**Core Concept**
Simple mastoidectomy is a surgical procedure performed to remove diseased mastoid air cells in the temporal bone. It is typically done to treat mastoiditis, a complication of acute otitis media, or to relieve pressure and alleviate symptoms. The procedure involves accessing the mastoid air cells through a posterior auricular incision.

**Why the Correct Answer is Right**
The primary indication for a simple mastoidectomy is the presence of mastoiditis, which is an infection of the mastoid air cells. This can occur as a complication of acute otitis media, where bacteria spread from the middle ear to the mastoid air cells. The infection can cause erosion of the mastoid bone, leading to symptoms such as severe pain, fever, and hearing loss. Simple mastoidectomy is performed to drain the infected mastoid air cells, relieve pressure, and prevent further complications.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a simple mastoidectomy is not typically performed for chronic otitis media, which is a long-standing infection of the middle ear. While mastoidectomy may be required in some cases of chronic otitis media, it is not the primary indication for a simple procedure.

**Option B:** This option is incorrect because a tympanomastoidectomy is a more extensive surgical procedure that involves removal of both the middle ear and mastoid air cells. It is typically performed for more severe conditions, such as cholesteatoma or chronic otitis media with significant mastoid involvement.

**Option C:** This option is incorrect because a cortical mastoidectomy is actually a more extensive procedure than a simple mastoidectomy, involving removal of the entire mastoid cortex. It is typically performed for conditions such as mastoiditis with significant cortical involvement or cholesteatoma.

**Clinical Pearl / High-Yield Fact**
The key to distinguishing between simple and more extensive mastoidectomy procedures lies in understanding the specific indications and extent of the surgical intervention required. A simple mastoidectomy is typically reserved for cases of mastoiditis with limited disease, whereas more extensive procedures are required for more severe conditions.

**Correct Answer:** C. Cortical mastoidectomy is actually more extensive than simple mastoidectomy. However, the correct answer is not listed.