Choanal atresia is due to persistence of ?
**Core Concept**
Choanal atresia is a congenital condition characterized by the abnormal closure or blockage of the posterior nasal aperture, also known as the choana. This condition can be unilateral or bilateral and may be associated with other congenital anomalies.
**Why the Correct Answer is Right**
The correct answer is related to the embryological development of the nasal cavity. During embryogenesis, the nasal pit and the stomadeum fuse to form the nasopharynx. If this fusion does not occur properly, it can lead to the persistence of the buccopharyngeal membrane, which is a membrane that separates the nasal cavity from the pharynx. This persistence of the buccopharyngeal membrane can result in the formation of a bony or cartilaginous obstruction in the posterior nasal aperture, leading to choanal atresia.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not directly related to the embryological development of the nasal cavity.
**Option B:** This option is incorrect because it is not a known cause of choanal atresia.
**Option C:** This option is incorrect because it is not a known cause of choanal atresia.
**Clinical Pearl / High-Yield Fact**
Choanal atresia is often associated with other congenital anomalies, such as CHARGE syndrome, which is characterized by coloboma, heart defects, atresia of the choanae, restricted growth and development, and genital and ear abnormalities.
**Correct Answer: D. Persistence of the buccopharyngeal membrane.**