Quartz 4

L3 Occlusal Splints

14 min read

Occlusal Splints

Overview

Occlusal splints are utilized by Oral Medicine Specialists for various therapeutic purposes involving the masticatory system and dentition.

Common Uses

  • Management of bruxism and parafunctional habits.
  • Treatment of fatigued masticatory muscles and headaches.
  • Relief for sore or worn teeth.
  • Addressing malocclusion.
  • Management of noisy or uncomfortable temporomandibular joints (TMJ).
  • Protection of dentition and dental restorations.

Selection Criteria

The choice of splint depends on:

  • Clinical findings from the examination.
  • The differential diagnosis.
  • Understanding the specific effects of each splint design.

Materials

  • Hard Acrylic Resin: Can be self-cured, heat-cured, or milled. Provides a rigid tooth-borne and occlusal surface.
  • Soft or Resilient: Flexible and pliable (e.g., silicone).
  • Dual Laminated: Features a hard acrylic occlusal surface with a soft material on the tooth-borne surface.

Clinical Evidence and Emergency Use

  • Hard Appliances: Research (Okeson) indicates significantly reduced nocturnal muscle activity.
  • Soft Appliances: Research (Savabi et al.) suggests that immediate insertion may actually increase masseter muscle activity during maximum clenching.

Additional Dawson Classification Details

Albagieh et al., 2023, p. 71

  • Permissive Splints: Allow free movement of the mandible
  • Non-Permissive Splints: Guide or restrict mandibular positioning
  • Hydrostatic Splints: Water-filled and rarely utilized

Material Types

  • Hard Acrylic: Available as self-cured, heat-cured, or milled (current mainstay). Provides durability but requires adjustment capability.
  • Nylon: Alternative for patients with methyl methacrylate allergies; notably difficult to adjust clinically.
  • Soft/Resilient: Silicone-based, similar to thickened whitening trays; generally contraindicated for long-term TMD management due to increased muscle activity.
  • Dual Laminated (Talon Splints): Feature a soft liner on the tissue-bearing surface with a hard occlusal surface; offers comfort but not typically recommended for patients with temporomandibular disorders.

Classifications1

Okeson Classification

  1. Stabilisation Appliance / Muscle Relaxation Appliance: Used to reduce muscle activity.
    • Additional characteristics: These are passive devices that allow free mandibular movement.
    • ==Active Appliances: Used for repositioning, with some applications overlapping orthodontic therapy==.
  2. Anterior Repositioning Appliances: Mandibular orthopedic repositioning appliance.
  3. Other Types:
    • Anterior/Posterior bite planes.
    • Pivoting appliances.
    • Soft/resilient appliances.
    • Anterior-Posterior Plane Splints engage only specific segments of the dentition.
    • Pivoting Appliances are designed to pivot the mandible in a specific direction.
    • Soft and Resilient Splints are fabricated from silicone-based materials.

Dawson Classification

  1. Permissive Splints: Muscle deprogrammers.
  2. Non-permissive Splints: Directive splints.
  3. Pseudo-permissive Splints: Includes soft splints and hydrostatic splints.

Stabilisation Appliance2

Function and Features

The stabilisation appliance is a permissive splint and the most commonly used occlusal appliance. Its primary functions include:

  • Providing joint stabilisation and protecting teeth.
  • Redistributing occlusal forces.
  • Relaxing elevator muscles and decreasing the effects of bruxism.

Key Design Features:

  • Uniform, even, and simultaneous occlusion with opposing dentition.
  • Multiple even contacts on posterior teeth in the retruded contact position; lighter contacts on anterior teeth.
  • Incorporation of canine or anterior ramps to disocclude posterior teeth during eccentric movements.
  • ==Also referred to as the Okeson classification, or the permissive splint per Dawson classification==
  • The occlusal surface must be completely flat without cusp indentations; wear facets must be removed during recalls to maintain flatness
  • All opposing teeth must contact the splint simultaneously when measured with articulating paper
  • Ramps (anterior or canine) guide excursive movements

Clinical Applications

  • Reducing TMD symptoms.
  • Prosthodontics: Eliminating discrepancies between seated joints and seated occlusion (CR = CO), providing a large surface area for force distribution, and allowing for the observation of joint stability over time.
  • Facilitates reproducible centric relation records by deprogramming muscles; essential for full mouth reconstructions to ensure stable, repeatable bite positions
  • Stability monitoring: Serial examinations can detect TMJ changes; if occlusion on the splint changes between appointments (e.g., teeth losing contact), this indicates joint or muscle stabilization changes requiring adjustment

Arch Selection (Maxillary vs. Mandibular)

Generally, the splint is fabricated for the jaw with the most missing teeth to increase stability.

  • Maxillary (e.g., Michigan Splint): Preferred for increased incisor overjet (Severe Angle Class II).
  • Mandibular (e.g., Tanner Splint): Preferred for Class III cases, deep curve of Spee, reduced speech interference, lower visibility, and reduced airway obstruction

Fabrication Requirements

  • Must seat firmly without rocking; patient should not need to actively hold it in place during sleep
  • Must cover all teeth, including unerupted third molars in teenagers, to prevent super-eruption of unopposed teeth
  • Minimum 4mm vertical thickness recommended for strength
  • Arch selection: Generally fabricate on the arch with fewer missing teeth for stability; maxillary preferred for significant Class II skeletal patterns to avoid excessive bulk; mandibular often better tolerated except in tongue thrusters .

Thickness Guidelines

  • Tooth Wear Prevention: Minimal thickness based on material capabilities.
  • Muscle Relaxation: Splints with 4.4 mm to 8.2 mm vertical dimension increase are more effective than 1 mm splints for bruxism and myofascial pain.
  • Disk Displacement:
    • 4 mm thickness for disk displacement with reduction.
    • 6 mm thickness for disk displacement without reduction.

Anterior Bite Plane

  • Design: Engages only 2-4 maxillary incisors (e.g., NTI splint).
  • Purpose: Disengages posterior teeth to eliminate occlusal influences on the masticatory system.
  • Recommendation: Generally NOT ADVISED due to potential complications.

Orthodontic Considerations

Following orthodontic treatment, stabilization splints can function as retainers:

  • ==Maxillary Splint: Serves as the maxillary retainer (with separate lower retainer)==
  • ==Limitations: Does not extend to the cervical margin on all surfaces like traditional retainers, potentially providing less retention for certain tooth movements==
  • ==Protocol: Patients should periodically verify fit with their orthodontic retainers==

Soft Splints vs. Hard Splints

  • ==EMG Evidence: Hard occlusal appliances significantly reduce nocturnal muscle activity, while soft appliances may increase maximum clenching forces in the masseter muscle upon immediate insertion==
  • ==Emergency Use: Soft splints are reserved for short-term emergency pain relief only (maximum one week), as they can exacerbate clenching forces long-term==

NtI Splint3

Theoretical Premise

  • Muscle clenching forces are significantly reduced when contact is isolated to the incisors.
  • Eliminating posterior contact reduces noxious sensory feedback through trigeminal afferents, potentially reducing temporalis muscle soreness and intracranial sympathetic vascular changes.
  • The appliance design specifically engages the central incisors and reduces masseter muscle contraction in addition to temporalis activity.

Clinical Comparisons

  • NTI vs. Flat Plane Appliance: A double-blind RCT found no significant difference over three months regarding muscle tenderness, self-reported pain, or mouth opening
  • No significant difference was found regarding headache improvement..
  • Effectiveness: Other studies indicate the NTI is less effective than a standard stabilisation appliance for treating TMDs.

Duration Limitation

Maximum recommended use is three months only; long-term use carries significant risks of occlusal changes.

Adverse Effects

  • Occlusal Changes: Potential for overeruption of posterior teeth or intrusion of maxillary anterior teeth, leading to an anterior open bite.
  • Tooth Mobility: Unfavourable movement of supporting teeth.
  • Safety: Risk of swallowing the small appliance.

Case Study: Complications of Anterior Bite Planes

  • Patient: 47-year-old female with clenching and headaches.
  • Initial Treatment: Anterior plane splint (provided elsewhere) initially reduced headaches.
  • Outcome: Recurrence of pain and development of a significant malocclusion. Posterior teeth supraerupted, resulting in occlusion occurring only on the second molars (7’s).
  • The patient was also bruxing on these contacts, loading the periodontal ligaments.
  • Management: Required waiting for the anterior teeth to supraerupt to close the open bite before fabricating a proper stabilisation appliance.
  • ==Lesson: Anterior-only appliances risk creating iatrogenic open bites through differential super-eruption.==

Anterior Repositioning Appliance4

Purpose and Design

  • Purpose: To alter the maxillomandibular relationship, directing the mandible into a more anterior position.
  • Design: Includes an acrylic guiding ramp on the anterior third of a maxillary appliance and occlusal indentations in the protruded position.
    • Unlike stabilization splints, these appliances lock the jaw in a specific forward position
  • Duration: Intended for short-term use only.

Clinical Indications

  • Treating anterior disk displacement with reduction (attempting to “recapture” the disk).
    • Specifically attempts to reduce clicking by repositioning the condyle under the anteriorly displaced disc
  • Managing acute trauma with retrodiscal oedema.

Mechanism of Action

Following injury with bruising/edema of retrodiscal tissues, anterior positioning reduces pressure on posterior joint structures to facilitate healing

  • Chronic, painful disc displacement where the goal is to keep the condyle away from inflamed retrodiscal tissues.
  • Also utilized in appliances for obstructive sleep apnoea.

Mechanism of Action

Bimaxillary designs engage both arches to bring the mandible and tongue forward, opening airway space

Risks and Adverse Effects

  • Long-term use can lead to permanent and irreversible occlusal changes.

  • Must be used with caution as a temporary therapeutic measure.

  • Irreversible changes may require orthodontic treatment and potentially orthognathic surgery to correct

  • Must transition to stabilization appliances within approximately three months

  • Cost considerations: Patients must pay for both the repositioning appliance and subsequent stabilization appliance

Posterior Bite Plane Appliance

  • Design: Worn on the lower arch; features bilateral hard acrylic tables over mandibular molars/premolars to disocclude anterior teeth.
  • Intended Effect: Changes vertical dimension and horizontal relationship.
  • Adverse Effects: Can lead to a posterior open bite due to the overeruption of anterior teeth and intrusion of posterior teeth.

Clinical Recommendation

Not recommended for general practice

Neuromuscular Appliances5

Neuromuscular Dentistry (NMD) Approach

  • Utilizes jaw muscle stimulators and jaw-tracking technology to determine an “ideal” vertical and horizontal mandibular position.
  • Process:
    1. Muscle relaxation using Transcutaneous Electrical Neural Stimulation (TENS).
    2. Optimal jaw position identification using a K7 machine.
    3. Recording of muscle tension and joint sounds via electromyography, sonography, and jaw-tracking scans during rest and function.

Clinical Reality

Despite marketing claims and high costs (up to 10x standard splints), dentists invariably grind these appliances chairside to achieve accurate occlusion and comfort, effectively negating the computerized positioning data. Clinicians should interpret marketing claims cautiously.

Clinical Stages of Splint Fabrication clinicalProcedure

  1. Initial Stage: Clinical occlusal analysis (Item 963).
    • Assessment of tooth relationships in centric/eccentric positions.
    • Muscle palpation and TMJ assessment.
    • Evaluation of tooth wear.
  2. Technique and Registration:
    • Impressions: Alginate, silicone, or digital scanning.
    • Bite registration at the anticipated vertical dimension using a leaf gauge or Lucia jig.
    • Mounting: Using traditional articulators or digital software to check interocclusal separation.

Adjusting The Splint6

Armamentarium

  • Articulating paper (red and blue) with Miller’s forceps.
  • Acrylic and exudate burs.
  • Shim stock for checking contact intensity.
  • ==Fabrication Techniques:==
    • ==Impressions: Digital scanning (mainstay) or conventional alginate/silicone==
    • ==Bite Registration: Record desired vertical dimension with patient in relaxed position; use leaf gauges or Lucia jigs rather than closed-bite records to prevent laboratory error==

Adjustment Procedure

  • Verification: Ensure the splint is fully seated; check retention and stability.
  • Occlusal Goals:
    1. Eliminate premature or deflective contacts.
    2. Establish uniform occlusion across the entire surface.
    3. Eliminate interferences in lateral and protrusive movements (use red for excursive, blue for static).
  • Maintenance: Always ensure the maintenance of the holding contact.

Patient Expectations

- Increased salivation initially - Possible subconscious removal of the appliance during the first week of adaptation - Should not cause discomfort or jaw soreness (provided vertical dimension is not excessive)

  • ==Detailed Verification Steps:==
    1. ==Verify Seating: Ensure complete, stable seating (no rocking) and adequate retention (removable but secure)==
    2. ==Eliminate Slide: Check that patient bites directly into centric occlusion without sliding; identify and remove interfering contacts first==
    3. ==Establish Uniform Centric: Create small, distinct dots on all opposing teeth using articulating paper; ensure even contact distribution==
    4. ==Adjust Excursions: Maintain centric holding contacts while eliminating excursive interferences; during lateral and protrusive movements, only desired guiding contacts (canines or anterior ramp) should remain==

Troubleshooting Common Problems

  • Instability: Caused by distorted impressions or air bubbles; solution is to remake or perform selective grinding.
  • Too Retentive: Caused by excessive acrylic overlap or undercuts; solution is to shorten overlap or ease internal fitting areas.
  • Looseness: Caused by lack of undercuts or short crowns; solution is to remake or add clasps.

Recall and Monitoring

  • Schedule: Initial check at 1-2 weeks; follow-up at 3 months.
  • Stability: Once the patient is stable (no pain on loading, comfortable musculature), definitive treatments like restorative work, orthodontics, or surgery can begin.
  • ==Clinical Stages Overview:==
    • ==Initial Analysis (Item 963): Comprehensive occlusal examination including muscle palpation, TMJ assessment, and wear pattern evaluation==
    • ==Insertion Protocol: Never send appliance to patient without insertion appointment for fitting and adjustment==
    • ==Recall Schedule: 2-week assessment (comfort/usage), 3-month secondary assessment, and 6-month reviews monitoring for super-eruption of unerupted teeth==
  • Young Patients: Monitor closely for erupting third molars.

Case Study: Occlusal Change

  • A patient provided with a lower stabilisation appliance for nocturnal grinding developed a slight anterior open bite after 4 months.
  • Comparison with initial diagnostic casts confirmed the change, despite the patient’s belief that their bite had always been that way.

Idiopathic Condylar Resorption

Diagnosis and Imaging

  • MRI Findings: Evidence of erosion and remodelling of articular surfaces, specifically a sclerotic and irregular condylar stump.

Pathophysiology

Idiopathic condylar resorption involves progressive shortening of the mandibular condyles, resulting in posterior rotation of the mandible and anterior open bite. It may be associated with juvenile idiopathic arthritis, psoriatic arthritis, or rheumatoid arthritis affecting the TMJ. Patients may be asymptomatic despite significant structural changes.

  • Differential Diagnosis: Sequelae of idiopathic condylar resorption or juvenile idiopathic arthritis.

Case Study: 20-Year-Old with Anterior Open Bite

==Presentation: Lower stabilization appliance fabricated for nocturnal bruxism; uniform occlusion confirmed at 2 and 6 weeks Complication: After 4 months, anterior open bite developed despitets proper splint wear and initial stability Investigation: Comparison with initial casts and clinical records confirmed the open bite was new; father incorrectly believed it was pre-existing Diagnosis: Idiopathic condylar resorption (or juvenile idiopathic arthritis) causing condylar shortening and mandibular rotation Significance: Highlights the importance of maintaining initial records and casts to detect pathological changes masquerading as occlusal shifts==

Splint Care7

Maintenance Instructions

  • Storage: Do not store in direct sunlight; keep away from pets.
    • Direct sunlight causes warping; store in closed cases as dogs commonly destroy appliances
  • Cleaning:
    • Use liquid soap and lukewarm water.
    • NEVER use toothpaste or hot water.
    • Toothpaste contains abrasive particles that scratch the surface
  • Disinfection: Weekly 15-minute soak in diluted white vinegar or denture cleaning tablets.
    • This soak dissolves calcium deposits

Clinical Conclusions

  • Patients must not adjust their own appliances.
  • Cracked splints require professional repair to maintain occlusal accuracy and avoid liability
  • Regular monitoring is mandatory to detect occlusal changes.
  • Patients should bring splints to all recall appointments to verify fit and detect wear patterns
  • Pre-treatment casts and photographs are essential for comparison.
  • Splints must be selected appropriately for the specific clinical situation and patient compliance.

Audio Appendix

Additional Audio Content

The following sections from the lecture audio did not correspond to any heading in the main document.

Conclusions

Stabilization appliances represent the most predictable, “fall-proof” option for clinicians beginning splint therapy. Success requires appropriate patient selection, meticulous fabrication and adjustment, regular monitoring for occlusal changes, and patient compliance. Clinicians must maintain initial casts and photographs to detect pathological changes such as idiopathic condylar resorption, and always prioritize long-term stability over short-term convenience when selecting splint designs.

Introduction and Clinical Rationale

Occlusal splints represent a prominent prosthodontic intervention, but their application requires careful patient selection and diagnostic justification. Not every patient requires a splint; prescription must be based on specific diagnoses and an understanding of potential complications associated with long-term use. Prior to fabrication, clinicians must establish a definitive diagnosis and select an appropriate design, as certain splint types carry significant risks if used indefinitely.

Indications for Use

Splints serve multiple therapeutic and protective functions:

  • Bruxism Management: Reduces tooth wear and may decrease associated headaches
  • Muscle Relaxation: Alters vertical dimension to deprogram masticatory muscles, reducing fatigue and force generation
  • Dental Protection: Safeguards dentition following extensive restorations (e.g., veneers, full mouth rehabilitation) in patients with parafunctional habits
  • Periodontal Support: Addresses fremitus (visible tooth movement on occlusion) commonly seen in periodontally compromised patients or those with posterior support loss
  • TMJ Stabilization: Manages clicking joints and facilitates diagnosis of joint stability
  • Malocclusion Management: Reduces discomfort from certain occlusal interferences

“he modified PSQ was adapted from the original PSQ developed by the University of Michigan with the exclusion of 1 of the 22-questions: ‘. . .interrupts or intrudes on others (e.g. butts into conversations or games)’.” (Wellham et al., 2023, p. 28) (pdf)

Footnotes

  1. Original PDF page 1: L3 Occlusal Splints 2026, p.1 ↩

  2. Original PDF page 2: L3 Occlusal Splints 2026, p.2 ↩

  3. Original PDF page 3: L3 Occlusal Splints 2026, p.3 ↩

  4. Original PDF page 4: L3 Occlusal Splints 2026, p.4 ↩

  5. Original PDF page 5: L3 Occlusal Splints 2026, p.5 ↩

  6. Original PDF page 6: L3 Occlusal Splints 2026, p.6 ↩

  7. Original PDF page 7: L3 Occlusal Splints 2026, p.7 ↩

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