When the occlusal scheme and alignment won't allow for efficient use of the pre-fabbed matrices...
Custom Fabrication of an NTI-tss type device

"Crystal Clear NTI-plus"

A custom NTI device (Photo provided by Keith of KB Lab)

For a laboratory produced NTI device, contact Keller Lab.  (NTI-TSS, Inc. has trained and licensed Keller Labs to be the exclusive laboratory provider of the NTI device.

If orthodontic retention or periodontal stabilization  is desired, add a Discluding Element to a vacuum formed stent.

Grinding down the Discluding Element for a patient with a very deep overbite may simply make the Standard NTI device too brittle to use.  If so, make a custom device with the DE as shown:

(above left) Using .06" vacuum form sheet and cold-cure acrylic with pre-sculpted DE, and
above right: for deep overbite cases when making a custom NTI-type device.

The above example shows the modification of a traditional hard occlusal splint,

NTI device adapted with rigid bite registration material for the "incisorly edentulous"
both examples courtesy of Dr. Michael Drance

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Custom "Daytime" device

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Regardless of the occlusal scheme, the therapeutic goal of an NTI-tss type appliance, whether it has been retrofitted from a prefabricated matrix, or custom fabricated, is to prevent the occluding scenarios that allow for near maximal temporalis contraction and strain on the TM joint.  Since both posterior and canine occluding allow for maximal temporalis contraction the therapeutic goal of an NTItss-type appliance is to prevent posterior and/or canine occlusion in all parafunctional movements.

This requires that the practitioner establish what the full range of parafunctional range-of-motion is.  The difficulty here is that the patient will typically claim, "I don't go that far excursively/protrusively".  When asked why, they respond, "Because it hurts to do that".  The reality of the situation is that is hurts because they do that (a parafunctional sleep disorder).

The steps for custom fabrication of an NTItss-type device:

1.  Take impressions and pour a model of the maxillary  and mandibular arches.

2.  Using .06" thick plastic sheeting for vacuum forming,  make a "suck-down" of the entire
     (usually maxillary) model (referred to here as a "stent").

3.  With the stent still adapted to the maxillary model,  articulate the two models to confirm
     where on the maxillary model's vacuum formed material that the midline between the
     mandibular central incisors opposes.   Mark the stent to indicate this location.

4.  Using orthodontic acrylic in a damp, doughy stage,  form a DE on the warm stent at the
     mark made in #3 above. Some examples of the DE.

5.  Regardless of the degree of overjet, the DE  must be extended lingually and labially enough
     so that the incisal edges of the mandibular incisors contact perpendicular to the DE and
     maintaining disclusion of the posterior teeth.

     5a.  Occasionally, with large overjets, the orientation of the lower incisors will not allow the
            DE to be able to contact the mandibular incisors perpendicular to their long axis.
            DO NOT increase the height of the DE to create a perpendicular contact in this
            scenario.  It is preferable to maintain the occlusal surface of the DE parallel to the
            maxillary occlusal plane.

6.  Depending on the alignment of the maxillary incisors, cut away the stent from the model to
     include as many anterior incisors as necessary for adequate retention (lateral to lateral is
     recommended).

7.  Direct re-line the custom matrix on the internal lingual surface with a small amount of
     methacryate.  This is a critical step and ensures stability and enhanced retention.

Protocol for an Anterior Midline Point Stop