Dysgnathia (jaw and tooth anomaly, tooth misspacing, macillodento-facial anomaly) influences to a certain degree the development of defects of articulation especially sigmatism. Other factors, such as mild motor system inco-ordination and hearing defects, besides dysgnathia, are frequently observed. Speech therapy is necessary preceding as well as together with the maxillofacial treatment. The dental, prosthodontic and maxillofacial prostheses may likewise interfere with enunciation, but this will disappear spontaneously within 2 weeks or will be compensated for. If necessary the prosthesis will have to be altered.