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Periodontology

Anatomy and Histology of the Periodontium

Gingiva (normal clinical appearance): no muscles, no glands; keratinized

  • Color: coral pink but does vary with individuals and races due to cutaneous pigmentation
  • Papillary contour: pyramidal shape with one F and one L papilla and the col filling interproximal space to the contact area (col the starting place gingivitis)
  • Marginal contour: knife-edged and scalloped
  • Texture: stippled (orange-peel texture); blow air to dry out and see where stippling ends to see end of gingiva
  • Consistency: firm and resilient (push against it and won’t move); bound to underlying bone
  • Sulcus depth: 0-3mm
  • Exudate: no exudates (blood, pus, water)

  Anatomic and histological structures

Gingival unit: includes periodontium above alveolar crest of bone

a. Alveolar mucosa: histology- non-keratinized, stratified, squamous epithelium, submucosa with glands, loose connective tissue with collagen and elastin, muscles.  No epithelial ridges, no stratum granulosum (flattened cells below keratin layer)

b. Mucogingival junction: clinical demarcation between alveolar mucosa and attached gingiva

c. Attached gingiva: histology- keratinized, stratified, squamous epithelium with epithelial ridges (basal cell layer, prickle cell layer, granular cell layer (stratum granulosum), keratin layer); no submucosa

  • Dense connective tissue: predominantly collagen, bound to periosteum of bone by Sharpey fibers
  • Reticular fibers between collagen fibers and are continuous with reticulin in blood vessels

d. Free gingival groove: demarcation between attached and free gingiva; denotes base of gingival sulcus in normal gingiva; not always seen

e. Free gingival margin: area from free gingival groove to epithelial attachment (up and over ® inside)

  • Oral surface: stratified, squamous epithelium with epithelial ridges
  • Tooth side surface (sulcular epithelium): non-keratinized, stratified, squamous epithelium with no epithelial ridges (basal cell and prickle cell layers)

f. Gingival sulcus: space bounded by tooth surface, sulcular epithelium, and junctional epithelium; 0-3mm depth; space between epithelium and tooth

g. Dento-gingival junction: combination of epithelial and fibrous attachment

  • Junctional epithelium (epithelial attachment): attachment of epithelial cells by hemi-desmosomes and sticky substances (basal lamina- 800-1200 A, DAS-acid mucopolysaccharides, hyaluronic acid, chondroitin sulfate A, C, and B), to enamel, enamel and cementum, or cementum depending on stage of passive eruption.  Length ranges from 0.25-1.35mm.
  • Fibrous attachment: attachment of collagen fibers (Sharpey’s fibers) into cementum just beneath epithelial attachment; ~ 1mm thick

h. Nerve fibers: myelinated and non-myelinated (for pain) in connective tissue.  Both free and specialized endings for pain, touch pressure, and temperature -> proprioception.  If dentures, rely on TMJ.

i.Mesh of terminal argyophilic fibers (stain silver), some extending into epithelium

ii  Meissner-type corpuscles: pressure sensitive sensory nerve encased in CT

iii.Krause-type corpuscles: temperature receptors

iv. Encapsulated spindles

i. Gingival fibers:

i.  Gingivodental group:

  • Group I (A): from cementum to free gingival margin
  • Group II (B): from cementum to attached gingiva
  • Group III (C): from cementum over alveolar crest to periosteum on buccal and lingual plates

ii.  Circular (ligamentum circularis): encircles tooth in free gingiva

iii. Transeptal fibers: connects cementum of adjacent teeth, runs over interdental septum of alveolar bone.  Separates gingival unit from attachment apparatus.

Transeptal and Group III fibers the major defense against stuff getting into bone and ligament.

 

2.  Attachment apparatus: periodontium below alveolar crest of bone

Periodontal ligament: Sharpey’s fibers (collagen) connecting cementum to bone (bundle bone).  Few elastic and oxytalan fibers associated with blood vessels and embedded in cementum in cervical third of tooth.  Components divided as follows:

i. Alveolar crest fibers: from cementum just below CEJ apical to alveolar crest of bone

ii.Horizontal fibers: just apical to alveolar crest group, run at right angles to long axis of tooth from cementum horizontally to alveolar bone proper

iii.Oblique fibers: most numerous, from cementum run coronally to alveolar bone proper

iv. Apical fibers: radiate from cementum around apex of root apically to alveolar bone proper, form socket base

v. Interradicular fibers: found only between roots of multi-rooted teeth from cementum to alveolar bone proper

vi. Intermediate plexus: fibers which splice Sharpey’s fibers from bone and cementum

vii. Epithelial Rests of Malassez: cluster and individual epithelial cells close to cementum which are remnants of Hertwig’s epithelial root sheath; potential source of periodontal cysts.

viii. Nerve fibers: myelinated and non-myelinated; abundant supply of sensory free nerve endings capable of transmitting tactile pressure and pain sensation by trigeminal pathway and elongated spindle-like nerve fiber for proprioceptive impulses

Cementum: 45-50% inorganic; 50-55% organic (enamel is 97% inorganic; dentin 70% inorganic)

i.  Acellular cementum: no cementocytes; covers dentin (older) in coronal ½ to 2/3 of root, 16-60 mm thick

ii. Cellular cementum: cementocytes; covers dentin in apical ½ to 1/3 of root; also may cover acellular cementum areas in repair areas, 15-200 mm thick

iii. Precementum (cementoid): meshwork of irregularly arranged collagen in surface of cementum where formation starts

iv. Cemento-enamel junction (CEJ): 60-65% of time cementum overlaps enamel; 30% meet end-to-end; 5-10% space between

v. Cementum slower healing than bone or PDL.  If expose dentinotubules ® root sensitivity.

Alveolar bone: 65% inorganic, 35% organic

i. Alveolar bone proper (cribriform plate): lamina dura on x-ray; bundle bone receive Sharpey fibers from PDL

ii. Supporting bone: cancellous, trabecular (vascularized) and F and L plates of compact bone

Blood supply to periodontium

i. Alveolar blood vessels (inferior and superior)

A) Interalveolar: actually runs through bone then exits, main supply to alveolar bone and PDL

B) Supraperiosteal: just outside bone, to gingiva and alveolar bone

C) Dental (pulpal): to pulp and periapical area

D) Terminal vessels (supracrestal): anastomose of A and B above beneath the sulcular epithelium

E) PDL gets blood from: most from branches of interalveolar blood vessels from alveolar bone marrow spaces, supraperiosteal vessels when interalveolar vessels not present, pulpal (apical) vessels, supracrestal gingival vessels

ii. Lymphatic drainage: accompany blood vessels to regional lymph nodes (esp. submaxillary group)

Modified Gingival Index (MGI)

The Modified Gingival Index (MGI) is a clinical tool used to assess the severity of gingival inflammation. It provides a standardized method for evaluating the health of the gingival tissues, which is essential for diagnosing periodontal conditions and monitoring treatment outcomes. Understanding the scoring criteria of the MGI is crucial for dental professionals in their assessments.

Scoring Criteria for the Modified Gingival Index (MGI)

The MGI uses a scale from 0 to 4 to classify the degree of gingival inflammation. Each score corresponds to specific clinical findings:

  1. Score 0: Absence of Inflammation

    • Description: No signs of inflammation are present in the gingival tissues.
    • Clinical Significance: Indicates healthy gingiva with no bleeding or other pathological changes.
  2. Score 1: Mild Inflammation

    • Description:
      • Slight change in color (e.g., slight redness).
      • Little change in texture of any portion of the marginal or papillary gingival unit, but not affecting the entire unit.
    • Clinical Significance: Suggests early signs of gingival inflammation, which may require monitoring and preventive measures.
  3. Score 2: Mild Inflammation (Widespread)

    • Description:
      • Similar criteria as Score 1, but involving the entire marginal or papillary gingival unit.
    • Clinical Significance: Indicates a more widespread mild inflammation that may necessitate intervention to prevent progression.
  4. Score 3: Moderate Inflammation

    • Description:
      • Glazing of the gingiva.
      • Redness, edema, and/or hypertrophy of the marginal or papillary gingival unit.
    • Clinical Significance: Reflects a moderate level of inflammation that may require active treatment to reduce inflammation and restore gingival health.
  5. Score 4: Severe Inflammation

    • Description:
      • Marked redness, edema, and/or hypertrophy of the marginal or papillary gingival unit.
      • Presence of spontaneous bleeding, congestion, or ulceration.
    • Clinical Significance: Indicates severe gingival disease that requires immediate intervention and may be associated with periodontal disease.

Clinical Application of the MGI

  1. Assessment of Gingival Health:

    • The MGI provides a systematic approach to evaluate gingival health, allowing for consistent documentation of inflammation levels.
  2. Monitoring Treatment Outcomes:

    • Regular use of the MGI can help track changes in gingival health over time, assessing the effectiveness of periodontal treatments and preventive measures.
  3. Patient Education:

    • The MGI can be used to educate patients about their gingival health status, helping them understand the importance of oral hygiene and regular dental visits.
  4. Research and Epidemiological Studies:

    • The MGI is often used in clinical research to evaluate the prevalence and severity of gingival disease in populations.

Periodontal Diseases Associated with Neutrophil Disorders

  1. Acute Necrotizing Ulcerative Gingivitis (ANUG)

    • Description: A severe form of gingivitis characterized by necrosis of the interdental papillae, pain, and foul odor.
    • Association: Neutrophil dysfunction can exacerbate the severity of ANUG, leading to rapid tissue destruction.
  2. Localized Juvenile Periodontitis

    • Description: A form of periodontitis that typically affects adolescents and is characterized by localized bone loss around the permanent teeth.
    • Association: Impaired neutrophil function contributes to the pathogenesis of this condition.
  3. Prepubertal Periodontitis

    • Description: A rare form of periodontitis that occurs in children before puberty, leading to rapid attachment loss and bone destruction.
    • Association: Neutrophil disorders can play a significant role in the development and progression of this disease.
  4. Rapidly Progressive Periodontitis

    • Description: A form of periodontitis characterized by rapid attachment loss and bone destruction, often occurring in young adults.
    • Association: Neutrophil dysfunction may contribute to the aggressive nature of this disease.
  5. Refractory Periodontitis

    • Description: A form of periodontitis that does not respond to conventional treatment and continues to progress despite therapy.
    • Association: Neutrophil disorders may be implicated in the persistent nature of this condition.

Periodontal Fibers

Periodontal fibers play a crucial role in maintaining the integrity of the periodontal ligament and supporting the teeth within the alveolar bone. Understanding the different groups of periodontal fibers is essential for comprehending their functions in periodontal health and disease.

1. Gingivodental Group

  • Location:
    • Present on the facial, lingual, and interproximal surfaces of the teeth.
  • Attachment:
    • These fibers are embedded in the cementum just beneath the epithelium at the base of the gingival sulcus.
  • Function:
    • They help support the gingiva and maintain the position of the gingival margin.

2. Circular Group

  • Location:
    • These fibers course through the connective tissue of the marginal and interdental gingiva.
  • Attachment:
    • They encircle the tooth in a ring-like fashion.
  • Function:
    • The circular fibers help maintain the contour of the gingiva and provide support to the marginal gingiva.

3. Transseptal Group

  • Location:
    • Located interproximally, these fibers extend between the cementum of adjacent teeth.
  • Attachment:
    • They lie in the area between the epithelium at the base of the gingival sulcus and the crest of the interdental bone.
  • Function:
    • The transseptal fibers are primarily responsible for the post-retention relapse of orthodontically positioned teeth.
    • They are sometimes classified as principal fibers of the periodontal ligament.
    • Collectively, they form the interdental ligament of the arch, providing stability to the interproximal areas.

4. Semicircular Fibers

  • Location:
    • These fibers attach to the proximal surface of a tooth immediately below the cementoenamel junction (CEJ).
  • Attachment:
    • They go around the facial or lingual marginal gingiva of the tooth and attach to the other proximal surface of the same tooth.
  • Function:
    • Semicircular fibers help maintain the position of the tooth and support the gingival tissue around it.

5. Transgingival Fibers

  • Location:
    • These fibers attach to the proximal surface of one tooth and traverse the interdental space diagonally to attach to the proximal surface of the adjacent tooth.
  • Function:
    • Transgingival fibers provide support across the interdental space, helping to maintain the position of adjacent teeth and the integrity of the gingival tissue.

Periodontal Medicaments

Periodontal diseases often require adjunctive therapies to traditional mechanical treatments such as scaling and root planing. Various medicaments have been developed to enhance the healing process and control infection in periodontal tissues. This lecture will discuss several periodontal medicaments, their compositions, and their clinical applications.

1. Elyzol

  • Composition:
    • Elyzol is an oil-based gel containing 25% metronidazole. It is formulated with glyceryl mono-oleate and sesame oil.
  • Clinical Use:
    • Elyzol has been found to be equivalent to scaling and root planing in terms of effectiveness for treating periodontal disease.
    • However, no adjunctive effects beyond those achieved with mechanical debridement have been demonstrated.

2. Actisite

  • Composition:

    • Actisite consists of tetracycline-containing fibers.
    • Each fiber has a diameter of 0.5 mm and contains 12.7 mg of tetracycline per 9 inches of fiber.
  • Clinical Use:

    • The fibers are placed directly into periodontal pockets, where they release tetracycline over time, helping to reduce bacterial load and promote healing.

3. Arestin

  • Composition:

    • Arestin contains minocycline, which is delivered as a biodegradable powder in a syringe.
  • Clinical Use:

    • Arestin is indicated for the treatment of periodontal disease and is applied directly into periodontal pockets, where it provides localized antibiotic therapy.

4. Atridox

  • Composition:

    • Atridox contains 10% doxycycline in a syringeable gel system that is biodegradable.
  • Clinical Use:

    • The gel is injected into periodontal pockets, where it solidifies and releases doxycycline over time, aiding in the management of periodontal disease.

5. Dentamycin and Periocline

  • Composition:

    • Both Dentamycin and Periocline contain 2% minocycline hydrochloride.
  • Clinical Use:

    • These products are used similarly to other local delivery systems, providing localized antibiotic therapy to reduce bacterial infection in periodontal pockets.

6. Periochip

  • Composition:

    • Periochip is a biodegradable chip that contains chlorhexidine.
  • Clinical Use:

    • The chip is placed in the gingival crevice, where it releases chlorhexidine over time, providing antimicrobial action and helping to control periodontal disease.

Modified Widman Flap Procedure

The modified Widman flap procedure is a surgical technique used in periodontal therapy to treat periodontal pockets while preserving the surrounding tissues and promoting healing. This lecture will discuss the advantages and disadvantages of the modified Widman flap, its indications, and the procedural steps involved.

Advantages of the Modified Widman Flap Procedure

  1. Intimate Postoperative Adaptation:

    • The main advantage of the modified Widman flap procedure is the ability to establish a close adaptation of healthy collagenous connective tissues and normal epithelium to all tooth surfaces. This promotes better healing and integration of tissues post-surgery
  2. Feasibility for Bone Implantation:

    • The modified Widman flap procedure is advantageous over curettage, particularly when the implantation of bone and other substances is planned. This allows for better access and preparation of the surgical site for grafting .
  3. Conservation of Bone and Optimal Coverage:

    • Compared to conventional reverse bevel flap surgery, the modified Widman flap conserves bone and provides optimal coverage of root surfaces by soft tissues. This results in:
      • A more aesthetically pleasing outcome.
      • A favorable environment for oral hygiene.
      • Potentially less root sensitivity and reduced risk of root caries.
      • More effective pocket closure compared to pocket elimination procedures .
  4. Minimized Gingival Recession:

    • When reattachment or minimal gingival recession is desired, the modified Widman flap is preferred over subgingival curettage, making it a suitable choice for treating deeper pockets (greater than 5 mm) and other complex periodontal conditions.

Disadvantages of the Modified Widman Flap Procedure

  1. Interproximal Architecture:
    • One apparent disadvantage is the potential for flat or concave interproximal architecture immediately following the removal of the surgical dressing, particularly in areas with interproximal bony craters. This can affect the aesthetic outcome and may require further management .

Indications for the Modified Widman Flap Procedure

  • Deep Pockets: Pockets greater than 5 mm, especially in the anterior and buccal maxillary posterior regions.
  • Intrabony Pockets and Craters: Effective for treating pockets with vertical bone loss.
  • Furcation Involvement: Suitable for managing periodontal disease in multi-rooted teeth.
  • Bone Grafts: Facilitates the placement of bone grafts during surgery.
  • Severe Root Sensitivity: Indicated when root sensitivity is a significant concern.

Procedure Overview

  1. Incisions and Flap Reflection:

    • Vertical Incisions: Made to access the periodontal pocket.
    • Crevicular Incision: A horizontal incision along the gingival margin.
    • Horizontal Incision: Undermines and removes the collar of tissue around the teeth.
  2. Conservative Debridement:

    • Flap is reflected just beyond the alveolar crest.
    • Careful removal of all plaque and calculus while preserving the root surface.
    • Frequent sterile saline irrigation is used to maintain a clean surgical field.
  3. Preservation of Proximal Bone Surface:

    • The proximal bone surface is preserved and not curetted, allowing for better healing and adaptation of the flap.
    • Exact flap adaptation is achieved with full coverage of the bone.
  4. Suturing:

    • Suturing is aimed at achieving primary union of the proximal flap projections, ensuring proper healing and tissue integration.

Postoperative Care

  • Antibiotic Ointment and Periodontal Dressing: Traditionally, antibiotic ointment was applied over sutures, and a periodontal dressing was placed. However, these practices are often omitted today.
  • Current Recommendations: Patients are advised not to disturb the surgical area and to use a chlorhexidine mouth rinse every 12 hours for effective plaque control and to promote healing.


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Neutrophil Disorders Associated with Periodontal Diseases

Neutrophils play a crucial role in the immune response, particularly in combating infections, including those associated with periodontal diseases. Various neutrophil disorders can significantly impact periodontal health, leading to increased susceptibility to periodontal diseases. This lecture will explore the relationship between neutrophil disorders and specific periodontal diseases.

Neutrophil Disorders

  1. Diabetes Mellitus

    • Description: A metabolic disorder characterized by high blood sugar levels due to insulin resistance or deficiency.
    • Impact on Neutrophils: Diabetes can impair neutrophil function, including chemotaxis, phagocytosis, and the oxidative burst, leading to an increased risk of periodontal infections.
  2. Papillon-Lefevre Syndrome

    • Description: A rare genetic disorder characterized by palmoplantar keratoderma and severe periodontitis.
    • Impact on Neutrophils: Patients exhibit neutrophil dysfunction, leading to early onset and rapid progression of periodontal disease.
  3. Down’s Syndrome

    • Description: A genetic disorder caused by the presence of an extra chromosome 21, leading to various developmental and health issues.
    • Impact on Neutrophils: Individuals with Down’s syndrome often have impaired neutrophil function, which contributes to an increased prevalence of periodontal disease.
  4. Chediak-Higashi Syndrome

    • Description: A rare genetic disorder characterized by immunodeficiency, partial oculocutaneous albinism, and neurological problems.
    • Impact on Neutrophils: This syndrome results in defective neutrophil chemotaxis and phagocytosis, leading to increased susceptibility to infections, including periodontal diseases.
  5. Drug-Induced Agranulocytosis

    • Description: A condition characterized by a dangerously low level of neutrophils due to certain medications.
    • Impact on Neutrophils: The reduction in neutrophil count compromises the immune response, increasing the risk of periodontal infections.
  6. Cyclic Neutropenia

    • Description: A rare genetic disorder characterized by recurrent episodes of neutropenia (low neutrophil count) occurring every 21 days.
    • Impact on Neutrophils: During neutropenic episodes, patients are at a heightened risk for infections, including periodontal disease.

Necrotizing Ulcerative Gingivitis (NUG)

Necrotizing Ulcerative Gingivitis (NUG), also known as Vincent's disease or trench mouth, is a severe form of periodontal disease characterized by the sudden onset of symptoms and specific clinical features.

Etiology and Predisposing Factors

  • Sudden Onset: NUG is characterized by a rapid onset of symptoms, often following debilitating diseases or acute respiratory infections.
  • Lifestyle Factors: Changes in living habits, such as prolonged work without adequate rest, poor nutrition, tobacco use, and psychological stress, are frequently noted in patient histories .
  • Smoking: Smoking has been identified as a significant predisposing factor for NUG/NDP .
  • Immune Compromise: Conditions that compromise the immune system, such as poor oral hygiene, smoking, and emotional stress, are major contributors to the development of NUG .

Clinical Presentation

  • Symptoms: NUG presents with:
    • Punched-out, crater-like depressions at the crest of interdental papillae.
    • Marginal gingival involvement, with rare extension to attached gingiva and oral mucosa.
    • Grey, pseudomembranous slough covering the lesions.
    • Spontaneous bleeding upon slight stimulation of the gingiva.
    • Fetid odor and increased salivation.

Microbiology

  • Mixed Bacterial Infection: NUG is caused by a complex of anaerobic bacteria, often referred to as the fusospirochetal complex, which includes:
    • Treponema vincentii
    • Treponema denticola
    • Treponema macrodentium
    • Fusobacterium nucleatum
    • Prevotella intermedia
    • Porphyromonas gingivalis

Treatment

  1. Control of Acute Phase:

    • Clean the wound with an antibacterial agent.
    • Irrigate the lesion with warm water and 5% vol/vol hydrogen peroxide.
    • Prescribe oxygen-releasing mouthwash (e.g., hydrogen peroxide DPF, sodium perborate DPF) to be used thrice daily.
    • Administer oral metronidazole for 3 to 5 days. If sensitive to metronidazole, prescribe penicillin; if sensitive to both, consider erythromycin or clindamycin.
    • Use 2% chlorhexidine in select cases for a short duration.
  2. Management of Residual Condition:

    • Remove predisposing local factors (e.g., overhangs).
    • Perform supra- and subgingival scaling.
    • Consider gingivoplasty to correct any residual gingival deformities.

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