Effect of Jaw-Thrust Instruction on Trumpet Performance and Overjet of Young Players

The primary purpose of this study was to compare the effect of eighteen weeks of jaw-thrust instruction with an equivalent amount of regular instruction on protrusion of the upper teeth (overjet), intonation, ascending range, descending range, and lip flexibility of young players having from one (beginners) to five years experience on the trumpet. Inherent in the design of the experiment was an attempt to control for possible differences in the age, pretreatment overjet, and accumulated hours of practice time of the subjects in the two treatment groups at each of the five levels of experience. Analysis of the data indicates that jaw-thrust instruction appears to be superior to regular instruction with respect to improving intonation, ascending range, and lip flexibility. Neither type of instruction appears to be superior relative to improving overjet or descending range.