According to WHO classification of periradicutar diseases, code number category K04.4 is
## **Core Concept**
The World Health Organization (WHO) classification of diseases, also known as the International Classification of Diseases (ICD), is a globally used diagnostic tool for epidemiology, health management, and clinical purposes. The classification includes codes for various conditions, including periradicular diseases, which are related to the periodontal ligament and surrounding tissues of the tooth root.
## **Why the Correct Answer is Right**
Periradicular diseases are conditions affecting the tissues surrounding the root of a tooth, including the periodontal ligament and bone. The code K04.4 in the WHO's ICD specifically refers to **Acute apical periodontitis**, which is an inflammatory condition of the periodontal ligament surrounding the apex (tip) of a tooth root, often in response to bacterial invasion or injury. This condition is a common pathology encountered in dental practice.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not correspond to the correct classification for periradicular diseases as specified by the WHO.
- **Option B:** Similarly, this option does not accurately represent the condition classified under K04.4.
- **Option C:** This is the correct classification; therefore, it is not incorrect but rather the focus of the explanation.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **Acute apical periodontitis (K04.4)** often results from pulp necrosis or as a result of an injury to the tooth. It presents with pain, which can range from mild to severe, and may be accompanied by swelling. Early diagnosis and treatment are crucial to prevent progression to more severe conditions such as apical abscess or cyst formation.
## **Correct Answer:** . Acute apical periodontitis.