Bracket Prescription Maneuvers: A Visual Ready Reckoner

Abstract

The article summarizes the common bracket prescription maneuvers used in preadjusted edgewise appliances and their effects on the inbuilt prescription. The illustrations presented are designed as a ready reckoner for teaching and chairside use.

Introduction

Bracket prescription maneuvers (BPMs) are intentional alterations in the bracket positioning aimed at changing the expression of the inbuilt bracket prescription. Although practiced right from the beginning of the nonprogrammed edgewise brackets,[1,2,3] they have assumed special relevance and popularity with the preadjusted edgewise appliances (PEAs).[4]

The common BPM[5,6,7,8,9] in vogue for the PEA bracket/tube [Figure 1] are as follows:

Figure 1.

The six possible bracket prescription maneuvers used in clinical practice

1. Flipping (inversion): Rotating the bracket 180° on the same tooth, reversing the occlusal and gingival sides, as used in a palatally blocked-out maxillary lateral incisor

2. Substituting: The intra-arch and ipsilateral movement of the bracket, like the maxillary incisor bracket on the canine that replaces the missing lateral incisor

3. Switching: The interarch and ipsilateral movement of the bracket (without flipping), like the ipsilateral mandibular premolar bracket on the maxillary canine, that substitutes the missing lateral incisor

4. Swapping: The intra-arch and contralateral movement of the bracket. For example, the mandibular canine brackets can be swapped to achieve distal tipping of the crowns in Class III camouflage cases

5. Blending: The combination of two or more of the above maneuvers. For example, flipping, switching, and swapping the mandibular II molar tube (with zero offset) to the contralateral maxillary first molar for a therapeutic Class II finish

6. Flocking: Similar maneuvering of brackets in a group of teeth.[3] For example, the brackets on all the maxillary incisors can be flipped to facilitate palatal tipping with early rectangular archwires.

Effects of Bracket Prescription Maneuver

The general effects of these BPMs are illustrated in Figure 2. However, their precise outcomes and utility depend on the actual prescription built into the bracket. There is no change when the attachment is not preprogrammed for a feature, as in the case of the standard edgewise bracket with zero tip and torque.

Figure 2.

The effects of bracket prescription maneuvers are illustrated using a right maxillary first molar tube with an inbuilt mesial crown tip, buccal root torque, and mesial-out offset. While a green dot indicates that the particular feature remains unchanged with the maneuver, a red dot indicates the directional reversal

Although these BPMs have been employed in various clinical scenarios, the following three are the most common and validated applications with the MBT prescription[4] in the authors’ practice: (1) flipping the bracket on palatally blocked the maxillary lateral incisor, (2) substituting an incisor or premolar bracket on the maxillary canine replacing the missing lateral incisor, and (3) blending the mandibular II molar tubes on the contralateral maxillary I molar for a Class II finish.

A few clinical limitations of BPMs need attention. The extent to which a particular feature is expressed may vary depending on the location and contour of the recipient tooth surface. Brackets with bases contoured for a specific tooth may fail to fit precisely elsewhere and may need some tooth surface alteration for better seating. Finally, trimming the hook/power arm on the bracket may be required in some instances to prevent occlusal interference.

To summarize and remember,

1. Flip spares the tip

2. Swap spares the torque

3. Switch spares the offset

4. Blending the three spares all.

The illustrations presented in this article can be printed as a poster and used as a teaching and chairside ready reckoner.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.