**Core Concept**
The maxillary sinus is a paranasal sinus located in the maxillary bone, and its relationship with the roots of the upper molars is critical during dental extraction. In cases of suspected antral perforation, it is essential to confirm the presence of air in the maxillary sinus to determine if the root has been pushed into it.

**Why the Correct Answer is Right**
Blowing air through the nose with the nostrils closed (A) is the correct method to determine antral perforation. When air is blown through the nose, it will enter the maxillary sinus if there is an opening (perforation) between the sinus and the oral cavity. This is a simple and non-invasive method to assess the presence of an opening. The air will escape through the perforation, indicating its presence. This technique is based on the principle of applying pressure to force air into the maxillary sinus and observing for any sign of air escaping through the oral cavity.

**Why Each Wrong Option is Incorrect**
**Option B:** Probing the socket to check for perforation (B) is not a suitable method for determining antral perforation. Probing can cause further damage to the surrounding tissues and may lead to complications such as infection or bleeding. Additionally, probing may not accurately detect a small perforation.

**Option C:** Enlarging the orifice to retrieve the root piece (C) is not a suitable method for determining antral perforation. Enlarging the orifice can lead to further complications such as infection, bleeding, or damage to surrounding tissues. Moreover, enlarging the orifice may not necessarily confirm the presence of an antral perforation.

**Option D:** Performing all of the above (D) is not a suitable method for determining antral perforation. This option is a combination of the incorrect methods mentioned above and would likely lead to further complications.

**Clinical Pearl / High-Yield Fact**
When suspecting antral perforation during dental extraction, it is essential to consider the anatomical relationship between the roots of the upper molars and the maxillary sinus. A thorough understanding of the anatomy and the use of non-invasive methods to determine antral perforation can help prevent complications and ensure successful extraction.

**✓ Correct Answer: A. Blow air through the nose with nostrils closed**