广西崇左智人洞早期现代人龋病及牙槽骨异常研究

Dental Caries and Mandibular Anomalies of Earlier Modern Humans from the Zhirendong Site,Chongzuo,Guangxi

2007-2008年,广西崇左智人洞发现了3件智人化石标本,智人Ⅱ号为下颌右侧第3臼齿伴有部分下颌骨,智人Ⅱ号为游离的下颌右侧第2或第3臼齿,智人Ⅲ号为人类下颌骨中间部分残段。釉系测年结果显示其为距今10万年左右,是目前东亚地区最古老的早期现代人。这3件化石标本显示出一系列的病理及异常现象:智人Ⅱ号牙齿齿根大部分暴露,牙槽骨萎缩,个体生前患有严重的牙周炎;智人Ⅱ号牙齿龋病严重伴随齿根部大区域突起的白色钙化状的牙骨质增生,个体生前可能患有严重的牙周组织炎症;智人Ⅲ号下颌骨牙列拥挤,双侧中门齿扭转,双侧前臼齿对称性出现根尖周炎症状,最大可能个体生前双侧前臼齿具有畸形中央尖,突出的牙尖折断后牙髓感染导致根尖部牙槽腔扩大。更新世古人类出现龋病的情况非常罕见,智人洞发现的人类龋齿是目前我国乃至东亚地区报道的最早的龋病病例。智人Ⅲ号下颌显示的牙列拥挤与牙齿扭转对于探讨人类咀嚼器官的退行性演化有重要参考价值。

Between 2007 and 2008, three human fossils were found in Zhirendong, Chongzuo, Guangxi. Zhiren Ⅰ is a small piece of alveolar bone around the second or third right mandibular molar. Zhiren Ⅱ is a single right mandibular third or second molar. Zhiren Ⅲ is the anterior portion of a mandible with 8 full alveoli present. They are dated by U-series to 100＋ka BP. The Zhiren fossils are the earliest modern humans in East Asia and present a suite of dentoalveolar abnormalities. Zhiren I shows strong bone resorption around the apices of the roots, which are largely exposed. The Zhiren I individual was suffering from serious periodontitis. The Zhiren Ⅱ molar has a severe carious and large lesion on the distal surface, which extends from the root of the tooth over the cement-enamel junction to the occlusal surface, and the pulp chamber is exposed. It is likely that there was pulpal infection and necrosis. Around the roots of the Zhiren Ⅱ, there is a large area of white calcification, probably from inflammation of periodontal disease. The ZhirenⅢ mandible has dental crowding, bilateral Ⅰ, rotation （winging）, and bilateral mesial premolar （P3） periapical lesions. Presumably, supernumerary cusps were situated at the occlusal surface of the bilateral premolars of the Zhiren Ⅲ individual, and this elevation sooner or later became damaged or broke off during tooth use. The root canal opened, the pulp chamber became infected and caused the bilateral mesial premolar periapical lesions. Dental caries in Middle and Late Pleistocene are very rare. The Zhiren II dental caries is the earliest case found in China and East Asia. It supplies new evidence in understanding the origin and history of the caries.