Despite recommendations for early treatment of hereditary Angle Class III syndrome, late pubertal growth may cause a relapse requiring surgical intervention. This study was performed to identify predictors of successful Class III treatment.Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Data were collected from the data archive, cephalograms, and casts, including pretreatment (T0) and posttreatment (T1) data, as well as long-term follow-up data collected approximately 25 years after treatment (T2). Each patient was assigned to a success or a failure group. Data were analyzed based on time (T0, T1, T2), deviations from normal (Class I), and prognathism types (true mandibular prognathism, maxillary retrognathism, combined pro- and retrognathism).Compared to Class I normal values, the data obtained in both groups yielded 11 significant parameters. The success group showed values closer to normal at all times (T0, T1, T2) and vertical parameters decreased from T0 to T2. The failure group showed higher values for vertical and horizontal mandibular growth, as well as dentally more protrusion of the lower anterior teeth and more negative overjet at all times. In adittion, total gonial and upper gonial angle were higher at T0 and T1. A prognostic score-yet to be evaluated in clinical practice-was developed from the results. The failure group showed greater amounts of horizontal development during the years between T1 and T2. Treatment of true mandibular prognathism achieved better outcomes in female patients. Cases of maxillary retrognathism were treated very successfully without gender difference. Failure was clearly more prevalent, again without gender difference, among the patients with combined mandibular prognathism and maxillary retrognathism. Crossbite situations were observed in 44% of cases at T0. Even though this finding had been resolved by T1, it relapsed in 16% of the cases by T2.The failure rate increased in cases of combined mandibular prognathism and maxillary retrognathism. Precisely in these combined Class III situations, it should be useful to apply the diagnostic and prognostic parameters identified in the present study and to provide the patients with specific information about the increased risk of failure.

To investigate the skeletal and dental changes during chincup versus facemask treatment, to compare the long-term effects of the two appliances, and to document the impact of each on treatment success.

The present study evaluated the temporal release of Co Cr, Mn, and Ni from the components of a typical orthodontic appliance during simulated orthodontic treatment. Several commercially available types of bands, brackets, and wires were exposed to an artificial saliva solution for at least 44 days and the metals released were quantified in regular intervals using inductively coupled plasma quadrupole mass spectrometry (ICP-MS, Elan DRC+, Perkin Elmer, USA). Corrosion products encountered on some products were investigated by a scanning electron microscope equipped with an energy dispersive X-ray microanalyzer (EDX). Bands released the largest quantities of Co, Cr, Mn, and Ni, followed by brackets and wires. Three different temporal metal release profiles were observed: (1) constant, though not necessarily linear release, (2) saturation (metal release stopped after a certain time), and (3) an intermediate release profile that showed signs of saturation without reaching saturation. These temporal metal liberation profiles were found to be strongly dependent on the individual test pieces. The corrosion products which developed on some of the bands after a 6-month immersion in artificial saliva and the different metal release profiles of the investigated bands were traced back to different attachments welded onto the bands. The use of constant release rates will clearly underestimate metal intake by the patient during the first couple of days and overestimate exposure during the remainder of the treatment which is usually several months long. While our data are consistent with heavy metal release by orthodontic materials at levels well below typical dietary intake, we nevertheless recommend the use of titanium brackets and replacement of the band with a tube in cases of severe Ni or Cr allergy.

Ziel: dieser Arbeit war es, das Klasse-III-Syndrom nach morphologischen Kriterien einzuteilen und deren Häufigkeit und die Unterschiede zwischen den einzelnen Formen im Therapieverlauf zu ermitteln. Material und Methoden: Im Rahmen einer retrospektiven Analyse wurden 54 Patienten mit einem Klasse-III-Syndrom zu 3 Zeitpunkten nachuntersucht (Ausgangssituation mit 6–9 Jahren, Evaluierung nach Therapie und Langzeitkontrolle beim ausgewachsenen Patienten nach ca. 25 Jahren). Zur Einteilung nach morphologischen Kriterien wurden nur die Anfangsunterlagen (vor Therapiebeginn) herangezogen. Ergebnisse: In 40% der Fälle war die Klasse III durch den Unterkiefer bedingt. Der Oberkiefer war in 11% der Fälle für das Entstehen des Klasse-III-Syndroms verantwortlich und in 49% lag eine Kombinationsform vor. Im Unterkiefer ist ein zu großer Unterkiefer (86,4%) die primäre Ursache für das Entstehen einer Klasse III, in 9,1% ist es die prognathe Lage des Unterkiefers und in 4,5% eine Kombination aus beiden. Im Oberkiefer ist hauptsächlich die retrognathe Lage des Oberkiefers für die Fehlstellung verantwortlich (66,6%), gefolgt zu jeweils 16,7% von einem zu kleinen Oberkiefer und einer Kombination aus Mikrognathie und Retrognathie. Bei der Kombinationsform dominieren ein zu großer Unterkiefer und die retrognathe Lage der Maxilla, danach folgen ein zu großer Unterkiefer und ein zu kleiner Oberkiefer. Bei der Einteilung nach Progenieformen zeigten sich signifikante Unterschiede bezüglich der Normwerte im Therapieverlauf. Bei Therapiebeginn war dies der kleinere SNA-Wert bei maxillärer Retrognathie. Bei der Kontrolluntersuchung wies die Gruppe mit der Kombination beider Progeniearten die größte maxillo-mandibuläre Differenz auf. Die maxilläre Retrognathie war bei den Werten APDI und NSGn den Normwerten am nächsten und zeigte eine größere untere Gesichtshöhe. Im Vergleich dazu waren die Werte APDI bei den Gruppen der echten Progenie und der Kombinationsform deutlich erhöht und stiegen im Verlauf noch weiter an. Der Wert NSGn zeigte sich zu allen Zeitpunkten vor allem in der Gruppe der echten Progenie erhöht. Conclusio: Die Manifestationen des Klasse-III-Syndroms sind durch die erbliche Komponente sehr unterschiedlich. Durch genaue Diagnose können Therapieansätze modifiziert und gezielter eingesetzt werden.

Aim: of this work was to classify the Class III syndrom according to morphological criteria, to determine their frequency and to identify differences between the various forms in the course of treatment.Materials and methods: In a retrospective analysis 54 patients with a Class III syndrome were examined at 3 time intervals (at the beginning of treatment at the age of 6-9 years, after treatment and at a long-term control in adult patients after about 25 years). For classification by morphological criteria only the initial documents were consulted (before therapy).Results: In 40 % the Class III syndrom was caused due to the lower jaw. The upper jaw was responsible in 11 % of cases for the appearance of the Class III syndrome and in 49% a combination form was evident. In the lower jaw the primary cause for the development of a Class III syndrom is due to a large mandible (86.4%), in 9.1% the prognathic position of the mandible and in 4.5% a combination of both. In the maxilla the retrognathic position of the upper jaw is mainly responsible for the deformity (66,6%), followed in 16.7% by a too small maxilla and a combination of micrognathia and retrognathia. In combination cases a large lower jaw and the retrognathic position of the maxilla were dominant, followed by a larger lower and a smaller upper jaw. By classification of the different manifestations of prognathism significant differences with respect to the standard values occured in the course of treatment. At the onset of treatment the smaller SNA value was evident by maxillary retrognathia. During the long term control analysis, the class III combination group presented the largest difference between maxilla and mandible. NSGn and APDI values were closest to the standard values in cases of maxillary retrognathia and showed a larger lower facial height. In comparison, the values APDI in the groups of mandibular prognathism and the combination form had been significantly increased and even rose further on. NSGn increased especially in the group of mandibular prognathism.Conclusion: Manifestations of Class III syndromes vary greatly due to hereditary components. Therapeutic approaches can be modified and used more effectively by an accurate diagnosis.

In the following article a general classification of the allergies, their etiology, the most frequent releasing allergens as well as existing diagnostic possibilities are shown.Nickel, chrome, manganese and cobalt are essential trace elements which have allergic, toxic and even carcinogenic effects when an excess of a certain limit value is reached.These heavy metals as potential allergenic materials, are also components in orthodontic materials. The emission of heavy metals from brackets, bands and wires was determined with the help of an in vitro investigation and a recommendation was derived from the results.

The decision for an extraction treatment in Class I borderline cases is sometimes difficult and is influenced by many factors.In this review article different aspects of extraction treatment are presented. The most frequent reasons will be discussed, as well as the occurrence of root resorptions, success of treatment, dental arch changes, influence of extraction on the duration of orthodontic treatment, condylar position and effects on profile and soft tissue - changes. Moreover the relation between extraction treatment and third molar impaction rate, stability and the tendency of incisor relapse is explained.

Zusammenfassung Im folgenden Artikel werden eine allgemeine Einteilung der Allergien, ihre Ätiologie, die häufigsten auslösenden Allergene sowie bestehende diagnostischen Möglichkeiten dargestellt. Nickel, Chrom, Mangan und Kobalt sind essentielle Spurenelemente, die bei Überschreiten bestimmter Grenzwerte allergene, toxische und sogar kanzerogene Wirkung haben. Diese Schwermetalle, als potentielle Allergene, kommen auch in kieferorthopädischen Materialien vor. Die Freisetzung dieser Schwermetalle aus Brackets, Bändern und Drähten wurde anhand einer In-vitro-Untersuchung ermittelt und aus den Ergebnissen eine Empfehlung abgeleitet.

Die Entscheidung zur Extraktionstherapie bei Klasse-I-Grenzfällen ist oft sehr schwierig zu treffen bzw. wird von verschiedenen Faktoren beeinflusst. In dieser Arbeit werden mittels Literaturrecherche unterschiedliche Aspekte zur Extraktionstherapie dargestellt. Dabei werden die häufigsten Extraktionsgründe und Extraktionsmuster, das Auftreten von Wurzelresorptionen, Behandlungserfolge, Zahnbogenveränderungen sowie der Einfluss einer Extraktionstherapie auf die Dauer der Behandlung, der Kondylenposition, mögliche Profil- und Weichteilveränderungen diskutiert. Auch der Zusammenhang zwischen Extraktionstherapie und der Impaktierung von Weisheitszähnen, der Stabilität und des Auftretens eines Frontzahnrezidivs wird erläutert.

The goal of this study was to assess the extent to which median mandibular distraction via a cemented and screw-retained full-coverage splint appliance employing a hinged expansion screw causes inclination changes in the lower first molars and widens the dental arch.

OBJECTIVES:To evaluate changes in the palatal vault after rapid maxillary expansion (RME) with bonded splint appliances. SETTING AND SAMPLE POPULATION:The sample comprised 24 children (12 boys and 12 girls) with mixed dentition (mean age 8.3 years; range 6.4-10.4 years). MATERIALS AND METHODS:Following expansion, the splint appliance was used as a retainer for 6 months and then removed. Study casts were taken before RME (T0) and when the appliance was removed (T1). Then, 3D laser scans were taken to build complete 3D jaw models. Frontal cross sections were constructed at 53-63, 55-65 and 16-26, exported as coordinates, and finite element calculated to quantify their area, width and height. Maxillary length was also determined. RESULTS:Paired t-tests indicated statistically significant increases in the average palatal width (T1-T0=6.53-6.79 mm) and cross-sectional area (T1-T0=20.39-21.39 mm2) after RME (p<0.001). However, small but statistically significant reductions were observed in palatal height (T1-T0=-0.49 mm, only at 55-65; p<0.001) and length (T1-T0=-0.54 mm; p<0.01). Linear regression analysis showed statistically significant (p<0.001) direct correlations between the widths and respective cross-sectional areas. Age did not influence any measurement. The reliability of the measurements was examined with an intraclass correlation coefficient (ICC). We found an ICC>0.99 (p<0.001) for all tested parameters. CONCLUSIONS:Rapid maxillary expansion distinctly increased mean palatal widths and cross-sectional areas. However, palatal height (55-65) and maxillary length decreased to a small extent.

An average rate of bracket loss of between 4.7 and 6 per cent is to be expected in daily clinical orthodontic practice during a typical 2 year treatment period. For reasons of economy, detached brackets are commonly reattached after sandblasting to remove adhesive, or replaced with used brackets reconditioned by specialist companies. In the present study, sandblasting and specialist bracket-reconditioning procedures were systematically compared by comparative shear testing of rebonded, reconditioned, and new brackets (n = 160) using light- and chemically cured adhesives. Statistical analysis was carried out with Kruskal-Wallis and Mann-Whitney tests. The mean bond strength of reconditioned brackets was, in each case, lower than that of new brackets, with the lowest value obtained with sandblasted brackets. This nevertheless exceeded the minimum recommended value of 5-8 MPa. Bond strength was generally higher with chemically than with light-curing adhesive; the chemically curing adhesive provided bond strength on previously bonded enamel higher than the light-curing adhesive on intact teeth. Consistent with this, the results of the adhesive remnant index (ARI) demonstrated improved bonding with the chemically curing than the light-curing adhesive to the bracket base. Despite resulting in a weaker bond strength compared with new brackets, sandblasting brackets accidentally detached during orthodontic treatment will generally allow effective reattachment to be achieved. Bond strength can be improved with the use of a chemically cured adhesive. Used brackets reconditioned by specialist companies provide a second alternative to new brackets and higher bond strengths than sandblasted brackets.

In order to apply high, short-term forces during rapid maxillary expansion (RME) to the sutures of the maxilla with minimum loss of force and without causing unwanted side-effects (dentoalveolar tipping, etc.), the appliance should be as rigid as possible. The retention arms of the RME screws, representing a particularly vulnerable and stressed weak point of RME appliances, were the focus of this laboratory technical study. Retention arms of 16 types of RME screws comprising four arms and one with eight arms were examined using a three-point bending test. According to their ability to absorb the applied bending loads, the screws were classified in product groups from 1 (highest) to 6 (lowest). Fifteen of the tested retention arms (stainless steel), despite having the same diameter (1.48-1.49 mm), differed up to 69.81 per cent between the highest (288.0 N) and lowest (169.6 N) maximum force parameters and up to 66.40 per cent between the highest (3325.9 N/mm(2)) and lowest (1998.7 N/mm(2)) maximum bending stress parameters. Due to optimum formability, though reduced rigidity, a titanium screw for nickel-sensitive patients (group 6) displayed the lowest force and bending tension values. The stainless steel double arms of the eight-arm screw device welded on both ends displayed the highest force data. The mean ductilities of the groups with the most and least rigid single steel arms differed by 22.77 per cent. Statistical analysis using the Pearson correlation coefficient revealed a significant indirect correlation between ductility and both maximum force (r = -0.780, P < 0.001) and maximum bending stress (r = -0.778, P < 0.001). The SUPERscrews, the Tiger Dental four-arm screw (group 1), and the eight-arm screw displayed the highest capacity to absorb an applied bending load. The screws in groups 3-6 appear acceptable for RME during the pre-pubertal period, whereas in the pubertal and post-pubertal period, groups 1 and 2 are sufficient. In early adulthood only the screws in group 1 and especially the eight-arm screw seem advisable, as mechanical demands increase with age.

Self-etching primers have simplified the process of direct bonding of dental resins, by eliminating the rinsing step after etching in conventional bonding, for example. Although it is generally assumed that all of the applied self-etching primer is incorporated into the resin, the possibility that a substantial amount remains free and extractable into a person’s saliva has not been investigated. The aim of the present study was to examine this issue by bonding brackets to extracted teeth with self-etching primers under controlled conditions and determining the proportion of the applied phosphoric acid ester that is subsequently extractable by high-performance liquid chromatography. Approximately half of the applied acid ester was extractable and thus not integrated into the polymeric network following standard light curing. This was reduced to 40% when the curing time was doubled. Acid ester leaching was a rapid process that was essentially completed within an hour.

SEP (= Self-Etching Primer) haben das Kleben von Brackets in der Kieferorthopädie deutlich vereinfacht. Ätzen, Primen und Bonden erfolgen in einem Arbeitsschritt und es muss nicht, wie bei herkömmlicher Phosphorsäureätzung, abgespült werden. Obwohl allgemein angenommen wird, dass der Phosphorsäureester durch die chemische Verbindung mit dem Kunststoffanteil in das polymere Netzwerk des Klebers eingebaut und dadurch inaktiviert wird, bleibt die Möglichkeit bestehen, dass doch ein Teil in die Mundhöhle freigesetzt wird. Ziel dieser Arbeit war es, den freien (nicht gebundenen) Phosphorsäureestergehalt im Self-Etching Primer nach Aktivierung und Auftragen des Primers auf die Schmelzoberfläche extrahierter Zähne in Abhängigkeit zu seiner ursprünglichen Konzentration zu messen. Dieser freie Phosphorsäureesteranteil wurde mittels HPLC (High Performance Liquid Chromatography) ermittelt. Die Hälfte des Phosphorsäureesters wurde bei herkömmlicher Härtung des Kunststoffklebers nicht in das polymere Netzwerk des Klebers eingebaut. Bei Verdoppelung der Härtungszeit reduzierte sich der in Lösung freigegebene Phosphorsäureester auf 40 %. Die Freisetzung des Phosphorsäureesters war in der ersten Stunde nach Applikation am höchsten und praktisch mit einer Stunde abgeschlossen.

The aim of this in vitro study was to investigate both shear bond strength (SBS) by shear testing of indirectly bonded brackets, and the accuracy of a new transfer method, the Aptus bonding device (ABD). For comparison, the SBS of directly bonded brackets in two experimental arrangements was also measured. The precision of the positioning of the indirect bracket transfer was assessed by photographic superimposition and three-dimensional (3D) measurement of the bracket positions on the working and plaster models using a 3D laser scan. Statistical analysis was carried out by means of descriptive and explorative data using the SPSS program. To compare groups, a one-factor analysis of variance and post hoc tests (Tukey-HSD) were used. The level of significance was set at P < 0.05. SBS using indirect and direct bonding, with the same experimental arrangement and the same adhesives (Concise and Transbond), showed no significant differences. For direct bonding, using only one adhesive (Transbond), lower values were observed, but they were only statistically significant for the premolar teeth. The clinically required minimum bond strength of 6 MPa was achieved in all groups. Superimposition of the photographs of the indirectly bonded upper labial segment brackets showed no deviations. The results of the 3D measurement of the positions of the brackets on the working and plaster models only yielded small deviations (0.15 mm along the X-axis in the centre, 0.17 mm along the Y-axis, and 0.19 mm along the Z-axis). The ABD is a useful adjunct to bond placement and does not compromise bond strength.

In the present paper the successful application of a Class II bionator in the deciduous dentition is demonstrated. A transverse and sagittal occlusal correction was achieved. The bite raising effect as a result of an extrusion of the deciduous molars was measured three-dimensionally.

In dieser Arbeit wird der erfolgreiche Einsatz eines Klasse-II-Milchzahnbionators demonstriert. Es konnte eine sagittale und transversale Korrektur erzielt werden. Die Bisserhöhung durch Extrusion der Milchmolaren wurde mittels dreidimensionaler Vermessung dokumentiert.

The purpose of this study was to compare different solutions for the storage of teeth and their influence on the enamel surface. The bond strength of bonded brackets on the enamel surface was determined by shear testing with an Instron measuring machine (feed rate 0.5 mm/min). Previously, these teeth had been stored in different solutions and their bond strengths were compared to the values of freshly extracted teeth. The statistical depiction was performed by means of descriptive and explorative data analysis. The analysis was carried out with the SPSS program. For group comparison purposes, the single-factor variance analysis (ANOVA) and the Post Hoc Test (Tukey HSD) were used. The level of significance was set at P < .05. The study showed that bond strength using formaldehyde fixation came closest to bond strength from freshly extracted teeth, so a formaldehyde solution should be used for storage. Only bond strength with teeth stored in thymol was significantly different (P = .02) from that observed with freshly extracted teeth.