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7 Mucogingival Deformities and Conditions

Chapter 7: Mucogingival Deformities and Conditions

Overview of Mucogingival Deformities and Conditions

  • Definition: Any defect associated with a deviation from the normal anatomic/morphologic relationship between gingiva and alveolar mucosa.
  • Susceptibility: All age groups are susceptible to mucogingival deformities. It can affect any tooth or implant.
  • Presence: These conditions can occur in the presence or absence of periodontal disease.

Examples of Mucogingival Deformities and Conditions

  • Gingival/Soft Tissue Recession: The most common form of mucogingival deformity.
  • Lack of Keratinized Gingiva: Insufficient keratinized tissue can weaken gingival integrity.
  • Decreased Vestibular Depth: A reduction in the space between the gingiva and the buccal mucosa.
  • Aberrant Frenum/Muscle Position: Unusual positioning of frenums or muscles can impact oral function.
  • Gingival Excess: An overabundance of gingival tissue.
  • Abnormal Color: Discoloration of the gingiva or mucosal tissues.

Normal Mucogingival Condition

  • Absence of Diseased State: Health of the gingiva in the absence of any disease states.

Lack of Keratinized Tissue

  • Commonly observed in the absence of underlying disease.
  • Causes may include congenital or developmental reasons.

Aberrant Frenum and Decreased Vestibular Depth

  • These conditions commonly occur for reasons other than disease.

Periodontal Biotypes

  • Definition: Features of the periodontium influenced by genetic and environmental factors, including:
    • Gingival biotype
    • Bone morphology related to supporting structures
    • Tooth dimension of any given tooth

Thin-Scalloped Gingival Biotype

  • Characteristics:
    • Slender, triangular-shaped crown.
    • Thin, delicate, friable soft tissue with thin alveolar bone.
    • Narrow zone of keratinized tissue.
    • Accentuated scalloped gingival margin contour.
  • Implication: Greater tendency for the onset and progression of mucogingival deformity.

Thick-Scalloped Gingival Biotype

  • Characteristics:
    • Slender, triangular-shaped crown.
    • Thick, fibrotic gingiva.
    • Narrow-to-moderate zone of keratinized tissue.
    • Accentuated scalloped gingival margin contour.
  • Implication: Prone to the development of mucogingival deformities.

Thick-Flat Gingival Biotype

  • Characteristics:
    • Wide, square-shaped crown.
    • Thick, dense, and fibrotic tissue.
    • Wide band of keratinized tissue.
    • Flat gingival margin contour.
  • Implication: More resilient and less susceptible to inflammation and trauma than thin- and thick-scalloped biotypes.

Variation in Periodontal Biotype in Individuals

  • Dental professionals must recognize that periodontal biotypes can vary among different teeth within the same individual.

Assessing the Periodontal Biotype

  • Purpose: Certain biotypes confer risks for the development and progression of mucogingival deformities.
  • Importance of Assessment:
    • Allows for timely identification of susceptible individuals.
    • Facilitates the understanding of patient-specific risk factors that can be mitigated.
  • Strategies:
    • Collaborate with patients to implement simple lifestyle interventions to modify self-injurious habits.
    • Consider procedures that minimize the risk of inflammation and/or mechanical injury to susceptible tissues.
    • All dental team members play an essential role in prevention.

Recession of the Gingival Margin (Gingival Recession)

  • Definition: Movement of the gingival margin to a point apical (towards the root) to the cementoenamel junction.
  • Prevalence: It is the most common mucogingival deformity and can affect any age group.
  • Correlation: Corresponds to attachment loss that exposes root surfaces to the oral environment.

Clinical Implications of Recession

  • Aesthetics: It may be esthetically unacceptable for many patients.
  • Sensitivity: Can contribute to dentin hypersensitivity.
  • Oral Health: May be associated with carious or noncarious cervical lesions.

Risk Factors for Gingival Recession

  • Thin Tissue Biotype: Higher susceptibility to recession due to lesser tissue volume.
  • Narrow Band of Keratinized Tissue: Limited protection against mechanical trauma.
  • Reduced Thickness of Alveolar Bone: May occur during abnormal tooth positions in the dental arch.
  • Mechanical Trauma: Poor oral hygiene practices or aggressive tooth brushing can lead to recession.
  • Orthodontics: Some orthodontic treatments may contribute to tissue recession.

Miller Classification System for Recession of Gingival Margin

  • The most widely used classification system for nearly four decades, based on the level of the gingival margin with respect to the mucogingival junction (MGJ) and underlying alveolar bone.
  • Categories: The system consists of four recession categories:
    • Class I: Marginal tissue that does not extend to the MGJ.
    • Class II: Marginal tissue recession that extends to or beyond the MGJ with no periodontal loss in the interdental area.
    • Class III: Marginal tissue recession that extends to or beyond the MGJ with interdental bone or soft-tissue loss and/or malpositioning of teeth.
    • Class IV: Marginal tissue recession that extends beyond the MGJ with severe loss of interdental bone to the level corresponding to the most apical extent of marginal tissue recession.

Criticism of the Miller Classification System

  • Challenges:
    • Sometimes difficult to identify the exact location of the apical extent of the recession defect concerning the MGJ.
    • Does not clearly define the amount of interproximal soft/hard tissue loss needed to differentiate Class III from Class IV.
    • Reliability is unavailable as it has not been tested in a clinical setting.

Cairo Classification System for Recession of Gingival Margin

  • An alternative classification that uses an objective identifiable criterion (clinical attachment level) to classify the extent and severity of soft tissue recession.
  • Reliability: This classification system is noted for its greater reliability and can be used in clinical practice.
  • Types of Recession: It identifies three gingival recession types:
    • Recession Type 1 (RT1): Gingival recession with no loss of interproximal attachment.
    • Recession Type 2 (RT2): Gingival recession with loss of interproximal attachment, where the amount of interproximal attachment loss is less than or equal to buccal attachment loss.
    • Recession Type 3 (RT3): Gingival recession with loss of interproximal attachment, where the amount of interproximal attachment loss is greater than buccal attachment loss.

Treatment Considerations for Gingival Recession Defects

  • Initial Steps:
    • Clinicians must carefully assess the severity and extent of symptoms, tissue biotype, and other individualized patient-specific factors.
  • Determining Action:
    • Assess whether monitoring with no treatment is sufficient or if restorative/surgical periodontal intervention is necessary.

Surgical Interventions

  • Considerations:
    • Thin gingival biotype is typically less stable over time, prompting some clinicians to intervene surgically.
    • Possible interventions include soft-tissue augmentation procedures aimed at increasing gingival thickness and the zone of keratinized tissue.
  • Indications for Surgical Intervention:
    • If gingival recession is associated with esthetic impairment, dentin hypersensitivity, increased root caries activity, and/or severe plaque-induced gingival inflammation.

Non-Intervention Scenarios

  • Surgical intervention may not be required if:
    • Progression of gingival recession is arrested early on.
    • The gingiva on the affected tooth appears stable and clinically healthy.