Pathology of Periapical Periodontitis Flashcards
What is periapical periodontitis?
Inflammation of periodontal ligament and other tissues around tooth apex
What are usually the causes of PA perio? (3)
- Usually due to spread of infection following death of pulp
- Extrusion of antiseptics through apex during root canal treatment
- High filling or biting suddenly on hard object - can cause an acute (usually transient) PA perio
Describe the clinical findings of acute periapical periodontitis (8)
- History of pulpitis
- Escape of exudate into periodontal ligament causes small amount of tooth extrusion
- Pain well localised: tender to touch/percussion
- Tooth not vital and not responsive to vitality tests (unless pulpal necrosis limited to single canal in multi-rooted tooth)
- As inflammation becomes more severe there can be intense throbbing pain
- Infection usually remains localised
- Abscess can develop
- Can spread in tissue planes causing facial swelling
Give examples of 2 rarer clinical findings with acute periapical periodontitis
Local lymphadenopathy
Osteomyelitis or cellulitis
What may the radiology show if the patient is suffering from acute PA periodontitis?
Only radiographic change may be widening of periodontal ligament space
(due to bone resorption not having time to happen)
Name the 3 ways acute PA periodontitis can be managed
- Endo tx
- XLA
- Open drainage though skin or mouth if needed (due to abscess causing swelling)
What are the clinical symptoms of chronic PA periodontitis? (5)
- May have minimal symptoms
- Can be TTP
- Low grade infection
- May follow acute PA perio
- Tooth not vital (unless very rarely pulpal necrosis is limited to a single canal in a multirooted tooth)
Which type of PA perio would you be more likely to be able to identify on a radiograph?
Chronic
Often shows PA radiolucency
What other 3 things may you see with chronic periapical periodontitis?
- Periapical granuloma, and in some cases radicular cyst
- Acute exacerbation with suppuration (pus)/abscess, cellulitis and sinus formation
- Very rarely focal sclerosing osteitis
What is the treatment for chronic periapical periodontitis? (3)
- XLA
- RCT
- Radicular cyst may need to be enucleated (removal of cyst in its entirety)
What are the characteristics of a periapical granuloma? (4)
- Mostly asymptomatic
- May have history of pulpitis
- MAY be symptomatic (usually if they have coexisting pulpitis)
- Tooth is not vital and will not be responsive to vitality tests (unless pulpal necrosis is limited to single canal in multirooted tooth)
What percentage of apical inflammatory lesions are periapical granulomas?
75%
How are most PA granulomas discovered?
Routine radiographs
What may you see on a radiograph that may indicate PA granuloma?
- Loss of lamina dura
- Bone resorption appearing as radiolucency that may circumscribed or ill-defined.
What size may a PA granuloma be?
Small - around 2cm
Larger lesions may be radicular cysts
Can you distinguish radicular cysts from PA granulomas based on size alone?
No
What is rarely seen on a radiograph with PA granulomas?
Root resorption is rarely seen
Why do PA granulomas form?
It is a defensive reaction secondary to the presence of bacteria in the root canal with spread of related toxins into the apical zone
What may you see if you were studying the pathology of PA granuloma? (10)
- Granulation tissue
- Neutrophils
- Lymphocytes
- Plasma cells
- Histiocytes multinucleated giant cells
- Cholesterol clefts
- Hemosiderin
- Small foci of acute inflammation (may be seen with focal abscess but does not warrant the diagnosis of PA abscess)
- Surrounding fibrous wall
- Bone resorption (tooth can be resorbed but generally more resistant than bone)
When may an apical scar form?
Defect created by periapical inflammatory lesions may rarely heal by filling with dense fibrous tissue rather than normal bone.
When do periapical scars occur most frequently?
When both the facial and lingual cortical plates have been lost
Describe the relation of periapical granulomas to periapical abscesses?
PA granulomas may arise after a dormancy period of a PA abscess
OR it may develop as the initial periapical pathology
What is a cyst?
It s an epithelial lined cavity
What are the ‘Epithelial cell rests of Malassez’?
They are discreet clusters of residual cells from Hertwig’s epithelial root sheath that didn’t completely disappear. They are part of the periodontal ligament.
How may the cell rests of Malassez be involved in the formation of radicular cysts?
If they lie within the vicinity of the PA area, they may show reactive proliferation to inflammation/infection leading a radicular cyst
In what age demographic is focal sclerosing osteitis most frequent?
Most frequent in children and young adults
can occur in older people
In what areas of the mouth does focal sclerosing osteitis mostly occur?
Lower premolars
Molar areas
Describe focal sclerosing osteitis
Localised, usually uniform bone sclerosis (radiodense) adjacent to toot apex with periapical periodontitis
Would focal sclerosing osteitis be radiolucent or radio-opaque?
It would be radio-dense, it does not exhibit a radiolucent border -
although, an adjacent radiolucent inflammatory lesion may be present
How do you treat focal sclerosing osteitis?
RCT or XLA
What is the prognosis of focal sclerosing osteitis?
85% of cases will regress (partially or totally) after treatment.
Bone scars may be present (residual area of condensing osteitis)
