Written by Joseph Whitehouse, MS, DDS Monday, 09 April 2012 08:42
Nearly every dental student gets some exposure to some orthodontic training, but what of that learning is actually applied in practice? Many general practitioners (GPs) have opportunities presented to provide care that would make a difference to their patients, but they may simply not recognize the need or possibly ignore applying an orthodontic procedure that would be beneficial to the patient. Often, some GPs decide to learn more, using continuing education to perfect orthodontic techniques that can be easily applied for an enhanced outcome to a routinely provided procedure. What follows are procedures that can be applied as opportunities present themselves.
Severely Worn Mandibular Anterior Teeth
It is common to see patients with severe tooth surface loss who would like protection against further loss, and may desire better aesthetics. Figure 1 shows such an example. In this case, during a period of several years and with the patient respectfully educated about his condition, he finally made a decision to seek care to resolve the problem. The issue pertinent to this article is: what options were available to eliminate the tooth surface loss? Remember, exposed dentin of this magnitude disappears with normal incising and eating foods with any acidity. A nightguard is a given.
One option was to remove some incisal dentin and fill in with composite. I use this procedure frequently in cases with less loss. In this case, a very large amount surface area of composite would be needed, but these teeth could be rebuilt if the bite could be opened. The second choice would be to crown/veneer the teeth. However, that would require substantial incisal preparation, leaving possible endodontic considerations, but certainly very short teeth that could affect retention of the crown/veneers.
|Figure 1. Severely worn teeth (from bruxism) with supereruption.||Figure 2. Initial placement of brackets and Ni-Ti wire.|
|Figure 3. Progress of intrusion of lateral incisors.||Figure 4. Completion of intrusion of incisors.|
|Figure 5. Prepartion for wrap-around veneers, with no incisal prepartion.||Figure 6. Completion of veneering.|
Here is a case for application of GP orthodontics. Intrusion of the incisors is an option that I have applied many times. I will demonstrate both conventional straight wire and Invisalign techniques in 2 cases so you can see an outcome that enhances the final results. I want to emphasize that anyone can accomplish the procedure with proper training, especially if you have already been providing orthodontic care for your patients.
Figure 2 shows the initial placement of the brackets and Ni-Ti wire for the intrusion of the 4 lower incisors. Basic brackets from most orthodontic companies (I use Ortho Organizers) will suffice, and arch wires can be Ni-Ti of 0.018 round or rectangular of .020 x .020 or .018 x 0.022. One must be sure to get the correct arch wire by width needed so as to not expand or contract the lower arch.
The placement of the anterior brackets is dependent on the overbite and overjet. In cases where the bite is very tight, the incisor brackets may need to be placed with the mouth closed so that the upper edge of the brackets nearly touch the upper incisors. If that is the case, the arch wire could be placed on top of the bracket slot. The case here (Figure 2) shows enough room for placement of the brackets. The main issue in placement is to have the brackets on the teeth to be intruded closer to the incisal than the brackets on the cuspids. Second, at least one if not 2 bicuspids, should be included for anchorage.
The intrusion is a slow process that can easily take 6 months, depending upon the amount of intrusion desired. In this case, we wanted to intrude enough to prevent the need for incisal preparation for the veneers. Figure 3 shows how progress can be seen by intruding 2 incisors at a time. I have found that by doing this, the intrusion seems to work faster and is also more controllable. Once the 2 lateral incisors were down, the archwire was moved over the top of the central brackets. Figure 4 exhibits total movement of the 4 lower incisors. The goal of not having to prepare incisally was reached. Figure 5 shows the preps with wrap-around veneer preps for retention but no incisal prepping. The final outcome (Figure 6) (Lute-It [Pentron Clinical]) gave the patient the outcome he desired.
Intrusion Using Invisalign
With a similar tooth surface loss situation (Figure 7), the patient chose to have us use Invisalign to intrude her inciors for the same clinical outcome shown in the previous case. My experience with this technique is varied; I have learned that there is less predictability and, for those doing Invisalign, a need for a refinement. Anchorage is critical and may mean attachments on subject incisors, such as the laterals while the centrals are being intruded.
|Figure 7. Bruxed lower anterior teeth to be intruded.||Figure 8. Invisalign ClinCheck before intrusion.|
|Figure 9. Invisalign ClinCheck of completed intrusion.||Figure 10. Completed veneers, after intrusion of the incisors.|
Having said that, you can see from the patient's Invisalign ClinCheck (Figure 8) at the beginning of treatment to the end (Figure 9), an excellent result was obtained.
Figure 10 shows the final veneers (Lute-It; San Ramon Dental Lab).
Erupting Fractured Teeth
Several articles have been published concerning the erupting of fractured teeth, enabling an adequate ferrule effect to be provided for a predictable outcome for crown placement. However, I believe that all those articles feature only anterior teeth. It is possible to erupt bicuspids as well. In fact, any tooth can be erupted. Here, I will feature a bicuspid that needed erupting for predictable survival.
Figure 11 shows No. 13 broken at the gumline. The choices are: (1) extract and leave a space, or place an implant; (2) extract and place a fixed bridge; (3) do crown lengthening to gain ferrule effect for a crown; or (4) erupt the tooth enough to expose enough healthy tooth structure to gain an adequate ferrule for retention and strength of the final restoration. Each of these choices has its benefits and drawbacks. First, and obviously, the patient must be involved. Second, the considerations are: root length, periodontal consideratons, and cost-predictablity. In this case (as in all the others I have done), the benefit of saving the tooth predictably outweighed the other options to the patient.
|Figure 11. Crown fractured off at gumline, tooth No. 13.||Figure 12. Cutting the circumferential perio ligament to allow extrusion.|
|Figure 13. Etching before ortho bracket placement.||Figure 14. Ortho brackets and wire in place to begin eruption.|
|Figure 15. Completed eruption of tooth.||Figure 16. Eruption allowing for an adequete ferrule effect.|
In each eruption case, it is critical to sever the circumferential periodontal fibers so the tooth will erupt without the bone coming with it. This can be done with a scalpel or a laser. Figure 12 shows the use of a laser (in another case) for this severing. Figure 13 shows the etching process after the root canal and post and core buildup. As you can see, it does not matter if a crown (Porcelain Etch [Ultradent Products]) is an adjacent tooth. Figure 14 shows the wire and brackets in place to start the eruption.
The erupting process is over when the wire is straight (Figure 15) so there will be an adequate ferrule effect upon preperation (Figure 16). It is critical to hold the tooth at the erupted level for 2 to 3 months before crown preparation to allow bone to fill in at the apex so the ligaments will not return the tooth back up/down. (I made this mistake once; a central incisor retruded one millimeter, and then I had to re-erupt it. Embarrassing.)
A removable Invisalign type of appliance can be used for supereruption by creating a reservoir for the tooth to move into and an elastic over the tray connected to buttons on the buccal and lingual. However, I choose fixed for predictability. Every patient I have had who had broken a tooth needing eruption, has chosen the fixed technique.
Preparing For A Bridge
Finally, how many mesially inclined molars have we all seen, well knowing the angle leaves something to be desired as abutment? Figure 17 shows such an example. I have seen these teeth used in this position for bridge abutments, but the outcome is compromised. The movement of this second molar is very predictable for any GP using a removable appliance. Figure 18 shows the appliance in its final stage after about 5 months. Now, a reasonable approach to making a bridge is possible and, in this case, as many I have done, inlays were used as the retainers for the pontic. Figure 19 shows the minimally invasive bridge resulting from employing basic orthodontics prior to the restorative work.
|Figure 17. Panoramic radiograph exhibiting mesially inclined tooth No. 31.||Figure 18. Completion of uprighting of this second molar for bridge preparation (mirror view).|
|Figure 19. A minimally invasive inlay bridge was placed with the second molar in a more ideal location (mirror view).|
The case examples shared here serve to illustrate the options that GPs have to move teeth into more treatable positions. GPs, with some proper training and knowledge, can easily use these techniques with full confidence for success. Start with a simple case for building confidence. Personally, I started many years ago only using removable appliances, then moving to fixed techniques and by reading, and then taking a 4-part course from Dr. Brock Rondeau (available at the Web site rondeauseminars.com).
Patients come to us seeking the best results possible. Why not enhance the outcomes by using prerestorative orthodontics?
Disclosure: Dr. Whitehouse reports no disclosures.
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