Pre-prosthetic Treatment: TMDs Management

Pre-prosthetic Treatments: A Cheatsheet for Prosthodontics III

Pre-prosthetic treatments are essential procedures designed to facilitate the fabricationof a prosthesis and improve the long-term prognosis of prosthodontic care.

1. Concept and Aim

• Definition: Procedures to aid prosthesis fabrication and enhance prognoses.
• Purpose: Eliminate pathological conditions, uncertainties, and risks to ensuresuccessful prosthodontic outcomes.
• Keystone to Success: Good clinical history & examination, good diagnosis, and a well-thought-out treatment plan.
• Aims to restore: Aesthetic and functional needs.
• Includes: Urgent treatments, tooth extractions, periodontal, orthodontic, endodontic, restorative treatments, occlusal equilibration, and TMD treatments.

2. Medical History and Examination

Medical History

• Chief Complaint: "What brings you here?", "Since when?", "What do you think is the reason?".
• Personal Data: Basic patient information.
• Medical Condition: Identifygeneral diseases and pathologies that may influence or modify treatment.
• Examples of diseases affecting treatment:
  • Epilepsy: Consider metal occlusal surfaces and shorter appointments.
  • Allergies: Nickel, acrylic resins, alginatemust be identified.
  • Xerostomia (dry mouth): Higher caries incidence.
  • Diabetes/HIV: Higher incidence of periodontal disease.
  • Hydantoin treatment: May cause gingival hyperplasia.
  • Sjögren syndrome: Causes xerostomia.

Extraoral Examination

• Look for: Muscular hypertrophy, scars, old traumatisms, paralysis, and vertical dimension (VD) changes.
• Facial Examination: Assessfistulas, alopecia, facial profile, lip support, smile line, and lip seal.
• Cranio-cervical Palpation: Check for adenopathies, and issues with thyroid or salivary glands.

Intraoral Examination

• DentalAssessment: Count teeth, assess horizontal/vertical migrations, re-evaluate existing treatments, evaluate pulp vitality, and perform periodontal assessment.
• Crucial Note: If pulp invasion is anticipated, schedule endodontic treatment before dental preparation.
• Dental Pathology: Look for wear facets, abrasion, erosion (may indicate parafunctional habits).
• Soft Tissue Assessment: Identify lesions and exostosis (e.g., tori).
• Aesthetics: Evaluate tooth color, shape, andposition.
• Edentulous Space: Assess morphology, extension, date of last extraction, and relation to adjacent teeth.
• Periodontal Indicators: Probing depth, bleeding, calculus, tooth mobility, attached gingiva, and percussion.
• Occlusion Assessment:
  • Static Relationships: Evaluate MI stability, overbite, overjet, crossbite, cusp-to-cusp occlusion, occlusal plane uniformity, and midline.
  • Dynamic Relationships: Assess disocclusions, prematurities, and interferences.
  • Decision: Maintain correct occlusion; modify wrong occlusion before or during treatment.

Muscular Examination

• Purpose: Identify muscular pain, often related to parafunctional habits, stress, or occlusion.
• Palpation: Locate painful muscular points (e.g., TMJ, temporalis, masseter, pterygoids, sternocleidomastoid, digastric).
• Functional Examination:
  • Assess pain during maximal stretching, contraction, maximummouth opening, and resisted movements (protrusion, clenching, laterality).
  • Look for muscle hypertrophy, facial asymmetries, and hypertonicity.
• Functional Limitation of Muscular Movements:
  • Maximum Mouth Opening: Less than 40mm indicates pain/spasm of elevator muscles (soft "end-feel" where opening can be gently forced).
  • Protrusion/Lateralities: Usually not limited unless pterygoids are highly affected.
  • Opening-Closing Path:
    • Variable deviated path: Muscular problem.
    • Always the same path: Articular problem.

Joint Examination

• Prevalence: Articular pathology is less frequent thanmuscular pathology; often intracapsular.
• Articular Pain: Usually from surrounding tissues, not articular surfaces themselves.
• Articular Sounds:
  • Clicks: Single "explosive" noise, often indicating anterior functional displacement of the disc.
    • During opening: Early stage, nearer MI.
    • Reciprocal click (opening and closing): Disc dislocation with reduction (more advanced stage).
    • During mediotrusion: Medial disc dislocation.
  • Crepitus: Continuous "grating" noise, usually due to wear of articular surfaces (TMJ Osteoarthrosis), visible on Schüller's transcranial radiography.
• Movement Limitation:
  • Max Mouth Opening < 40mm with hard end-feel: Articular problem, likely anterior disc dislocation without reduction.
  • Mediotrusion < 8mm: Likely anterior disc dislocation without reduction.
  • Lateral deflection during protrusion: Deflection towards the affected side.
• Deflection during Opening-Closing:
  • > 2mm deflection: Pathological sign.
  • With reduction: Deflection returns to midline.
  • Without reduction: Deflection does not return to midline.

3. Urgent Treatments

• Definition: Pathologies requiring immediate treatment (pain or infection), but not life-threatening.
• Examples: Acute pulpitis, periodontal abscesses, tooth fractures, acute TMDs (trismus).

4. Tooth Extractions

• Indications: Too damaged to restore, high mobility/extrusion, or for better treatment planning.
• Anterior Extractions: Immediate provisional denture (fixed/removable) must beprepared beforehand.
• Third Molars:
  • Often lack attached gingiva, cause periodontal problems for 2nd molars, have fused/conical roots, and inadequate positions.
  • Extract adjacent to bridges unless in perfect condition ORrisk to inferior alveolar nerve.
  • If extracting a 3rd molar, consider extracting the opposing one to prevent extrusion and prematurities.
• Waiting Period Post-Extraction:
  • 6months to 1 year: For healing, tissue stabilization.
  • Less than 6 months: Risk of bone resorption, gingival migration, pontic-gingiva separation.
  • More than 1 year: Risk of tooth migrations.
  • Meanwhile: Use temporary RPD or immediate provisional bridge.

5. Periodontal Treatments

• Periodontal Assessment: Probing, bleeding, calculus, mobility, plaque index, attached gingiva, percussion.
• Treatment Phases:
  1. Initial Treatment: Hygiene instructions, motivation, prophylaxis, scaling and root planing (S&RP), correction of iatrogenic irritants.
  2. Surgical Treatment: If needed.
  3. Maintenance.
• Benefits of Initial Treatment: Better visibility (no plaque/calculus), easier tissue handling (no inflammation), less bleeding, less post-treatment inflammation, and patient motivation.
• Surgical Treatment: For esthetic reasons, periodontal issues, or to access subgingival decays.
• Waiting Period Post-Periodontal Treatment:
  • 2 months after S&RP: Reevaluation for surgical treatment, more S&RP, or prosthetic treatment. Allows stabilization of gingival tissues.
  • If surgery involves only gingiva: 1 to 3 months wait.
  • If surgery involves gingiva and bone: 6 months wait.
  • Wait until tissues are fully healed and stabilized.

6. Orthodontic Treatment

• Objectives: Improve periodontal health, enhance occlusion, prevent occlusal trauma, and ease prosthodontic procedures (e.g., correcting inclinations, extrusions).
• Options: Distalize teeth, extrude teeth for ferrule effect, align crowded teeth, achieve good anterior guidance.
• Disadvantages: May affect crown-to-root ratio, time-consuming.

7. Endodontic Therapy

• When Needed: Only when required and justified.
• Necrotic Tooth/Infection:
  • For necrotic teeth, fistulas, or abscesses, wait 6 months after treatment to ensure pathology remission before prosthodontic treatment.
• Vital Teeth:
  • Indicated when fiber post or cast post-and-core is needed for retention, or for extrusions/severe inclinations.
  • Wait 1 month after treatment.
• Apicectomy:
  • Evaluate crown-to-root ratio.
  • Wait 6 months for full healing.
  • Disadvantages: Low crown-to-root ratio, restrictive scar, increased tooth mobility.

8. Restorative Treatment

• Actions: Remove/restore caries, trim/polish overcontoured restorations, repeat sub-optimal restorations on abutment teeth.
• Rule of thumb: When in doubt, repeat the restoration.

9. Occlusal Equilibration

• Nature: Irreversible and non-conservative treatment.
• Process: Eliminates prematurities and interferences.
• Key Step: Perform occlusal analysis on articulated models in CR; eliminate contacts on casts first.
• Caution: If more than 4 contacts need elimination, it's not recommended due to difficulty in reproduction and potential for new contacts.
• When Indicated: Only for contacts clearly harmful (fremitus, extrusions interfering with denture, uneven occlusal plane, lack of occlusal stability).

10. Treatment of Temporomandibular Disorders (TMDs)

• Okesson's Principle: "The more complex a system, the more probability of breakdown."
• Etiological Considerations: Occlusal condition, trauma, emotional stress, deep pain input, parafunctional activities.
• Dental Signs: Dental wear, cervical erosion, tooth mobility, gingival recessions, dental migrations, alveolar bone exostosis.
• General Treatment Approach:
  • Education and home care.
  • Relaxation and stress control.
  • Physiotherapy, pharmacotherapy, psychological support.
  • Occlusal splints.
• Principles: Reversible and conservative whenever possible.
• Physiotherapy: Massages, therapeutic exercises, TENS (Transcutaneous Electrical Nerve Stimulation), infrared light.
• Pharmacotherapy: Muscle relaxants, sedatives, analgesics, anti-inflammatories, vasoactive drugs, infiltrations.
• External Agents: Heat (increases blood flow, relaxes muscles), cold (anesthetic effect, reduces spasms, inflammation).
• Psychological Support: For stress/anxiety (cause and consequence of TMDs).
• PatientEducation: Soft diet, voluntary disengagement of teeth, avoiding parafunctional habits and stressful activities.

Occlusal Splint

• Definition (GPT-9): "Any removable artificial occlusal surface used for diagnosis or therapy affecting the relationship of the mandible to the maxillae."
• Mechanism: Alters mandibular position and tooth contact pattern; resets neuromuscular patterns.
• Uses: Occlusal stabilization, TMD treatment, prevention of dentition wear.
• Key Feature: Reversible treatment.
• Therapeutic Objectives: Relax masticatory muscles, provide orthopedic stability to TMJs, lower parafunctional activity, protect periodontium, prevent tooth wear.
• Effectiveness: Very effective for muscular pain; poorly effective for joint sounds.
• Indications: Muscle relaxation, pain reduction, TMD treatment, occlusal stabilization, reducing tooth wear, provisional increase in VD.
• Characteristics:
  • Must cover all teeth (prevents extrusions).
  • Provide occlusal stability at CR.
  • Increase VD (1.5 - 2 mm).
  • Flat and polished occlusal plane (freedom of movement).
  • Only occlusal contact points at MI/CR.
  • Occlusal scheme: Mutually Protected Articulation.
• Procedure:
  • Craneomaxilar transfer and upper mounting.
  • Intermaxillary transfer and lower mounting (at final VD, in CR) to achieve optimum condyle-disc-fossa position.
  • Manufacturing: Heat-curing acrylic resin (good mechanical properties, allows adjustments).
  • Splint Type: Upper for night bruxism, lower for day bruxism; or arch providing more stability.
  • Design: Retention via survey line, avoid contact with periodontium, flat occlusal surface, mutually protected articulation, soft canine and anterior guidance.
  • Contacts: Even contacts on all teeth (prevents extrusions), minimum VD to prevent myotatic reflex.
• Time of Use: Varies by pathology (e.g., bruxist patients may use forever).
• Adjustments: Monthly appointments for adjustments to the splint as MI at CR is rarely achieved initially.
• Avoid soft splints (increase parafunction, stimulate chewing).