engleski

Influence of secular trends in the development of permanent teeth from 1977 to 2007

Aim: The aim of this study was to evaluate the influence of secular trend on dental development or dental age in latest thirty years. Materials and methods: Sample consisted of 1200 orthopantomograms of children between 6 and 17 years, divided in two groups, from region of Istria and Primorje (Craotia). Group A consisted of 600 orthopantomograms (307 boys and 293 girls) , x-rayed between the years of 1977. and 1979. Group B consisted of 600 orthopantomograms (251 boys i 349 girls), x-rayed between the years of 2007. and 2009. Chronological age was determinated according to day of birth. Dental age of was assessed according to the method proposed by Demirjian. Results: Subjects from group A had statistically significant higher chronological than dental age (P‹0, 001), as well as subjects from group B ; average chronological age was higher than dental age (P=0, 003). Man –Whitney test showed statistically significant difference in dental age between group A and B. (P‹0.001). Subjects from group B had significantlly advanced-older dental age from subjects in group A. Difference rated on average 0.9 years (10.8 months). Subjects from group A had statistically significant higher chronological than dental age (P‹0.001), as well as subjects from group B ; average chronological age was higher than dental age (P=0.003). Dental age was underestimated for 0.4 years (4.8 months) in Group B and 1.2 years (14.4 months) in Group A. Stage C and D were significantly more rapresented in group A than in group B (stage C: P=0.019, stage D: P<0.001). Stages F and G were more rapresented in group B (both P=0.001). For all left lower seven teeth there were more advanced stages (F, G, H) in Group B, than in Group A. Correlation coeficient in Group A was high , r=0.746. Correlation coeficient was also high in Group B, r=0.885. Development of all left lower seven teeth was advanced in Group B, except for the first left lower molar (P =0.375). Conclusions: Difference in dental age between groups was, on avrage, 0, 9 years or 10.8 months. In group B there were present more advanced stages - F, G, H than in Group A. Those results confirm the influence of positive secular trend in development of permanenth teeth in population of Istria and Primorje (Croatia). Dental age was underestimated in relation to chronological age, for 0, 4 (B) to 1, 2 (A) years. Correlation between dental and chronological age was high.

secular trend; permanent teeth

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