Lingual Orthodontic Appliances Research Articles

Comparison of functional impairments and discomfort with bonded labial and lingual orthodontic appliances - a questionnaire survey

ObjectiveTo compare the levels of functional impairments, discomfort and satisfaction experienced by those treated with full-mouth customized lingual appliances (Lingual appliances), full-mouth self-ligating bracket (Labial appliances), or upper lingual and lower labial appliances (Mixed appliances) using questionnaires.Materials and methodsPatients within one year of the end of treatment were included in the survey and given a questionnaire concerning different kinds of discomfort and difficulties during the treatment process. The questionnaires focused on the following aspects including speech difficulty, pain (lip, cheek or tongue), difficulty in chewing, difficulty in tooth brushing and overall aesthetics and comfortability. Ordinary one-way ANOVA Tukey’s multiple comparison tests and Kruskal–Wallis tests were employed to analyze the data.ResultsA total of 115 patients participated in the study. In terms of functional impairments and discomfort, the rate and degree of speech difficulty was significantly higher in the Lingual appliances Group than that in the Labial appliances Group. But there was no difference among the three groups for difficulty in chewing and tooth brushing. Both lingual and labial appliances caused a similar level of overall pain, however, those treated with lingual appliances experienced more tongue pain, and those treated with labial appliances experienced more cheek and lip pain. The most common sites of irritation were the tongue lateral and tongue tip in the Lingual appliances Group, tongue lateral and cheek in the Mixed appliances Group, and cheek and lower lip in the Labial appliances Group. In total, patients gave highest scores to mixed appliances for comfortability and lowest scores to labial appliances for aesthetics when it came to satisfaction.ConclusionsLingual and labial appliances caused similar level of overall pain. Taking into account the overall comfortability, aesthetics and cost, the mixed appliances may be suitable for some patients who have aesthetic and comfort pursuits.

Finite element analysis of the effects of different archwire forms and power arm positions on maxillary incisors in en masse retraction using fixed lingual orthodontic appliances.

This study aimed to investigate the effects of archwire form and power arm positions on maxillary incisors during lingual en masse retraction supported by miniscrew implants, using the finite element analysis method. Sliding mechanics for lingual en masse retraction were simulated using the finite element method. Power arms were placed mesial and distal to the maxillary canine with straight and mushroom-shaped archwires. Miniscrews provided absolute anchorage for retraction force. When power arms were positioned mesial to the canine teeth, an increase in the intercanine distance was observed, while a decrease was noted when the power arms were distal to the canine tooth. Lateral incisors exhibited a greater torque loss, particularly when the power arm was mesial to the canine tooth. In the central incisors, the mushroom archwire resulted in intrusion, while the straight archwire showed an extrusion tendency. Movements in groups using the straight archwire were less controlled compared to those in groups using the mushroom archwire. The archwire form and the position of the power arm affected the torque loss and vertical position of incisors during lingual en masse retraction supported by miniscrew implants. The most controlled movement was achieved with the combination of a power arm positioned distal to the canine tooth and a mushroom archform.

White Spot Lesions (WSLs)-Post-Orthodontic Occurrence, Management and Treatment Alternatives: A Narrative Review.

Although treatment with fixed or mobile appliances has become an important part of modern orthodontics, side effects such as white spot lesions (WSLs) have a negative impact on the aesthetic outcome of orthodontic treatment. The purpose of this article was to review current evidence on the diagnosis, risk assessment, prevention, management and post-orthodontic treatment of these lesions. Data collection was performed electronically, and the initial search using the keywords "white spot lesions", "orthodontics", "WSL", "enamel" and "demineralization" in different combinations resulted in 1032 articles for the two electronic databases used. Ultimately, a total of 47 manuscripts were considered relevant to the aim of this research and included in this review. The results of the review indicate that WSLs remain a significant problem during orthodontic treatment. According to studies in the literature, the severity of WSLs correlates to the duration of treatment. Using toothpaste with more than 1000 ppm fluoride at home reduces the frequency of WSL separation and regular application of varnishes in the office reduces the frequency of the occurrence of WSLs only in the context of maintaining a strict hygiene regime. The old hypothesis that elastomeric ligatures retain more dental plaque than metal ones has been refuted. There are no differences in the appearance of WSLs between conventional brackets and self-ligating brackets. Clear aligner mobile devices develop fewer WSLs but are more extensive as opposed to conventional fixed devices, while lingual orthodontic appliances have a lower incidence of WSLs, and the most effective device for preventing these lesions is WIN, followed by Incognito.

Finite Element Study to Compare Stress Distribution and Displacement in the Palatal Implant in Lingual Orthodontics in Four Different Combinations of Palatal Implant and Lever Arm

Introduction: The choice of orthodontic appliance depends upon the patients age, profession and availability of them. Lingual orthodontic appliances are preferred over labial by patients because of its invisibility. The aim of this research is to compare the Von Mises stress distribution and displacement of palatal implants in the lingual orthodontic system among four different combinations of palatal implant and lever arm. Materials and Method: Four Finite element models were constructed for the bilaterally extracted first premolar maxillary arch. In all these models 0.018” slot lingual brackets were placed at the center of the clinical crown. A similar retraction force (150gm) was applied with the help of NiTi closed coil spring for all the models but the length of the lever arm vary as well as the palatal implant position also varies in these models. Finite element analysis was then performed to compare the Von Mises stress distribution, and displacement of the palatal implant using ANSYS 12.1 software. Result: In this study, displacement was the same (0.0005 mm) for all four models. Highest amount von mises stress was observed in Model 3 (3.4798 MPa) as a comparison to Model 1 (2.5442 MPa), Model 2 (2.5018 MPa), and Model 4 (3.3854 MPa). The stress value for the palatal implant was within the acceptable fatigue limit of the titanium of 193 MPa therefore all four models combination was safe for the clinical application. Conclusion: Double palatal implant systems were more effective in comparison to the single palatal implant system in lingual orthodontics. In this study, we found that the displacement of the palatal implants was not affected by the length of the lever-arm and the amount of stress was decreased when we increase the length of the lever-arm.

TAD Assisted Retraction in A Lingual Appliance for Correction of Dentoalveolar Class II Malocclusion

ABSTRACT
 Orthodontics, in today’s contemporary world, is focused mainly on aesthetics. Most of the adult patients are reluctant to orthodontic treatment due to their un-aesthetic appearance. To answer such problems several options are available, ranging from aesthetic brackets, made from tooth-coloured plastic or ceramic, another option is Invisalign, which is restricted to the treatment of only certain kinds of simple malocclusions. Hence, the lingual appliance selected for this case is by far the best option available from the aesthetic outlook and mechanical aspect however torque control of anterior teeth in lingual orthodontic appliance has always been considered a major problem. For maintaining the torque value of anterior teeth either we have to apply direct moment and force to the lingual brackets or by using a different combination of lever-arm and mini-screws mechanics to deliver force in a line that passes through or near to the center of resistance. In the present case, we utilized the combination of long lever-arm and palatal mini-implant system to produce a controlled en-masse retraction of the anterior teeth. This customised long lever arm created by soldering one power to others such that the point of force application is close the center of resistance.

Fluorescence-Aided Identification Technique (FIT) Improves Tooth Surface Clean-Up after Debonding of Buccal and Lingual Orthodontic Appliances.

The aim of this study was to evaluate the use of fluorescence inducing light to aid the clean-up of tooth surfaces after bracket removal when using buccal or lingual orthodontic appliances. Two full sets of dental arches using extracted human teeth were assembled, with 14 teeth per arch. All teeth were bonded on their buccal and lingual surfaces. After debonding, a single blinded operator performed the tooth surface clean-up, as commonly performed in clinical practice; without the use of fluorescent light (non-FIT) and with two methods using fluorescent light to identify composite remnants on the tooth surfaces (FIT; OPAL and BRACE). Tooth surfaces were scanned before bonding and after clean-up, and the two scans were superimposed using the best-fit method. The results showed that the debonding method, type of tooth and type of tooth surface had a significant effect on the presence of composite remnants, enamel defects, and on debonding time. Contrary to the non-FIT method, there were no composite remnants after clean-up with the use of fluorescence inducing light. Clean-up time was significantly reduced on the buccal surfaces when using the FIT methods. On the lingual surfaces, the FIT methods resulted in larger enamel defects.

Oral Impacts of Aligners versus Fixed Self-Ligating Lingual Orthodontic Appliances

The aim of this prospective study was to compare a fixed lingual orthodontic appliance with a commonly used aligner system, focusing on oral impacts and speech disturbances, during the first 3 months of orthodontic treatment. Two groups of adults were evaluated: 21 treated with Invisalign® and 26 with In-Ovation L® lingual brackets. Health-related quality of life questionnaires were used to assess the oral impacts, and speech samples were collected for speech evaluation by professionals. The levels of pain and painkiller intake were similar, increasing on the first day, and decreasing at 3 months. Subtle injuries on the lip and cheeks were initially reported in the aligner group. Lingual patients experienced more discomfort in swallowing and opening the mouth, tongue injuries and food residues, even at 3 months. The consonants “s” and “z” were mainly affected in both groups immediately after appliance insertion, but more often in the aligner group. These speech disturbances recovered in the following 3 months. In conclusion, both groups reported disturbances in quality-of-life measures; however, patients wearing lingual appliances experienced more disturbances, which persisted after three months. Speech disturbances were slightly more pronounced in the aligner group and recovered after three months.

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

To assess the efficacy of lingual orthodontics by comparing setups and post-treatment casts. Thirty-two consecutive patients treated with a customized lingual orthodontic appliance were included in this retrospective study. 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. 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. 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.

Accuracy of three different customized lingual orthodontic appliance systems in achieving predicted results on maxillary anterior teeth: A Retrospective Cohort Study.

OBJECTIVE:To comparatively evaluate the ability of three different customized lingual appliance systems in achieving predicted results with respect to the mesiodistal crown tip, labiolingual crown inclination, in–out position of Maxillary permanent anterior teeth, and Maxillary arch form.METHODS:Three commercial houses: Incognito, iLingual 3D, and Lingual matrix were analysed in this study. The final sample size consisted of 42 cases. Fourteen digital prediction and posttreatment models of the maxillary arch were provided by three orthodontic offices each using a different system. Discrepancies between the prediction and posttreatment model in mesiodistal tip, labiolingual inclination, in–out position of anterior teeth, and arch form were analyzed.RESULTS:Incognito displayed the highest accuracy in all parameters except for in–out positioning. Lingual Matrix showed greater precision in achieving planned mesiodistal positions than labiolingual inclination while it was just the opposite for iLingual 3D. All three systems proved to be clinically reliable in achieving the predicted in–out positions of permanent Maxillary anterior teeth.CONCLUSION:These systems were considerably accurate in achieving planned treatment goals with minute deviations from the predicted value.

Oral Discomfort And Impaired Oral Function In The Fixed Lingual Orthodontic Treatment

Introduction: Aesthetic consideration has become an important component for patients to decide the use of fixed orthodontic appliance, one of which is the fixed lingual orthodontic appliance. However, there are still many complaints about the discomfort felt by the patient that affects their compliance to the treatment. This paper aims to deliver the knowledge regarding oral discomfort and impaired oral function in the fixed lingual orthodontic treatment to be used as operator and patient education material. Materials and Methods: “lingual braces” was the sole keyword used in three journal databases (Google Scholar, ScienceDirect, and PubMed) resulted in 11 journals that was used in this paper. Results: complaints were mostly about speech disturbance (6 journals), discomfort on the tongue (5 journals), pain (1 journal), difficulty in cleaning the oral cavity (4 journals), difficulty in chewing and dietary changes (3 journals), and caries (2 journals). Discussion: discomfort arising during treatment was largely associated with the reduced space which was occupied by the tongue at rest. This resulted in the continuous contraction of the tongue muscles. The contraction increases discomfort and resulted in impaired oral functions such as speech and chewing. The use of bracket that is closer to the surface of the teeth can reduce complaints. Conclusion: the lingual orthodontic bracket position and type of the system used in the treatment affects the patient's comfort. Most of the discomfort appeared in the first 3 months of treatment and decreased with time.

Effects of fixed labial and lingual orthodontic appliances on speech sound production: A comparative in vivo study

Effects of fixed labial and lingual orthodontic appliances on speech sound production: A comparative in vivo study

Evaluation of initial displacement and stresses in the maxillary dentition following en masse retraction using fixed lingual appliance and micro-implants: A finite element analysis

To evaluate and compare the stress and displacement pattern between conventional and micro-implant supported retraction in lingual orthodontic system. A finite element model of the maxilla, teeth, periodontal ligament, lingual-orthodontic appliance and a micro-implant complex was constructed using ANSYS 12.1 software. Two sizes of micro-implants, 6mm and 8mm, were constructed producing a simulated model of 99,190 nodes and 32,4364 elements. A retraction force of 200g was applied from an anterior retraction hook to the molar tube in the conventional model and from the micro-implants in the implant supported model. The initial displacement and stress patterns in the X-Y-Z axes were obtained using Hyper-view software. The maximum von Mises stresses in the 6mm, 8mm and conventional model were 22.164 Megapascals (MPa), 28.603MPa and 16.491MPa respectively. The bucco-lingual displacement of the maxillary anteriors was greater in the 8mm implant model with 23×10-3mm lingual displacement observed. The least lingual displacement of 11×10-3mm was noted for the conventional model while a slightly higher moderate reading of 15×10-3mm was seen in the 6mm micro-implant supported model. The maximum displacement of the periodontal ligament was noted in the 8mm micro-implant model. Within the limitations of this research, the 8mm micro-implant model displayed high initial stresses and greater initial displacement of the anterior teeth in the X-Y-Z coordinates in comparison to conventional retraction method.

Treatment of the Deep Overbite Malocclusion with Lingual Orthodontic Appliance during the Patient was Pregnant

While the mini-implant technique is common to use this technique to control vertical malocclusion, lingual orthodontic appliance is also a powerful method to deal with this malocclusion. And pregnancy is quite a challenge for the patients under orthodontic treatment and for the orthodontist. In this article we used the customized lingual orthodontic appliance to treat the patient with Class Ⅱ division 2 deep overbite malocclusion in the efficient way. The patient satisfied with the result of non-extraction orthodontic treatment and obtained an esthetic smile and the self-confidence.

Lingual extraction and non-extraction case reports

This paper presents two case reports illustrating extraction and non-extraction treatment using a custom lingual orthodontic appliance system (Incognito). The initial pretreatment records and treatment setups are presented. Treatment mechanics are described and illustrated. Pre-treatment and post-treatment cephalometric superimpositions are presented.

Lingual orthodontics – clinical applications and patient information

The demand for adult orthodontic treatment is an ever-increasing trend that has driven the development of aesthetic orthodontic systems. Lingual orthodontic appliances provide the ultimate in aesthetics and their use has grown with the development of the appliances. The clinical application of different lingual appliances is described and evidence-based patient information is provided. CPD/Clinical Relevance: Increasing demand for aesthetic orthodontic systems means that lingual appliances are, and are likely to become, more popular in the future. A broad knowledge of their clinical application and useful evidence-based information to give to patients is invaluable for all dental practitioners.

Congenitally absent maxillary lateral incisors. A case report illustrating the use of a Mesialslider and a customised lingual appliance

Abstract Background A young adolescent female, aged 17 years and one month, presented seeking orthodontic treatment to address the congenital absence of her maxillary lateral incisors. Aims The therapeutic aims were to provide an adequate aesthetic and functional occlusion, coupled with sound adjunctive periodontal tissue relationships and a favourable long-term prognosis. Methods The malocclusion was managed by customised lingual orthodontic appliances and the adjunctive use of direct skeletal anchorage derived from two palatal mini-implants. Results The treatment objectives of good aesthetics, a functional occlusion, normal function, a healthy periodontium and a balanced profile were readily achieved. The retention records demonstrate the stability of the correction. The treatment duration was approximately 41 months, which encompassed the use of full fixed customised lingual appliances over a period of 24 months.

Are there more adverse effects with lingual orthodontics?

Data sourcesPubMed, Embase, Cochrane Library and LILACS database, review of references cited in included articles and a manual search of leading orthodontic journals. No language restrictions were imposed in the search. Study authors were contacted when necessary.Study selectionRandomised controlled trials (RCTs) and controlled clinical trials (CCTs) in healthy patients that directly compared the adverse effects following treatment using buccal and lingual appliances. Studies involving single arch or dual arch appliances were considered. Studies on patients with systemic diseases, animal studies and in vitro studies were excluded. The primary outcomes of interest to the authors were a list of adverse effects: pain, caries, eating and speech difficulties and oral hygiene.Data extraction and synthesisTwo authors reviewed the titles and abstracts of all studies identified through the search without blinding to names of authors or publication dates. Selected articles from searches were evaluated independently by two authors against established inclusion criteria, disagreements were resolved by consensus or by consulting a third author. Two authors independently assessed the risk of bias using the Cochrane Collaboration's tool (randomised trials) and the Newcastle-Ottawa Scale for non-randomised studies. The level of agreement between the authors was assessed using the Cohen kappa statistic. A meta-analysis was performed to provide pooled effect estimate (expressed as odds ratio) as well as 95% confidence interval. The outcomes of interest were pain, caries, eating difficulties, speech difficulties and deficient oral hygiene. Heterogeneity was quantified using I2 statistic and potential causes explored. Publication bias was assessed using a funnel plot.ResultsEight articles were included; three RCTs and five CCTs. One RCT was considered to be at high risk of bias, one moderate risk and one low risk. Of the non-randomised studies, four were low risk and one was high risk of bias. Six studies involving a total of 131 patients were included in a meta-analysis. The lingual appliance was associated with significant pain in the tongue (OR=28.32, 95% CI 8.6-93.28), difficulty in maintaining oral hygiene (OR=3.49, 95%CI 1.02-11.95) and greater speech difficulty (OR = 9.39, 95% CI 3.78-23.33) compared to buccal appliances. On the other hand, patients with lingual appliances had decreased pain in the lips and cheeks. There was no difference between the two appliances with regards to caries risk.ConclusionsLimited available evidence indicates that lingual orthodontic appliances are associated with increased pain in the tongue, speech difficulties and difficulty in maintaining oral hygiene.

Evaluation of Lingual Orthodontic appliances

Evaluation of Lingual Orthodontic appliances

Measurement of forces and moments around the maxillary arch for treatment of a simulated lingual incisor and high canine malocclusion using straight and mushroom archwires in fixed lingual appliances.

An Orthodontic SIMulator (OSIM) was used to investigate the propagation of forces and moments around a simulated archform for a gingival displaced canine and lingual displaced lateral incisor using fixed lingual orthodontic appliances. In-Ovation L self-ligating lingual brackets were bonded to anatomically shaped teeth on the OSIM, and the teeth were positioned such that a G4 NiTi 0.016" large maxillary mushroom archwire could be ligated in passive position. Each trial consisted of two movements: a 3mm lingual displacement of the 1-2 lateral incisor at 0.2 mm increments, and a 1.5 mm gingival displacement of the 2-3 canine at 0.15 mm increments (n = 50). Anterior brackets were repositioned to accommodate G4 NiTi 0.016" universal straight archwires (n = 50). Tests were completed at 37°C, and force and moment data in all directions was collected for each tooth around the arch at all increments. In general, the straight archwire produced significantly larger forces and moments at the centre of resistance for teeth of interest than did mushroom archwires. Specifically, the straight archwire produced 2.62 N and 3.81 N more force in the direction of tooth movement on the tooth being moved for a gingival displaced canine and lingual displaced lateral incisor, respectively, as compared to mushroom archwires. Results from this study suggest that mushroom archwires may provide better mechanics for movement of teeth in the anterior segment when using a round archwire; however, only biomechanical data was considered in this study and there are many factors that need to be considered in treatment planning.

Torque Control During Intrusion on Upper Central Incisor in Labial and Lingual bracket System - A 3D Finite Element Study.

BackgroundThe aim of present study was to investigate the difference of torque control during intrusive force on upper central incisors with normal, under and high torque in lingual and labial orthodontic systems through 3D finite element analysis.Material and MethodsSix 3D models of an upper right central incisor with different torque were designed in Solid Works 2006. Software ANSYS Version 16.0 was used to evaluate intrusive force on upper central incisor model . An intrusive force of 0.15 N was applied to the bracket slot in different torque models and the displacements along a path of nodes in the upper central incisor was assessed.ResultsOn application of Intrusive force on under torqued upper central incisor in Labial system produce labial crown movement but in Lingual system caused lingual movement in the apical and incisal parts. The same intrusive force in normal-torqued central incisor led to a palatal movement in apical and labial displacement of incisal edge in Lingual system and a palatal displacement in apical area and a labial movement in the incisal edge in Labial systemin. In overtorqued upper central incisor, the labial crown displacement in Labial system is more than Lingual system.ConclusionsIn labial and lingual system on application of the same forces in upper central incisor with different inclinations showed different responses. The magnitudes of torque Loss during intrusive loads in incisors with normal, under and over-torque were higher in Labial system than Lingual orthodontic appliances. Key words:FEM, lingual orthodontics, intrusion, torque control, labial bracket systems