A dental appliance for protecting teeth has two front flaps separated by a forward cusp, and two side flaps separated from the forward front flaps by side cusps. An open area is provided in each of the forward front flaps. The appliance may also have a rear palate portion with a rear cusp. The appliance may have a line of symmetry that extends from the forward cusp to the rear cusp. Open spaces may be distributed throughout the sheet of material.A method of protecting the dentition of a patient during a transoral procedure or intubation includes the steps of providing the appliance in a planar first state and placing the appliance in the mouth of a patient so the patient's dentition crowns are located along a bite line on the appliance. The method also includes molding the appliance into a second, non-planar state to conform to the patient's dentition and palate so that the dentition are protected during the transoral procedure or intubation.