CHAPTER 20 Precision finishing
As with any preadjusted appliance, Tip-Edge has an inbuilt ability to produce a self-limited precision finish. Moreover, in the hands of an experienced operator, it is capable of achieving such goals in considerably more difficult malocclusions than can normally be handled with conventional bracket systems. In this, it is worth stating the obvious, in that the proven intra-arch detail finishing, for which the straight-wire appliance is recognized, is wasted if a Class I interarch relationship cannot be achieved. This happens all too easily if the anchorage demands of the appliance exceed the co-operative abilities of the patient. With a light anchorage technique, this becomes much less likely.
Also, as with any fixed appliance, final detailing depends upon the accuracy with which the case is set up and it is towards the finish that previously unnoticed small errors in bonding come to light. Of these, incorrect bracket angulations can be corrected surprisingly easily during Stage III, without having to step down into a lighter archwire, so long as the tooth in question has not been allowed to ‘over upright’. If it has, re-angling the bracket will result in an over-closed slot that will not accept the rectangular archwire. This may mean abandoning the deep tunnels and fitting a reverse Side-Winder for one visit, to undo the excess tip, before repositioning the bracket.
Assuming correct bracket and tube positioning, all that should be required during the brief finishing phase is occlusal seating; this is essentially the same as with straight-wire appliances. First, however, the second molars should be assessed for inclusion in the appliance.
Little has so far been said about second molars. This is because banding of second molars is very seldom required until late in treatment, in marked contrast to conventional appliances. Overbites reduce with only light intrusive forces, since the anterior teeth are not restrained apically. For this reason, the additional vertical ‘leverage’ afforded by second molars is not necessary. In fact, including second molars from the outset is more often obstructive, adding unwanted friction, particularly during the first and second stages. There may be rare exceptions to this, however, such as in a deep bite non-extraction adult lower arch.
Routinely, as treatment nears conclusion, the second molars should be assessed carefully for alignment and function, including testing for non-working side interferences in lateral mandibular excursion. It will be found that lower second molars will require picking up more often than uppers, and most frequently in adults. Conventional straight-wire type .022 × .028 inch second molar rectangular tubes are suitable.