Orthodontic Treatment of Impacted Teeth. Adrian Becker

Orthodontist’s presence unnecessary Bond failure – needs no surgery Disadvantages Greater risk of infection Greater discomfort Interference with functions of eating, chewing, talking Wider bone exposure Bad taste and smell in mouth Possibility of re‐closure of exposure – dictates re‐exposure Bonding reliability poorer Delayed initiation of traction Poorer periodontal condition Extra visits to change packs

The team approach to attachment bonding

      It is appropriate to note that the development of the team approach to the bonding of an attachment was exemplified in the cooperation, expertise and forbearance of two (now retired) senior oral and maxillofacial surgeons in Jerusalem, Professors Arye Shteyer and Joshua Lustmann. The approach primarily represents an adjunctive surgical procedure, whose aim is to provide a small area of exposed enamel of the impacted tooth for the application of an orthodontic force‐delivery system. Accordingly, it should be carried out on the surgeon’s territory, rather than in the orthodontic clinic.

      Before the surgical exposure is attempted, orthodontic treatment will have been initiated and, in most cases, will have reached the stage where levelling and alignment will have been prepared. More substantial steel archwires will have been used during space preparation and a heavier base arch will usually be in place to combine all the teeth into a composite anchor unit.

Those orthodontic procedures that remain to be carried out during the surgical episode are few and relatively simple and can all be performed in the oral surgeon’s operatory. If they are properly prepared in advance, these procedures will not be time‐consuming and will not disturb the surgeon’s patient flow. Practical experience will dictate that the orthodontist should prepare a small tray of instruments and materials that are not normally available in the operating room. In addition, the orthodontist will have prepared an auxiliary device, which will have been chosen or customized at a previous visit, for the purpose of applying a directional force to the impacted tooth. This may take the form of a prepared and individualized ballista spring, or a flexible palatal arch or an auxiliary labial arch (see Chapter 7). The instrument tray should contain the items listed in Table 5.2.

      In the treatment of an impacted palatal canine or of almost any other impacted tooth and immediately prior to the surgical exposure, it has been the author’s practice to tie the labial auxiliary arch or other auxiliary into the orthodontic brackets. In its passive mode, the active loop will stand well away from the immediate surgical field and will not interfere with the work of the surgeon. As a poorer alternative, these auxiliaries may be placed on the instrument tray, in readiness for placement at the end of the surgical procedure.

Table 5.2 An instrument tray for a team approach.

Instruments
Fine wire bending plier (e.g. Begg plier)
Fine wire cutter
Reverse‐action bracket‐holding tweezers, which are closed when not held and release when handles lightly squeezed
Ligature director
Mosquito or Matthieu forceps
Fine scaler
Materials
Etching gel
Composite bonding material, preferably a light‐curing material
Applicators (sponge buds, fine brushes, etc.)
Attachments
Eyelets welded to thin band material, backed with stainless steel mesh; these should be cut and trimmed into patches of various sizes, but no larger than the base of a small bracket
Cut lengths of dead soft stainless steel ligature wire of gauge 0.012 in. or 0.014 in.
Elastic thread and elastic chain

In the first stage of the treatment, the surgeon reflects the palatal soft tissue flap over the impacted tooth and removes the intervening bone, which is usually very thin and easy to peel with a scalpel blade. If a supernumerary tooth or odontome is present, this will be removed first. The dental follicle is then cut open in the target area, immediately overlying the crown, and the resultant exposure is widened. The increase of the width of the exposure should not be more than is necessary to satisfy two basic requirements: (a) to provide enough enamel surface to accept a small attachment; and (b) to do so in an area wide enough for adequate haemostasis to enable the bonding procedure to take place, without fear of contamination.

      The next stage requires the surgeon to move to the other side of the operating table in order to be positioned to concentrate on maintaining the enamel surface, free of blood and saliva, throughout the critical bonding phase. In this function, and under these conditions of exposed and oozing soft tissue and bone surfaces, the surgeon will generally need to use a regular suction tip and a second and very fine tip in the form of a canula no. 14 or 16, in order to maintain a blood‐free field of operation for the bonding procedure. Occasionally, the surgeon may be required to attend to a persistent bleeding point from the bone surface and may apply pressure from a blunt instrument or use bone wax to occlude the tiny vessel. In the case of soft tissue bleeding, electro‐cautery may be employed, or a hot burnisher or even ligation of the vessel. Bleeding does not occur in the follicular space, but seepage from adjacent areas may happen and is best arrested with the use of light pressure from a strip of gauze, which may be left in place until suturing is ready to begin – but it must not be forgotten! Then, holding a retractor in one hand and alternating the suction tips as necessary with the other, the surgeon will be able to maintain the access and haemostasis to the immediate area of the newly exposed and impacted tooth.

      The orthodontist, who has been waiting patiently for the surgeon to achieve the required state, will now step in and proceed directly to rinse the tooth surface with atomized water spray. This will be done from a standard triple syringe (or, if preferred, with sterile saline from a large syringe) through a wide‐bore needle, in order to disperse any blood from the tooth surface. The saline is evacuated through the broad suction tip, operated by the surgeon. The fine suction tip then takes over and is made to hover over the entire exposed crown, close to the tooth surface, with the aim of achieving an air flow over the clean enamel. This produces and maintains effective drying, while the use of sterile saline as a rinsing agent does not appear to undermine the reliability of the bonded union.

      Liquid etchants should not be used in the exposed surgical field [5, 25, 45], since it is difficult to limit their spillage and dispersal onto the exposed soft tissues and bone surfaces and, even more important, to prevent their spreading to the area of the CEJ, the PDL and cementum. There is mounting clinical evidence that excessive orthophosphoric acid etchant, which seeps onto the exposed root areas, will damage the cementum cover of the root. It may also