Mallampati score is for:
Ref. Oxford textbook of anesthesia. Page. 397
 
Modified Mallampati classification 

Class 0: Ability to see any part of the epiglottis upon mouth opening and tongue protrusion
Class I: Soft palate, fauces, uvula, pillars visible
Class II:Soft palate, fauces, uvula visible
Class III: Soft palate, base of uvula visible
Class IV: Soft palate not visible at all

Test: The assessment is performed with the patient sitting up straight, mouth open and tongue maximally protruded, without speaking or saying “ahh.
Inspection of oral cavity
Tracheostomy
Intubation
Assessing airway
Assessing airway