What is the Mallampati Classification?
The Mallampati classification is a bedside airway assessment tool that grades the visibility of oropharyngeal structures (soft palate, uvula, faucial pillars, and tonsillar pillars) when a patient opens their mouth and protrudes their tongue, used to predict the difficulty of laryngoscopy and intubation.
Classification System
The modified Mallampati classification consists of four grades 1:
- Class I: Soft palate, uvula, faucial pillars, and tonsillar pillars fully visible
- Class II: Soft palate, uvula, and faucial pillars visible
- Class III: Soft palate and base of uvula visible
- Class IV: Only hard palate visible
Clinical Significance
Higher Mallampati classes (III and IV) indicate increased tongue size relative to oral cavity size and suggest potentially difficult laryngoscopy 2. However, this tool has important limitations:
- Sensitivity and specificity are modest: The modified Mallampati classification shows sensitivity of 0.56 and specificity of 0.69 for predicting difficult intubation 3
- Should never be used in isolation: Even patients with Mallampati class I or II can have difficult airways when other risk factors are present 1
Proper Examination Technique
The standard modified Mallampati classification is performed with the patient:
- Sitting upright
- Mouth fully open
- Tongue protruded maximally
- Without phonation
- Head in neutral position 4, 3
Common Pitfall to Avoid
The "best visible Mallampati score" (using cervical extension, tongue in, and phonation) is not recommended as it decreases sensitivity by 30% and falsely reclassifies 53% of patients with difficult airways as low-risk 3. Stick to the standard technique.
Integration into Airway Assessment
The Mallampati classification must be combined with other airway predictors 1:
- Neck movement and extension
- Mouth opening (interincisor distance)
- Thyromental distance
- Jaw protrusion/presence of micrognathia
- Previous difficult airway history
- Body mass index (BMI >30 kg/m² increases risk) 5
- Diabetes mellitus (independent predictor in obese patients) 4
Special Considerations in Pregnancy
Mallampati class increases significantly during pregnancy and labor, with grades III/IV rising from 10.3% pre-pregnancy to 51.7% at delivery 6. This change is particularly pronounced in women with preeclampsia or hypertensive disorders 6. The classification typically returns to baseline within 36-48 hours postpartum 6, 7.