六千年前河南淅川下王岗人群下颌骨形态的观察对比

Observation and comparison of mandibular morphology of Xiawanggang population 6 000 years ago

目的:分析河南淅川下王岗人群下颌骨第3磨牙、颏形、舌骨沟桥、舌骨沟、下颌前翘、摇椅式下颌等性状的表现特点,并通过对比探讨相关的时代变异。方法:对44例下王岗下颌骨的这些性状特点进行分类和记录,并对比全新世其他人群这些性状的表现特点。结果:下王岗第3磨牙正常的比例为63.6%,颏形主要表现为圆形(68.2%),舌骨沟桥出现率为6.8%,下颌前翘出现率为18.2%,摇椅式下颌出现率仅2.3%。下王岗与其他人群对比中,颏形的表现及摇椅式下颌出现率有显著差异。结论:下王岗人群第3磨牙“正常”率可能代表了新石器时代早期人群相应的表现特点;不同人群中颏形、摇椅式下颌的相应出现率差异显著,可能主要源于观测标准的把握上不同观测者间差异很大,这一定程度上反映了传统形态分类及观测方法的弊端,包括颏形在内的轮廓形状研究中几何形态测量方法更有优势。

Objective:To analyze the physique characteristics of lower third molars,chin form,hyoid groove bridge,hyoid groove,mandibular anterior tilt and rocking chair in Xiawanggang population of Xichuan County,Henan Province,and to explore the age variation.Methods:The physical traits of 44 Xiawanggang mandibles were classified,recorded and compared with other Holocene populations.Results:63.6%of the third molars were normal.The chin form was mainly round(68.2%).The occurrence rate of hyoid groove bridge was very low(6.8%),mandibular anterior tilt was 18.2%,and rocking chair was only 2.3%.There was a significant difference in the comparison of chin form and rocking chair between Xiawanggang and other population.Conclusion:The normal rate of the third molars in Xiawanggang population may represent the characteristics of the early Neolithic population.The corresponding occurrence rates of chin form and rocking chair in different populations are significantly different,which may be mainly due to the great differences in the observational criteria,reflecting the disadvantages of traditional morphological classification and observation methods.It is better to use geometric morphometrics to study the chin form.