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

Biofilmvolumen und Azidifizierung in den ersten in situ auf bukkal und palatinal exponiertem Bracketmaterial gebildeten Biofilmen

Purpose: Acidification by bacterial biofilms at the bracket/tooth interface is one of the most common problems in fixed orthodontic treatments, which can lead to white spot lesions (WSL) and caries. As lingual brackets were shown to exhibit reduced WSL formation clinically, the aim of this in situ study was to compare initial intraoral biofilm formation and acidification on bracket-like specimens placed buccally and palatally in the upper jaw as a possible cause for this observation. Methods: Intraoral biofilm was collected from splints equipped with buccally and palatally exposed test specimens, which were worn by 12 volunteers for a total of 48 h. The test specimens consisted of standard bracket material cylinders on top of a hydroxyapatite disc to represent the bracket/tooth interface. They were analyzed for three-dimensional biofilm volume and live/dead distribution by fluorescence staining and confocal laser scanning microscopy as well as for acidification by fluorescence-based pH ratiometry. Results: Similar general biofilm morphology with regard to volume and viability could be detected for buccally and palatally exposed specimens. For pH values, biofilms from both positions showed increased acidification at the bottom layer. Interestingly, the pH value at the top layers of the biofilms was slightly lower on palatally than on buccally exposed specimens, which may likely be due to anatomic conditions. Conclusion: Based on the results of this study, initial intraoral biofilm formation and acidification is almost similar on the bracket material/biomimetic tooth interface when placed buccally or palatally in the upper jaw. As lingual brackets were shown to exhibit reduced WSL formation clinically, future studies should investigate further factors like bracket geometry.Zielsetzung: Die durch bakterielle Biofilme verursachte Ansäuerung an der Bracket/Zahn-Grenzfläche ist eines der häufigsten Probleme während der festsitzenden kieferorthopädischen Behandlung, das zu White-Spot-Läsionen (WSL) und Karies führen kann. Da linguale Multibracketapparaturen klinisch eine verminderte WSL-Bildung aufweisen, war das Ziel dieser In-situ-Studie, die initiale intraorale Biofilmbildung und Ansäuerung an bukkal und palatinal im Oberkiefer platzierten Bracket-ähnlichen Probekörpern als mögliche Ursache zu analysieren. Methoden: Mit Probekörpern bestückte Miniplastschienen dienten der intraoralen Biofilmgewinnung in 12 Probanden für insgesamt 48 h. Die Probekörper wurden bukkal und palatinal platziert und bestanden aus Standard-Bracketmaterialzylindern, welche auf Hydroxylapatitscheiben befestigt wurden, sodass die Bracket/Zahn-Grenzfläche imitiert werden konnte. Die Analyse des dreidimensionalen Biofilmvolumens und der Lebend/tot-Verteilung erfolgte durch Fluoreszenzfärbung und konfokale Laserscanningmikroskopie. Die Auswertung der Ansäuerung erfolgte durch fluoreszenzbasierte pH-Ratiometrie. Ergebnisse: In Bezug auf das Volumen und die Viabilität konnte für bukkal und palatinal exponierte Probekörper eine allgemein ähnliche Biofilmmorphologie nachgewiesen werden. An beiden Positionen war eine erhöhte Ansäuerung in den unteren Schichten des Biofilms zu detektieren. Interessanterweise war der pH-Wert in den obersten Schichten der Biofilme bei palatinal positionierten Probekörpern etwas niedriger als bei bukkal positionierten Probekörpern, was vermutlich durch anatomische Gegebenheiten bedingt ist. Schlussfolgerung: Basierend auf den Ergebnissen dieser Studie ist die initiale intraorale Biofilmbildung und Ansäuerung an der Grenzfläche zwischen Bracketmaterial und biomimetischem Zahn bei bukkaler bzw. palatinaler Platzierung im Oberkieferbereich ähnlich. Da linguale Multibracketapparaturen klinisch eine reduzierte WSL-Bildung aufweisen, sollten zukünftige Studien weitere Faktoren wie die Bracketgeometrie untersuchen

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

The Erasmus programme for postgraduate education in orthodontics in Europe: an update of the guidelines

In 1989, the ERASMUS Bureau of the European Cultural Foundation of the Commission of the European Communities funded the development of a new 3-year curriculum for postgraduate education in orthodontics. The new curriculum was created by directors for orthodontic education representing 15 European countries. The curriculum entitled ‘Three years Postgraduate Programme in Orthodontics: the Final Report of the Erasmus Project' was published 1992. In 2012, the ‘Network of Erasmus Based European Orthodontic Programmes' developed and approved an updated version of the guidelines. The core programme consists of eight sections: general biological and medical subjects; basic orthodontic subjects; general orthodontic subjects; orthodontic techniques; interdisciplinary subjects; management of health and safety; practice management, administration, and ethics; extramural educational activities. The programme goals and objectives are described and the competencies to be reached are outlined. These guidelines may serve as a baseline for programme development and quality assessment for postgraduate programme directors, national associations, and governmental bodies and could assist future residents when selecting a postgraduate programm

Comparative analysis of slot dimension in lingual bracket systems

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