Hi Dear, Indentations sometimes occur along the lateral borders (the sides), as the result of compression of the tongue against the adjacent teeth . When tongue becomes larger than normal, it will press onto your teeth. This tends to cause indentations. There can be many reasons for indentations like Swollen tongue , which could be due to allergies, some disease and conditions such as amyloidosis, hypothyroidism, tongue cancer, canker sores, scarlet fever and angioedema . If light test doesn t show anything then there is nothing to panic . The lumps you mention in query are probably due to canker sore due to frictional trauma . These usually go away in few days without any treatment . Do betadine rinses , speak less so that your tongue doesn t get hurt and do hydrogen peroxide rinses mix with equal amount of water twice a day . If condition persist then consult oral pathologist for proper evaluation . Hope your concern has been resolved. Dr. Harry Maheshwari