While placing the mouthpiece on the vermillion of the lips is commonly described by brass teachers as inherently damaging to the player’s lips or limiting to the player’s technique, the rational for these arguments lacks sufficient evidence to support this opinion. A review of the medical research found no specific evidence supporting the contention that the vermillion is incapable of withstanding the mouthpiece pressure applied by typical brass playing and found some evidence to the contrary. The music literature related to embouchure technique shows some support for the argument that rim contact on the upper lip will limit the vibrations of the top lip, however this position fails to take into account the differences between upstream and downstream brass embouchure technique.
To determine if an aural effect caused by mouthpiece placement on the vermillion could be noted a survey was conducted asking participants to listen to short sound clips of six professional trumpet players and guess whether the player placed the mouthpiece with significant rim contact on the vermillion. The 98 participants scored an average accuracy rate of 51.9%, suggesting that there is no noticeable aural difference between placing the mouthpiece on the vermillion or not.
It was noted that the lack of sufficient collaboration between the medical and musical fields has hindered research in the area of injuries and other medical issues caused by brass playing. Medical experts typically have an insufficient background in brass technique to understand how improper playing mechanics may contribute to injuries. Musical experts frequently make incorrect statements regarding the anatomy of the lips and often demonstrate limited understanding of how anatomical features affect individual player’s embouchure form and function.
Here is the full paper.