Boyle Davis Mouth gag

Boyle Davis mouth gag was initially used for inhalational anesthesia to keep the patient's mouth open. In 1910 Edward C Sewall published an exhausive description of a mouth gag which he had designed. He admitted that it was a variant of a mouth gag designed earlier by Hartman.

This mouth gag was noticed by S Griffith Davis. He modified it further to be used to performe tonsillectomy. In 1912, a description of Davis gag was published by Harvey W cushing. British anesthesiologist Henry E.G. Boyle when he was in US impressed by Davis gag bought one. He modified it and christened it as Boyle Davis mouth gag.

Its frame is open and is C shaped. The frame has an handle. A set of tongue depressors of varying sizes are supplied along with the gag. The tongue blade would slide into the slot provided for it in the handle of the mouth gag. The tongue blade will fill the space within the C limb. The tongue blade will hold the tongue thereby preventing it from falling into the surgeon's field. There are two extensions known as incisor prongs at the top of the frame which will fit into the patient's upper teeth. This extension is rubber lined to prevent injury to teeth. Since its invention and design this gag has undergone close to 20 modifications by different surgeons.

The size of the tongue blade varies from patient to patient. The rough size of the blade is chosen by keeping the blade across the patient's chin and oral cavity. The length of the blade should not exceed this distance. The gag is usually held in position by a M stand or a Draffin pod.

Advantages:

• Easy to apply
• Adjustable
• Allows both hands of the surgeon free
• Can be stablized using M jack / Draffin pod

Uses:

1. Tonsillectomy

2. Adenoidectomy

3. Palatal surgeries

4. Pharyngeal surgeries like UPPP

5. Surgeries of oral cavities

One disadvantage of this gag is that it cannot be used in tongue surgeries because of the presence of tongue blade