What is the most accurate way to diagnose a deviated septum?

Diagnosing Deviated Nasal Septum: Most Accurate Methods

Clinical anterior rhinoscopy and endoscopic examination is the reference standard for evaluating nasal septal deviation, with nasal endoscopy being the most accurate diagnostic method. 1

Diagnostic Approach

Primary Diagnostic Methods

• Nasal endoscopy is the most accurate first-line confirmatory test for diagnosing deviated nasal septum, offering superior visualization of the nasal cavity structures 1
• Endoscopic evaluation can be performed with either flexible or rigid endoscopes after application of topical decongestant and anesthetic 1
• Nasal endoscopy allows visualization of critical structures including the nasal cavity, turbinates, meatus areas, uncinate process, hiatus semilunaris, maxillary ostia, ethmoidal bulla, and nasopharynx 1
• Clinical anterior rhinoscopy (using an otoscope in primary care settings) is also effective but less sensitive than endoscopy 1

Systematic Anatomical Assessment

• Divide the nose into horizontal thirds (upper, middle, lower) when evaluating for deviation 1
  • Upper third: bony pyramid
  • Middle third: dorsal septum and upper lateral cartilages
  • Lower third: alar cartilages, caudal septum, and alar base
• Assess each third in relation to the midline to facilitate analysis and guide potential surgical treatment 1
• Look for asymmetries in shape, width, and length of nasal components that may compound the deviation 1

Role of Imaging

• CT scanning should NOT be performed solely for evaluation of septal deviation 1

• CT has limited correlation with physical examination and may underestimate the degree of nasal obstruction due to septal deviation at the internal nasal valve 1

• CT is appropriate when:

  • Evaluating associated symptoms of chronic rhinosinusitis 1
  • Surgical planning is needed 1, 2
  • Hidden sinonasal pathologies are suspected 2

• Ultrasound has shown high accuracy (90-100% sensitivity, 98-100% specificity) for detecting isolated nasal bone fractures, but is not typically the first-line imaging test for evaluation of deviated septum 1

Clinical Significance and Associated Conditions

• The nasal septum is off-center in approximately 80% of the general population, but only about 26% have clinically significant deviation causing symptoms 3
• Anterior septal deviation is more clinically significant than posterior deviation as it affects the nasal valve area responsible for more than 2/3 of airflow resistance 3
• Increasing septal angle deviation correlates with higher incidence of maxillary sinus mucosal changes and chronic rhinosinusitis 4
• Deviated septum can cause compensatory structural changes in the turbinates and lateral nasal wall, potentially leading to ostiomeatal complex obstruction 4

Common Pitfalls to Avoid

• Relying solely on CT imaging without clinical examination may lead to underestimation of the functional impact of septal deviation 1
• Failing to distinguish between true deviation and nasal asymmetry can lead to inappropriate treatment planning 1
• Not recognizing that the maxillary sinus is the most commonly affected sinus (73.13%) in patients with deviated septum 4
• Overlooking the need for endoscopic evaluation of posterior deviations that may be inaccessible to anterior rhinoscopy 5

Endoscopic Approach Advantages

• Endoscopic septoplasty has been shown to be more effective than traditional septoplasty in relieving contact areas and nasal obstruction 5
• Endoscopic approach allows for precise identification of pathological abnormalities of the nasal septum in relation to the lateral nasal wall 5
• A combined approach may be optimal - endoscopic for inaccessible posterior deviation and traditional techniques for accessible anterior deviation 5