Modification of Heister Jaw Opener.

Heister introduced a mouth gag of incentric pattern which is still being used. Heister jaw opener has narrow blades which rest on the occlusal surface of molar teeth. The force of mouth gag is not equally distributed on all the teeth, therefore there is great risk of tooth avulsion in periodontally compromised dentition and fracture of tooth while using standard Heister appliance. To overcome this modification of Heister mouth gag is done.