Lingual Appliance 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.

Favourable dentoalveolar changes after lower premolar extractions for Class III camouflage with completely customized lingual appliances

BackgroundThe aim of the investigation was to evaluate if the inclination of the lower anterior teeth can be controlled reliably after lower premolar extraction for Class III camouflage treatment with completely customized lingual appliances (CCLAs). Treatment outcome was tested against the null hypothesis that lower premolar extractions for non-surgical camouflage treatment of a Class III malocclusion will lead to further compensation by retroclining mandibular incisors during CCLA treatment.MethodsThis retrospective study included 25 patients (f/m 12/13; mean age 20.7 years, SD 9.5 years) with uni- or bilateral Class III molar relationship and a Wits value of ≤ -2 mm. In all consecutively debonded patients, lower premolars were extracted to correct the sagittal relationship with a non-surgical camouflage approach. Lateral head films prior to (T1) and at the end of lingual orthodontic treatment (T2) were used to evaluate skeletal and dentoalveolar effects. A paired t-test with alpha = 5% was used to define differences between the endpoints. The linear correlation between the inclination of the mandibular incisors at T1 and the achieved correction was measured with the Pearson correlation coefficient (PCC). A Schuirmann’s TOST equivalence test was used to check if the final lower incisor inclination was within the defined norms.ResultsThe null hypothesis was rejected as the mean lower incisor inclination was improved by 1.8° despite lower premolar extractions (T1: 86.8°/ T2: 88.6°). There was a strong correlation (-0.75) between the lower incisor inclination at T1 and the achieved correction indicating a controlled correction towards the norm regardless of the initial incisor position. At T2, the interincisal angle as well as the lower incisor inclination were within the norm.ConclusionLower premolar extractions for non-surgical camouflage treatment of a Class III malocclusion will not lead to undesired retroclining of mandibular incisors during CCLA treatment even in severe cases.

Quality of occlusal outcome in adult Class II patients treated with completely customized lingual appliances and Class II elastics compared to adult Class I patients.

The aim of this investigation was to evaluate whether Class II malocclusion in adult patients can be successfully corrected using a completely customized lingual appliance (CCLA) in combination with Class II elastics. In order to detect differences in the final treatment outcome, two groups were matched for age and gender. Treatment results of 40 adult orthodontic patients with a Class I malocclusion (Group 1) were compared to 40 adults with a Class II malocclusion (Group 2). All patients had completed treatment with a CCLA (WIN, DW Lingual Systems, Bad Essen, Germany) without known centric occlusion-centric relation discrepancies, issues of compliance, or overcorrection in the individual treatment plan which was defined by a target set-up. In order to compare the treatment results of the two groups, 7 measurements using the American Board of Orthodontics Model Grading System (ABO MGS) and linear measurements for anterior-posterior (AP) and vertical dimensions were assessed at the start of lingual treatment (T1), after debonding (T2B) and compared to the individual target set-up (T2A). A statistically significant AP correction was achieved in Group 2 which represented 95% of the planned amount. The planned overbite correction was fully achieved in the Class I and Class II group. In both groups, there was a statistically significant improvement in the ABO scores, with no significant difference between the two groups at T2. 100% of the patients in Group 2 and 92.5% in Group 1 would meet the ABO standards after CCLA treatment. The main limitation of this study is that only patients who were wearing the elastics as prescribed were retrospectively included. Therefore, the results of this study may have limited generalizability. Completely customized lingual appliances in combination with Class II elastics can correct a Class II malocclusion successfully in adult patients. The final treatment outcome can be of a similar high quality in Class I and Class II patients.

Modified single rigid vacuum-formed indirect bonding trays for lingual bracket application: a case report

Abstract Lingual orthodontic treatment offers an aesthetic alternative but presents unique challenges in bracket positioning. The present article introduces a modified design and fabrication process for rigid vacuum-formed indirect bonding trays for lingual bracket application. The technique is presented through a clinical case report of an adult patient who presented with bimaxillary dentoalveolar protrusion and managed using lingual appliances, premolar extractions, and mini-screws. The modified rigid vacuum-formed trays enabled the accurate simultaneous bonding of multiple teeth as well as individual teeth. The technique offers several advantages over existing indirect bonding methods, including time-saving, simplicity, easy removal of excessive adhesive, and potential cost-effectiveness. The superimposition of post-bonding scans and the digital orthodontic setup showed high agreement between the planned and actual bracket positions. Additionally, the close alignment between the planned orthodontic setup and the achieved treatment outcome highlights the reliability of the technique for predictable lingual orthodontic treatment. Further clinical studies with larger sample sizes are needed to confirm the effectiveness of this technique.

Esthetic outcomes in orthodontics through digital customization with a lingual appliance system.

Contemporary fixed orthodontic appliances are shifting from non-customized pre-adjusted appliances to custom-designed and printed appliances with novel digital setup systems. We are one step closer to precision dentistry and orthodontics using personalized mechanics and custom appliances. However, despite the evidential enhancement and other improvements to fixed appliances, tooth movement is still limited to five degrees of freedom. Opening or closing spaces still requires manually placing elastomeric chains or coil springs. In this article, we aimed to demonstrate how advancements in CAD/CAM technology, reverse engineering, and digital customization are helping orthodontics constantly evolve, enabling treatment with enhanced esthetics and minimal compliance. The clinical system (InBrace®, Irvine, CA) described in this article uses a patient-specific, digitally designed multiloop NITI wire that delivers friction-free, light, and continuous forces and activates automatically whenever the malocclusion deviates from the digital setup. Through digital customization, InBrace allows for automated tooth movement in all six degrees of freedom, including space opening or closure, via programmed non-sliding mechanics. Precision orthodontics and personalized treatment have been significant developments in orthodontics recently. This article focuses on how a technologically advanced lingual appliance system could achieve targeted cosmetic results methodically via automation and personalization.

Quality of occlusal outcome in adult class II patients after maxillary total arch distalization with interradicular mini-screws

BackgroundThe aim of the investigation was to evaluate if a Class II malocclusion in adult patients can be successfully corrected by maxillary total arch distalization with interradicular mini-screws in combination with completely customized lingual appliances (CCLA).MethodsTwo patient groups were matched for age and gender to determine differences in the quality of final treatment outcome. The treatment results of 40 adult patients with a Class I malocclusion (Group 1) were compared with those of 40 adult patients with a moderate to severe Class II malocclusion (Group 2). All patients had completed treatment with a CCLA (WIN, DW Lingual Systems, Bad Essen, Germany) without overcorrection in the individual treatment plan defined by a target set-up. To compare the treatment results of the two groups, 7 measurements using the American Board of Orthodontics Model Grading System (ABO MGS) and linear measurements for anterior-posterior (AP) and vertical dimensions were assessed at the start of lingual treatment (T1), after debonding (T2B), and compared to the individual target set-up (T2A).ResultsA statistically significant AP correction (mean 4.5 mm, min/max 2.1/8.6, SD 1.09) was achieved in Group 2, representing 99% of the planned amount. The planned overbite correction was fully achieved in both the Class I and Class II groups. There was a statistically significant improvement in the ABO scores in both groups (Group 1: 39.4 to 17.7, Group 2: 55.8 to 17.1), with no significant difference between the two groups at T2B. 95% of the adult patients in Group 1 and 95% in Group 2 would meet the ABO standards after maxillary total arch distalization with a CCLA and interradicular mini-screws.ConclusionsCCLAs in combination with interradicular mini-screws for maxillary total arch distalization can successfully correct moderate to severe Class II malocclusions in adult patients. The quality of the final occlusal outcome is high and the amount of the sagittal correction can be predicted by the individual target set-up.

Hybrid Orthodontics for Aesthetic Deep Bite Correction—Case Series and General Clinical Considerations

Background: A range of psychosocial and aesthetic factors motivate patients to undergo orthodontic treatment. The appliance choice depends not only on the type of malocclusion, but also on the aesthetic and functional demands of the patients themselves. Nowadays, digital planning enables the manufacture of individualised and customised orthodontic appliances. However, the predictability of movements with aligner treatment has long been under discussion. This article illustrates, through a series of case reports, how a hybrid approach combining individualised aesthetic orthodontic appliances can improve the predictability of tooth movements, thereby providing additional tools for clinicians charged with choosing the best indicated and biomechanically advantageous technique. To this end, three patients with different malocclusions were treated via a hybrid approach involving clear aligners in the upper arch followed by lingual fixed appliances in the upper and lower arches. All patients were treated using ALIAS lingual PSL 0.018 × 0.018-inch slot brackets and in-house 3D-printed aligners. Findings: The hybrid approach combining aligners and fixed lingual appliances led to the successful resolution of all three complex cases in the series without prolonging treatment time. The superimpositions demonstrate the predictability of even traditionally difficult movements. In particular, the Alias PSL lingual system, used from the beginning, enabled good control of both the torque and inclination of the lower incisors. Conclusions: Combining clear aligners and fixed lingual appliances provides a highly efficient means of treating malocclusions aesthetically. In our cases, the aligners offset the lack of bite-plate effect from the lingual brackets and appliances, providing advantageous biomechanics for rotation correction and control of tip, torque and root movements. Understanding how to exploit the strengths of each appliance enables the clinician to treat adult patients efficaciously, efficiently and aesthetically.

The treatment of severe class II division 2 patients with deep overbites and gummy smiles using lingual appliances: a case series

Abstract The treatment of Class II division 2 patients with palatally inclined upper incisors using lingual appliances is generally challenging due to difficulties in achieving upper incisor torque control. The present case series aims to describe a simple method combining lingual appliances and mini-screws for the non-surgical management of two severe Class II division 2 patients presenting with deep overbites and gummy smiles. The treatment plans involved initial bite opening and upper incisor torque recovery, followed by distalisation of the entire upper arch using mini-screw anchorage. In one case, additional anterior labial mini-screws were necessary to assist incisor intrusion and complete upper arch levelling. Favourable treatment results suggest that lingual appliances, when combined with mini-screws and pre-torqued arch wires, may offer an effective approach for the non-surgical management of severe Class II division 2 patients with deep overbites and gummy smiles.

Digital workflows for 3D-printed customised double-slotted lingual appliances: a case report

Abstract With the advancement of three-dimensional (3D) printing technology, orthodontists are able to design and manufacture customised lingual appliances, which may increase treatment versatility and reduce treatment costs. The present article describes the digital workflows associated with the design and manufacture of customised double-slotted lingual brackets and arch wires. Also demonstrated is the technique’s efficiency through a non-extraction case report. An adult patient with moderate crowding in both arches was successfully treated using 3D-printed customised double-slotted lingual appliances combined with miniscrews and interproximal reduction. The moderate crowding was addressed without incisor proclination despite the non-extraction strategy.

Management of an adult patient with severe crowding using lingual appliances and mini-screw anchorage: A case report

At present, more adult patients seek orthodontic treatment so orthodontists are more likely to face periodontal patients and esthetic appliance demand increases. This case report presents the management of an adult patient with mild periodontitis and severe crowding using lingual appliances and mini-screw anchorage. Interproximal stripping was performed to create space and correct the triangular tooth shape and gingival black triangles. Four mini-screws were implanted in the palatal alveolar bone and mandibular buccal shelf to distalize the entire upper and lower arch. According to the case report, interproximal stripping in combination with mini-screw-assisted entire arch distalization and lingual appliances may be an effective space-creation approach in patients treated with non-extraction way.

Non-Surgical Transversal Dentoalveolar Compensation with Completely Customized Lingual Appliances versus Surgically Assisted Rapid Palatal Expansion in Adults-Tipping or Translation in Posterior Crossbite Correction?

The aim of this study was to investigate buccolingual tooth movements (tipping/translation) in surgical and nonsurgical posterior crossbite correction. A total of 43 patients (f/m 19/24; mean age 27.6 ± 9.5 years) treated with surgically assisted rapid palatal expansion (SARPE) and 38 patients (f/m 25/13; mean age 30.4 ± 12.9 years) treated with dentoalveolar compensation using completely customized lingual appliances (DC-CCLA) were retrospectively included. Inclination was measured on digital models at canines (C), second premolars (P2), first molars (M1), and second molars (M2) before (T0) and after (T1) crossbite correction. There was no statistically significant difference (p > 0.05) in absolute buccolingual inclination change between both groups, except for the upper C (p < 0.05), which were more tipped in the surgical group. Translation, i.e., bodily tooth movements that cannot be explained by pure uncontrolled tipping, could be observed with SARPE in the maxilla and with DC-CCLA in both jaws. Dentoalveolar transversal compensation with completely customized lingual appliances does not cause greater buccolingual tipping compared to SARPE.

Novel concept for posterior crossbite correction : Preliminary results.

The efficiency of dentoalveolar compensation involving both jaws for posterior crossbite correction using computer-aided design/computer-aided manufacturing (CAD/CAM) expansion and compression archwires was evaluated. Treatment outcome was tested against the null hypothesis that the transverse correction achieved would be significantly smaller than planned. This retrospective study included 64patients (mean age 23.5years, median17.0, minimum/maximum:9.0/63.0, standard deviation13.7) with uni- or bilateral posterior crossbite. In all consecutively debonded patients, expansion and/or compression archwires were used for dentoalveolar correction involving both jaws. Plaster casts prior to(T1) and following treatment(T2) with completely customized lingual appliances (CCLA) were compared with the treatment plan represented by an individual target set-up. The statistical analysis was carried out using the Schuirmann TOST (two one-sided t‑tests) equivalence test on the basis of aone-sample t‑test with α = 0.025 to one side. The non-inferiority margin was set at δ = 0.5 mm. All posterior crossbites could be corrected by dentoalveolar compensation involving both jaws. The mean total correction achieved was 6.9 mm (mean maxillary expansion: 4.3 mm/mean mandibular compression: 2.6 mm) with amaximum of 12.8 mm. The transverse corrections achieved in both arches atT2 were equivalent to the planned corrections in the set-up (p < 0.001). The results of this study indicate that CAD/CAM expansion and compression archwires can be an efficient tool to achieve the desired correction in patients with aposterior crossbite even in more severe cases.

Gain the skills to fit lingual appliances.

Gain the skills to fit lingual appliances.

A three dimensional finite element analysis of apical stress distribution during intrusion of maxillary central incisor with different inclinations in labial and lingual appliance systems

The objective of this study was to evaluate apical stress distribution during intrusion of the maxillary central incisor with different inclinations in the labial and lingual appliance systems using a three-dimensional finite element model.The three-dimensional finite element models of the maxillary central incisor were produced with 25 ° (normoclined), 30 ° (proclined), and 20 °(retroclined) inclinations. Each incisor model was subjected to an intrusive force of 15cN. The stress level at the apex was calculated in terms of maximum principal stresses.The stress distribution at the apex and cervix was lower in the labial compared to the lingual appliance system for the maxillary central incisor models with an inclination of 25° (normoclined) and 30° (proclined). Whereas the maxillary central incisor model with 20° (retroclined) inclination in the lingual appliance system showed the maximum stress in the cervical region.During intrusion, no significant differences in stress patterns were seen at the root apex in normoclined and proclined maxillary central incisor models in either of the appliance systems, except for the retroclined central incisor model which showed maximum stresses in the cervical region.

The in vitro biomechanics of anterior arch expansion using fixed lingual appliances with coil springs or archwire stops.

The presented study investigates differences in the biomechanics of straight and mushroom fixed lingual appliances when implementing coil springs and stops for anterior arch expansion. An in vitro orthodontic simulator was used to measure three-dimensional forces and moments on each tooth of a simulated maxillary arch. Mushroom and straight archwire forms of 0.016″ NiTi round archwire were considered, using 0.010″ × 0.030″ NiTi open coils and 0.016″-0.018″ archwire stops (n= 44 per group). Teeth in the anterior dental arch were moved from a neutral to crowded position to replicate anterior crowding of central and lateral incisors. Forces and moments of interest for lateral incisors and first premolars were compared using repeated measures mixed multivariate analysis of variance (α= 0.05). Three comparisons between straight versus mushroom archwires and two comparisons of coil springs vs. stops were not statistically significant. Overall, it was found that the use of a straight lingual archwire produced larger differences in forces and moments between using stops and coil springs than when using a mushroom archwire. Using stops produced larger forces and moments for both types of archwires as compared to using coil springs. The largest expansion forces were produced using straight archwires with stops, exceeding 3.0N of force. Straight archwires with coil springs produced the lowest expansion forces on lateral incisors, just exceeding 1.5N. The findings of this study have elucidated significant differences in the biomechanics of transverse arch expansion using straight or mushroom fixed lingual appliances with coil springs or stops.

Conventional and self-ligating lingual orthodontic treatment outcomes in Class I nonextraction patients: A comparative study with the American Board of Orthodontics Objective Grading System

This study aimed to assess and compare the duration and outcomes of orthodontic treatment with conventional and self-ligating lingual fixed appliances with the American Board of Orthodontics (ABO) Objective Grading System. Thirty consecutive patients with a complete dentition and Angle Class I malocclusion treated with a conventional lingual bracket system (STb; Ormco, Glendora, Calif) or self-ligating lingual bracket system (GC Experience-L; GC Orthodontics, Breckerfeld, Germany) were included. The occlusal outcome was assessed with the ABO instrument. The treatment duration and ABO scores of the 2 groups were recorded. Statistical analyses were evaluated using independent-sample t tests. The conventional group had a mean treatment time of 2.10 ± 0.69 years, and the self-ligating group had a treatment duration of 1.68 ± 0.48 years (P>0.05). The mean posttreatment ABO scores in the conventional group were 20.23 ± 5.13, and the mean posttreatment ABO scores in the self-ligating group were 21.00 ± 5.66. No difference was found between the groups regarding the criteria of ABO (P>0.05). The highest scores were given in the assessment of buccolingual inclinations in both conventional and self-ligating lingual bracket groups. The design of the lingual appliances used in this study did not influence the treatment duration and the total ABO scores in treating patients with a Class I relationship in this sample. Both types of lingual brackets were especially deficient in correcting buccolingual inclinations. The strengths were their ability to close spaces and correct anterior rotations and overjet regardless of the bracket types.

Digital lingual appliance combined with micro-screws for the treatment of a skeletal bimaxillary protrusion and ‘gummy’ smile

Abstract This case report describes the lingual orthodontic treatment of a 28-year-old female patient who presented with a bimaxillary protrusion malocclusion, a hyperdivergent facial pattern, mentalis strain, and a ‘gummy’ smile. To achieve favourable occlusal and facial results, the four first premolars were extracted, and micro-screws utilised to provide maximum anchorage. With the widespread application of three-dimensional technology, a digital goal-oriented treatment plan was applied for its predictability and precision. A fully customised lingual appliance system with preset torque in the anterior teeth combined with ribbon-wise arch wires was placed to prevent excessive lingual inclination of the incisors during retraction. As a result, an attractive facial profile and a well-aligned dentition with ideal intercuspation was obtained.

CAD/CAM in Orthodontics –A Magnanimous Journey

Orthodontics is one branch of dentistry which deals with dynamic manipulation and function of the stomatognathic system. Likewise, it has to witness the dynamic changes in its diagnosis method and treatment planning. The field of orthodontics has witnessed many revolutionary techniques and evolved enormously in terms of benefiting the patient. CAD/CAM is one promising methodology that has shown a significant impact in modern dentistry and surpassed some of the challenges an orthodontist has been facing all these years. It has changed the view through which we see the patient’s condition. The application of 3D technology allows the practitioner and patient to utilize virtual treatment planning software to better identify case objectives and visualize treatment outcomes. CAD/CAM has many applications in orthodontics, which include aids for diagnosis and treatment planning, clear aligner treatment, customized lingual appliances, customized brackets with patient-specific torque, machine-milled indirect bonding jigs, robotically bent archwires, indirect bonding systems, customization of orthodontic appliances like distalization appliance etc., Acceleration of orthodontic treatment (OT) has received growing attention in recent years, especially in adult patients.Digital workflow is the current trend in orthodontic practice and has speckled every aspect of orthodontics in terms of documentation, study casts, analysis of dental malocclusion, smile designing, treatment planning and fabrication of orthodontic appliances. The current article aimed to establish a narrative description of the digital workflow and applications of the CAD/CAM process in Orthodontics.

Non-Surgical Transversal Dentoalveolar Compensation with Completely Customized Lingual Appliances versus Surgically Assisted Rapid Palatal Expansion in Adults-The Amount of Posterior Crossbite Correction.

The aim of this study was to compare the crossbite correction of a group (n = 43; f/m 19/24; mean age 27.6 ± 9.5 years) with surgically assisted rapid palatal expansion (SARPE) versus a non-surgical transversal dentoalveolar compensation (DC) group (n = 38; f/m 25/13; mean age 30.4 ± 12.9 years) with completely customized lingual appliances (CCLA). Arch width was measured on digital models at the canines (C), second premolars (P2), first molars (M1) and second molars (M2). Measurements were obtained before treatment (T0) and at the end of lingual treatment (T1) or after orthodontic alignment prior to a second surgical intervention for three-dimensional bite correction. There was no statistically significant difference (p &gt; 0.05) in the amount of total crossbite correction between the SARPE and DC-CCLA group at C, P2, M1 and M2. Maxillary expansion was greater in the SARPE group and mandibular compression was greater in the DC-CCLA group. Crossbite correction in the DC-CCLA group was mainly a combination of maxillary expansion and mandibular compression. Dentoalveolar compensation with CCLAs as a combination of maxillary expansion and mandibular compression seems to be a clinically effective procedure to correct a transverse maxillo-mandibular discrepancy without the need for surgical assistance.

Third-Order Effects and Maxillary Incisor Control in Lingual Orthodontics – A Finite Element Study of a Ribbon Arch and Edgewise Straight Wire System

Introduction: The aim of the present study was to analyze the effects of retraction mechanics on torque control when retraction forces were applied on the maxillary anterior dentition in two distinct lingual appliance systems. Materials and Methods: A three-dimensional bilateral maxillary model was created where the first premolar extraction case was included. 150 g (1.47 N) of retraction force was applied on each side from canine (C) hook to molar for both edgewise straight wire system and ribbonarch appliances. Results: In the edgewise appliance, it was observed in the X-axis that there was less amount of tipping of the six anterior teeth of the canine and central incisor (CI) when compared with the lateral incisor (LI) at occlusal point. In the Y-axis, overall extrusion was observed. In the Z-axis, there was less lingual crown movement. In the ribbonarch appliance, it was observed in the X-axis that there was less tipping, prominently in the canine and CI than in the LI. In the Y-axis, overall extrusion was observed. In the Z-axis, there was less lingual crown movement, whereas the CI and canine showed less movement when compared with the LI. Conclusions: It was observed that there was greater torque loss and extrusion in the edgewise appliance along with greater maximum principal stress in the cervical half of the facial side in the periodontal ligament (PDL) and minimum principal stress on the cervical half of the palatal side in the PDL when compared with the ribbonarch appliance.