Deviated Nasal Septum

Definition & Anatomy - Septal Skew Show

• Deviated Nasal Septum (DNS): Displacement of the nasal septum from the nasal cavity's centreline.
• Anatomy:
  • Cartilaginous: Quadrangular cartilage.
  • Bony: Perpendicular plate of ethmoid, vomer, maxillary crest, palatine crest.
• Blood Supply:
  • Kiesselbach's plexus (anterior epistaxis site).
  • Sphenopalatine artery, Anterior & Posterior Ethmoidal arteries.
• Nerve Supply:
  • Anterior Ethmoidal nerve (branch of V1).
  • Nasopalatine nerve (branch of V2).

⭐ The nasal septum is roughly 1/3 cartilaginous (anterior) and 2/3 bony (posterior).

Etiology & Types - Why It Bends

• Etiology (Causes):
  • Trauma: Leading cause.
    • Birth injury: Molding during passage, forceps.
    • Later life: Accidental, sports, altercations.
  • Developmental Errors:
    • Unequal growth rates between septum and surrounding structures (skull base, palate).
    • Associated with high arched palate.
• Common Types/Patterns:
  • Anterior (caudal) dislocation: Septum slips off maxillary crest.
  • C-shaped deformity: Simple curve.
  • S-shaped deformity: More complex, often bilateral obstruction.
  • Septal spur: Shelf-like projection (bone/cartilage).
  • Thickening: Due to overriding of dislocated fragments.

⭐ Most common cause of DNS is trauma.

Clinical Features & Complications - The Blocked Truth

• Symptoms:
  • Nasal obstruction: Unilateral/bilateral; paradoxical (wider side blocked due to turbinate hypertrophy).
  • Headache: Contact point, Sluder's neuralgia.
  • Epistaxis: Stretched mucosa over spur.
  • Anosmia/hyposmia.
  • Snoring, mouth breathing, dry throat.
• Signs:
  • External nasal deformity (occasional).
  • Deviated septum on anterior rhinoscopy.
  • Compensatory inferior turbinate hypertrophy.
• Complications (Untreated DNS):
  • Recurrent sinusitis.
  • Mucocele.
  • Obstructive Sleep Apnea (OSA).
  • Middle ear infections (via Eustachian tube dysfunction).

⭐ Paradoxical nasal obstruction: The wider nasal cavity (contralateral to septal deviation) can feel more blocked due to reactive inferior turbinate hypertrophy caused by altered airflow dynamics and chronic irritation. This is a common exam question!

Diagnosis - Spotting the Swerve

• History Taking: Focus on nasal obstruction, headache, epistaxis, anosmia.
• Clinical Examination:
  • Anterior Rhinoscopy: After decongestion (if needed), assess septal deviation.
  • Nasal Endoscopy: Visualizes posterior deviations, spurs, contact points.

    ⭐ Nasal endoscopy is the gold standard for assessing posterior deviations and spurs.

  • Cottle's Test: Assesses nasal valve area contribution to obstruction.
  • Probing: Determines consistency of spur (bony/cartilaginous).
• Investigations (Indications-based):
  • CT Scan (Nose & PNS): Suspected sinusitis, planned FESS, osseocartilaginous issues, pre-revision.
  • Acoustic Rhinometry/Rhinomanometry: Objective airflow assessment (not routine).

Management - Fixing the Bend

• Medical (Symptomatic Relief):
  • Decongestants (short-term), antihistamines, topical nasal steroids.
• Surgical Management:
  • Indications: Symptomatic obstruction, recurrent sinusitis/epistaxis due to DNS, OSA, surgical access (FESS, hypophysectomy).
  • Procedures:
    • Septoplasty: Preferred; reconstructs, preserves cartilage. Age >17 yrs.
    • SMR (Submucous Resection): Removes deflected cartilage/bone. Age >17 yrs.
  • Incisions: Killian's, Hemitransfixion/Freer's.
  • Complications: Septal hematoma, abscess, perforation, saddle nose, columellar retraction, persistent deviation, anosmia, CSF leak (rare), toxic shock syndrome.

    ⭐ Persistent deviation and septal hematoma are common complications of septal surgery.

High‑Yield Points - ⚡ Biggest Takeaways

• Nasal obstruction is the hallmark symptom, often worse on one side.
• Cottle's test is positive, indicating internal nasal valve compromise.
• Compensatory inferior turbinate hypertrophy frequently occurs on the contralateral side.
• Septoplasty is the preferred surgical treatment for symptomatic DNS.
• Anterior (caudal) dislocations can cause severe external deformity and obstruction.
• Complications include septal hematoma, abscess, and saddle nose deformity or perforation.
• DNS can predispose to recurrent sinusitis and epistaxis.