摘要
多生齿为正常齿列数目以外的牙齿,在现生人类中研究较多,但关于古人类多生齿的报道较少。晚更新世现代人-柳江人上颌硬腭中线右侧存在一颗圆锥型埋伏多生齿,通过高精度断层扫描和三维重建技术,发现其呈水平放置的状态,位置对应中腭区,齿尖朝向腭部后方,没有发现明显并发症。柳江人多生齿发生位置、形态、方向与包括全新世早期现代人在内的现生人类的部分案例重叠度较高,但是其综合特征具有特殊性。现代临床中有跟踪发现上颌前区的埋伏多生齿向腭部后方迁移的病例,因此推测柳江人多生齿特殊的发生状态可能是其迁移后的结果。柳江人作为东亚早期现代人的重要代表,不仅将中腭区水平放置多生齿的出现时间提早到更新世晚期,为埋伏多生齿的迁移现象提供了更早的化石证据,也为牙齿数目以及位置异常的古病理研究提供了新的参考案例。
Hyperdontia or supernumerary(or extra)teeth is one of the most common developmental anomalies in modern humans.Most supernumerary teeth are typically found in the maxillary anterior region,with about half occurring along the midline of the maxilla between the two central incisors,known as mesiodens.While supernumerary teeth have been extensively documented clinically,reports of such cases in human fossils are rare.This study describes a mesiodens embedded in the mid-palatal region of the Liujiang cranium,which is an early modern human from the Late Pleistocene in southern China discovered in the 1950s.The Liujiang mesiodens is partially exposed near the intermaxillary suture on the right side of the hard palate.High-resolution microcomputed tomography and three-dimensional virtual reconstruction further revealed that the mesiodens is conical in shape and horizontally positioned in the hard palate,with its long axis parallel to the intermaxillary suture.This mesiodens is situated distally to the long axis of the right central incisors with its cuspal apex facing the back of the palate,thus it is classified as a labiopalatinal type.Its crown corresponds to the position of the second premolar,away from the alveolar bone.Despite some distinctive features the location,shape,and direction of the Liujiang mesiodens overlapped with certain cases found in modern humans including that those from the Early Holocene.Based on clinical observations of pathological cases in modern humans,it is proposed that the Liujiang mesiodens may have migrated from the anterior region of the maxilla to the mid-palatal area.During this migration process,this supernumerary tooth adjusted its long axis from its original inverted form to its current horizontal position.This study provides evidence,dating back to the Late Pleistocene early modern humans for the occurrence of a horizontally positioned mesiodens in the mid-palatal region.Additionally,the Liujiang mesiodens presents early fossil evidence of supernumerary teeth in this special position and form than previously reported,as well as offers a case for the paleopathological study of abnormal number and position of teeth.
作者
孙琦雅慧
邢松
SUN Qiyahui;XING Song(Key Laboratory of Vertebrate Evolution and Human Origins,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049)
出处
《人类学学报》
CSSCI
CSCD
北大核心
2024年第6期1027-1037,共11页
Acta Anthropologica Sinica
基金
中国科学院战略性先导科技专项(B类)(XDB26000000)
国家自然科学基金(41872030)。
关键词
早期现代人
多生齿
古病理
牙齿畸形
Early modern human
Supernumerary tooth
Paleopathology
Dental anomaly
