Mallampati Class Zero airway: a narrative review

Mallampati Class Zero airway describes a visible epiglottis on pharyngoscopic view. It was first noted by Tobold A in 1869 and was proposed as a new class in modified Mallampati Classification by Ezri T. et al. We aim to summarize the current knowledge about Mallampati Class Zero airway and its implication on airway management.

We reviewed the reported studies about visible epiglottis on pharyngoscopy and 34 publications were selected.

The diagnosis of Mallampati Class Zero airway is usually achieved as a casual finding during airway assessment of Mallampati Test, during a regular checkup at the dentist, or even after a medical consultation due to a suspected visualization of a foreign body at the back of the throat. Mallampati Class Zero airway has a low prevalence in the general population (prevalence of 0.7-1.7% of adults and 0.3-6% of children) and it is more frequent in children and female. The cause for this phenomenon is not well understood but in clinical practice it is associated with an easy airway. Interestingly, in the pediatric population with Mallampati class zero airway, the difficult airway has not been reported to date.

Mallampati Class Zero is associated with an easy airway and it should be included as a different class in the modified Mallamapti classification, which would also contribute to its spread between professionals involved in the airway management and will favour increasing investigation and knowledge about it.