Posterior Rhinoscopy

👃 Posterior Rhinoscopy

Posterior rhinoscopy is an essential part of the ENT clinical examination.

It allows visualization of the posterior nares (choanae) and nasopharynx using a mirror, helping detect important pathologies in this region.

🔍 What is Posterior Rhinoscopy?

It is the visual examination of the posterior nasal cavity and nasopharynx using a posterior rhinoscopy mirror.

This mirror typically ranges from 8 to 15 mm in diameter, with a 10 mm mirror being most commonly used.

🧪 Procedure of Posterior Rhinoscopy

Here is a step-by-step guide to performing posterior rhinoscopy:

🔸 Preparation

• Prevent mirror fogging by:

  • Dipping the mirror in warm water
  • Warming it over a spirit lamp
  • Rubbing it on the buccal mucosa (frictional heating)
  • Using defogging agents like Cetramide

• Test mirror temperature on the flexor surface of your wrist before use.

🔸 Anesthetize the Pharynx

• Use 10% lignocaine spray on the posterior pharyngeal wall
• Wait 2 minutes for the anesthesia to take effect

🔸 Examination Technique

1. Depress the tongue using a tongue depressor with your left hand.
2. Hold the mirror like a pen in your right hand.
3. Insert the mirror behind the soft palate, without touching the uvula or surrounding structures to minimize gagging.
4. Ask the patient to breathe through the nose to move the soft palate forward.
5. Visualize the posterior nasal cavity and nasopharynx.

🧠 Structures Seen in Posterior Rhinoscopy

✅ Midline Structures

• Posterior end of the nasal septum (first structure to be identified)

✅ Turbinates and Meatuses

• Posterior ends of:
  • Inferior turbinate
  • Middle turbinate
  • Superior turbinate (may or may not be visible)
• Posterior parts of:
  • Superior meatus
  • Middle meatus

✅ Nasopharyngeal and Soft Palate Structures

• Nasal surface of the uvula and soft palate (if the mirror is tilted anteriorly)

✅ Lateral Structures

• Eustachian tube orifices and tubal elevations
• Fossa of Rosenmüller (behind Eustachian tube)

✅ Superior and Posterior Structures

• Roof of the nasopharynx
• Adenoids (in children, at junction of roof and posterior wall)
• Posterior pharyngeal wall

⚠️ Abnormalities Seen in Posterior Rhinoscopy

While examining, you must look for:

• Polyps (e.g., antrochonal polyp)
• Cysts
• Secretions
• Foreign bodies
• Ulcers
• Tumors
  • Juvenile nasopharyngeal angiofibroma (JNA)
  • Nasopharyngeal carcinoma

⚠️ Common Difficulties in Performing Posterior Rhinoscopy

📌 Conclusion

Posterior rhinoscopy is a crucial diagnostic tool in ENT, though technically demanding. With proper technique and patient preparation, it can reveal important findings in the nasopharynx and posterior nasal cavity.