OCCLUSAL EVALUATION AND THERAPY / CORONOPLASTY

I. DEFINITIONS AND TERMINOLOGICAL FRAMEWORK

• A physiologic occlusion is defined as one that "maintains a state of homeostasis within the periodontium without producing damage, injury, or dysfunction." Maintenance of a physiologic occlusion requires "favorable structure-function relationships and optimal tissue adaptation throughout the masticatory system."
• A nonphysiologic (traumatic) occlusion is "associated with dysfunction or disease caused by tissue injury, and treatment may be indicated." The text is explicit: "the criterion that determines if an occlusion is traumatic is whether it produces periodontal injury, not how the teeth occlude."
• A therapeutic occlusion is "the result of specific interventions designed to treat dysfunction or disease."

• Damaged teeth and restorations
• Abnormal mobility
• Fremitus
• A widened periodontal ligament
• Pain
• A subjective sense of bite discomfort

II. CLINICAL EVALUATION PROCEDURES

A. Temporomandibular Disorder (TMD) Screening Evaluation

1. Maximal interincisal opening (range, 40-50 mm)
2. Opening or closing pathway
3. Range of lateral and protrusive excursions (7-9 mm)
4. Auscultation for temporomandibular joint sounds
5. Palpation for temporomandibular joint tenderness or tissue displacement
6. Palpation for muscle tenderness
7. Load testing of the patient's temporomandibular joints

B. Intraoral Occlusal Evaluation

1. Identification of occlusal contacts in maximum intercuspation
2. Guidance in excursive movements
3. Initial contact in the centric-relation closure arc
4. Tooth mobility
5. Attrition

C. Testing for Tooth Mobility and Fremitus

• Classically, a dental instrument is used to exert pressure in the facial or lingual direction, and the dentist places his or her finger on the opposite side of the tooth to feel and see movement if it occurs.
• Fremitus is defined as "vibration, or micromovement of a tooth that can be felt when patients tap their teeth together." To measure fremitus, "a dampened index finger is placed along the buccal and labial surfaces of the maxillary teeth and the patient is asked to tap the teeth together in the maximum intercuspal position and then grind systematically in the lateral, protrusive movements and positions."

• Class I Fremitus: Mild vibration or movements detected
• Class II Fremitus: Easily palpable vibration, but no visible movements
• Class III Fremitus: Movements visible with the naked eye

D. Centric Relation Assessment

III. REQUIREMENTS FOR OCCLUSAL STABILITY

1. Forces on an individual tooth that "do not exceed the support and resistance of the tooth's periodontium" and are "vertically oriented to the long axis of each tooth as much as possible"
2. Even and simultaneous contact of all posterior teeth in the centric relation closure or in maximal intercuspation, with minimal difference between the two
3. "Little or no contact of the anterior teeth in centric occlusion, although such contact is readily available to provide guidance in excursion and to produce posterior disclusion"
4. "Harmonious excursive movement of the mandible within the patient's envelope of function and with complete absence of occlusal interference"
5. No trauma from occlusion
6. Favorable subjective response to occlusal form and function

IV. OCCLUSAL THERAPY

A. Definition and Purpose

B. Procedures Contributing to Occlusal Therapy

• Interocclusal appliance therapy
• Occlusal adjustment (coronoplasty)
• Both provisional and final restorative procedures
• Orthodontic tooth movement
• Orthognathic surgery

C. Types of Occlusal Therapy

1. Reversible - Temporarily alters occlusal condition, e.g., an Occlusal appliance
2. Irreversible - Permanently alters occlusal condition, e.g., coronoplasty

D. General Guidelines for Occlusal Therapy

1. A sound biologic rationale should exist for the intervention - "Has the patient's susceptibility to periodontitis been confirmed?"
2. Occlusal interventions should be considered an adjunct to periodontal therapy - "Is there clinical evidence that the periodontal disease experience of certain teeth has been negatively influenced by occlusal trauma?"
3. Significant, irreversible occlusal changes should be considered in the context of the restorative care planned for the patient.
4. Thorough, informed consent must be provided to the patient; "it is critical that the patient understands the goals, limitations, and consequences of the occlusal intervention."

E. Sequence and Timing of Occlusal Therapy

F. Evidence Base for Occlusal Therapy in Periodontitis

• "In patients experiencing moderate to severe periodontitis, Nunn and Harrell were able to identify significantly increased loss of attachment for specific teeth with occlusal discrepancies when compared to teeth without occlusal discrepancies."
• "Evidence supports the expectation that occlusal therapy will positively influence the outcome of both nonsurgical and surgical therapy for patients affected by moderate to severe periodontitis."
• "No intervention with traumatic occlusion allows periodontitis to progress more readily."
• Burgett et al. (1992) in a randomized clinical trial with 2-year follow-up concluded that "occlusal adjustment adjunctive to either scaling and root planing or modified Widman flap therapy resulted in a more favorable attachment level but no differences in reduction of mobility or pocket depth."

G. Management Based on Type of Occlusal Trauma

• Primary occlusal trauma with gingivitis or periodontitis: "The treatment is simple and conservative. First, periodontal therapy is done, which includes plaque control, scaling and root planing. If there is progressive mobility then occlusal therapy in the form of selective grinding and the use of night guard may be justified."
• Secondary occlusal trauma and advanced periodontitis: "The treatment is often complicated. It often requires advanced periodontal therapy, including root resection, antimicrobial therapy and regenerative procedures along with adjunctive orthodontics, occlusal adjustment by selective grinding and splinting for periodontal stabilization is advocated."

H. Interocclusal Appliance Therapy

• Fabricated on accurately mounted diagnostic casts
• Providing bilateral, simultaneous contact of the cuspids and all posterior teeth in centric relation
• Providing "smooth, relatively flat anterior guidance with immediate and sustained disclusion of all posterior teeth in both lateral excursions and in protrusion"
• Subject to "multiple adjustments in anticipation of reduced mobility of teeth and functional changes in musculature and in joint relationships"
• May or may not be followed by occlusal adjustment, depending on individual patient needs

V. CORONOPLASTY (OCCLUSAL ADJUSTMENT)

A. Definition

B. Irreversibility and Pre-procedural Considerations

• "Because occlusal adjustment is an irreversible intervention, the prudent clinician should carefully weigh the scientific and clinical evidence in support of such therapy."
• "Occlusal adjustment had once been the most commonly employed procedure for treating occlusal trauma, TMJ problems and other associated problems. Since occlusal adjustment is an invasive, irreversible intervention, it should rarely be considered. It should never be undertaken as a preventive measure."
• "In the case of TMD, the evidence leads to the conclusion that occlusal adjustment should rarely be considered as a primary component of TMD treatment and never as a preventive measure."
• "There is no evidence that occlusal adjustment is useful in the management of bruxism."

C. Timing: When to Perform Coronoplasty

• "It is generally recommended that occlusal adjustment be deferred until inflammation is controlled, time is allowed for tissue healing, and reevaluation determines that any residual mobility is the result of adverse tooth loading rather than decreased support."
• "Coronoplasty is generally performed after gingival inflammation and periodontal pockets have been eliminated."
• Exceptions: "the need to address pain or dysfunction clearly determined to be the result of occlusal trauma."

D. Pre-adjustment Protocol

• "Trial adjustment on accurately mounted diagnostic casts is recommended to determine the extent of alteration required to meet the goals of occlusal stability and elimination of interferences."
• "When any teeth subject to the occlusal equilibration are mobile, multiple appointments are necessary to address changes resulting from the progressive tightening of individual teeth and the recognition of interferences to harmonious occlusal function that the tighter teeth create."
• "If equilibration follows accommodation to an occlusal appliance (a strongly recommended sequence), having the patient wear the appliance before the appointment for equilibration (e.g., overnight and until seated in the operatory) will encourage the teeth to be as tight as possible."
• "A major consideration before occlusal adjustment is the restorative needs of the patient."

E. Goals of Occlusal Adjustment (Coronoplasty)

F. Clinical Evidence for Coronoplasty Adjunctive to Periodontal Therapy

• Burgett et al. (1992): In a randomized trial, 50 patients with periodontitis received root debridement ± flap surgery; 22 patients additionally received comprehensive occlusal adjustment. "Re-examinations performed 2 years later disclosed that probing attachment gain was on average about 0.5 mm greater in patients who received the combined treatment, that is debridement and occlusal adjustment, than in patients who did not receive occlusal adjustment."
• Nunn and Harrel (2001) and Harrel and Nunn (2001): Teeth with occlusal discrepancies had significantly deeper pocket depth values; teeth receiving occlusal adjustment responded better (reduction in pocket depth and attachment level gain).

VI. RELATIONSHIP BETWEEN TRAUMA FROM OCCLUSION AND CORONOPLASTY - BIOLOGICAL BASIS

VII. SUMMARY

1. Carranza's Clinical Periodontology, 10th Edition - Chapter 56 (Occlusal Evaluation and Therapy)
2. Newman & Carranza's Clinical Periodontology and Implantology, 14th Edition - Chapters 5, 35, 45, 47
3. Clinical Periodontology and Implant Dentistry, 6th Edition (Lindhe) - Chapter: Trauma from Occlusion
4. Essentials of Clinical Periodontology and Periodontics (S. Reddy) - Chapters 49 and 55

Why the "10 Steps of Coronoplasty" Were Not Included

What the Uploaded References Actually State About the Procedure

"Trial adjustment on accurately mounted diagnostic casts is recommended to determine the extent of alteration required to meet the goals of occlusal stability and elimination of interferences... Clark et al., McNeill, and Dawson provide detailed practical protocols for occlusal adjustment procedures."

"The author recommends a reference book for a detailed description on the procedure of occlusal adjustment."

Conclusion