applianceAs it is taught in as taught in Spear’s occlusion workshop, partial coverage appliances like NTIs and anterior bite planes can be wonderful appliances when it comes to decreasing muscle activity. However, they do have some significant downsides and limitations. First of all, small appliances like the NTI have a choking risk if they become loose while the patients is sleeping; this is one of the reasons why a larger appliance is taught at Spear. Partial coverage appliances, no matter how they are designed, carry a risk of intrusion and/or super-eruption with them.

This potential for tooth movement is the reason we recommend limiting the wear of an appliance to eight hours or less a day. The trouble comes when we – or our patients – want or need to wear the appliance for more than eight hours a day.  In this article, I’d like to discuss a solution that will help decrease the risks associated with longer wear of a deprogrammer that we teach in the workshop.

Key step to increasing wear time of an anterior appliance

Obviously, the first step is to fabricate a full arch anterior deprogrammer. For those of you that have not taken this workshop, this is a full arch essix-like shell made out of 1.5mm Biocryl with a flat bite place from canine to canine. (Figure 1)

appliances

The next step is to make the lower component that allows for the increased wear time.  To do this, you need to form a piece of Isofolan over the lower model first like you do for the maxillary bite plane. (Figure 2)

appliance

The next step is to place composite over the lower central incisors in the shape of a small mound, creating a stylus. (Figure 3)

appliance

The next step is to form a sheet of 1.5mm Biocryl over the model. The last and final step is to trim and polish the lower appliance which should leave you with an appliance like you see in the final photo. (Figure 4) Now, when the patient wears the two appliances at the same time all of their teeth are covered, which results in a greatly decreased risk of any intrusion or super-eruption. Another side benefit of fabricating the lower stylus is that you essentially eliminate any need for adjustments when you deliver the appliance.

John R. Carson, DDS, PC, Spear Visiting Faculty and Contributing Author www.johncarsondds.com



Comments

Commenter's Profile Image Richard Weber
February 6th, 2015
I have not yet taken the workshop. Step 1 is for the maxillary arch? So the end result is a maxillary full coverage with an anterior bite plane opposing a mandibular full coverage appliance with a small composite stylus acting almost like a Lucia jig? That is a very cool technique! Do you need a ministar or some other positive pressure former?
Commenter's Profile Image John Carson
February 6th, 2015
Thanks Richard! Yes you end up somewhat like a Lucia Jig but all the teeth are covered and you have a larger area for the patient to slide around on. I would not say you "need" a positive pressure former but I have found I get better results with them vs a vacuum former and both I and my assistants find our Mini-Biostar way more efficient and easy to use than our old vacuum former. Hope that helps, John
Commenter's Profile Image Michael Zonder
February 7th, 2015
The lower is a great addition. Generally I make a full maxillary with only contact on the two centrals. Occasionaly I have seen movement of the lower anteriors. Never again. Thanks
Commenter's Profile Image Kathy Noordeh
February 9th, 2015
Why are you adding a stylus to the lower appliance. I know that Dr. Spear recommends fabricating a lower essex with a stylus in case of irregular mandibular incisors in addition to a flat plane upper appliance. Do you add a stylus to all your lower appliances? Thank you
Commenter's Profile Image John Carson
February 9th, 2015
Thanks Michael.
Commenter's Profile Image John Carson
February 9th, 2015
Kathy, The reason for the lower stylus is to keep the two appliances functioning as an anterior deprogrammer, without it you would have posterior interfaces. Sure you can do just a maxillary deprogrammer but you are then limited to 8 or so hours of wear per day.