However, the dental morphology is simplified given the low frequency of shovel-shaped incisors and double-shovel pattern, the layered fold, and cusps 6 and 7 (17,18) .
Ceron (21) compared some discrete dental and cranial traits among a group of Andean mestizos and a native Embera population, noting that the latter group had high frequencies of shovel-shaped incisors and cusp 6.
Feature Tooth Temporary Dentition Winging ui1 Crowding Ui2 Upper central incisors ui1 Upper lateral incisors ui2 Double shovel ui1 Carabelli cusp um2 Reduction of the hypocone um2 Metaconules um2 Protostylid um2 Layered fold lm2 Cusp pattern lm2 Number of cusps lm2 Cusp 6 lm2 Cusp 7 im2 Permanent Dentition Winging UI1 Feature Tooth Crowding ui2 Upper incisors UI1 Shovel-shaped Incisors UI2 Double shovel UI1 Carabelli cusp UM1/UM2 Reduction of the hypocone UM1/UM2 Metaconules UM1/UM2 Protostylid LM1/LM2 Layered fold LM1/LM2 Cusp pattern LM1/LM2 Number of cusps LM1/LM2 Cusp 6 LM1/LM2 Cusp 7 LM1/LM2 Feature Gradation Temporary Dentition Winging 0.
0 was later used to determine the correlations of these CMDTs: shovel-shaped incisors (11 versus 12, 21 versus 22, FDI notation), Carabelli's cusp (16 versus 17, 26 versus 27, FDI notation), cusp pattern (36 versus 37, 46 versus 47, FDI notation), cusp number (36 versus 37, 46 versus 47, FDI notation), cusp 6 and cusp 7 (36 versus 37, 46 vs 47, FDI notation), and protostylid (36 versus 37, 46 versus 47, FDI notation) by means of the Spearman non-parametric correlation test.
Significant differences of these CMDTs were observed: Carabelli's cusp, configuration of cusps X5 and X6 (36, 46, FDI notation), and +4 and +5 (37, 47, FDI notation), absence of hypocone reduction, relative frequency of cusp 7, and low frequency of shovel-shaped incisors and double shovel, which are typical of the groups belonging or influenced by populations of the Caucasoid dental complex.
Let's observe then that shovel-shaped incisors (11, 12, 21, 22, FDI notation) present high correlation; protostylid (36, 37, 46, 47, FDI notation) present moderate correlation; and Carabelli's cusp (16, 17, 26, 27, FDI notation) and cusp pattern (36, 37, 46, 47, FDI notation) present low correlation, while cusp number, and cusp 6 and 7 between lower molars do not present any kind of correlation (table 3).
9) This is why low and middle expressions occur in the correlations of CDTMs among first and second upper molars (16/26 y 17/27, FDI notation) and the and second lower molars (36/37 y 46/47, FDI notation) while among upper central incisors (11/12, FDI notation) and upper lateral incisor (21/22, FDI notation) the trait of shovel-shaped incisors presented a high correlation.
We must take into account that, according to Turner, (24) the American continent was initially occupied by sinodont human groups--first subdivision of the Mongoloid dental complex--characterized by shovel-shaped incisors, deflecting wrinkle, Y6 cusp pattern, protostylid, and winging, such as the case of populations of Northern Asia that migrated from Northern China and crossed Beringia.
Talon cusps may be associated with other dental anomalies, especially in the permanent dentition, such as peg-shaped lateral incisors, impacted mesiodens and canines, odontoma, macrodontia, dens invaginatus, supernumerary teeth, shovel-shaped incisors
, bifid cingulum, additional tubercle on incisors, exaggerated Carabelli cusps, and microdontia of antimere teeth [Al-Omari et al.