Sažetak sa skupa
The Comparison of Molar Traits in Krapina Hominids and Contemporary Humans
M. Maćešić
Zvonimir Kaić
Sažetak
The aim of this study was to investigate morphological characteristics of occlusal surfaces of permanent molars in Krapina hominid (KH) and to compare them with the findings in the modern population (control group, CG). ASU (Arizona State University Dentoanthropological System) standards for the characterization of morphological variants of permanent molars were used for classification of occlusal molar surface characteristics. A total number of 77 KH molars, among them 34 upper and 43 lower, as wel as 4836 CG molars, among them 2548 upper and 2288 lower ones was analysed. The analysis of occlusal molar surfaces revealed a lower incidence of distolingual cusps in CG third and second upper molars.
The disappearance of reduction in size of distolingual cusp resulted in a change in occlusal surface contour from rhomboid to triangular and H-shaped grooves were lost; these characteristics were more grequently present in KH (p < 0.05). The least difference was found in the first upper molar; the only significant difference was the Carabelli trait, present significantlly more frequently in KH (p <
0.01). In lower KH molars (M1, M2, M3) the incidence of distal cusp was reduced (p < 0.01). In both study groups the most frequent groove shape in M3 and M2 was + shape. X-shape was seen only in CG. The predominanat groove shape in M1 was Y-shape in both study groups. Based on these results, it may be concluded that the number of cusps was reduced ond the shape of occlusal surface
was changed in modern humans, leading to a reduction in the tital masticatory surface. Since Y-shape is considered most conservative and X-shape considered the most advanced by athropologist, we conclude that M1 remained the most conservative and did not undergo any progression in tooth evolution. The dominant groove shape in M2 was +shape. Since the +shaped groove is considered
intermediate stage the highest evolutionary stage of Y-shape, i.e. the initial stage in X-shape formation, this tooth can be considered the transitional stage in tooth evolutionary development. X-shape was found only in CG, indicating the significant advancement in tooth evolutionary development in comparisom with KH. The dominant
groove shape in M3 was +shape in both study groups. X-shape was not found in any of KH M3 in contrast to CG, where it was found in more than one fourth of teeth. This finding indicates that M3 reached the highest developmental stage among all lower molars in CG.
Ključne riječi
Hrčak ID:
3442
URI
Datum izdavanja:
15.9.2003.
Posjeta: 1.970 *