PERO

Periapical inflammatory lesions

Lesions whose radiographic features vary depending on the time course of the condition.

Early periapical inflammatory lesions

Lesions that may not show any radiographic changes, requiring diagnosis to rely solely on clinical symptoms.

Chronic periapical inflammatory lesions

Lesions that may exhibit lytic changes, sclerotic changes, or a combination of both.

Lytic changes

Radiographic features characterized as radiolucent.

Sclerotic changes

Radiographic features characterized as radiopaque.

Periapical inflammatory lesion

A local response of the bone around the apex of a tooth that occurs as a result of necrosis of the pulp or through destruction of the periapical tissues by extensive periodontal disease.

Necrosis of the pulp

One of the primary causes of a periapical inflammatory lesion, leading to a local response of the bone around the tooth apex.

Extensive periodontal disease

A condition that can result in a periapical inflammatory lesion through the destruction of periapical tissues.

Apical periodontitis

An inflammatory reaction in the periapical periodontal ligament and surrounding bone incited by toxic metabolites from necrotic pulp exiting the root apex.

Osteomyelitis

A condition resulting from the spread of pyogenic organisms into the surrounding bone marrow, transforming a localized periapical abscess into an inflammatory reaction no longer centered on the tooth apex.

Pyogenic organisms

Organisms that spread inflammatory reactions to the bone marrow, potentially causing a periapical abscess to transform into osteomyelitis.

Epicenter (periapical lesion)

The location in the vicinity of the tooth apex where a periapical lesion typically remains centered, unless it has extended and suggests a diagnosis of osteomyelitis.

Periapical abscess

A localized lesion that may transform into osteomyelitis if the inflammatory reaction involves the surrounding bone marrow through the spread of pyogenic organisms.

Periapical inflammatory lesions (symptom spectrum)

A broad range of symptoms from being asymptomatic to occasional toothache to severe pain, with or without facial swelling, fever, and lymphadenopathy.

Periapical abscess

A condition that usually manifests with severe pain, tooth mobility and sometimes elevation, swelling, and tenderness to percussion.

Apical region palpation

A clinical examination technique that elicits pain in the presence of a periapical abscess.

Parulis

A fistula through which spontaneous drainage into the oral cavity occurs, potentially relieving acute pain.