By Melissa Pandika Whenever Matt Maxion approached the counter at McDonald’s, he wanted nothing more than to order chicken nuggets. But the bespectacled 7-year-old knew what would happen when he reached the “n” in “nuggets”: the tremulous, uncontrollable stutter that sometimes made his jaw clench and his chest ache as he felt himself shrink with shame. His tongue caught on harsh consonants — …