Okay, let's tackle this question. The question is about the 'tear-drop' appearance on a PNS x-ray. First, I need to recall what PNS stands for. PNS is Posteroanterior Nasal Septum view, but wait, maybe it's Posteroanterior Sinus, or Posteroanterior Projection of the Nasal Sinuses. Either way, the tear-drop shape is a key finding here.

The 'tear-drop' appearance is a classic radiological sign. I remember that in certain sinus conditions, like in a deviated nasal septum or maybe in sinusitis, there can be specific shapes. Wait, no. Another thought: the tear-drop sign is associated with a specific anatomical structure. Oh, right! In the context of the nasal cavity, a tear-drop shape on imaging might indicate a nasal polyp or a deviated septum. But wait, I think the tear-drop appearance is more related to the maxillary sinus. Wait, no. Let me think again.

Wait, the tear-drop sign is often seen in the context of the sella turcica in pituitary issues, but that's not related to nasal sinuses. Hmm. Maybe I'm mixing up signs. Let me focus on the nasal area. Another possibility is that the tear-drop appearance is a feature of a deviated nasal septum. When the septum is deviated, especially posteriorly, it can create a tear-drop shape on a PNS x-ray. Alternatively, a nasal polyp could cause a similar appearance, but I'm more familiar with the tear-drop sign in the context of a deviated septum.

Wait, another angle: in the context of the nasal septum, a posterior deviation can lead to a tear-drop shape. The PNS x-ray is a standard view for nasal structures. So, if the septum is deviated, especially posteriorly, the x-ray might show a tear-drop shape. So the correct answer would be a deviated nasal septum. Let me verify. Yes, in a deviated nasal septum, especially when there's a posterior bowing, the PNS view can show a tear-drop appearance. That's the key point here.

Now, the options aren't provided, but the correct answer is likely to be "Deviated nasal septum". Common distractors would be things like nasal polyps, sinusitis, or tumors. So, the explanation would need to clarify why the other options are incorrect. For example, nasal polyps might cause a rounded shadow, not a tear-drop. Sinusitis might show fluid levels or opacification. Tumors could present as irregular masses. The core concept here is the radiological appearance of a deviated septum on PNS x-ray.

**Core Concept** The "tear-drop" appearance on a posteroanterior nasal projection (PNS) x-ray is a classic radiological sign of a **posteriorly deviated nasal septum**. This occurs when the septum bows or shifts posteriorly, creating a teardrop-shaped shadow due to the altered airway anatomy.

**Why the Correct Answer is Right** A posteriorly deviated nasal septum causes narrowing of the nasal airway and creates a characteristic teardrop shadow on PNS x-ray. This is due to the septal cartilage or bone curving backward, compressing

✓ Correct Answer: D. Fracture floor of the orbit