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Radiographic Features of Periapical Lesions

A periapical lesion is a lesion located around the apex of a tooth. It cannot be evaluated clinically alone, the use of dental radiographs is important. Radiographically :It appears either radiolucent or radiopaque.

Pulpitis

Acute chronic
Apical periodontitis
Acute chronic
Periapical abscess
Periapical granuloma
Periapical cyst
Acute chronic
Osteomyelitis
Acute chronic
Focal Diffuse

A:PA granuloma / cyst B:PA granuloma

A: Acute apical periodontitis B: PA lesion in 5 & early apical changes in 6

PA lesion

PA lesion

White arrow :PA granuloma/cyst . Black arrow : sclerosing ostetitis

Periapical Radiolucency
A. Periapical Abscess: . Acute Periapical Abscess: No radiographical changes is seen, but some time the early radiographic changes shows widening of the apical periodontal ligament.

. Chronic Periapical Abscess: long standing, low grade, pus-producing process. It may develop from an acute abscess or a periapical granuloma. It is usually asymptomatic because the pus drains through the bone or the periodontal ligament. Clinically : a gumboil (sinus) may be seen in the apical region of the tooth at the site of drainage. Radiographically: appears as a round or ovoid apical radiolucency with poorly defined margins, the lamina dura is absent in the site of lesion.

B. Periapical granuloma: It is a localized mass of chronic inflamed granulation tissue at the apex of a non vital tooth, due to pulp death & necrosis. A periapical granuloma may give rise to a periapical cyst or abscess. It's asymptomatic but has a previous history of prolong sensitivity to heat & cold. Radiographically: widened periodontal ligament space at the root apex, with time the widened periodontal space enlarged & appears as round or ovoid radiolucency with absent lamina dura .


C. Periapical Cyst (Radicular Cyst): is developed over a prolonged period of time, it is takes place within a periapical granuloma. The tooth is non vital & necrotic. Periapical cyst form 50-70% of the cystic lesions in the oral region. Radicular cyst is asymptomatic, unless secondary infection is occurring. Radiographically:appears as a well localized, round or ovoid radiolucency with the demarcated outline. Treatment: either by the surgical curettage or extraction of the offending tooth.

Periapical Radiopacities

A-Condensing Osteitis : It is a response of bone to some form of injury (low-grade infection or excessive physical stress). Is a well-defined radiopacity that is seen below the apex of a non-vital tooth with history of long standing pulpitis. Apical opacity represents a proliferation of periapical bone due to a low grade inflammation or mild irritation. It may vary in size & shape & dose not appear to be attached to the root apex, most commonly occur in the mandibular molar region. Associated tooth have a large carious lesion or large restoration, this lesion may disappear after proper endodontic therapy.


Condensing Osteitis

b-Hypercementosis: Is the deposition of cementum on root surface. Causes idiopathic or resulted from supra-eruption, inflammation or trauma. Radiographically: is visible as an excess amount of cementum along all or part of a root surface. The apical area is affected & appears enlarged & bulbous, it separated from periapical bone by a normal periodontal ligament space & surrounding lamina dura is normal. The tooth is vital, asymptomatic; no treatment is required & discovered by routine radiograph. Complications: interfere with extractions, also result in pulpal necrosis by blocking blood supply via the apical foramen.

Hypercementosis