When I first saw this paper, I was very interested to see that a team had done an overdue piece of research. Importantly, they did not find an increased loss of anchorage with either technique. They concluded that both methods of space closure were effective and there were no differences in the type and amount of tooth movement. They did not report the 95% confidence intervals. When I looked at the effect sizes, these were all in the order of 0.01 to 0.7 mm. In summary, they found no statistically significant differences in the incisor and molar movements between the two techniques. If you are interested, you can easily have a look at the paper. As you know, I am not a fan of cephalometric research, and I found it very difficult to interpret the tables. They provided a large amount of cephalometric data on the movement of the teeth. What did they find?Ĥ8 participants started and completed the study. The person who did the ceph analysis was blinded to the allocation. I do not have the space to go through this in detail. They then did a complex cephalometric analysis and measured tooth movements relative to a vertical reference line. Surprisingly, they did not report a sample size calculation. Unfortunately, I could not see any information on their method of randomisation and allocation concealment. They then tied the canines to the posterior block of teeth and retracted the remaining anterior teeth in one block on 017×025 SS using Ni-Ti springs. They retracted the canines with Ni-Ti spring. In the TSR group, they retracted the canines on 020 wire with omega loops wired to the molars. Then they did the extractions and started space closure 7-14 days after the extractions.įor the EM group, they tied all the anterior teeth together and retracted the teeth as a single block on 017X025 SS wires using Ni-Ti springs to soldered hooks on the archwires. They did levelling and alignment until they could fit 020 round SS wires. They treated all the patients with Ovation 022 brackets and bands on the first and second molars. I think that it worth looking closely at their mechanics. Outcome: Cephalometric measurements from radiographs taken before extractions (T1) and after all spaces were closed (T2). Participants: Orthodontic patients older than 18 years with bimaxillary protrusion requiring the extraction of four first premolars. “Are there any differences in anterior retraction and posterior anchorage control between Two Stage Retraction (TSR) and En Masse retraction (EM)”? What did they do? What did they ask?Īs a result, they did this study to answer the following question. The studies that have been done are restricted to the upper teeth or have confounders, for example, the use of anchorage reinforcement. In their literature review, they pointed out that there has been limited research into this question.

The Angle Orthodontist published the paper, and it is open access.Ĭomparison of anterior retraction and anchorage control between en masse retraction and two-step retraction: A randomised prospective clinical trialĪngle Orthodontist: Online DOI: 10.2319/051518-363.1 A team from Sao Paulo and St Louis did this trial. As a result, I was keen to read and review this new study. Interestingly, there has been limited research on this very clinically relevant question. I have always wondered which is the best method. Currently, we do this by either retracting the canines and then the incisors (two-step) or by retracting the canines and incisors in one go (En Masse). When we extract teeth as part of orthodontic treatment, we have decisions to make on the best method of space closure. But we now have a new trial! Let’s have a look at it. Then we changed to en masse retraction with no evidence. When I was doing specialist training, we used to close space by retracting canines and then the incisors.

En masse meaning