Aix-Marseille Univ, IFSTTAR, LBA UMR_T24, Marseille, France.
YooMed, Montpellier, France.
Am J Phys Anthropol. 2019 Dec;170(4):496-506. doi: 10.1002/ajpa.23933. Epub 2019 Oct 25.
Numerous tools have been developed to characterize the morphometry of 3D models. The aim of this study was to apply these techniques to better understand the morphometric growth pattern of healthy children's mandibles.
The study sample was composed of 480 very young children aged from 36 gestational weeks to 7 years old. The sample was divided into three subsamples according to the development stages of their deciduous dentition. Several biometric data were collected on 3D mandibular models.
There was homothetic growth during the first years of life. Once all deciduous teeth were fully erupted, the mandibular corpus warped more independently of the ramus, and the inter-individual variability was more pronounced. Throughout the growth period, several subgroups could be identified, highlighting the morphological growth pattern of the mandible.
A particular morphogenesis of the mandible during the growth period was observed, which was correlated with deciduous dentition development. In younger individuals, this morphological pattern was mainly characterized by the progressive closure of the chin symphysis and ramus growth. The tongue movements in the oral space, depending on whether the child was bottle- or breast-fed, may explain this result. As the children grew older, the mandible widened to create sufficient space for the developing teeth buds. During the eruption of deciduous dentition, the mandible took on various morphologies, which was likely based on the child's sex and diet. Therefore, we assume that this mandibular morphogenesis is induced by the functional strains affecting the mandible during deciduous teeth development.
已经开发出许多工具来描述 3D 模型的形态计量学。本研究旨在应用这些技术更好地理解健康儿童下颌骨的形态计量生长模式。
研究样本由 480 名从 36 孕周到 7 岁的非常年幼的儿童组成。根据其乳牙的发育阶段，样本被分为三个亚组。在 3D 下颌模型上收集了几个生物计量数据。
在生命的最初几年存在同形生长。一旦所有乳牙完全萌出，下颌体就会更独立于下颌支弯曲，个体间的可变性更加明显。在整个生长期间，可以确定几个亚组，突出下颌骨的形态生长模式。
在生长期间观察到下颌骨的特殊形态发生，这与乳牙的发育有关。在年幼的个体中，这种形态模式主要表现为颏部联合的逐渐闭合和下颌支的生长。舌在口腔空间中的运动，取决于儿童是奶瓶喂养还是母乳喂养，可能解释了这一结果。随着儿童年龄的增长，下颌骨变宽以在萌出的乳牙间隙中为发育中的牙蕾创造足够的空间。在乳牙萌出期间，下颌骨呈现出各种形态，这可能基于儿童的性别和饮食。因此，我们假设这种下颌骨形态发生是由影响乳牙发育期间下颌骨的功能应变引起的。
