US Patent 7988626 Lip and cheek expander

A lip and cheek expander for use when performing dental medicine, dental hygiene or dental-documenting activities has two tensioning frames (1, 2) and non-profiled film-like means (3) connecting the tensioning frames (1, 2). When the expander is fitted, the inner tensioning frame (1) inside the oral cavity and the outer tensioning frame outside lies against the lips and cheeks. The film-like means (3) are connected at one end to the inner tensioning frame (1) and at the other end to the outer tensioning frame (2). The film-like means (3) oppose forces (5) to the closure and contraction forces of the lips and cheek muscles and conduct them away onto the tensioning frames (1, 2). The mouth opening is thereby kept open and the lips and cheeks held back from the rows of teeth. A closing of the mouth is also possible when the lip and cheek expander is fitted.