Non-metric Dental Traits in Koreans and Its Racial Differences / 체질인류학회지

ABSTRACT

Since the non-metric traits of the human teeth are various according to the genetic or environmental factors, these dental traits are significantly used in distinguishing the different racial groups. The purpose of this study was to evaluate the non-metric dental traits of Koreans among the various races on the viewpoints of the physical anthropology. The materials of this study were conducted with incisors, canine, and molars collected from 168 Korean cadavers and the upper and lower dental models of 160 Koreans. We evaluated the 15 criteria of the non-metric dental traits of Korean teeth. The results were as follows. 1. Most of the Koreans' maxillary incisors were revealed to the shovel-shaped incisor, whereas, none of the mandibular incisors showed the shoveling. The double shoveling of the maxillary central incisors and the lateral incisors were observed in 31.2%, 7.6%, respectively. The presence of the shoveling of Korean maxillary incisors was the most compared to the other racial groups. 2. The peg lateralis were only seen in the maxillary lateral incisor by 10.2%. 3. It showed a relatively low rate in the presence of the distal accessory ridge of the canine and it was more commonly seen in the maxillary canine than in the manibular canine. 4. It was most common that the maxillary molar had 4 cusps (maxillary 1st molar: 96%, maxillary 2nd molar: 81.7%). On the other hand, mandibular 1st molars having 5 cusps were most common in 81.1% and mandibular 2nd molar having 4 cusps was most common in 52%. 5. The cusp-groove patterns of the maxillary molar occlusal surface were classified into 4 categories. Among these categories, "4" patterns were most in the maxillary 1st molars and "4-" patterns were most in the mandibular 2nd molars. 6. Carabelli's trait was mostly observed in the maxillary 1st molar and "high cone patterns" among the Carabelli's traits were shown in 9.9% Korean males. The presence of the Carabelli's trait was much lower than the Caucasian. 7. The cusp-groove patterns of the mandibular molar were classified into 4 categories. The presences of "Y5" pattern (45.6%) and "+5" pattern (51.6%) were equally observed in the mandibular 1st molars, while the "+" patterns ("+4" pattern : 46.3%, "+5" pattern : 40.0%) were most in the mandibular 2nd molars. From these results, the presence of "Y5" patterns in the Korean mandibular molars were lower, but it had a tendency that presence of "+5"patterns was higher than the other races. 8. The cases in which "cusp 6" was observed in the mandibular 1st molar and 2nd molar were 5.3%, 5.1%, respectively. And the presences of "cusp 7" were observed in the mandibular 1st molar and 2nd molar by 7.5%, 4.1%, respectively.