Last week teaching a hands on equilibration course one of the participants told a story about a new patient to his office who was in active appliance therapy and frustrated because the former dentist wouldn’t move to the next step of the treatment plan and the patient felt “stuck” in the appliance. His question to me was whether it was wise to move ahead with definitive restorative therapy. So when is appliance therapy complete? The answer to that question hinges on your reasons for placing a patient in an appliance.
Are you willing to make adjustments to an occlusal appliance that you did not make? Over the years I have met dentists who “never” adjust an appliance that was made by another dentist, and others who are willing to. In my experience either way it is a challenging situation and a challenging discussion with the patient. One of the key pieces I have learned over the years is whether I made the occlusal appliance or not, the instant I adjust it I am fully responsible for it. That means if it works I win, but if the patient continues to have problems, or no resolution of symptoms I am responsible. Challenge number two, is that without a complete joint, ,muscle and occlusal exam I am not fully versed in the patient’s condition and the goals of appliance therapy. therefore I do not know how the appliance should be adjusted to gain maximum benefit. The last piece of the puzzle is figuring out a fair fee for adjusting an appliance.
In yesterday’s blog post I talked about how we support our patients in remembering post operative instructions. I started with a story about a patient who recently melted his anterior bite plane appliance trying to tighten it himself. I have had numerous inquiries today about what my post-op instructions are when I deliver an anterior bite plane appliance. My delivery process is simple:
- Seat the appliance and adjust for appropriate fit by trimming the labial flange of the biocryl.
- Create even stops in ICP
- Create smooth even guidance in excursions.
The last step in creating an anatomic appliance is to create the occlusal design prior to polishing the appliance for delivery. Anatomic appliances are designed to capture an actual occlusal scheme that can be created on the patient’s teeth onto an artificial acrylic surface. Alterations from the existing occlusion to the acrylic are designed to eliminate signs and symptoms of occlusal disease and stabilize joints and muscles. The anterior guidance can be designed as either a canine guidance or a group function, and normally mimics the existing interincisal angle or is more shallow. The combination of anterior guidance on the appliance and the angle of the eminence create posterior disclusion.
To complete our series on occlusal appliances I wanted to include this video of doing an intraoral reline. Hard acrylic appliances need to be both passive, meaning they do not exert orthodontic pressure, and retentive such that the patient can not remove it with tongue pressure or when half asleep. Accomplishing this magic combination requires utilizing methyl methacryalte and performing a reline in the mouth that creates a path of insertion. I have yet to find an appliance that works as well without being relined, despite trying many different types. Although the taste of the reline material is unpleasant, the end result is well worth the five minutes of time. I make sure my patients know ahead of time that once set the material has no odor and no flavor.
In this segment Dr, Mark Kleive demonstrates trimming the acrylic shell using a Scotchbrite wheel on a lathe. The lathe is an efficient and effective way to not only remove the gross excess of acrylic, but as you will see also a great tool to great the initial shape of the posterior and anterior segments of the appliance. In addition the lingual flanges can be shaped and thinned, thereby minimizing the amount of work we do with an e-cutter on a slow speed handpiece.
The next step in our series of videos on fabrication of an anatomic appliance is fabricating the acrylic shell. In last week’s segment Dr. Mark Kleive demonstrated mixing the acrylic to achieve a dense, smooth acrylic appliance. In this video, the acrylic is now ready to remove from the former and be moved to the articulator. Once placed over the lower model, it is important to trim and shape the acrylic to minimize adjustment after it is set. It is also imperative to imprint the acrylic with certain occlusal landmarks that allow for proper adjustment of the occlusal surface of the acrylic.
In the second part to this video series, Dr, Mark Kleive demonstrates a technique for mixing acrylic to fabricate an anatomic appliance. I utilize this exact technique for both anatomic and flat plane occlusal appliances. I have found that acrylic is still the easiest material to use in order to custom fit appliances so they are both passive and fit firmly without any “squish”. Additionally acrylic seems to survive the longest in the oral environment, and allows repairs and changes over time that minimize replacement of the entire appliance.
I use anatomic appliances, sometimes known as Tanner Style appliances, very commonly in my practice. They are the appliance design that allows me to test alterations to the patient’s functional occlusion prior to replicating it on their teeth or in a reconstruction. This appliance design gives me the ability to vary inter-incisal angle, guidance, protrusive and intercuspal contacts and observe the impact on the patient’s muscles and joints. In addition the patient has the opportunity to experience what the proposed occlusion will feel like and add their preferences into the design. The final design of the occlusal scheme can be transferred into a wax-up or a final equilibration.
You may have hear both positive and negative things about all soft occlusal appliances. A common conversation is that they will aggravate muscle signs and symptoms. It is true that some patients will increase the amount of clenching they do in response to the squish of a soft appliance. For patients with muscle signs and symptoms and a healthy condyle disc assembly a soft appliance would not be my first choice. Another factor to consider is the amount of grinding and tooth wear a patient has. Soft appliances will protect the teeth from wear, where hard appliances do still have the ability to cause tooth wear, albeit at a much reduced rate than tooth against tooth.