The En Masse and the Sequential Retraction Procedures

Abstract

In this article, the authors discuss two preeminent notions in orthodontics; those are the approaches of “En Masse Retraction” and “Sequential Retraction” in orthodontic cases. The “Sequential Retraction” is identified by retraction of canines firstly, forming one group of retracted canine and posterior teeth in the respective side, then retraction of the incisors. Besides, the approach of “En Masse Retraction” is identified by retraction of the six anterior teeth “as one group”. Sequential Retraction is called “two-phased retraction”, whereas “En Masse Retraction” termed as “one-phased retraction”. Sequential Retraction has been justified for its characteristic of upholding anchorage, while En Masse Retraction is beneficial in keeping the alignment of the anterior teeth during treatment. Sequential Retraction has two phases: Firstly, canines are moved posteriorly, then canines are congregated with the posterior units of second premolars and first molars (in addition to second molars if they are banded) to form one group. Secondly, the anterior four incisors are retracted. Sequential Retraction may cause temporary spaces especially in between lateral incisors and canines what are unwelcome sometimes. In addition, in the first phase of sequential retraction, it is recommended that a “stop” on the mesial of the molar tube be placed, to “maintain the anchorage” by preventing its “burning” (by a potential movement of the first molar mesially). Nonetheless, this stop has its own reaction on the pertinent incisors, consequently the incisors move anteriorly little bit, in the canine retraction phase, what in turn, increases the burden on the anchorage units, during the “phase-two” of incisors retraction. In other word, the conception that sequential retraction is more “harmless” towards the anchorage units is gradually becoming a debatable issue. Furthermore, an advantage of the “En Masse” retraction in maintaining the “Leveling of Alignment” of anterior teeth should be taken into account by clinician. By applying the “theory of Optimal Force Values”, (which depends on using continuous low force, as minimal as available, and simultaneously over the due threshold that is sufficient to cause tooth movement), it is available to achieve canines and incisors “en masse” retracted without such an overload onto anchorage segments. As the standpoint would be to apply optimal forces on the anterior teeth, with least counteracted movements onto anchorage units proposing forces dissipation until be below the sufficient threshold for posterior teeth movement.