Effect of palatal bar on maxillary molars during swallowing

Abstract

We measured the vertical force transmitted through a palatal bar to the maxillary first molars during swallowing in 22 subjects with normal occlusion and mean age of 22.3 years. An intraoral sensor (cantilever type strain gauge transducer), a direct current amplifier, and a recorder were used for the measurements. The sensor was placed on the left maxillary molar band. The right end of the palatal bar was attached to the right maxillary molar band and the left end was connected to the sensor. A Goshgarian type palatal bar was used.
The measurements produced biphasic wave forms. Mean vertical forces were 743.3 g for 5 ml of water, 816.0 g for saliva and 925.2 g for 180 ml of water. Mean durations of applied force were 1.30 sec for 5 ml of water, 1.63 sec for saliva, and 10.37 sec for 180 ml of water. Mean integrals of force over time were 396.2 g・sec for 5 ml of water, 628.2 g・sec for saliva and 2,792.4 g・sec for 180 ml of water.
These results suggest that the palatal bar effectively controls vertical forces on the maxillary molars during orthodontic treatment. Shika Igaku (J Osaka Odontol Soc) 1996 Mar; 59 (1): 53-63.