Show keeping UP 4 i cien n e n er v e 0 silence SO nce service service cat clue ic in geography to too lh decay i found by research effects of latitude and drinking drinkin water baltimore dentists socking seeking ways to pro prevent vent caries or tooth decay took a lesson in I 1 geography at the meeting hero here of the international association for dental research latitude hardness of drinking water and nearness to mining regions all seem to havo have an effect on tooth decay dr clarence A mills professor of experimental medicine at tile the university of cincinnati told the dentists the amount of tooth decay in american school children increases steadily throughout hout the tha united states as tile the distance from the tropics increases dr mills said tile the increase In creaso Is roughly 15 more decayed teeth per children tor for each added degree of latitude or well over per cent from gulf to canadian border E effects of ultraviolet ultra violet light dr wils mills explains this as being duo due to tile the decreased amount of ul tra violet light reaching inhabitants of tile the more northern latitudes the only exception to the increase of tooth decay toward tho the north Is found in the northern plains section I 1 where the sunlight Is more mora plentiful than in other northern regions of the country the part played by ul tra violet light in stimulating development of strong bones and teeth has already been shown dr mills pointed out hard bard water Is good for the teeth even though it makes dishwashing laundering and other household chores more difficult and presents a n serious problem to fac factories dr mills found almost so 30 per cent more caries among the children of cities using river and lake water than among those using water from wells or springs even though the mean latitude of the two groups was the same the reason for this ho he believes Is the degree of hardness of the water his data show that caries diminishes as hardness increases animal studies havu already shown that the calcium and magnesium supply in the drinking water and food affect bone and tooth formation and tooth decay caries and soil leaching another relation between geography and tooth decay is the finding that children living near the headwaters of a river have less caries than those living near the same rivers mouth this Is probably related to soil leaching dr mills suggests A high caries rate Is found tn in mining regions in pennsylvania and on down the ohio river thir may bo be accounted for by the millions of tons of sulp sulphuric hurle acid which seep each year from the mines into pennsylvania streams and on down the ohio besides corroding boilers metal pipes and river craft dr mills believes this acid may lead to tooth decay in persons drinking tho the water sulphuric acid will liberate calcium from bones and teeth in large amounts studies on lead poisoning treatment have shown tills this point and a possible relation between amount of tooth decay and amount of oxidized sulphur from coal combustion in the air of smoky cities need to be investigated further dr mills suggested exploring geographers know that primitive people usually have good teeth until they come in contact with civilization and that one of the first articles of trade brought to such peoples Is salt laboratory scientists know that when animal diets contain large amounts of salt calcium and phosphorus important bone constituents are excreted from the body in larger amounts recalling these two facts dr mills made a rough survey of salt use and tooth decay ile he found that children and adults who salt their food heavily have more decayed teeth |