Wang Qian, Zhang Qun, Han Tao, Sun Zhichao, Dechow Paul C, Zhu Hong, Zhang Quanchao
Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, U.S.A.
School of Humanities, Nanyang Technological University, Singapore.
Homo. 2019 Aug 29;70(1):15-30. doi: 10.1127/homo/2019/1007.
Recent studies indicate that evolution of the craniofacial skeleton is influenced by dietary behavior, which in turn alters masticatory efficacy and temporomandibular joint (TMJ) stability. In this study the mechanical properties of the masticatory system and the integrity of the TMJ in human populations from Northern China, dated to between 3800 BCE and 100 CE, were assessed. The results demonstrate that the mechanical efficiency is comparable to other modern human populations, though variations are present across different populations. While the ratio of overall weighted muscle efficiency for incisor loading vs. molar loading in pastoral and some recent agricultural groups is similar to early , the ratio in more ancient agricultural groups is similar to the ratio in populations with heavy anterior paramasticatory activities, such as Neandertals, Inuits, and Native Americans. The TMJ vulnerability negatively correlates with the maxillary dental arch size, and positively with the condylar size. These findings suggest that there are multi-directional strategies in adaptation to heavy anterior teeth loading, such as increasing anterior teeth loading efficiency, increasing facial height, increasing facial breath and facial orthognathy, or decreasing anterior facial length. Furthermore, populations or individuals with a smaller dental arch and high biting efficiency could more easily injure the TMJ during unilateral loadings, which may explain the higher prevalence of TMJ disorders in modern humans, especially in women. These findings further reflect the impact of diachronic changes of the masticatory apparatus and lifestyle and their impact on oral health during recent human history.
近期研究表明，颅面骨骼的进化受饮食行为影响，而饮食行为又会改变咀嚼效能和颞下颌关节（TMJ）稳定性。在本研究中，对中国北方公元前3800年至公元100年间人群咀嚼系统的力学性能和颞下颌关节的完整性进行了评估。结果表明，尽管不同人群存在差异，但该人群的力学效率与其他现代人群相当。虽然牧民群体和一些近代农业群体中，切牙负荷与磨牙负荷的总体加权肌肉效率之比与早期人群相似，但更古老农业群体中的这一比例与前磨牙活动频繁人群（如尼安德特人、因纽特人和美洲原住民）的比例相似。颞下颌关节易损性与上颌牙弓大小呈负相关，与髁突大小呈正相关。这些发现表明，在适应前牙重度负荷方面存在多方向策略，如提高前牙负荷效率、增加面部高度、增加面部宽度和面部正颌，或缩短面部前部长度。此外，牙弓较小且咬合效率高的人群或个体在单侧负荷时更容易损伤颞下颌关节，这可能解释了现代人类尤其是女性中颞下颌关节紊乱症患病率较高的原因。这些发现进一步反映了咀嚼器官和生活方式的历时性变化及其在近代人类历史中对口腔健康的影响。
