Difficult intubation: thyromental distance and the atlanto-occipital gap.

Ten patients with a history of difficult intubation and 10 control patients were examined clinically and radiologically. It was shown that thyromental distance can be measured reliably clinically and further support is given to its usefulness as a predictor of difficult intubation. We were unable to demonstrate a conclusive link between thyromental distance and atlanto-occipital or atlanto-axial gaps. A review of X rays in other collections may add to the understanding of these factors in difficult intubation.