Question

Deficiency of flourine causes ______.​

Answer 1

Fluoride or fluorine deficiency is a disorder which may cause increased dental caries (or tooth decay, is the breakdown of dental tissues by the acidic products released by the "bacterial fermentation of dietary carbohydrates.") and possibly osteoporosis (a bone disorder which leads to a decrease in bone mass

Answer 2

Simple Answer :

TOOTH DECAY
OSTEOPOROSIS at a later stage