VARIATION IN TORUS PALATINUS PREVALENCE IN NORWAY

The variation in torus palatinus (TP) prevalence was investigated amon g a total of 2010 dental patients over 10 yr of age native to two diff erent regions in Norway, the Lofoten Islands in northern Norway and th e Gudbrandsdalen valley, an inland area in the southeastern part of th e country. The two groups were presumed to belong to the same Caucasia n stock, but were extremes with regard to the fish-to-meat ratio of th e diet, which was 3:1 in Lofoten and 1:3 in Gudbrandsdalen, respective ly representing a soft type of diet, and a tough type requiring greate r muscular forces during mastication. The study revealed: 1) the preva lence of TP was higher among women than men; 2) TP seemed likely to ar ise from a multifactorial liability, with part of the genetic factors residing on the X chromosome; 3) the prevalence of TP appeared to be h igher among natives of Lofoten, who consume the softer food, than amon g natives of Gudbrandsdalen, the higher prevalence being hypothesized to have some connection with nutrient substances present in saltwater fish, possibly Omega 3 polyunsaturated fatty acids and vitamin D; and 3) TP seemed to be a dynamic phenomenon capable of growth and subject to resorption remodeling.