Periapical Periodontitis

							      Dent 355-10 Oral
          Pathology
    Periapical Periodontitis
     Etiology
     Acute Periapical Periodontitis
     Chronic Periapical Periodontitis
     (Periapical Granuloma)
     Acute Periapical Abscess &
     Spread of Inflammation



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    Periapical Periodontitis
    Particular Features:

    • Confinement within bone may
      result in bone and/or root
      resorption.

    • Potential for complete healing
      if irritant is eliminated is the
      basis for endodontic treatment.

    • Pain well-located by patient
      due to proprioceptors.

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Periapical Periodontitis:
Etiology

• Pulpitis and pulp necrosis.

• Trauma: occlusal, direct blow, hard
  object in food.

• Endodontic treatment: mechanical
  instrumentation, chemical irritation,
  forcing of bacteria into periapical
  tissues.




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    (Primary) Acute Periapical
          Periodontitis
• Extremely painful upon external pressure.

• Tooth feels elevated in socket.

• Thermal stimulation does not cause pain.

• No radiographic changes initially, with
  progression slight widening of PDL, lamina dura
  may become less defined.

• May be transient if due to acute trauma, and
  resolves soon.

• If irritant persists e.g. pulp necrosis, it may:

a) become chronic and may be associated with bone
   resorption.
b) or suppuration may occur if there is severe
   irritation associated with necrosis, leading to
   acute periapical abscess formation.

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    Chronic Periapical Periodontitis
       (Periapical Granuloma)

Histopathologic Features:

• Chronically inflamed granulation tissue
  which replaces resorbed bone around
  root apex.

• Lymphocytes, plasma cells,
  macrophages.

• Condensed collagen around lesion
  separating it from bone.

• Proliferative epithelial islands: epithelial
  rests of Malassez, with degenerated
  neutrophil infiltrates.

• Deposits of hemosiderin & cholesterol
  clefts with foreign body giant cells.
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    Chronic Periapical Periodontitis
       (Periapical Granuloma)

Clinical Features:

• Usually asymptomatic with occasional
  tenderness.

• Percussion my produce a dull note.

• Mixed bacterial culture with
  predominance of obligate anaerobes and
  smaller numbers of facultative
  anaerobes.

• Untreated root canals serve as a
  continuous source of infection.

• Most periapical lesions heal only after
  root canals are sealed by satisfactory
  endodontic treatment.
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    Chronic Periapical Periodontitis
       (Periapical Granuloma)

Radiographic Features:

• Initially widened PDL space.

• Later, periapical radiolucency
  which may be well-defined and
  corticated or at times poorly defined
  depending on activity of
  inflammation at margins of lesion.

• Root resorption may be detected
  radiographically.




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     Chronic Periapical Periodontitis
    (Periapical Granuloma): Sequelae

1. Granuloma may continue to enlarge
     asymptomatically with continued bone and/or
     root resorption.

2. Acute exacerbation presenting as acute apical
     periodontitis.

3. Suppuration and formation of an acute (or chronic)
     periapical abscess.

4. Proliferation of epithelial rests of Malassez and
      formation of a radicular cyst.

5. Sometimes bone apposition may occur instead of
     resorption (osteosclerosis, condensing osteitis).

6. Hypercementosis.




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    Acute Periapical Abscess &
     Spread of Inflammation:
     Etiology & Microbiology
• May develop directly from acute
  apical periodontitis.

• More usually from a chronic
  periapical granuloma or periapical
  cyst.

• Generally, a result of mixed
  bacterial infection.

• Predominance of anaerobes such
  as Prevotella, Porphyromonas and
  anaerobic Sterptoccoci.
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    Acute Periapical Abscess &
     Spread of Inflammation:
        Routes of Spread
•   If cause is not removed by extraction,
    RCT or antibiotics:

1. Suppuration continues and abscess
    enlarges.

2. Balance between irritant and host
    defenses may cause abscess to become
    chronic and localized.

3. Increase in hydrostatic pressure causes
    pus to track in one of a number of
    directions:
a) Through an open root canal.
b) Through gingival sulcus.
c) Through cancellous bone then
    perforating the cortex, then buccally or
    lingually, intraorally or extraorally
    depending on anatomy and muscle
10 attachments relative to root apices.
     Acute Periapical Abscess &
      Spread of Inflammation:
         Routes of Spread
•    Possible outcomes:

1. Pus may discharge directly into oral
   cavity through a sinus track.

 This may occur with or without pain or
  swelling.

 A nodule of granulation tissue often
  forms and opening of sinus track-
  “gumboil” or “parulis”.

2. Pus tracking palatally may spread under
    the dense palatal mucoperiosteum
    posteriorly to the junction of hard and
    soft palate, presenting as a palatal
    abscess.

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   Acute Periapical Abscess &
    Spread of Inflammation:
       Routes of Spread
3. Abscesses in molar regions may
   penetrate the buccal cortical plate above
   (maxilla) or below (mandible)
   attachments of buccinator muscle.

 Inflammatory edema and suppuration
  may spread into soft tissues of face or
  neck, presenting as cellulitis or as a
  localized soft tissue abscess.

 Such an abscess may discharge through
  a sinus on skin surface.

 It may then become chronic with periodic
   pus discharge, associated with increasing
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   fibrosis, scarring, and disfigurement.
     Acute Periapical Abscess &
      Spread of Inflammation:
         Routes of Spread
4. Abscesses related to anterior
  maxillary teeth may perforate bone
  above attachment of levator anguli
  oris muscle.

 Infection then passes medially and
  upwards towards inner canthus of
  eye and into lower eyelid.

 Alternatively, it may pass into upper
  lip.

5. Abscesses related to maxillary
  molars and premolars may
  discharge into the maxillary sinus.

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     Acute Periapical Abscess &
      Spread of Inflammation:
         Routes of Spread
6. Abscesses related to mandibular
premolar or molar teeth may
perforate lingual plate of mandible
below mylohyoid muscle
attachment to involve
submandibular space which has
communications with sublingual
and lateral pharyngeal spaces.

7. Pus from abscess associated with
a mandibular incisor or canine may
track labially and perforate bone
below mentalis muscle insertion
and pass downwards to present as
a subcutaneous abscess in the
midline.

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  Acute Periapical Abscess &
Spread of Inflammation: Cellulitis
• Rapidly spreading inflammation of the
  soft tissues particularly associated with
  streptococcal infections.

• In contrast to an abscess, it is not well-
  localized.

• Release of streptokinase and
  hyaluronidase.

• Diffuse, tense & painful swelling.

• Malaise & elevated temperature.

• Extension of cellulitis associated with
  maxillary teeth towards the eye is a
  potentially serious complication.

• Involvement of veins at inner canthus of
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  eye may result in cavernous sinus
  thrombosis.
     Acute Periapical Abscess &
      Spread of Inflammation:
          Ludwig’s Angina
• Severe cellulitis involving the
  submandibular, sublingual, and
  submental spaces.

• A result of initial involvement of the
  submandibular space.

• Rare since advent of antibiotics.

• Swelling of floor of mouth, elevated
  tongue, difficult eating , swallowing, &
  breathing.

• If it tracks backwards to involve pharynx
  and larynx, with edema of the glottis,
  suffocation may occur.
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