NTI Clinical Protocols

Appliance Selection ↓   |   Discluding Element ↓   |   Slider Protocol ↓   |   Fitting & Verification ↓   |   Follow-Up ↓

Successful implementation requires attention to appliance selection, retention, discluding element geometry, vertical dimension, and the relationship between the appliance and opposing dentition throughout the patient's range of mandibular movement.

The objective is not simply to separate the posterior teeth. It is to establish an anterior contact relationship that minimizes opportunities for forceful clenching without unnecessarily restricting mandibular movement.

The following clinical guidance outlines the principles of appliance fitting, adjustment, and ongoing evaluation. Appliance configuration must be individualized according to the patient's anatomy, occlusion, mandibular movement, and clinical findings.

Selecting the Maxillary or Mandibular NTI Configuration

The NTI Therapeutic Protocol can be implemented using either a maxillary or mandibular anterior appliance. The preferred configuration depends on the patient's occlusal anatomy, vertical incisal overlap, and range of mandibular movement.

Maxillary NTI Configuration

For many patients, the maxillary NTI provides a straightforward means of establishing anterior disclusion.

In patients with substantial vertical incisal overlap (deep overbite), the maxillary configuration may be particularly advantageous because the discluding element can be contoured or ramped to accommodate the opposing mandibular incisors while maintaining posterior disclusion.

The objective is to achieve the desired disclusion with the minimum effective increase in vertical dimension.

Mandibular NTI Configuration

A mandibular NTI may be preferable when the patient's mandibular excursions create an unfavorable contact relationship with a maxillary discluding element.

For example, in patients capable of extreme lateral mandibular movement, a mandibular canine may approach or engage the discluding element of a maxillary NTI.

In such circumstances, placing the NTI on the mandibular arch, with an appropriately configured opposing maxillary contact surface, may provide a more favorable arrangement.

Evaluate the Full Range of Movement

Regardless of which arch is selected, the clinician should evaluate the appliance throughout the patient's available mandibular movement—not simply in the habitual closing position.

The clinical objectives are to:

• Maintain posterior and canine disclusion.

• Avoid unintended engagement of the discluding element by opposing canines.

• Minimize unnecessary vertical opening.

• Establish a smooth anterior contact relationship that does not unnecessarily impede lateral mandibular movement.

The preferred appliance is the one that best achieves these objectives for the individual patient.

Designing and Adjusting the Discluding Element (DE)

Establishing the Minimum Effective Vertical Dimension

The Discluding Element (DE) is the anterior contact platform that separates the posterior teeth and prevents canine engagement during clenching.

The clinical objective is to achieve reliable posterior and canine disclusion with the minimum effective increase in vertical dimension.

Excessive opening is generally unnecessary and may introduce unfavorable mandibular positioning or contact relationships.

More vertical separation is not necessarily better. The goal is sufficient disclusion—not maximum disclusion.

Evaluating the Contact Relationship

With the appliance seated, evaluate the relationship between the DE and the opposing anterior dentition.

The clinician should confirm that:

• The intended anterior contact is established.

• Posterior teeth remain discluded.

• Canine engagement is avoided.

• The DE does not create an unnecessary obstacle to lateral mandibular movement.

• Contact remains appropriate throughout the patient's available mandibular excursions.

Adjustment should be guided by the patient's actual occlusal anatomy and movement patterns rather than by a predetermined DE height alone.

Avoiding Canine Interference

Particular attention should be directed toward patients with extensive lateral mandibular movement.

A mandibular canine may approach or engage the DE of a maxillary NTI during extreme excursions, potentially creating an unintended contact relationship.

The clinician should evaluate these movements directly and modify the appliance configuration when necessary.

The Clinical Objective

An appropriately configured DE establishes a controlled anterior contact relationship while minimizing opportunities for forceful posterior or canine clenching.

The quality of the contact relationship matters as much as the presence of disclusion itself.

The Opposing Slider: Facilitating Mandibular Freedom of Movement

Beyond Posterior Disclusion

The traditional NTI configuration uses an anterior Discluding Element (DE) to prevent posterior and canine engagement.

However, achieving disclusion does not necessarily ensure that the opposing anterior teeth can move smoothly across the contact surface during lateral mandibular excursions.

An unfavorable opposing tooth contour may introduce resistance or interference, even when the posterior teeth remain separated.

The Purpose of the Slider

The opposing Slider provides a smooth, controlled contact surface against which the NTI's Discluding Element can function.

Its intended objectives are to:

• Minimize resistance to lateral mandibular movement.

• Reduce the likelihood of unintended contact with irregular opposing incisal anatomy.

• Help maintain a consistent anterior contact relationship throughout mandibular excursions.

• Complement the DE without requiring unnecessary increases in vertical dimension.

Selecting the Appropriate Configuration

When using a maxillary NTI, the Slider is placed on the opposing mandibular anterior dentition.

When using a mandibular NTI, the Slider is placed on the opposing maxillary anterior dentition.

The clinician should evaluate the interaction between the DE and Slider throughout the patient's available range of movement, confirming that the combination does not introduce undesirable interference.

A Refinement of the NTI Therapeutic Protocol

The opposing Slider represents a refinement incorporated into contemporary clinical application of the NTI concept.

Its purpose is not to increase disclusion, but to improve the quality and consistency of the anterior contact relationship.

Although the biomechanical rationale is straightforward, the incremental clinical benefit of adding a Slider has not been independently established in controlled trials.

The clinical objective remains the same: reliable posterior and canine disclusion, minimum effective vertical dimension, and minimal resistance to mandibular movement.

Initial Fitting, Clinical Verification, and Follow-Up

Initial Appliance Fitting

The first objective is to establish a stable, comfortable, and appropriately retentive appliance.

Before evaluating the occlusal relationship, confirm that the appliance is fully seated and does not produce excessive pressure on individual teeth or surrounding soft tissues.

Retention should be sufficient to maintain the appliance during intended use without creating unnecessary discomfort.

Verifying the Discluding Element

With the appliance fully seated, evaluate the contact relationship between the Discluding Element (DE) and the opposing dentition.

Confirm that:

• The intended anterior contact is established.

• Posterior teeth and canines remain discluded.

• Vertical opening is limited to the minimum necessary to maintain reliable disclusion.

• The opposing contact does not create an unintended mechanical obstacle during mandibular excursions.

• When a Slider is used, the DE moves smoothly across its opposing surface.

Evaluate the relationship during gentle closure and controlled mandibular movements, rather than relying exclusively on a single static contact position.

Patient Instructions

Before the patient begins using the appliance, explain its intended purpose, proper insertion and removal, cleaning, and maintenance.

The patient should understand that the appliance is intended to modify occlusal contact conditions during use—not to reposition the jaw or encourage forceful biting against the device.

Patients should be instructed to discontinue use and contact the treating clinician if they experience persistent pain, tooth discomfort, appliance instability, altered occlusion, or other unexpected symptoms.

Clinical Follow-Up

Follow-up provides an opportunity to assess both the appliance and the patient's response.

Reevaluate:

• Appliance retention, integrity, and comfort.

• DE geometry and opposing contact relationships.

• Posterior and canine disclusion.

• Mandibular freedom of movement.

• Changes in symptoms, including the frequency and intensity of morning headache or discomfort.

• Any reported changes in the patient's bite or jaw function.

Adjust, discontinue, or reconsider the appliance when clinical findings warrant.

Evaluating the Patient's Response

For patients presenting with frequent morning headache or discomfort, the ZERO interview provides a practical way to monitor changes over time.

Rather than asking only whether headaches have improved, consider asking:

“How many mornings per week are you now waking with a ZERO?”

The answer may help reveal meaningful changes in the patient's morning symptom pattern.

The Therapeutic Objective

The NTI Therapeutic Protocol is not defined simply by the presence of an anterior appliance.

It is defined by the deliberate establishment, verification, and maintenance of an appropriate anterior contact relationship, together with careful assessment of the patient's clinical response.

Successful clinical application requires attention to both biomechanics and the individual patient.