social and psychological aspects, such as SE. However, the direct relationship between SE and orthodontic treatment has not yet been confirmed. This systematic review aimed to evaluate the existing evidence in the literature concerning the influences of orthodontic treatment on patients' SE systematically and critically. An electronic search in the following databases was done in September 2022: PubMed®, Web of Science™, Scopus®, Embase®, GoogleTM Scholar, Cochrane Library databases, Trip, and OpenGrey. Then, the reference list of each candidate study was checked for any potentially linked papers that the electronic search might not have turned up. Inclusion criteria were set according to the population/intervention/comparison/outcome/study design (PICOS) framework. For the data collection and analysis, two reviewers extracted data separately. The risk of bias 2 (RoB-2) and the risk of bias in non-randomized studies (ROBINS-I) tools were used to assess the risk of bias for randomized controlled trials (RCTs) and non-RCTs, respectively. The grading of recommendations assessment, development and evaluation (GRADE) approach was employed to evaluate the quality of the evidence for each finding. Sixteen studies (five RCTs, seven cohorts, and four cross-sectional) were included in this review. Unfortunately, the results could not be pooled into a meta-analysis. Only six studies have reported an increase in SE after orthodontic treatment (P<0.05 in these studies). No agreement between the included studies was observed regarding the influence of fixed orthodontic treatment, gender, or age on SE. The quality of evidence supporting these findings ranged from very low to low. There is low evidence indicating that fixed orthodontic treatment can improve patients' SE. In addition, unclear data are available about the influence of patients' gender and age on SE after orthodontic treatment. Therefore, high-quality RCTs are required to develop stronger evidence about this issue.

Preclinical in vitro study of streptococcus mutans accumulation in three fixed retainer designs: Microbiological assay

The use of fixed retainers in the lower arch is frequent; however, its presence increases the accumulation of biofilm and dental calculus. The objective of this research was to evaluate, in vitro, the accumulation of Streptococcus mutans (S. mutans) in 3 designs of fixed retainers. Nine models were reproduced in heat-cured acrylic resin and divided into groups: straight retainer (SR), retainer with vertical strap (RVS), retainer with horizontal strap (RHS). The accumulation of S. mutans was assessed using the MTT assay (3-4,5-dimethyl-thiazol-2-yl-2,5-diphenyltetrazolium bromide) and then measured using an automated reader. The RHS group showed less biofilm accumulation compared to the other groups (p<0.05). The distance between the tooth surface and the retainer showed a strong negative correlation with biofilm accumulation (rs=-0.79, p=0.00037). The RHS showed significantly less accumulation of S. mutans due to the distance between the retainer and the tooth surface. This research provides relevant data for a future randomized clinical trial.

Treatment Effectiveness of Clear Aligners in Correcting Complicated and Severe Malocclusion Cases Compared to Fixed Orthodontic Appliances: A Systematic Review

This systematic review aimed to critically assess the available evidence regarding the effectiveness and efficiency of clear aligners in the comprehensive treatment of complex cases accompanied by premolars extraction. An electronic literature search by two reviewers was independently done on 27 February 2023 in the following databases without time and language limitations: Pubmed®, Scoups®, Google Scholar, Cochrane Library database, Web of Science™, and Proquest Database Open. Randomized controlled trials (RCTs) of any type, non-randomized clinical trials (CCT), cohort studies, and prospective, retrospective, and cross-sectional studies were reviewed. The risk of bias in included studies was assessed using the Risk of Bias (RoB 2.0) tool for randomized trials and the Risk of Bias in Non-randomized Studies (ROBINS-I) tool for non-randomized studies. After carefully searching the literature, six trials were included in this systematic review, three RCTs, two retrospective cohort studies, and one CCT. Two hundred eighty-three patients were included (186 females, 97 males). Three studies found that there were no differences between the clear aligners and fixed appliances when evaluations were done using the American Board of Orthodontists Objective Grading System (ABO-OGS) or the Peer Assessment Rating (PAR) index. Two studies found that there were some differences between predicted and achieved tooth movements when clear aligners were used in premolars extraction cases. Based on the included studies, the duration of treatment was shorter with fixed appliances than the clear aligners when applied to orthodontic extraction cases. Both clear aligners and fixed appliances were found effective in the orthodontic treatment of premolar extraction-based cases. Fixed appliances have the advantage of achieving better buccolingual inclination and occlusal contacts in a shorter treatment duration. Treatment with clear aligners might be associated with differences between predicted and achieved tooth movements. Therefore, the characteristics of these techniques should be considered when making a treatment decision.

Speech assessment tool methods for speech impaired children: a systematic literature review on the state-of-the-art in Speech impairment analysis

Speech is a powerful, natural mode of communication that facilitates effective interactions in human societies. However, when fluency or flow of speech is affected or interrupted, it leads to speech impairment. There are several types of speech impairment depending on the speech pattern and range from mild to severe. Childhood apraxia of speech (CAS) is the most common speech disorder in children, with 1 out of 12 children diagnosed globally. Significant advancements in speech assessment tools have been reported to assist speech-language pathologists diagnosis speech impairment. In recent years, speech assessment tools have also gained popularity among pediatricians and teachers who work with preschoolers. Automatic speech tools can be more accurate for detecting speech sound disorders (SSD) than human-based speech assessment methods. This systematic literature review covers 88 studies, including more than 500 children, infants, toddlers, and a few adolescents, (both male and female) (age = 0-17) representing speech impairment from more than 10 countries. It discusses the state-of-the-art speech assessment methods, including tools, techniques, and protocols for speech-impaired children. Additionally, this review summarizes notable outcomes in detecting speech impairments using said assessment methods and discusses various limitations such as universality, reliability, and validity. Finally, we consider the challenges and future directions for speech impairment assessment tool research.

Impacts of anterior-posterior jaw disproportions on speech of dentofacial disharmony patients

BACKGROUND/OBJECTIVES

Articulation problems impact communication, development, and quality of life, and are diagnosed in 73-87% of patients with Class II Dentofacial Disharmony (DFD). We evaluated whether differences exist in stop (/t/ or/k/), fricative (/s/ or/ʃ/), and affricate (/tʃ/) consonant sounds of Class II DFD subjects, and whether extent of malocclusion correlates with severity of speech distortion. We hypothesized that Class II patients display milder distortions than Class III and anterior open bite (AOB), as Class II patients can posture into a Class I occlusion.

MATERIALS/METHODS

Audio and orthodontic records were collected from DFD patients (N = 53-Class II, 102-Class III, 72-Controls) who were pursuing orthodontics and orthognathic surgery. A speech pathologist perceptually scored speech. Acoustic differences in recordings were measured using Spectral Moment Analysis.

RESULTS

When Class II subjects were compared to controls, significant differences were found for the centroid frequency (M1) of the /s/ sound and the spectral spread (M2) of /t/, /tʃ/, and /s/ sounds, with pairwise significance for controls relative to Class II AOB and all Class II subjects. Class II AOB subjects had higher M1 and M2 values than patients with Class II closed bites and Class I controls for most sounds. When comparing across anterior-posterior (AP) groups, differences exist between controls, Class II and III DFD subjects for M1 of /t/, /tʃ/, and/ʃ/ and M2 for /t/, /tʃ/, /s/, and /ʃ/ sounds. Using linear regression, correlations between Class II and III severity and spectral measures were found for /t/ and /tʃ/ sounds.

CONCLUSIONS/IMPLICATIONS

Class II and III patients have a higher prevalence of qualitative distortions and spectral changes in consonants compared to controls, but Class II spectral shifts are smaller and affect fewer sounds than in Class III and AOB cohorts. Linear correlations between AP discrepancy and spectral change suggest causation and that treatment may improve articulation problems.

The effect of clear aligners on speech: a systematic review

OBJECTIVE

To assess the effect of clear aligners on the speech of patients undergoing orthodontic therapy through a systematic review of the literature. Search methods and selection criteria: The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) CRD42021278694. An electronic search of the Scopus, Embase, Pubmed, and Web of Science databases was done for papers published between January 2000 till September 2021. Studies that evaluated speech difficulties in patients undergoing orthodontic treatment with clear aligners using objective and subjective analyses were included. The evaluated primary outcome was speech difficulties. Secondary outcomes were time to adaptation and recovery from speech difficulties. Study quality was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions Handbook guidelines and ROBINS-I tool.

RESULTS

Two hundred and eighty-three articles were screened to identify seven studies (n = 332 patients) that assessed speech difficulty with aligners, of which two were randomized trials. Meta-analysis was not performed due to the heterogeneity in the study designs. Five studies compared speech difficulty with aligners to fixed appliances. Two studies showed a moderate risk of bias and five studies had a serious risk of bias. Level of evidence was downgraded to low due to the methodological insufficiencies and risk of bias in the studies. All seven studies reported that aligners could influence the clarity and delivery of speech, similar to fixed appliances. Various phonemes were affected including /s/,/z/,/zh/,/sh/,/th/,/ch/ on wearing aligners. Errors in articulation of consonants and sibilants were noted with lisping and speech impairment. These speech difficulties were temporary and most patients recovered in 7-14 days while few patients took 30-60 days to recover.

CONCLUSION

The likelihood of speech difficulties appears high with clear aligners. However, patients adapt quickly and speech returns to normal. The results of this review must be interpreted with caution and more well-designed randomized trials examining long-term effects of aligners on speech are indicated.

CLINICAL SIGNIFICANCE

Orthodontists should counsel patients opting for clear aligner treatment of the potential transient speech difficulties.

REGISTRATION

The protocol for this systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) CRD42021278694.

Pain, Discomfort, and Functional Impairments When Retracting Upper Anterior Teeth Using Two-Step Retraction With Transpalatal Arches Versus En-Masse Retraction With Mini-implants: A Randomized Controlled Trial

Background This study aimed to evaluate the levels of pain and discomfort associated with employing mini-implants as a temporary skeletal anchorage device compared to the traditional transpalatal arches (TPAs) during upper anterior teeth retraction in patients with upper dentoalveolar protrusion and to determine the level of acceptance of both techniques among patients. Methodology The study sample consisted of 38 patients (29 women and nine men) with an average age of 21.7 years. The patients were randomly and equally distributed into two groups. In the first group: upper anterior teeth were en-masse retracted using mini-implants (the TAD group), whereas, in the second group, TPAs were used during the two-step retraction of upper anterior teeth (the TPA group). Standardized questionnaires were distributed to all patients after 24 hours of mini-implant application. The questionnaire asked the patients to rate their pain perception, swelling sensation, eating difficulties, talking impairments, and cleansing difficulties on a four-point Likert scale on the third-day, one-week, two-week, and one-month follow-ups after the anchorage application. Wilcoxon matched-pairs signed-rank tests were used to evaluate intragroup changes, whereas Mann-Whitney U tests were employed to examine intergroup differences. Results Patients in the TAD group had higher pain and swelling levels than those in the TPA group, and differences were statistically significant at the first three assessment time points. The differences between the two groups were statistically insignificant regarding eating and talking difficulties, whereas differences were statistically significant for brushing difficulties. These impairments decreased to almost normal levels after one month of treatment initiation. Conclusions TPAs, when used for anchorage in the two-step retraction technique, were less problematic compared to mini-implants with en-masse retraction, where the sensation of pain or swelling around the mini-implants did not last for more than a week. The difficulties of cleaning, chewing, and speaking in the presence of mini-implants were temporary and mostly disappeared within two weeks of mini-implant application.

Impacts of Skeletal Anterior Open Bite Malocclusion on Speech

INTRODUCTION

Articulation problems are seen in 80-90% of dentofacial deformity (DFD) subjects compared with 5% of the general population, impacting communication and quality of life, but the causal link is unclear. We hypothesize there are both qualitative (perceptual) and quantitative (spectral) differences in properties of stop (/t/ or /k/), fricative (/s/ or /∫/), and affricate (/t∫/) consonant sounds and that severity of anterior open bite (AOB) jaw disharmonies correlates with degree of speech abnormality.

METHODS

To test our hypotheses, surgical orthodontic records and audio recordings were collected from DFD patients (n=39 AOB, 62 controls). A speech pathologist evaluated subjects and recordings were analyzed using spectral moment analysis (SMA) to measure sound frequency distortions.

RESULTS

Perceptually, there is a higher prevalence of auditory and visual speech distortions in AOB DFD patients when compared to controls. Quantitatively, a significant (p<0.01) increase in the centroid frequency (M1) was seen in the /k/, /t/, /t∫/, and /s/ sounds of AOB subjects compared to the controls. Using linear regression, correlations between AOB skeletal severity and spectral distortion were found for /k/ and /t/ sounds.

CONCLUSIONS

A higher prevalence of qualitative distortion and significant quantitative spectral distortions in consonant sounds were seen in AOB patients compared to controls. Additionally, severity of skeletal AOB is correlated with degree of distortion for consonant sounds. These findings provide insight into how the surgical and/or orthodontic treatment of AOB may impact speech.

Orthognathic speech pathology: impacts of Class III malocclusion on speech

INTRODUCTION

Patients with dentofacial disharmonies (DFDs) seek orthodontic care and orthognathic surgery to address issues with mastication, esthetics, and speech. Speech distortions are seen 18 times more frequently in Class III DFD patients than the general population, with unclear causality. We hypothesize there are significant differences in spectral properties of stop (/t/ or /k/), fricative (/s/ or /ʃ/), and affricate (/tʃ/) consonants and that severity of Class III disharmony correlates with the degree of speech abnormality.

METHODS

To understand how jaw disharmonies influence speech, orthodontic records and audio recordings were collected from Class III surgical candidates and reference subjects (n = 102 Class III, 62 controls). A speech pathologist evaluated subjects and recordings were quantitatively analysed by Spectral Moment Analysis for frequency distortions.

RESULTS

A majority of Class III subjects exhibit speech distortions. A significant increase in the centroid frequency (M1) and spectral spread (M2) was seen in several consonants of Class III subjects compared to controls. Using regression analysis, correlations between Class III skeletal severity (assessed by cephalometric measures) and spectral distortion were found for /t/ and /k/ phones.

CONCLUSIONS

Class III DFD patients have a higher prevalence of articulation errors and significant spectral distortions in consonants relative to controls. This is the first demonstration that severity of malocclusion is quantitatively correlated with the degree of speech distortion for consonants, suggesting causation. These findings offer insight into the complex relationship between craniofacial structures and speech distortions.

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

Background

The C-lingual retractor (CR) is an alternative lingual technique to retract anterior teeth with minimum torque expression loss. Although the effects of lingual braces upon speech and oral comfort have been studied previously, there is no published data about the C-lingual retractor in this aspect. The aims of this trial were to compare (1) speech performance based on objective acoustic analysis and (2) levels of oral impairment between C-lingual retractor and conventional lingual brackets (LBs).

Materials and methods

A parallel-group randomized controlled trial was conducted on patients with class II division 1 malocclusion who sought orthodontic treatment at the Department of Orthodontics, Hama University Dental School. Thirty-six patients who met inclusion criteria were randomly selected and divided into two groups. Eighteen patients in the C-lingual retractor group (CR group) were treated with a C-lingual retractor, whereas eighteen patients in the lingual brackets group (LB group) were treated with conventional lingual brackets (Stealth H, American Orthodontics, Sheboygan, WI, USA). Fricative /s/ sound spectrograms were analyzed before (T0), immediately after (T1), one month after (T2), and three months after appliance placement (T3). The levels of oral discomfort were assessed using standardized questionnaires to evaluate speech, irritation, chewing difficulties, and other oral impacts.

Results

At all assessment times, the C-lingual retractor caused significant deteriorations in articulation, whereas in the lingual brackets group these deteriorations were statistically significant at T1 and T2 (P<0.001) but not significant at T3 (P=0.073). No intergroup differences were detected. Questionnaire analysis revealed that irritation of the tongue was significantly higher in the lingual brackets group after 24 hours of appliances' placement (P=0.007), whereas speech and mastication problems were insignificantly higher in the C-lingual retractor group.

Conclusions

The findings indicate that the C-lingual retractor has insignificantly a little more interaction with sound production than lingual brackets. Although the levels of oral impacts were almost similar among both groups, more tongue irritation was observed in the lingual brackets group. However, the oral discomfort decreased over the observation period in both groups.

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

Background

Wearing fixed orthodontic appliances may negatively impact oral health-related quality of life (OHRQoL) during treatment. This study aimed to compare the OHRQoL of patients treated with labial or lingual appliances.

Methodology

A total of 38 patients (23 females, 15 males; mean age: 21.3 years) with class I malocclusion and moderate crowding in the upper and lower dental arches were included. These patients were planned to be treated on a non-extraction basis and were randomly divided into the following two groups: the lingual appliance (LA) group and the buccal appliance (BA) group. The Oral Health Impact Profile-14 (OHIP-14) questionnaire was used to measure the OHRQoL at the following six assessment times: before treatment (T0), one week after treatment (T1), one month after treatment (T2), three months after treatment (T3), six months after treatment (T4), and at the end of the active treatment (T5).

Results

In total, 19 patients in each group were included in the final analysis with no dropouts. In both groups, the overall OHIP-14 scores increased and peaked on the first week following appliance placement and then significantly decreased over time. The LA group had significantly greater overall OHIP‑14 scores than the labial group at T1 (p < 0.001) and T2 (p = 0.004) only.

Conclusions

The OHRQoL improved in both lingual and labial groups after treatment. Moreover, it was better in the labial group compared to the lingual group during the first month of treatment. In both groups, the greatest deterioration in OHRQoL occurred in the first week and gradually decreased over time.

Activation and installation of orthodontic appliances temporarily impairs mastication

OBJECTIVES

To investigate the masticatory (masticatory performance, bite force, swallowing threshold, muscle activity, and questionnaires) and nutritional (nutrient intake) impacts of the activation and/or installation of different orthodontic appliances (fixed labial, lingual appliances, and clear aligners).

MATERIALS AND METHODS

Six electronic databases and gray literature were searched (up to May 2021) for relevant studies evaluating mastication and nutrition after activation/installation of orthodontic appliances. This review followed PRISMA guidelines and was registered at PROSPERO (CRD42020199510). The risk of bias (RoB 2 and ROBINS-I) and evidence quality Grading of Recommendations Assessment, Development, and Evaluation were analyzed.

RESULTS

Of 4226 recorded and screened, 15 studies were finally included. Masticatory performance (standardized mean difference [SMD]: 1.069; 95% coefficient interval [CI]: 0.619 to 1.518) and bite force (SMD: -2.542; 95% CI: -4.867 to -0.217) reduced in the first 24 to 48 hours of fixed labial appliance installation/activation, but they were both normalized after 30 days (P > .05). The swallowing threshold remained constant (P > .05). Nutritional intake was rarely reported but showed copper (P = .002) and manganese (P = .016) reductions, with higher calorie and fat intake (P < .05). Lingual appliances impacted chewing more than labial, and clear aligner wearers reported fewer chewing problems (P < .001). Low to very low levels of evidence were found.

CONCLUSIONS

Based on low to very low levels of evidence, mastication was reduced during the first 24 to 48 hours of fixed labial appliance activation/installation, but it was transitory (up to 30 days). Due to insufficient data, the nutritional impact of orthodontic appliances was not conclusive.

Assessment of Patient-Centered Outcomes When Treating Maxillary Constriction Using a Slow Removable Versus a Rapid Fixed Expansion Appliance in the Adolescence Period: A Randomized Controlled Trial

Objective

This study aimed to evaluate and compare the levels of pain, discomfort, and functional impairments between slow and rapid maxillary expansion (RME) in treating skeletal maxillary constriction in the adolescence period (i.e., between 12 and 16 years).

Materials and methods

The study sample consisted of 52 patients (21 males and 31 females) with maxillary skeletal constriction in the posterior region. The patients were randomly distributed into either RME (26 patients, with a mean age of 13.87 (± 1.31) years) or slow maxillary expansion group (SME, 26 patients, with a mean age of 14.31 (± 1.19) years). The levels of pain, discomfort, and functional difficulties were assessed after 24 hours (T1), 7 days (T2), 15 days (T3), one month (T4), and four months (T5) following the onset of the expansion procedure.

Results

Patients in the RME group encountered significantly greater levels of pain and discomfort than those in the SME group at T1, T2, and T3 (p>0.001). Chewing and swallowing difficulties were significantly greater in the RME group at T1, T2, T3, and T4 (P≤0.001). The pressure on soft tissue was greater in the RME group at T2 and T3 (p>0.001). After four months (T5), the levels of pain and discomfort decreased to their lowest levels, as well as the difficulties of chewing and swallowing, and the pressure on soft tissue were almost non-existent in both groups.

Conclusion

Patients treated with the removable slow maxillary expander reported lower levels of pain and discomfort, fewer chewing and swallowing difficulties, and less pressure on soft tissues than those treated with the bonded rapid maxillary expander. These difficulties gradually decreased over time in both groups. The lower levels of pain and discomfort may make the SME an effective and comfortable treatment alternative for adolescents with skeletal maxillary constriction.

A Simple Technique Using a Modified Nance Appliance as Anchorage for Maxillary Molar Distalization—Two Case Reports

Maxillary molar distalization to correct a dental Class II molar relationship and to create space to relieve crowding has been a long-lasting subject of debate in orthodontics. Generally, to distalize maxillary molars, an intra-arch distalization appliance is favored over an inter-arch appliance since it does not utilize mandibular dentition as an anchorage, so some unwanted side effects on mandibular incisors can be avoided. A variety of intra-arch appliances have been developed to distalize maxillary molars, such as the pendulum, Jones jig, first class appliance, distal jet, and modified C-palatal plate. Although they could achieve efficient molar distalization, the learning curve of proper appliance insertion and activation is relatively long. In addition, the appliances are not comfortable for the patients due to the bulky activation units, especially when the activation units are designed in the palatal area. The current manuscript describes a novel and effective maxillary intra-arch molar distalization appliance—a modified Nance appliance technique, which consists of: (1) palatally, a big acrylic button against the palatal rugae and connected to the premolars with wide mesh pads; (2) buccally, regular brackets on maxillary premolars and first molars with sectional round stainless steel archwires and open coil springs between the second premolar and first molar. Either bilateral or unilateral maxillary molar distalization can be achieved with this appliance, and the Class II elastics are not needed. It is simple to be fabricated, delivered, and activated, and it is comfortable for patients.

Effects of orthodontic treatment with aligners and fixed appliances on speech

OBJECTIVES

To evaluate effects of orthodontic treatment with aligners and conventional fixed appliances on production of speech.

MATERIALS AND METHODS

This was a parallel, randomized clinical trial. Patients with Angle Class I malocclusion, moderate crowding, and no speech impairment were randomly allocated to two groups: patients with orthodontic aligners (OAs; n = 20; mean age = 23.60 ± 5.65 years) and those with conventional fixed appliances (n = 20; mean age = 20.56 ± 4.51 years) and treated at the University of North Parana's clinic in Londrina, Brazil. Evaluation of speech production was performed semiobjectively by a speech therapist (myofunctional orofacial examination) and subjectively (self-assessment) at five time points: baseline, immediately after insertion of appliances, and subsequently at 3, 30, and 180 days after insertion. For intergroup comparison, independent t, χ2, Fisher exact, and Mann-Whitney tests were used; for intragroup comparison, the Friedman test was applied (α = 5%).

RESULTS

In the semiobjective evaluation, patients with OAs exhibited a change in production of speech production, compared with patients with fixed appliances, immediately and 3 days after insertion of appliances (P < .001). Thirty days after insertion, the groups were similar (P = .487), an outcome that was unchanged at 180 days. However, in the self-assessments, patients in both groups reported significant speech difficulties immediately and 3 days after insertion of appliances, but such impairment was no longer perceived at 30 days or 180 days.

CONCLUSIONS

Although the speech therapist identified changes in speech production at the start of treatment in the OA group only, patient self-assessments demonstrated that orthodontic treatment, regardless of the type of appliance used, interfered with their perception of speech.

How efficient is customized lingual orthodontics? An assessment of treatment outcome

OBJECTIVE

To assess the efficacy of lingual orthodontics by comparing setups and post-treatment casts.

SETTING AND SAMPLE POPULATION

Thirty-two consecutive patients treated with a customized lingual orthodontic appliance were included in this retrospective study.

MATERIALS AND METHODS

Initial casts, post-treatment casts and setups were scanned, and the digital models produced were analysed in terms of overjet; overbite; molar and canine relationships; intercanine, interpremolar and intermolar distances; upper and lower arch lengths; midline deviation; bucco-lingual angulation of all teeth and mesio-distal angulation of anterior teeth. Comparisons between setups and post-treatment casts were performed via paired t tests. Relationships between the planned and actual correction were studied using regression analysis.

RESULTS

Statistically significant differences in bucco-lingual torque between setups and post-treatment casts were found for all upper teeth, except for central incisors. In the lower jaw, statistically significant differences in bucco-lingual torque were found between setups and post-treatment casts for the lower incisors and molars. No statistically significant differences in mesio-distal angulation of anterior teeth were found between setups and post-treatment casts. Upper and lower arch widths did not vary significantly between setups and final casts, except upper inter-second premolar and intermolar distances.

CONCLUSION

Customized lingual appliances offer efficient control of mesio-distal angulation of all anterior teeth. Significant differences in torque between setups and post-treatment casts were observed for upper lateral incisors, canines, premolars and molars, as well as lower incisors and molars. However, the torque difference was clinically significant (over three degrees) for upper second premolars and molars only.

Professional consensus on orthodontic risks: What orthodontists should tell their patients

INTRODUCTION

Effective communication of risk is a requisite for valid consent, shared decision-making, and the provision of person-centered care. No agreed standard for the content of discussions with patients about the risks of orthodontic treatment exists. This study aimed to produce a professional consensus recommendation about the risks that should be discussed with patients as part of consent for orthodontic treatment.

METHODS

A serial cross-sectional survey design using a modified electronic Delphi technique was used. Two survey rounds were conducted nationally in the United Kingdom using a custom-made online system. The risks used as the prespecified items scored in the Delphi exercise were identified through a structured literature review. Orthodontists scored treatment risks on a 1-9 scale (1 = not important, 9 = critical to discuss with patients). The consensus that a risk should be discussed as part of consent was predefined as ≥70% orthodontists scoring risk as 7-9 and <15% scoring 1-3.

RESULTS

The electronic Delphi was completed by 237 orthodontists who reached a professional consensus that 10 risks should be discussed as part of consent for orthodontic treatment; demineralization, relapse, resorption, pain, gingivitis, ulceration, appliances breaking, failed tooth movements, treatment duration, and consequences of no treatment.

CONCLUSIONS

A professional orthodontic consensus has been reached that 10 key risks should be discussed with patients as part of consent for orthodontic treatment. The information in this evidence base should be tailored to patients' individual needs and delivered as part of a continuing risk communication process.

Health communication in low-income countries: A 60-year bibliometric and thematic analysis

BACKGROUND

Health communication is a field that uses social and behavioral models to improve health outcomes and raise awareness on major health risks that threaten human well-being. Low-income countries (LICs) suffer from the effects of communicable and noncommunicable diseases that are exacerbated by weak health-care systems, lack of awareness campaigns, and ineffective communication tactics. This work aims to explore health communication research in LICs to find strategies that help improve health outcomes in the future.

MATERIALS AND METHODS

The PubMed database was explored systematically for publications related to health communication from LICs between January 1, 1960, and January 1, 2020. Publications were categorized according to country of origin and were analyzed with respect to population size, gross domestic product (GDP), and primary school enrollment of each state as obtained from the World Bank Open Data.

RESULTS

Collectively, LICs published 796 contributions, comprising 1.08% of the total biomedical research published by LICs and 0.27% of the world's health communication research. Malawi had the highest number of publications per GDP, with 32.811 publications per billion US$. Uganda had the most contributions per population, with 9.579 publications per million persons. Ethiopia had the highest amount of contributions per primary school enrollment with a ratio of 2.461 publications per %gross. The role of health communication in promoting HIV awareness and prevention was the most common theme explored. Other infectious diseases, such as malaria, tuberculosis, and Ebola, were also highlighted. Improving communication in health education was also explored.

CONCLUSION

Health communication is a rising field in LICs, with research focusing on disease prevention. Efforts to amplify research are key to effectively utilize the health communication models and improve health outcomes in LICs.

Pain and Oral-Health-Related Quality of Life in Orthodontic Patients During Initial Therapy with Conventional, Low-Friction, and Lingual Brackets and Aligners (Invisalign): A Prospective Clinical Study

The aim of this study was to compare pain and its relationship with the oral quality of life of patients with different types of orthodontic appliances: conventional and conventional low-friction brackets, lingual brackets, and aligners. A prospective clinical study was carried out with a sample size of 120 patients (54 men, 66 women) divided into 4 groups of 30 patients each. The modified McGill questionnaire was used to measure pain at 4, 8, and 24 h and 2, 3, 4, 5, 6, and 7 days after the start of treatment, and the Oral Health Impact Profile-14 (OHIP-14) questionnaire was used to measure the oral-health-related quality of life (OHRQoL) in the first month of treatment. The maximum peak of pain was obtained between 24 and 48 h of treatment. It was found that patients in the lingual orthodontic group described lower levels of pain at all times analyzed, and their scores in the total OHIP-14 indicated less impact on their oral quality of life (1.3 ± 1.2, p < 0.01) compared with the other groups analyzed. There was little difference with the aligners group (Invisalign) (1.7 ± 1.9, p < 0.01). The technique used influences the pain and quality of life of patients at the start of orthodontic treatment.

Comparison of pain levels in patients treated with 3 different orthodontic appliances - a randomized trial

Background and aims

To compare pain levels experienced during initial alignment with three different orthodontic appliance types and to correlate pain with male and female differences, if any.

Methods

A prospective, randomized 3-arm parallel trial allocated 36 adult orthodontic patients into three appliance groups: MBT 0.022" slot (Mini Twin, Ormco, Glendora, USA), self ligating 0.022" slot Damon 3MX (Ormco, Glendora, USA) and clear aligners (Smile align, Mumbai, India). The level of discomfort was assessed through a questionnaire based on the visual analogue scale at four hours, twenty four hours, third and seventh day after appliance placement.

Results

Patients treated with clear aligners reported less pain than patients treated with conventional and self ligating fixed appliances. Patients treated with MBT conventional appliances showed greater pain levels than Damon appliances. A significantly higher visual analogue scale score was observed at 24 hours and the least visual analogue scale scores on the seventh day post appliance placement.

Conclusion

During the first week of orthodontic treatment, patients treated with clear aligners reported lower pain than those treated with conventional and self-ligating appliances.

Lingual Orthodontic Treatment: Efficacy and Complications

Aims and Objectives:

The high esthetic demands led to the promotion of various esthetic appliances like lingual orthodontics. This study aimed to review clinical outcome and potential complications of lingual orthodontics to achieve an evidence-based decision for orthodontic therapies.

Materials and Methods:

A comprehensive electronic search was conducted from January 1975 to March 2019 which was limited to English language and administrations of lingual orthodontics treatment which evaluated its efficacy and potential complications. Data extraction was performed according to the PRISMA statement.

Results:

49 studies were selected and analyzed in this systematic review. The pain of lingual appliances starts a little earlier and lasts longer, and patients with lingual appliances experience more tongue discomfort and less cheek and lip pain and greater eating difficulties especially after placement and take a longer time to adapt to appliances. Lingual appliances generally cause more plaque accumulation and gingivitis especially in lingual anterior teeth; however, labial appliances are associated with high frequency in posterior maxillary teeth.

Conclusion:

This systematic review shows that despite the drawbacks of these appliances such as pain and eating difficulties, they can accomplish treatment goals with the same outcomes in comparison with conventional approaches, within the same duration and even lesser anchorage loss.

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 (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 7^th 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 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.

Adverse effects of lingual and buccal orthodontic techniques: A systematic review and meta-analysis

INTRODUCTION

The aim of this systematic review was to assess the prevalence of adverse effects associated with lingual and buccal fixed orthodontic techniques.

METHODS

Two authors searched the PubMed, EMBASE, Cochrane Library, and LILACS databases up to October 2014. Agreement between the authors was quantified by the Cohen kappa statistic. The following variables were analyzed: pain, caries, eating and speech difficulties, and oral hygiene. The Newcastle-Ottawa scale was used to assess risk of bias in nonrandomized studies, and the Cochrane Collaboration's tool for assessing risk of bias was used for randomized controlled trials.

RESULTS

Eight articles were included in this systematic review. Meta-analysis showed a statistically greater risk of pain of the tongue (odds ratio [OR], 28.32; 95% confidence interval [95% CI], 8.60-93.28; P <0.001), cheeks (OR, 0.087; 95% CI, 0.036-0.213; P <0.0010), and lips (OR, 0.13; 95% CI, 0.04-0.39; P <0.001), as well as for the variables of speech difficulties (OR, 9.39; 95% CI, 3.78-23.33; P <0.001) and oral hygiene (OR, 3.49; 95% CI, 1.02-11.95; P = 0.047) with lingual orthodontics. However, no statistical difference was found with respect to eating difficulties (OR, 3.74; 95% CI, 0.86-16.28; P = 0.079) and caries (OR, 1.15; 95% CI, 0.17-7.69; P = 0.814 [Streptococcus mutans] and OR, 0.67; 95% CI, 0.20-2.23; P = 0.515 [Lactobacillus]).

CONCLUSIONS

This systematic review suggests that patients wearing lingual appliances have more pain, speech difficulties, and problems in maintaining adequate oral hygiene, although no differences for eating and caries risk were identified. Further prospective studies involving larger sample sizes and longer follow-up periods are needed to confirm these results.

Phonetic analysis during treatment with rapid maxillary expander

OBJECTIVES

To investigate possible changes and/or device-related impairments in phonetic habits produced by rapid maxillary expansion (RME).

MATERIALS AND METHODS

Thirty-five patients scheduled for RME were divided into two groups: Group A (banded two-arm Hyrax) and Group B (banded four-arm Hyrax). Speech samples were collected at six time points, before, during and after RME removal. Acoustical analysis was performed using PRAAT and BioVoice analysis tools. Ten volunteers completed a questionnaire on the acceptability of patient's speech. Maxillary dimensions and palatal volume were measured on dental casts before and after expansion using a digital gauge.

RESULTS

Voice analysis showed an increase in the peak frequency of fricative consonants (/s/,/ʃ/) after expansion, whereas there was no change of formant frequencies of palatal consonants (/ɲ/,/ʎ/). Vowel /i/ displayed a lowering of the first formant frequency, and an increase in the second and third formant frequencies. After bonding, Group B showed both a greater reduction in the peak frequency of fricatives and a greater increase in the formant frequencies of palatal consonants than Group A.

CONCLUSION

Rapid maxillary expansion causes a slight phonetic change in the acoustical parameters of both consonants and vowels. The two-arm Hyrax caused less speech impairment than the four-arm Hyrax during the treatment.

Speech effects of Hawley and vacuum-formed retainers by acoustic analysis: A single-center randomized controlled trial

OBJECTIVE

To investigate the effects of alteration on speech articulation of adult patients between Hawley retainers and vacuum-formed retainers by an objective acoustic analysis of vowels and voiceless fricatives.

MATERIALS AND METHODS

Twenty adults, aged 19.0-29.0 years, who had just finished active orthodontic treatment were included in this study. They were divided into a Hawley retainer group and a vacuum-formed retainer group by sortation randomization method. The assessment of speech sounds was performed objectively using acoustic analysis before and after retainer application at the following time points: before wearing (T0), immediately after wearing (T1), and at 24 hours (T2), 1 week (T3), 1 month (T4), and 3 months (T5).

RESULTS

The production of /з:/, /i:/, /f/, /θ/, /s/, and /∫/ sounds for the Hawley retainer group and /i:/, /θ/, /s/, and /∫/ sounds for the vacuum-formed retainer group showed severe speech impairment according to acoustic analysis (P < .05). A comparison of the Hawley retainer group with the vacuum-formed retainer group revealed that the performance of /i:/, /f/, and /s/ sounds were significantly different (P < .05).

CONCLUSION

Although sound distortion could be found in both the Hawley retainer group and the vacuum-formed retainer group, changes in articulation were more obvious in the Hawley retainer group.

[Effects of Hawley retainer and vacuum-formed retainer on articulation of Chinese speech of adult orthodontic patients: a randomized controlled trial]

OBJECTIVE

This study investigated the influence of Hawley retainer and vacuum-formed retainer on the articu-lation of Chinese speech of adult orthodontic patients.

METHODS

A total of 20 volunteers were recruited in this randomized controlled trial in accordance with the inclusion criteria. Participants were randomly distributed into two groups, namely, the Hawley retainer group and the vacuum-formed retainer group. Speech performance was evaluated at the following time inter-vals: before wearing retainers (T0), immediately after wearing both upper and lower retainers (T1), 24 h later (T2), 1 week later (T3), and 1 month later (T4). The phonetic parameters were acquired through the use of computer-based voice analysis software Praat version 5.4.21, and the final data were analyzed using SPSS 19.0.

RESULTS

Both retainers can influence the phonetic parameters of vowels /e/, /i/, and /ü/ and consonants /s/, /f/, /x/, /t/, /j/, and /q/. However, the Hawley retainer showed a more remarkable effect on the articulation of Chinese speech, and the distortion of /i/, /ü/, and /s/ sounds can last for more than 1 month. Nevertheless, the recovery period of the patients' phonetic function in the vacuum-formed retainer group was within 1 month.

CONCLUSIONS

Both retainers can induce distortion of some Chinese vowels and consonants in the speech of adult orthodontic patients, but the Hawley retainer can more significantly influence the articulation of Chinese speech than vacuum-formed retainer.
.

Evidence regarding lingual fixed orthodontic appliances' therapeutic and adverse effects is insufficient

Data sourcesMedline, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Virtual Health Library and Web of Science were systematically searched up to July 2015 without limitations. Scopus, Google Scholar, ClinicalTrials.gov, the ISRCTN registry as well as reference lists of the trials included and relevant reviews were manually searched.Study selectionRandomised (RCTs) and prospective non-randomised clinical trials (non-RCTs) on human patients that compared therapeutic and adverse effects of lingual and labial appliances were considered. One reviewer initially screened titles and subsequently two reviewers independently screened the selected abstracts and full texts.Data extraction and synthesisThe data were extracted independently by the reviewers. Missing or unclear information, ongoing trials and raw data from split-mouth trials were requested from the authors of the trials. The quality of the included trials and potential bias across studies were assessed using Cochrane's risk of bias tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. For parallel trials, mean difference (MD) and the relative risk (RR) were used for continuous (objective speech performance, subjective speech performance, intercanine width, intermolar width and sagittal anchorage loss) and binary outcomes (eating difficulty), respectively. The standardised mean difference (SMD) was chosen to pool, after conversion, the outcome (oral discomfort) that assessed both binary and continuous. Random-effects meta-analyses were conducted, followed by subgroup and sensitivity analyses.ResultsThirteen papers pertaining to 11 clinical trials (three parallel RCTs, one split-mouth RCT and seven parallel prospective non-RCTs) were included with a total of 407 (34% male/66% female) patients. All trials had at least one bias domain at high risk of bias. Compared with labial appliances, lingual appliances were associated with increased overall oral discomfort, increased speech impediment (measured using auditory analysis), worse speech performance assessed by laypersons, increased eating difficulty and decreased intermolar width. On the other hand, lingual appliances were associated with increased intercanine width and significantly decreased anchorage loss of the maxillary first molar during space closure. However, the quality of all analyses included was judged as very low because of the high risk of bias of the included trials, inconsistency and imprecision.ConclusionsBased on existing trials there is insufficient evidence to make robust recommendations for lingual fixed orthodontic appliances regarding their therapeutic or adverse effects, as the quality of evidence was low.

Effects of fixed labial orthodontic appliances on speech sound production

OBJECTIVE

To explore the impact of fixed labial orthodontic appliances on speech sound production.

MATERIALS AND METHODS

Speech evaluations were performed on 23 patients with fixed labial appliances. Evaluations were performed immediately prior to appliance insertion, immediately following insertion, and 1 and 2 months post insertion. Baseline dental/skeletal variables were correlated with the ability to accommodate the presence of the appliances.

RESULTS

Appliance effects were variable: 44% of the subjects were unaffected, 39% were temporarily affected but adapted within 2 months, and 17% of patients showed persistent sound errors at 2 months. Resolution of acquired sound errors was noted by 8 months post-appliance removal. Maladaptation to appliances was correlated to severity of malocclusion as determined by the Grainger's Treatment Priority Index. Sibilant sounds, most notably /s/, were affected most often.

CONCLUSIONS

(1) Insertion of fixed labial appliances has an effect on speech sound production. (2) Sibilant and stopped sounds are affected, with /s/ being affected most often. (3) Accommodation to fixed appliances depends on the severity of malocclusion.

Frictional property comparisons of conventional and self-ligating lingual brackets according to tooth displacement during initial leveling and alignment: an in vitro mechanical study

Objective

We evaluated the effects of tooth displacement on frictional force when conventional ligating lingual brackets (CL-LBs), CL-LBs with a narrow bracket width, and self-ligating lingual brackets (SL-LBs) were used with initial leveling and alignment wires.

Methods

CL-LBs (7th Generation), CL-LBs with a narrow bracket width (STb), and SL-LBs (In-Ovation L) were tested under three tooth displacement conditions: no displacement (control); a 2-mm palatal displacement (PD) of the maxillary right lateral incisor (MXLI); and a 2-mm gingival displacement (GD) of the maxillary right canine (MXC) (nine groups, n = 7 per group). A stereolithographic typodont system and artificial saliva were used. Static and kinetic frictional forces (SFF and KFF, respectively) were measured while drawing a 0.013-inch copper-nickel-titanium archwire through brackets at 0.5 mm/min for 5 minutes at 36.5℃.

Results

The In-Ovation L exhibited lower SFF under control conditions and lower KFF under all displacement conditions than the 7th Generation and STb (all p < 0.001). No significant difference in SFF existed between the In-Ovation L and STb for a 2-mm GD of the MXC and 2-mm PD of the MXLI. A 2-mm GD of the MXC produced higher SFF and KFF than a 2-mm PD of the MXLI in all brackets (all p < 0.001).

Conclusions

CL-LBs with narrow bracket widths exhibited higher KFF than SL-LBs under tooth displacement conditions. CL-LBs and ligation methods should be developed to produce SFF and KFF as low as those in SL-LBs during the initial and leveling stage.

Lingual vs. labial fixed orthodontic appliances: systematic review and meta-analysis of treatment effects

The aim of this systematic review was to compare the therapeutic and adverse effects of lingual and labial orthodontic fixed appliances from clinical trials on human patients in an evidence-based manner. Randomized and prospective non-randomized clinical trials comparing lingual and labial appliances were included. Risk of bias within and across studies was assessed using the Cochrane tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random-effects meta-analyses were conducted, followed by subgroup and sensitivity analyses. Six electronic databases were searched from inception to July 2015, without limitations. A total of 13 papers pertaining to 11 clinical trials were included with a total of 407 (34% male/66% female) patients. Compared with labial appliances, lingual appliances were associated with increased overall oral discomfort, increased speech impediment (measured using auditory analysis), worse speech performance assessed by laypersons, increased eating difficulty, and decreased intermolar width. On the other hand, lingual appliances were associated with increased intercanine width and significantly decreased anchorage loss of the maxillary first molar during space closure. Based on existing trials, there is insufficient evidence to make robust recommendations for lingual fixed orthodontic appliances regarding their therapeutic or adverse effects, as the quality of evidence was low.

Parent-assessed quality of life among adolescents undergoing orthodontic treatment: a 12-month follow-up

OBJECTIVE

To assess parents' and caregivers' view of the first twelve months of adolescents' orthodontic treatment with fixed appliances and to assess the evaluative properties of the Brazilian version of the Parental-Caregiver Perceptions Questionnaire (P-CPQ) in the orthodontic setting.

METHODS

Data from a sample of 96 parents and caregivers of adolescents undergoing orthodontic treatment with fixed appliances were collected by means of P-CPQ. Assessments were performed before banding and bracket bonding (T1) and 12 months after placement of fixed appliances (T2). Statistical analysis included Wilcoxon signed-rank test for the overall P-CPQ score and Bonferroni correction for P-CPQ subscales. The evaluative properties of the P-CPQ were assessed through responsiveness calculation and the minimally clinical important difference (MCID).

RESULTS

Among the 96 participants, 76 were mothers of patients, 16 were fathers, and four were other family members. Adolescents' mean age was 11.49 ± 0.50 years. Most families earned equal to or less than three times the Brazilian monthly minimum wage. There was significant improvement in the emotional and social well-being subscales (p< 0.001), which contributed to improve patient's overall quality of life (p< 0.001). Reductions in scores were associated with clinically meaningful moderate changes in the overall score as well as in the emotional and social well-being subscales. The MCID was 6.16 for the P-CPQ overall score.

CONCLUSION

Parents and caregivers reported significant improvement in the quality of life of adolescents undergoing orthodontic treatment with fixed appliances.

Periodontal CGRP contributes to orofacial pain following experimental tooth movement in rats

Calcitonin-related gene peptide (CGRP) plays an important role in orofacial inflammatory pain. The aim of this study was to determine whether periodontal CGRP contributes to orofacial pain induced by experimental tooth movement in rats. Male Sprague-Dawley rats were used in this study. Closed coil springs were used to deliver forces. Rats were euthanized on 0d, 1d, 3d, 5d, 7d, and 14d following experimental tooth movement. Then, alveolar bones were obtained for immunostaining of periodontal tissues against CGRP. Two hours prior to euthanasia on each day, orofacial pain levels were assessed through rat grimace scale. CGRP and olcegepant (CGRP receptor antagonist) were injected into periodontal tissues to verify the roles of periodontal CGRP in orofacial pain induced by experimental tooth movement. Periodontal CGRP expression levels and orofacial pain levels were elevated on 1d, 3d, 5d, and 7d following experimental tooth movement. The two indices were significantly correlated with each other and fitted into a dose-response model. Periodontal administration of CGRP could elevate periodontal CGRP expressions and exacerbate orofacial pain. Moreover, olcegepant administration could decrease periodontal CGRP expressions and alleviate orofacial pain. Therefore, periodontal CGRP plays an important role in pain transmission and modulation following experimental tooth movement. We suggest that it may participate in a positive feedback aiming to amplify orofacial pain signals.

Lingual orthodontic treatment: what is the current evidence base?

As the number of adults that seek orthodontic treatment continues to grow, so too is the popularity of lingual fixed appliances. Although the aesthetic advantages associated with these systems are obvious, for some orthodontists, there has been a reluctance to offer lingual-based treatment to their patients. This is often based upon the perceived problems associated with lingual braces, relating to discomfort and difficulties with speech for the patient, and problems in using these appliances for the orthodontist. Although some of these factors have been investigated, the current evidence base is weak, possibly due to the fact that these are evolving appliance systems. Among the studies that have been carried out to date, pain and discomfort for the patient appears to be similar following the placement of labial or lingual appliances, although the onset can be earlier with lingual brackets and the location different, with the tongue more frequently being involved. Customized lingual brackets may be associated with less pain than pre-fabricated. In addition, patients do seem to be more likely to experience difficulties with speech and mastication when fitted with a lingual appliance. However, there is some evidence that the lingual surfaces of the teeth are more resistant to early demineralization and caries. Little data exist regarding treatment outcome and ease of use for the orthodontist, either between lingual or labial appliances or between different lingual systems. Further research is required to investigate the efficiency of lingual appliance systems, both for the patient and orthodontist.

Speech and discomfort during lingual orthodontic treatment

The increased use of lingual appliances has meant a continued evolution in the design of lingual brackets. These changes in appliance and bracket design have tended to focus on reducing bracket thickness, with the aim of making appliances more comfortable. A thinner bracket design appears to have had some positive effects on the quality of speech, as well as comfort whilst appliances are in place. However, despite these improvements, some patients do struggle with their speech during treatment, far more than others. It is important therefore, when consenting patients for lingual orthodontic treatment, to ensure that they are made aware of the potential for speech to be disturbed, particularly in the early stages of treatment. The purpose of this article is to outline some of the issues associated with speech problems and discomfort during lingual appliance treatment, so that practitioners are able to advise patients who may be considering this kind of treatment. Advice given during the consent process, including appliance selection, procedures for maintaining oral comfort and management of individual speech issues, will all help lingual patients cope with any speech problems they may experience during their treatment.

[Invisible and almost invisible orthodontic appliances]

Patient demand for invisible esthetic orthodontic appliances is steadily increasing. Two types of orthodontic appliances have a high rate of patient acceptance. The lingual technique has continually evolved by offering both prefabricated brackets or custom-made brackets. The various techniques have been improved over time, and the results are better than ever. Thermoplastic aligners are an alternative to lingual devices and their use is rapidly growing. Their specific properties make it easier to assess their indications and limitations. A review of the literature, the development of these systems and a presentation of some clinical examples of treated cases will help us to provide some of the basics for understanding each of these two types of appliances and to demonstrate the advantages and disadvantages of each system.