The Y doesn't stand for anything. It is part of the word RAY. In fact, the X doesn't stand for anything either. They were called x-rays because the type of radiation was unkno â¦ wn at the time. is added to make the name sound better. Megaman X, Sonic X, etcetera. It could stand for Extreme or something but that's looking a bit t â¦ oo much into it. 1  Cancers: X-Ray Identification of a Sarcoma Tumor In orthopedics, cancer is a serious issue because of the metastatic nature of cancerous malignancies.
Calculus is the study of how things change. It provides a framework for modeling systems in which there is change, and a way to deduce the predictions of such models. I have been around for a while, and know how things change, more or less.
Calculus is the result of dental plaque calcification. Keeping it for too long can lead to an inevitable premature tooth loosening and thus to teeth loss. A teeth cleaning consists in removing all the calculus coating fixed on the dental surfaces and especially in between the teeth.