Hi.. Can understand your concern.. As per your complain a white strip over the frenulum can not be a serious issue and as you have a tongue tied condition any pressure or trauma inflicted on the frenulum can lead to injury and causing inflammation and the white line can be as a result of the trauma and nothing serious.. It can also be a traumatic ulcer or a canker sore.. There are some minor salivary glands present in that region and any trauma to the gland or its ducts can lead to spillage of its content in the soft tissues leading to formation of a white appearing lesion or a small bump like of thing.. It seems most probably due to trauma and you need not to worry as it will heal by itself .. In case there is any exaggeration in pain or size you can consult a dentist.. For permanent relief from the issues of injury to frenulum and other problems you can get the Frenulectomy done in which the frenulum is incised and the muscles are dissected and sticthes are placed and the tongue is freed.. It is a minor surgical procedure but can be very much relieving.. Hope this information helps.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.