Nemoto, Toshio. Ageing and Dental Problems of Brass Players. Brass Bulletin 103, no. 3 (1998): 102-4.
Over time, mouthpiece and tongue pressure may cause teeth to change angles. These changes are gradual but may affect range and endurance. One tell-tale sign is a change of playing angle. Traditional orthodontic treatment may not be used in these cases as it may damage or weaken the alveolar (bone) structure. Instead, a removable retainer worn at least two hours a day is best.