How does LTV affect mortgage interest rates?

My mortgage was approved putting 10% down for a purchase. My appraisal was not conducted yet, so it is 90% LTV based on the purchase price. If my appraisal comes in higher or if I put another 5% – 10% down, could this affect my interest rate? (Not taking PMI into consideration). Basically, do LTV’s [...] http://bit.ly/lVRJSO