After neck surgery 20 years ago, he developed a weak voice from a left sided paralyzed vocal cord. Five months ago Teflon was injected into the left vocal cord for a left paralyzed vocal cord. His voice has gotten worse since the injection.
His symptoms of poor vocal quality and singing impairment continued to worsen and he returned 18 months later. His left vocal cord has enlarged, most likely from his body's reaction to the Teflon particles in the injection. This is called a Teflon granuloma. The left vocal cord is more convex, thicker and stiffer.
With a flexible fiber-optic endoscope, the thickness of the left vocal cord can be easily perceived.
In order to improve his voice, the Teflon would need to be surgically removed.