I greatly thank Drs. Downing and Baysinger for raising an important issue, my mistranslation of the Mallampati classification in my Editorial view for the noticeable article by Kodali et al.1,2
I totally agree with Drs. Downing and Baysinger that accurate knowledge and proper translation of the historical backgrounds of development of the anesthesia practice are important. Mallampati considered and hypothesized that the size of the base of the tongue is an important factor for determining the degree of difficulty during direct laryngoscopy.3
Mallampati et al.
prospectively tested and proved the clinical usefulness of a simple grading system of the relative tongue size into three classes by beautifully demonstrating its significant association with the laryngeal view during direct laryngoscopy in 210 adult patients.4
After the milestone article was published in 1985, Samsoon and Young recalled 13 patients with failed intubation who were anesthetized during 1982–1985 at their institute and performed the airway assessment proposed by Mallampati et al.
They noticed that even the soft palate was not visible in 12 of the 13 patients with failed intubation, and created the class 4 for these patients by modifying the original Mallampati classification.5
For reasons of historical accuracy and because of the fundamental differences between them, a clear distinction between the 3/3 Mallampati score4
and the 4/4 Samsoon–Young score5
is necessary. As Drs. Downing and Baysinger indicated in their letter, confusion was introduced after the article was published by Samsoon and Young, although, needless to say, they significantly contributed to the improvement of preoperative airway assessment. Most likely, careless reading of the articles resulted in the confusion of “modified” Mallampati score currently used by many clinicians and researchers. The number of airway classes is not the only difference between the airway classification systems. Very few careful readers may recognize that the anatomical landmarks used for definitions of the airway classes and order of concealment of the structures by the tongue base significantly differ between them. Mallampati et al.
defined three classes according to three anatomical landmarks seen as follows: class 1, faucial pillars, soft palate, and uvula; class 2, faucial pillars and soft palate; and class 3, soft palate.4
Samsoon and Young defined four classes according to four structures seen as follows: class 1, soft palate, fauces, uvula, and pillars; class 2, soft palate, fauces, and uvula; class 3, soft palate and base of uvula; and class 4, soft palate not visible.5
Clearly, the two airway classification systems are totally different.
The question is whether we have been accurately translating the difference between them for modifying and reshaping the Mallampati score; regretfully, we have not done well so far. There are confusions everywhere, but most of us do not realize them. Most anesthesia textbooks, including those mentioned by Drs. Downing and Baysinger, and original articles, even by Pilkington et al.6
and Kodali et al.
describe a “modified” Mallampati score with four classes defined by the three anatomical landmarks used by Mallampati et al.
The fourth is added as a condition that the soft palate is not visible. Clearly, the “modified” Mallampati score differs from the Samsoon–Young score. Despite using Mallampati’s anatomical landmarks, some anesthesia textbooks and even review articles use a figure published in the article of Samsoon and Young, introducing additional confusion. This confusion is possibly derived from the variability and complexity of the upper airway anatomy among patients. For example, it is difficult to determine the upper margins of the faucial pillars and the uvula. Mallampati et al.4
assume that the uvula is concealed by the tongue base first, whereas Samsoon and Young5
assume that the pillars are concealed by the tongue base first. Because of the anatomical variability, both could be wrong or correct. Compared with difficulty in determining the class 2 airway, both class 1 and class 3 are relatively easily determined. One solution to this inherent mistranslation or confusion would be to just define class 2 as an oropharyngeal view between classes 1 and 3. Now, many clinicians and researchers in nonanesthesia fields acknowledge the usefulness of Mallampati’s concept. I believe it is time for anesthesiologists to recognize the inherent lost-in-translation of the Mallampati score and to improve Mallampati’s concept. By doing so, Mallampati’s great work and his name will continue to live on in our medical field.
Shiroh Isono, M.D.
Graduate School of Medicine, Chiba University, Chiba, Japan. firstname.lastname@example.org
1. Isono S: Mallampati classification, an estimate of upper airway anatomical balance, can change rapidly during labor. Anesthesiology 2008; 108:347–9
2. Kodali BS, Chandrasekhar S, Bulich LN, Topulos GP, Datta S: Airway changes during labor and delivery. Anesthesiology 2008; 108:357–62
3. Mallampati SR: Clinical sign to predict difficult tracheal intubation (hypothesis). Can Anaesth Soc J 1983; 30:316–7
4. Mallampati SR, Gatt SP, Gugino LD, Desai SP, Waraksa B, Freiberger D, Liu PL: A clinical sign to predict difficult tracheal intubation: A prospective study. Can Anaesth Soc J 1985; 32:429–34
5. Samsoon GLT, Young JRB: Difficult tracheal intubation: A retrospective study. Anaesthesia 1987; 42:487–90
6. Pilkington S, Carli F, Dakin MJ, Romney M, De Witt KA, Doré CJ, Cormack RS: Increase in Mallampati score during pregnancy. Br J Anaesth 1995; 74:638–42
© 2008 American Society of Anesthesiologists, Inc.