Brachetta-Aporta Natalia, Gonzalez Paula N, Bernal Valeria
IIPG, Instituto de Investigaciones en Paleobiología y Geología, Río Negro, Argentina.
UNRN, Universidad Nacional de Río Negro. CONICET, Río Negro, Argentina.
Anat Rec (Hoboken). 2022 Jan;305(1):156-169. doi: 10.1002/ar.24640. Epub 2021 Apr 23.
The morphology of facial bones is modeled by processes of bone formation and resorption induced by interactions between tissues and compensatory responses. However, the role of remodeling patterns on the morphological changes within and among populations has been scarcely explored. Here, we assess the association between facial shape and the underlying bone cell activity throughout the ontogeny in two Amerindian populations that represent the extremes of craniofacial variation in South America. The sample comprises 71 individuals (36 adults and 35 subadults) representing hunter-gatherers from Patagonia and horticulturists from Northwest Argentina. We analyzed the shape and size of the zygomatic and the maxilla, and compared them with the patterns of bone formation and resorption. Bone formation and resorption were described by quantitative histological analysis of bone surfaces. Morphological changes were described by landmarks and semilandmarks digitized on 3D surfaces obtained from CT images. The results from multivariate statistics analysis show that the patterns of bone remodeling are associated with variation in the morphology of the middle face. We found a similar pattern of facial shape variation along the ontogenetic trajectory in the two samples, and a similar trend in the amount of formation and resorption activities across ages. The main differences between samples were found in the distribution of the areas of bone formation and resorption, possibly associated with mechanical bone response to masticatory loading. These findings provide clues about the processes and mechanisms of bone development involved in the facial morphological differentiation in human populations from southern South America.
面部骨骼的形态是由组织间相互作用和代偿反应诱导的骨形成与吸收过程塑造的。然而，重塑模式对种群内部和种群之间形态变化的作用却鲜有研究。在此，我们评估了两个代表南美洲颅面变异极端情况的美洲印第安人群体在个体发育过程中面部形状与潜在骨细胞活性之间的关联。样本包括71名个体（36名成年人和35名亚成年人），分别代表来自巴塔哥尼亚的狩猎采集者和来自阿根廷西北部的园艺种植者。我们分析了颧骨和上颌骨的形状及大小，并将其与骨形成和吸收模式进行比较。通过对骨表面进行定量组织学分析来描述骨形成和吸收情况。通过在从CT图像获取的三维表面上数字化的地标点和半地标点来描述形态变化。多变量统计分析结果表明，骨重塑模式与中面部形态变异相关。我们在两个样本中发现了沿个体发育轨迹相似的面部形状变异模式，以及各年龄段形成和吸收活动量的相似趋势。样本之间的主要差异在于骨形成和吸收区域的分布，这可能与骨对咀嚼负荷的机械反应有关。这些发现为南美洲南部人群面部形态分化所涉及的骨发育过程和机制提供了线索。
