Location and Formation
The inferior nasal meatus forms part of the lateral wall of the nasal cavity (cavitas nasalis ossea).
- Superior border: Formed by the inferior nasal concha (concha nasalis inferior). Unlike the superior and middle conchae, which are parts of the ethmoid bone, the inferior concha is an independent bone.
- Inferior border: Corresponds to the floor of the nasal cavity, formed by the hard palate.
- Medial relation: The common nasal meatus (meatus nasi communis) lies between the nasal conchae and the bony nasal septum (septum nasi osseum).
What Opens into the Inferior Nasal Meatus?
The primary anatomical communication of the inferior nasal meatus is the nasolacrimal canal (canalis nasolacrimalis) or nasolacrimal duct (ductus nasolacrimalis).
- It drains the contents of the lacrimal sac (saccus lacrimalis).
- The canal's opening is located approximately 3.0–3.5 cm posterior to the naris margin and 2 cm above the floor of the nasal cavity.
Clinical Significance in Surgery and Traumatology
The inferior nasal meatus serves as an access pathway in the management of maxillofacial trauma and pathologies:
- Maxillary sinus puncture: Puncture of the sinus is performed via the inferior nasal meatus to evacuate exudate and collect material for microbiological testing.
- Control of hemorrhage: A soft catheter or tube is introduced through this pathway to perform posterior nasal packing.
- Management of nasal fractures: Following the reposition of bone fragments, a polyvinyl chloride tube wrapped in iodoform gauze is inserted into the inferior nasal meatus to fix the fragments while maintaining nasal breathing.
- Gunshot wounds: During the initial surgical debridement of maxillary wounds, an anastomosis with the inferior nasal meatus is established.
- Anesthesia: During the Caldwell-Luc procedure, a gauze strip (turunda) soaked in 10% lidocaine solution is placed in the inferior nasal meatus for topical anesthesia of the nasal mucosa.
Use in Probing and Diagnostics
- Enteral nutrition: A gastric tube is passed into the stomach via the inferior nasal meatus. Nutrition is administered using a syringe or funnel in small portions at least 4 times a day. The daily volume is distributed as follows: 30% for breakfast, 40% for lunch, 20–25% for dinner, and 5–8% for a late-evening snack.
- Respiratory swab collection: If the nasal cavity is filled with mucus, the patient is asked to blow their nose prior to the procedure. A sterile swab is inserted along the lateral nasal wall for 2–3 cm, then slightly lowered and guided into the inferior nasal meatus beneath the inferior nasal concha. The swab is advanced to the nasopharynx to a total depth of about 5–6 cm (approximately half the distance from the nostril to the external acoustic meatus), rotated, and withdrawn.