Bevelling of the skull is seen in the –
**Core Concept**
Bevelling of the skull refers to the phenomenon where the inner table of the skull becomes thinner and more translucent than the outer table, often observed in conditions affecting the brain and skull.
**Why the Correct Answer is Right**
Bevelling of the skull is typically seen in conditions where there is increased intracranial pressure (ICP), such as in brain tumors, hydrocephalus, or other space-occupying lesions. The increased ICP causes the inner table of the skull to become thinner and more compressible, leading to bevelling. This can be due to the skull's inability to expand outward, causing the inner table to become concave and thinner. The process is often associated with the loss of the diploic space, which is the space between the inner and outer tables of the skull.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because bevelling of the skull is not typically associated with conditions that primarily affect the outer table of the skull, such as osteoporosis or trauma.
**Option B:** This option is incorrect because while certain infections may cause increased ICP, bevelling of the skull is not a specific characteristic of these conditions.
**Option C:** This option is incorrect because while certain conditions may cause thinning of the skull, bevelling of the skull specifically refers to the increased thinning of the inner table compared to the outer table.
**Clinical Pearl / High-Yield Fact**
Bevelling of the skull is often seen in conditions with increased intracranial pressure, and it can be a useful radiological sign in diagnosing these conditions.
**Correct Answer: B. Hydrocephalus**