Occlusal Deprogrammers & Anterior Stops — Descriptions

1. Lucia Jig

• Disengages all posterior teeth
• Allows the elevator muscles to seat the condyles in CR
• Facilitates accurate CR bite records (used with a wax or polyvinyl siloxane record)

2. Unwind MD

• Fits over the maxillary anterior teeth
• Creates a single anterior contact point
• Is ready-to-use without chairside fabrication
• Allows the clinician to take a CR record after a short deprogramming period (typically 5–20 minutes)

3. NTI-tss (Nociceptive Trigeminal Inhibition Tension Suppression System)

• Creates contact exclusively on anterior teeth, suppressing posterior muscle contraction via the nociceptive trigeminal inhibition reflex
• Reduces masseter and temporalis muscle activity by approximately 66–76% compared to full-coverage splints
• Is FDA-cleared for migraine prevention (as of 2001) and used for bruxism/TMD management
• Controversy: Concerns exist about potential posterior open bite development with long-term use due to supraeruption of posterior teeth

4. Denar Deprogrammer

• Deprograms the neuromuscular system from maximum intercuspation (MIP)
• Allows condyles to seat in CR for accurate facebow and bite record transfers
• Is used in conjunction with Denar articulators for complex occlusal rehabilitation and full-mouth reconstructions

5. Leaf Gauge

• Strips are added incrementally until the posterior teeth separate
• The patient's mandible is guided into CR under light muscle force
• A CR record is then taken with the leaf gauge in place
• Provides a quantifiable, reproducible anterior stop thickness
• Commonly associated with Peter Neff's technique and used widely in restorative dentistry and orthodontics

6. Kois Deprogrammer

• Worn for 1–3 weeks (or longer) to allow true neuromuscular deprogramming
• Unlike a single-appointment Lucia Jig, it is intended for extended wear to fully eliminate muscle memory from MIP
• Once muscles are fully relaxed and condyles are seated, a definitive CR record is taken
• Also used diagnostically to determine if a patient's symptoms resolve with anterior disclusion before committing to full occlusal treatment

Comparison Summary

Semiadjustable Articulator — Detailed Description & Use in Full Mouth Rehabilitation (FMR)

PART 1: DEFINITION

• A semiadjustable articulator is a mechanical device that simulates mandibular movements by replicating certain, but not all, determinants of occlusion.
• It accepts a facebow transfer to orient the maxillary cast to the simulated temporomandibular joint (TMJ) axis.
• It can be adjusted for condylar inclination and Bennett angle based on recorded jaw movement data, but uses average values or approximations for other parameters.
• It falls between a simple (non-adjustable) articulator and a fully adjustable articulator in terms of accuracy and clinical versatility.

PART 2: CLASSIFICATION OF ARTICULATORS (Context)

PART 3: TYPES OF SEMIADJUSTABLE ARTICULATORS

A. Arcon Type

• The condylar ball is part of the lower (mandibular) member.
• The condylar housing (fossa) is part of the upper (maxillary) member.
• Mimics the anatomical arrangement of the TMJ.
• Examples: Whip-Mix, Hanau Wide-Vue, Denar Mark II, Stratos 200
• Advantages: More anatomically accurate; easier to set condylar inclination; condylar path does not change when opening angle changes.

B. Non-Arcon (Condilar) Type

• The condylar ball is part of the upper member.
• The condylar housing is part of the lower member.
• Examples: Hanau H Series (Hanau 130-21), Dentatus
• Advantages: Stable; less prone to drifting during use.
• Disadvantage: Condylar inclination reading changes with instrument opening angle — less anatomically representative.

PART 4: COMPONENTS OF A SEMIADJUSTABLE ARTICULATOR

1. Upper member (maxillary arm) — holds the maxillary cast
2. Lower member (mandibular arm) — holds the mandibular cast
3. Condylar elements — simulate TMJ condylar movement
4. Condylar inclination adjustment — set based on protrusive record (Hanau's formula or actual recording)
5. Bennett angle adjustment — set for lateral movement component
6. Incisal guide table — flat or customizable; replicates anterior guidance
7. Incisal pin — maintains vertical dimension of occlusion (VDO)
8. Mounting plates — attach casts to the articulator
9. Facebow fork receptor — accepts the facebow for maxillary cast orientation
10. Intercondylar distance setting — small, medium, or large (approximated)

PART 5: ADJUSTABLE PARAMETERS

PART 6: RECORDS NEEDED TO SET A SEMIADJUSTABLE ARTICULATOR

1. Facebow record — transfers the spatial relationship of the maxilla to the transverse hinge axis
2. Centric relation (CR) record — mounts the mandibular cast in CR
3. Protrusive interocclusal record — used to set the condylar inclination
4. Lateral interocclusal records (right and left) — used to set the Bennett angle
5. Vertical dimension of occlusion (VDO) record — maintained via the incisal pin

PART 7: USE OF SEMIADJUSTABLE ARTICULATOR IN FULL MOUTH REHABILITATION (FMR)

Step 1 — Diagnosis and Treatment Planning

• Diagnostic casts are mounted on the semiadjustable articulator using the facebow transfer and CR record.
• Allows the clinician to evaluate the existing occlusion in three dimensions outside the mouth.
• Identifies: posterior interferences, premature contacts, loss of VDO, curve of Spee discrepancies.
• A diagnostic wax-up is performed on the mounted casts to plan the final occlusal scheme.

Step 2 — Facebow Transfer

• The facebow (earbow or kinematic type) records the relationship of the maxillary arch to the transverse hinge axis and the reference plane (Frankfurt horizontal or Camper's plane).
• This relationship is transferred to the articulator so that the maxillary cast opens and closes around an axis that approximates the patient's actual condylar axis.
• Without a facebow, mounting is done using an average value — introducing error in arc of closure.

Step 3 — Centric Relation Record and Mounting

• The mandibular cast is mounted in CR (not MIP) using a bite registration material (polyvinyl siloxane, Lucia Jig, or Kois deprogrammer-assisted record).
• CR is chosen because it is a reproducible, stable, anatomically based reference position.
• In FMR, all restorations are built to coincide CR with maximum intercuspation (CR = MIP) to eliminate slide and deflective contacts.

Step 4 — Setting Condylar Inclination

• A protrusive interocclusal record is taken at 6–8 mm of protrusion.
• The record is placed between the casts; the condylar inclination is adjusted until the condylar balls seat within the protrusive record.
• Alternatively, Hanau's formula can be used: Condylar guidance = (Protrusive guidance ÷ 8) + 12

Step 5 — Setting the Bennett Angle

• Right and left lateral records are taken.
• The working side and non-working side movements are replicated.
• Bennett angle is adjusted (typically 15° as an average, or set by measurement).

Step 6 — Establishing Vertical Dimension of Occlusion (VDO)

• The incisal pin is set at the desired VDO (opened or maintained from the original).
• In cases with worn dentition, VDO may need to be increased — planned and verified on the articulator before any tooth preparation.
• All provisional and final restorations are fabricated at this VDO.

Step 7 — Diagnostic Wax-Up and Occlusal Scheme Design

• With casts mounted and all parameters set, a full wax-up is completed.
• Occlusal goals in FMR established on the articulator:
  • Mutually protected occlusion (posterior teeth protect anteriors in CR; anteriors disocclude posteriors in excursions)
  • Proper anterior guidance (incisal guidance angle set on the incisal guide table)
  • Canine guidance or group function in lateral excursions
  • Even, simultaneous posterior contacts in CR/MIP

Step 8 — Provisional Restoration Fabrication

• Provisionals are fabricated using the wax-up and delivered to the patient.
• The articulator allows the technician to:
  • Pre-contour provisional crowns
  • Verify contacts and excursive movements before intraoral delivery
  • Maintain VDO throughout the provisional phase (typically 3–6 months)

Step 9 — Final Impression and Definitive Mounting

• After the patient adapts to provisionals and no TMD symptoms arise, final impressions are taken.
• New facebow and CR record are taken with provisionals in place.
• Definitive casts are mounted on the articulator; final restorations (ceramic, PFM, zirconia) are fabricated to match the proven provisional occlusion.

Step 10 — Verification and Delivery

• Final restorations are checked on the articulator for:
  • Proper contacts in CR/MIP
  • Smooth excursive movements without interferences
  • Correct VDO maintained
• After intraoral delivery, occlusion is refined with articulating paper; any adjustments are minor due to accurate pre-fabrication on the articulator.

PART 8: ADVANTAGES OF SEMIADJUSTABLE ARTICULATOR IN FMR

• Allows three-dimensional analysis of occlusion before any irreversible treatment.
• More accurate than simple or average-value articulators — replicates patient-specific condylar guidance.
• Less expensive and less technique-sensitive than fully adjustable articulators; suitable for most FMR cases.
• Enables precise communication with the dental laboratory — technician can replicate patient movements during fabrication.
• Facilitates verification of VDO changes before committing to definitive restorations.
• Allows sequential treatment planning — anterior teeth first (Dawson approach) or posterior-first approaches.
• Supports custom incisal guide table fabrication for cases with complex anterior guidance.

PART 9: LIMITATIONS

• Does not replicate immediate side shift (Bennett movement) accurately in most models.
• Intercondylar distance is approximated (small/medium/large), not measured precisely.
• Hinge axis location is approximated unless a kinematic facebow is used.
• Not suitable for highly complex cases requiring precise envelope of motion replication — a fully adjustable articulator (e.g., Panadent, SAM III) is preferred in those situations.
• Operator error in taking records (especially protrusive and lateral records) directly compromises the accuracy of condylar settings.

PART 10: COMMONLY USED SEMIADJUSTABLE ARTICULATORS IN FMR

Summary