The invention relates to a bite block comprising a support wing (2-2a-b) with an inner surface and an outer surface, and a bite portion (4, 4a-c). The bite portion extends from the inner surface of the support wing and is arranged such that it extends over the bite surface of the teeth, while the support wing is intended to be arranged along the outer side of the row of teeth. Having only one support wing, the bite block may more easily be used with jaws having varying width of the row of teeth. The bite portion (4, 4a-c) is constituted by at least one ply of a resilient substance that absorbs liquid and expands when having absorbed liquid. The bite portion is easily handled and placed in position when dry, but fills and becomes resilient after having absorbed liquid. The bite block may have a bite portion (4, 4a-c) that comprises a first part that extends from the inner surface of the support wing and a second part that extends from the outer surface of the support wing, where the first part is shorter than the second. The first part does after having absorbed liquid fill out the space between the row of teeth and the inside of the cheek.