Abstract: A mouthpiece for covering or protecting the upper dentition of patients under medical or surgical treatments involving oral intervention, comprising an arched tray member to be placed on the dentition and a resilient loop member connected with opposed exterior wall portions of the tray member and in its natural position extending rearwardly from the tray member in the general plane of this member. When the loop member is bent downwardly and forwardly against its own resiliency the foremost portion thereof may be placed in the groove between the outside of the lower dentition and the inside of the underlip and lower cheek portions of the patient, whereby the upper tray member will be effectively held in its mounted position with a low degree of discomfort for the patient. The mouthpiece also causes a certain cheek distension for better skin fit of a mask.

Abstract: A stop end piece for closing particularly gutters, comprises a plate having a peripheral channel which is formed by the bent peripheral edge of the plate and a portion extending along said edge, which portion protrudes from the plane of the plate in the same direction as said peripheral edge. The peripheral edge has teeth which extend across the channel obliquely towards said portion and bear against or terminate at a small distance from the boundary surface of said portion, which faces said peripheral edge. The end of the gutter to be closed can be pressed into the channel, the teeth urging the inner side of the gutter wall into snug engagement with said boundary surface and simultaneously preventing withdrawal of the gutter end from the channel by their engagement in the outer side of the end of the gutter.