In oro myofunctional therapy (OMFT) it is important to measure the muscular forces on a regular base, such as the strength of the tongue in extension, the lip pressure and masseter contractile force. This not only makes the diagnosis much clearer and more transparent, but the measurements also provide clear guidelines for therapy. Moreover, it is of great importance that the diagnosis, the therapy and the progress of the therapy can be demonstrated to referrers by means of reproducible measurements.