Comparative study of lower dental arch morphology between human samples from 3000 years ago and modern people

AIM: To investigate the human morphological evolution characteristics of lower dental arch by the measurement and comparison of the mandiblular arch shape of excavated samples with modern people in Xi'an City.METHODS: Forty well-preserved mandible samples of people living about 1,000 BC and those of modern people were selected.The existent length of dental arch,the length of dental arch,the length and width of anterior,middle and posterior segment of the dental arch were measured respectively.Data were analyzed with SPSS 13.0 for windows.RESULTS: The existent length of dental arch and the width of posterior segment of the dental arch of people of 1,000 years BC were larger than those of the modern people.There was no significant difference in all the other morphological indexes,including the length of dental arch,the length of anterior,middle and posterior segments of dental arch,the width of anterior and posterior segments of dental arch.CONCLUSION: No uniform decreasingtrend of the whole lower dental arch was observed,although some parts of the mandible dental arch showed slightly decreasing tendency over 3000 years in Xi'an inhahitants.