What Causes Food To Get Trapped In Oropharaynx Area?

When I eat, I frequently get small particles of food trapped in my posterior or anterior oropharaynx area; superior to the glottis, but posterior tongue. I cannot cough it up, swallow it down. or clear my throat to clear the particles. I am 45 yrs old. Never had a stroke, and can swallow a large bolus of food without difficulty. I was a trumpet player in my H.S. years. I am a R.N. for 22 years. Any ideas as to why food gets trapped in this area? I fear chocking at times, and I fear aspiration.