Remove larger bones from anchovy fillets. Place in a small mixing bowl and mash to a paste with the back of a spoon. Add in Greek yogurt, olive oil, lemon juice, mustard, Worcestershire sauce, garlic, pepper salt and sugar and stir until well blended. Chill in refrigerator while preparing remainder.
For the salad:
Cook pasta in salted water according to directions on package. Drain and rinse just briskly so noodles don't stick then let cool. Add lettuce, pasta, chicken and half of the tomatoes to a salad bowl. Pour dressing over top, sprinkle in half of the parmesan and toss to evenly coat. Top with remaining half of the tomatoes, the croutons and the remaining parmesan and serve immediately.
*Yes they smell terrible but that really are a must for this dressing, they are a key flavor for caesar dressing. It doesn't add a fishy taste just a rich flavor. I don't recommend anchovy paste as it's not quite as good as the freshly mashed stuff.