Vertical and Orovestibular Forces Generated by Beta-Titanium and Stainless-Steel Rectangular Wires in Labial and Fully Customized Lingual Bracket Systems

This study aimed to investigate the force values exerted from rectangular wires when combined with conventional labial and fully customized lingual appliances under predefined, idealized activation. Fully customized lingual brackets of two brands Incognito™ (3M Unitek, Monrovia, MN, USA) and WIN (DW Lingual Systems, Bad Essen, Germany) and labial brackets of another brand, discovery® MIM and discovery® smart systems (Dentaurum, Ispringen, Germany), were chosen. Stainless-steel and beta-titanium wires of 0.018” × 0.025” were examined. For IncognitoTM, 0.0182” × 0.025” beta-titanium wires were tested. Intrusion/extrusion and orovestibular movements were performed in a range of 0.2 mm, and the forces were recorded for each 0.1 mm of the movement. Mean values and standard deviations were calculated for all measurements, and ANOVA was performed for statistical analysis. Slight differences were observed between the forces generated from beta-titanium and stainless-steel wires. The same wire generated in some cases 5–53% higher forces with the lingual appliance due to the vertical orientation of the long walls during intrusion/extrusion and increased wire stiffness at the anterior region. Beta-titanium and stainless-steel 0.018” × 0.025” wires can generate similar force values during the final stages of the orthodontic therapy; thus, possibly only one of the two alloys could be used in each orthodontic wire sequence.

Comparison of the Treatment Effectiveness between Labial and Lingual Fixed Mechanotherapy and Patients’ Response toward Lingual Fixed Mechanotherapy: A Prospective Clinical Study

Objective: The present study was conducted to evaluate the effectiveness of treatment outcome using American Board of Orthodontics (ABO) scoring and total treatment time between labial and lingual appliance and also to assess patients’ perception of the lingual appliance system. Materials and Methods: Twenty patients requiring first premolar extraction were selected; 10 patients were treated with a lingual and 10 with a labial appliance. The treatment duration and ABO scores were recorded from the posttreatment dental casts and orthopantomogram (OPG). A questionnaire was used to evaluate the perception of patients on lingual treatment using a visual analogue scale (VAS). Results: The total ABO scores of the 2 groups were not statistically significant. The lingual- and labial-appliance treatments were completed in 19.30 ± 7.50 and 22.40 ± 6.35 months, respectively. The VAS showed that lingual-appliance patients experienced a moderate amount of pain and discomfort to the tongue and soft tissues. Patients did not have considerable difficulty with speech and in maintaining oral hygiene. Conclusion: Lingual appliance cases finished with a comparable quality of orthodontic treatment precision well within the normal treatment time frame. These patients had moderate difficulties with speech, tongue irritation, and pain. They did not have difficulty in maintaining their oral hygiene and were satisfied with their smile and treatment outcome.

Class II correction by maxillary en masse distalization using a completely customized lingual appliance and a novel mini-screw anchorage concept – preliminary results

Background The aim of the study was to evaluate the efficacy of a novel en masse distalization method in the maxillary arch in combination with a completely customized lingual appliance (CCLA; WIN, DW Lingual Systems, Germany). Therefore, we tested the null-hypothesis of a significant deviation from an Angle-Class I canine relationship and a normal overjet defined by an individual target set-up after dentoalveolar compensation in Angle Class II subjects. Methods This retrospective study included 23 patients, (m/f 3/20, mean age 29.6 years (min/max, 13.6/50.9 years)), with inclusion criteria of an Angle Class II occlusion of more than half a cusp prior to en masse distalization and treatment completed consecutively with a CCLA in combination with a mini-screw (MS) anchorage for uni- or bilateral maxillary distalization (12 bilateral situations, totalling 35). Plaster casts taken prior to (T0) and following CCLA treatment (T3) were compared with the treatment plan / set-up (TxP, with a Class I canine relationship and a normal overjet as the treatment objective). MSs were placed following levelling and aligning (T1) and removed at the end of en masse distalization at T2. Statistical analysis was carried out using Schuirmann’s TOST [two one-sided tests] equivalence test, based on a one-sample t-test with α = 0.025 on each side (total α = 0.05). Results Ninety-seven percent of planned correction of the canine relationship was achieved (mean 3.6 of 3.7 mm) and also 97 % of the planned overjet correction (mean 3.1 of 3.2 mm), with a statistically significant equivalence (p < 0.0001) for canine relationship and overjet between the individual treatment plan (set-up) and the final outcome. Adverse effects were limited to the loss of n = 2 of 35 mini-screws. However, in each instance, the treatment was completed, as scheduled, without replacing them. Accordingly, the null-hypothesis was rejected. Conclusions The technique presented allows for a predictable correction of an Angle-Class II malocclusion via dentoalveolar compensation with maxillary en masse distalization.

Skeletal Class III Malocclusion with Lateral Open Bite and Facial Asymmetry Treated with Asymmetric Lower Molar Extraction and Lingual Appliance: A Case Report

A skeletal Class III malocclusion with open bite tendency is considered very difficult to treat orthodontically without surgery. This case report describes the lingual orthodontic treatment of an adult skeletal Class III patient with mandibular deviation to the left side, lateral open bite, unilateral posterior crossbite, zero overbite and negative overjet. The lower incisors were already retroclined to compensate with the skeletal discrepancy. The patient was treated by asymmetric molar extraction in the mandibular arch to retract the lower incisors and correct the dental midline, with the help of intermaxillary elastics. Lingual appliance was used with over-torqued lower anterior teeth’s brackets to control the torque of mandibular incisors. After a 30-month treatment, satisfactory smile and facial esthetics and good occlusion was achieved. A 12-month follow-up confirmed that the outcome was stable. Asymmetric molar extraction could be a viable option to retract mandibular incisors in Class III malocclusion with lower dental midline deviation.

Effects of debonding a conventional & customized lingual appliance on enamel structure- An invitro study

Introduction: To evaluate the surface changes on enamel structure after debonding of customized and conventional lingual brackets bonded using restorative dual cure bonding material and a chemically cured bonding material with and without sandblasting. Materials and Method: The sample consisted of 40 premolar teeth extracted for the purpose of orthodontic treatment. Enamel surface changes, prior to bonding, were studied using a stereomicroscope (Olympus SZX7) and an optical microscope. 20 extracted premolars were arranged in 2 arch forms with 5 teeth in each quadrant, after which impression of the arches with rubber base impression material was made. These impressions were then sent to the laboratory for the fabrication of a customized lingual appliance. The remaining 20 premolars were divided into 2 arches, each arch having 10 extracted premolars divided into 4 sets, 1st to test customized brackets bonded with chemical cure resin without sandblasting, 2nd to test customized brackets with dual cure resin without sandblasting, 3rd to test conventional brackets with chemical sure resin with and without sandblasting and 4th to test conventional brackets bonded with dual cure resin with and without sandblasting. The post debonding photographs were analyzed using a standardized grid and Surface Roughness Index. Result: Thus, enamel defects are likely to be caused post debonding despite of using any combination. However, the surface roughness index has been shown to be highest post debonding in cases where customized brackets have been bonded using dual cure resin along with sandblasting. Conclusion: While a clinician may opt for a material like Rely X U200 to bond lingual appliances in order to have a better clinical management of the appliance, but he would have to keep the possibility of irreversible damage to enamel post debonding.

Current status of clinical orthodontics in European and American countries

Current status of clinical orthodontics in European and American countries was examined by means of a questionnaire survey through internet. In the European and American countries, most popular technique in daily orthodontic practice is preadjusted straight wire edgewise technique. In major developed countries in Europe and America, the treatment fee is considerably high, whereas the fee is relatively low in the countries under development and/or after economic crisis. Rate of non-extraction treatment among all the cases treated with multi-bracket appliances is significantly higher in Europe and America than in Asia except in a few countries. In the European and American countries, treatment system for jaw deformity patients is well developed with higher availability of the social health insurance than in Asia. The maximum CLP prevalence of 0.200 is found in Germany and Austria and the mean is around 0.140 or one to 700 births. In general, CLP treatment is covered by social health insurance in European and American countries. In Europe and America, lingual orthodontic technique has not become popular because patients never want to hide orthodontic appliance. Higher cost of lingual appliance and lack in information and technical skills may be the reasons of less frequent use of lingual appliance. Many interviewees replied that usage of TADs has not become so popular in USA and Canada as compared to that in Asia. In another word, the initial fascination with TADs wore off and are now used in selected patients as needed. This may be due to more harmonious maxillofacial structure with longer and wider dentitions in Caucasians which also results in higher rate of non-extraction treatment with multibracket appliances in European and American countries.