Sources: A Manual Of Peroral Endoscopy And Laryngeal Surgery

Wide gagging prevents proper exposure of the larynx by

forcing the mandible down on the hyoid bone. The mouth should be

gently opened and a bite block (Fig. 16) inserted between the teeth on

the left side of the patient's mouth, to prevent closing of the jaws

on the delicate bronchoscope or esophagoscope.

[FIG. 16.--Bite block to be inserted between the teeth to prevent

closure of the jaws on the endoscopic tube. This is the

McKee-McCready modification of the Boyce thimble with the omission of

the etherizing tube, which is no longer needed. The block has been

improved by Dr. W. F. Moore of the Bronchoscopic Clinic.]