Control of mandibular incisors with the combined Herbst and completely customized lingual appliance - a pilot study

<p>Abstract</p> <p>Background</p> <p>The traditional Herbst appliance induces mandibular incisor proclination independent of the anchorage system used. The dental effects of the Herbst appliance as an element of a completely customized lingual orthodontic (LO) appliance (Incognito, 3 M) has not been analyzed yet and the aim of this paper was to measure the effect of mandibular incisor proclination using this Herbst-LO device.</p> <p>Methods</p> <p>Retrospective study. Inclusion criteria: a) Class II ≥ 5 mm molar relationship; b) Herbst appliance ≥ 9 months in situ; and c) finished active treatment. Incisor position was measured on digital models before treatment, on the digital target setup, and on digital models obtained at the day of debonding. All measurements were performed by one investigator.</p> <p>Results</p> <p>Twelve patients (8 females, 4 males) out of 632 cases treated with a lingual appliance were included in the study. The measurement error computed with Dahlberg's formula was 0.2°. Seven cases had planned (target setup) mandibular incisor uprighting (ccr), and five cases had proclination (clockwise rotation). There was no statistical difference (p > 0.05) between planned incisor rotations of the target setup and achieved incisor rotations at the day of debonding. The overall mean difference was 2.2° ± 1.0°.</p> <p>Conclusions</p> <p>The Incognito-Herbst combination is the first Herbst device with full control over mandibular incisor movement. Using this system, anchorage loss or anchorage gain is independent of the Herbst treatment. It depends only on the planned tooth position of the individual target setup.</p

Analysis of the torque capacity of a completely customized lingual appliance of the next generation

INTRODUCTION: In lingual orthodontic therapy, effective torque control of the incisors is crucial due to the biomechanical particularities associated with the point of force application and the tight link between third order deviations and vertical tooth position. AIM: The aim of the present in vitro investigation was to analyze the torque capacity of a completely customized lingual appliance of the next generation (WIN) in combination with different finishing archwire dimensions. METHODS: Using a typodont of the upper arch carrying the WIN appliance, slot filling and undersized individualized β-titanium archwires were engaged. Horizontal forces ranging from 0 to 100 cN were applied at the central incisor by means of spring gauges. The resulting angular deviations were recorded and the corresponding torque moments were calculated. RESULTS: For fullsize archwires (0.018”×0.018” β-titanium and 0.018”×0.025” β-titanium), an initial torque play of 0-2° had to be overcome prior to the development of an effective torque moment. Thereafter, a linear correlation between torque angle and torque moment developed for both archwire dimensions with steeper slopes calculated for the specimens with the larger dimension. A torque moment of 2 Nmm required for effective torque correction was noted after a minimum of 2-3° of twist for the 0.018”×0.018” β-titanium wires as compared to 2-4° for the 0.018”×0.025” β-titanium study sample. When undersized archwires were analyzed (0.0175”×0.0175” β-titanium), the measured torque play ranged from 5-7°. After 8-12° of torque angle, the threshold of 2 Nmm was reached. A linear relationship between twist angle and torque moment in which the steepness of the slopes was generally flatter than the ones calculated for the slot filling archwires was noted. CONCLUSIONS: Given the high precision of the bracket slot-archwire-combination provided with the WIN appliance, an effective torque control can be clinically realized

Antibacterial properties and abrasion-stability: Development of a novel silver-compound material for orthodontic bracket application

Purpose: Bacteria-induced white spot lesions are a common side effect of modern orthodontic treatment. Therefore, there is a need for novel orthodontic bracket materials with antibacterial properties that also resist long-term abrasion. The aim of this study was to investigate the abrasion-stable antibacterial properties of a newly developed, thoroughly silver-infiltrated material for orthodontic bracket application in an in situ experiment. Methods: To generate the novel material, silver was vacuum-infiltrated into a sintered porous tungsten matrix. A tooth brushing simulation machine was used to perform abrasion equal to 2 years of tooth brushing. The material was characterized by energy dispersive X‑ray (EDX) analysis and roughness measurement. To test for antibacterial properties in situ, individual occlusal splints equipped with specimens were worn intraorally by 12 periodontal healthy patients for 48 h. After fluorescence staining, the quantitative biofilm volume and live/dead distribution of the initial biofilm formation were analyzed by confocal laser scanning microscopy (CLSM). Results: Silver was infiltrated homogeneously throughout the tungsten matrix. Toothbrush abrasion only slightly reduced the material’s thickness similar to conventional stainless steel bracket material and did not alter surface roughness. The new silver-modified material showed significantly reduced biofilm accumulation in situ. The effect was maintained even after abrasion. Conclusion: A promising, novel silver-infiltrated abrasion-stable material for use as orthodontic brackets, which also exhibit strong antibacterial properties on in situ grown oral biofilms, was developed. The strong antibacterial properties were maintained even after surface abrasion simulated with long-term toothbrushing

Comparative analysis of slot dimension in lingual bracket systems

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Single tooth torque correction in the lower frontal area by a completely customized lingual appliance

Abstract Background Aim of this study was to analyze the efficacy and precision of the completely customized lingual appliance (CCLA) regarding the single tooth torque correction. The study also examined external apical root resorptions as possible side effects of torque correction and the changings of the periodontal situation. Methods A case series of three patients were included. The patients showed a single tooth torque problem with a gingival recession and were treated with the CCLA. Plaster casts before and after treatment and plaster casts of the set up were scanned and superimposed. Deviations between the two plaster casts were analyzed at different points of interest. Changes of the gingival recession were compared before and after treatment. Relative root resorptions were measured by the orthopantomograms. Treatment times were assessed by the records of the patients. Results were presented descriptively. Results The mean change of the most apical part of the root reached by the orthodontic treatment was 1.8 ± 0.3 mm. The largest deviation between set up and final model was measured on the occlusal surface of the tooth 36 with 0.8 mm. Most measurement points showed a deviation of 0.5 mm or less. The depths of the gingival recession showed a significant reduction of 4.7 mm. The widths of the gingival recession were reduced by 1.1 mm. The average relative root resorption of the corrected teeth was 2.7 ± 1.5%. The average treatment time was 13.8 ± 4.5 months. Conclusions This is the first study showing that the CCLA with its high precision is very effective in correcting single tooth torque problems. Orthodontic torque correction resulted in a significant reduction of gingival recessions and caused only negligible root resorptions

Mandibular morphology in complete unilateral cleft lip and palate

Objective: The purpose of this study was to evaluate and compare mandibular morphology and spatial position in children with complete unilateral cleft lip and palate (UCLP) treated at two different cleft centers (Hannover and Brussels) following different surgical treatment protocols. Patients: A total of 62 Caucasian children (40 boys, 22 girls) with nonsyndromic complete unilateral cleft lip and palate (UCLP) were evaluated by means of conventional cephalometric analysis at approximately the age of 10 years. Data of both cleft groups were compared with a control, noncleft group (n = 40) matched according to age and sex. Interventions: The Hannover children with cleft (n = 36) underwent lip repair at a mean age of 5.83 ± 1.16 months. The hard and soft palates were closed at a mean age of 29.08 ± 4.68 and 32.25 ± 4.29 months, respectively. The Brussels children with cleft (n = 26) were treated according to the Malek surgical protocol with soft palate repair at a mean age of 3.04 ± 0.20 months and simultaneous lip and hard palate repair at a mean age of 6.15 ± 0.68 months. Results: Statistical analysis (analysis of variance with post hoc Tukey's test) showed a significant (p = .001) smaller mandibular ramus length (Co-Go) in the Brussels cleft group, compared with the control group. The Hannover-Brussels comparison data revealed that the S-N-B angle was significantly (p = .047) less in the Brussels cleft group. Conclusions: The influence of surgical procedures in patients with UCLP might not be restricted to the maxilla but could influence mandibular spatial position to the cranial base. Because of these positional changes of the mandible, both cleft groups showed facial balance.SCOPUS: ar.jinfo:eu-repo/semantics/publishe