Badri Thiruvenkatachari

Early treatment for Class II Division 1 malocclusion with the Twin-block appliance: a multi-center, randomized, controlled trial.

INTRODUCTION The aim of this study was to evaluate the effectiveness of early orthodontic treatment with the Twin-block appliance for the treatment of Class II Division 1 malocclusion. This was a multi-center, randomized, controlled trial with subjects from 14 orthodontic clinics in the United Kingdom. METHODS The study included 174 children aged 8 to 10 years with Class II Division 1 malocclusion; they were randomly allocated to receive treatment with a Twin-block appliance or to an initially untreated control group. The subjects were then followed until all orthodontic treatment was completed. Final skeletal pattern, number of attendances, duration of orthodontic treatment, extraction rate, cost of treatment, and the childs self-concept were considered. RESULTS At the end of the 10-year study, 141 patients either completed treatment or accepted their occlusion. Data analysis showed that there was no differences between those who received early Twin-block treatment and those who had 1 course of treatment in adolescence with respect to skeletal pattern, extraction rate, and self-esteem. Those who had early treatment had more attendances, received treatment for longer times, and incurred more costs than the adolescent treatment group. They also had significantly poorer final dental occlusion. CONCLUSIONS Twin-block treatment when a child is 8 to 9 years old has no advantages over treatment started at an average age of 12.4 years. However, the cost of early treatment to the patient in terms of attendances and length of appliance wear is increased.

Measuring 3-dimensional tooth movement with a 3-dimensional surface laser scanner

INTRODUCTION Our aims in this study were to (1) develop a method of measuring 3-dimensional (3D) tooth movement using a 3D surface laser scanner, (2) test the accuracy of this method, and (3) compare the measurements with those from cephalometric radiographs. METHODS A method of superimposing pretreatment and posttreatment models on the palatal rugae was developed, and an experimental model was prepared to evaluate the accuracy and reliability of the laser scanner. Records were obtained from a prospective longitudinal randomized clinical trial evaluating anchorage loss with headgears and midpalatal osseointegrated implants as a source of anchorage in Chesterfield, United Kingdom. The pretreatment and posttreatment study models were analyzed by using a 3D laser scanner to measure the 3D tooth movement. RESULTS The laser scanner was accurate to 0.0235 mm for anteroposterior measurements and 0.0071 mm for buccolingual movements for every 0.5 mm of movement. The study model analysis showed that mesial molar movements were 1.38 mm on the right side and 1.11 mm on the left side for the implant group, and 2.24 mm on right side and 1.63 mm on left side for the headgear group, with no statistically significant difference between the groups. The results for vertical movement of molars showed extrusion on both sides in both groups but no statistically significant difference between the groups. In the transverse plane, the results were not statistically significantly different between the groups. The results from superimposition of lateral cephalograms were similar to those obtained from the scanner. CONCLUSIONS The 3D laser scanner provides accurate and reliable measurements of tooth displacement and can be considered an alternative to cephalometric radiographs.

Prospective, multi-center study of the effectiveness of orthodontic/orthognathic surgery care in the United Kingdom

INTRODUCTION The aim of this study was to evaluate the effectiveness of orthodontic/orthognathic surgical care provided in the North West region of England. It was an observational, prospective cohort study at 13 maxillofacial clinics in the United Kingdom. METHODS The 131 patients comprised 47 males (35.9%) and 84 females (64.1%), with an average age of 22.6 years. They received orthodontic/orthognathic treatment according to the normal protocols of the operators. They were then followed until all orthodontic treatment was completed. Final skeletal pattern, final peer assessment rating score, number of attendances, and duration of treatment were recorded. RESULTS At the end of the 5-year study, 94 patients had completed treatment, and 71 had complete data. Data analysis showed that, overall, the treatments provided were effective in terms of skeletal and dental occlusal outcomes; the final mean peer assessment rating score was 10.58. However, treatment duration was longer than commonly expected, with a mean length of 32.8 months (SD,11.3). The outcome of treatment was influenced by only pretreatment skeletal discrepancy. CONCLUSIONS This prospective investigation showed that orthodontic/orthognathic surgical care was effective. The outcome of treatment was influenced only by the severity of the pretreatment skeletal discrepancy.

Comparison of rate of canine retraction with conventional molar anchorage and titanium implant anchorage

INTRODUCTION Various anchorage techniques have been designed for canine retraction. Intraoral techniques have not always been successful, and now implants are widely used for this purpose. A new type of titanium microimplant, with a small diameter and a button-like head, was shown to be an effective source of anchorage for distal movement of the canines. The purposes of this study were to measure and compare the rates of canine retraction with titanium microimplant anchorage and conventional molar anchorage. METHODS The sample comprised 12 patients (8 female, 4 male; mean age, 19.7 years; range, 16-22 years) who were scheduled for extraction of all first premolars. After leveling and aligning, titanium microimplants 1.2 mm in diameter and 9 mm in length were placed between the roots of the second premolar and the first molars. The implants were placed in the maxillary and mandibular arches on the same side in 10 patients and in the maxilla only in 2 patients. A brass wire guide and a periapical radiograph were used to determine the implant position. After 15 days, the implants and the molars were loaded with closed coil springs with a force of 100 g for canine retraction. Preretraction and postretraction lateral cephalograms were taken and superimposed for measuring the amount of retraction. The amount of canine retraction was measured from pterygoid vertical in the maxilla and SN perpendicular in the mandible. RESULTS Mean canine retraction amounts were 4.29 mm in the maxilla and 4.10 mm in the mandible on the implant-anchorage side, and 3.79 mm in the maxilla and 3.75 mm in the mandible on the molar-anchorage side. The rates of canine retraction were 0.93 mm per month in the maxilla and 0.83 mm per month in the mandible on the implant-anchored side, and 0.81 mm per month in the maxilla and 0.76 mm per month in the mandible on the molar-anchored side. CONCLUSIONS Canine retraction proceeds at a faster rate when titanium microimplants are used for anchorage.

Comparison of Twin-block and Dynamax appliances for the treatment of Class II malocclusion in adolescents: a randomized controlled trial.

INTRODUCTION The aim of this study was to compare the effectiveness of Twin-block and Dynamax appliances for the treatment of Class II Division 1 malocclusion. METHODS This was a randomized controlled trial involving 32 boys and 32 girls aged 10 to 14 years with Class II Division 1 malocclusion. They were randomly allocated to either the Dynamax appliance group or the Twin-block appliance group. Treatment was provided by 4 clinicians at 2 centers. Records were taken at the start and the end of the functional phase and after all treatment. In addition, incisal overjet, the number of appliance breakages, and adverse events or side effects of the treatment were recorded at each patient visit. RESULTS The data monitoring committee in an interim analysis at 18 months after the start of the trial found significantly greater overjet reduction in the Twin-block group than in the Dynamax group and more breakages and adverse events with the Dynamax appliance. As a result, treatment with the Dynamax appliance was terminated, and those patients completed treatment with the Twin-block or a fixed appliance. Regression analysis showed a statistically significant difference in the performance over time between the Twin-block and Dynamax appliances in terms of reduction in overjet, with the Twin-block appliance performing significantly better than the Dynamax. The incidence of adverse events was greater in the Dynamax group (82%) than in the Twin-block group (16%), with a statistically significant difference (P <0.001) between the 2 groups. CONCLUSIONS The Twin-block appliance was more effective than the Dynamax appliance when overjet was evaluated and the Dynamax appliance patients reported greater incidence of adverse events with their appliance than those who were treated with the Twin-block appliance.

Early orthodontic treatment for Class II malocclusion reduces the chance of incisal trauma: Results of a Cochrane systematic review.

UNLABELLED In this article, we summarize the most clinically relevant findings of our recently updated Cochrane systematic review into the treatment of Class II Division 1 malocclusion. METHODS A systematic review of the databases was performed to identify all randomized controlled trials evaluating early treatment with functional appliances to correct Class II Division 1 malocclusion. RESULTS Three early treatment studies with data from 353 participants were included in this review. The results showed no significant difference for any outcomes, except new incidence of incisor trauma, which was significantly less for the early treatment group. The risk ratio analysis for new incisor trauma showed that providing early treatment reduced the risk of trauma by 33% and 41% in the functional and headgear groups, respectively. However, when the numbers needed to treat were calculated, early treatment with functional appliances prevents 1 incidence of incisal trauma for every 10 patients (95% CI, 5-174), and headgear treatment prevents 1 incidence of incisal trauma for every 6 patients (95% CI, 3-23). CONCLUSIONS Orthodontic treatment for young children, followed by a later phase of treatment when the child is in early adolescence, appears to reduce the incidence of new incisal trauma significantly compared with treatment that is provided in 1 phase when the child is in early adolescence. However, these data should be interpreted with caution because of the high degree of uncertainty. There are no other advantages in providing 2-phase treatment compared with 1 phase in early adolescence.

Early orthodontic treatment for Class III malocclusion: A systematic review and meta-analysis

Introduction Class III malocclusion affects between 5% and 15% of our population. The 2 most common dilemmas surrounding Class III treatment are the timing of treatment and the type of appliance. A number of appliances have been used to correct a Class III skeletal discrepancy, but there is little evidence available on their effectiveness in the long term. Similarly, early treatment of Class III malocclusion has been practiced with increasing interest. However, there has been no solid evidence on the benefits in the long term. The aim of this systematic review was to evaluate the effectiveness of orthodontic/orthopedic methods used in the early treatment of Class III malocclusion in the short and long terms. Methods Several sources were used to identify all relevant studies independently of language. The Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase (Ovid), and MEDLINE (Ovid) were searched to June 2016. The selection criteria included randomized controlled trials (RCTs) and prospective controlled clinical trials (CCTs) of children between the ages of 7 and 12 years on early treatment with any type of orthodontic/orthopedic appliance compared with another appliance to correct Class III malocclusion or with an untreated control group. The primary outcome measure was correction of reverse overjet, and the secondary outcomes included skeletal changes, soft tissue changes, quality of life, patient compliance, adverse effect, Peer Assessment Rating score, and treatment time. The search results were screened for inclusion, and the data extracted by 2 independent authors. The data were analyzed using software (version 5.1, Review Manager; The Nordic Cochrane Centre, The Cochrane Collaboration; Copenhagen, Denmark). The mean differences with 95% confidence intervals were expressed for the continuous data. Random effects were carried out with high levels of clinical or statistical heterogeneity and fixed affects when the heterogeneity was low. Results Fifteen studies, 9 RCTs and 6 CCTs, were included in this review. In the RCT group, only 3 of 9 studies were assessed at low risk of bias, and the others were at high or unclear risk of bias. All 6 CCT studies were classified as high risk of bias. Three RCTs involving 141 participants looked at the comparison between protraction facemask and untreated control. The results for reverse overjet (mean difference, 2.5 mm; 95% CI, 1.21‐3.79; P = 0.0001) and ANB angle (mean difference, 3.90°; 95% CI, 3.54‐4.25; P <0.0001) were statistically significant favoring the facemask group. All CCTs demonstrated a statistically significant benefit in favor of the use of each appliance. However, the studies had high risk of bias. Conclusions There is a moderate amount of evidence to show that early treatment with a facemask results in positive improvement for both skeletal and dental effects in the short term. However, there was lack of evidence on long‐term benefits. There is some evidence with regard to the chincup, tandem traction bow appliance, and removable mandibular retractor, but the studies had a high risk of bias. Further high‐quality, long‐term studies are required to evaluate the early treatment effects for Class III malocclusion patients. Trial registration number: PROSPERO CRD42015024252. HighlightsEarly facemask treatment produces skeletal and dental changes in the short term.Evidence on long‐term benefits of early Class III treatment is lacking.Chincup, tandem traction, and removable retractors showed skeletal changes.Results should be interpreted with caution due to risk of bias in studies.Long‐term studies of early orthopaedic treatment for Class III patients are needed.

A three-dimensional comparison of torque achieved with a preadjusted edgewise appliance using a Roth or MBT prescription.

OBJECTIVE To investigate if there are any significant differences in the final inclination of the upper and lower anterior teeth of patients treated with a Roth or an MBT bracket prescription. MATERIALS AND METHODS Forty sets of posttreatment study models from patients treated using a preadjusted edgewise appliance (20 Roth and 20 MBT) were selected using predetermined inclusion and exclusion criteria. The models were masked and laser-scanned, and the final crown inclinations of UL1, UR3, and LR1 were assessed from the digital images. A two-way analysis of variance was undertaken with the dependent variable of final crown inclination and independent variables of bracket prescription (Roth or MBT) and tooth type. RESULTS There were no statistically significant differences in terms of the final inclination of the anterior teeth between the two bracket prescriptions (P  =  .132). Statistically significant differences were found between the final inclinations of different tooth types investigated (P < .001). CONCLUSION In this group of selected patient records, the differences in torque values between the two bracket prescriptions did not lead to any real clinically detectable differences in the final inclination of teeth.

Measuring molar movement: A reliable technique

A technique of accurately assessing left and right maxillary molar movement is described, using superimposition of digital study models. This method has distinct advantages over the traditional method of measuring tooth movement using cephalometric radiographs.

Randomized controlled trials: The technique and challenges

Randomised Controlled Trial (RCT) is recognised as the gold standard for testing treatment efficacy. In this article, I will explain some of the important terminologies, like randomization, stratification, allocation concealment, blinding, intention-to-treat, data monitoring committee and stopping rule, and the design of RCTs. I will also discuss the issues to be faced when designing a study with some examples on how to overcome them.