[Force-moment measurements on the passive palatal arch under the influence of the tongue].

Forces and moments, which the tongue transmits during swallowing to transpalatinally combined first upper molars, were measured in vivo. Three basic forms of the transpalatal arch were studied: one without an additional bend, one with a horse shoe bend facing the mesial, and one with a bend towards the distal. Regardless of which kind of palatal arch was used, tongue function caused intrusive, expansive and mesial directed forces. Using the arch form without an additional bend evoked both a mesial and a distal tipping moment. The arch form with the bend facing the mesial caused a mesial tipping moment during swallowing. When the horse shoe bend faced the distal, a distal directed moment predominated. For this reason in cases involving a problematical anchorage situation, a transpalatal arch with a horse shoe bend facing the distal should be employed.