Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
Philos Trans R Soc Lond B Biol Sci. 2010 Oct 27;365(1556):3397-410. doi: 10.1098/rstb.2010.0052.
A chronology of dental development in Pan troglodytes is arguably the best available model with which to compare and contrast reconstructed dental chronologies of the earliest fossil hominins. Establishing a time scale for growth is a requirement for being able to make further comparative observations about timing and rate during both dento-skeletal growth and brain growth. The absolute timing of anterior tooth crown and root formation appears not to reflect the period of somatic growth. In contrast, the molar dentition best reflects changes to the total growth period. Earlier initiation of molar mineralization, shorter crown formation times, less root length formed at gingival emergence into functional occlusion are cumulatively expressed as earlier ages at molar eruption. Things that are similar in modern humans and Pan, such as the total length of time taken to form individual teeth, raise expectations that these would also have been the same in fossil hominins. The best evidence there is from the youngest fossil hominin specimens suggests a close resemblance to the model for Pan but also hints that Gorilla may be a better developmental model for some. A mosaic of great ape-like features currently best describes the timing of early hominin dental development.
人科牙齿发育的年代表是目前为止最好的模型,可以用来比较和对比最早的化石人类重建的牙齿年代表。建立生长时间表是能够对牙齿骨骼生长和大脑生长过程中的时间和速度进行进一步比较观察的要求。前牙冠和根形成的绝对时间似乎并不反映身体生长的时期。相比之下,磨牙齿系最好地反映了总生长周期的变化。磨牙矿化的早期开始、较短的牙冠形成时间、牙龈萌出进入功能咬合时形成的较短根长,累积表现为磨牙萌出的年龄更早。现代人科与 Pan 相似的事物,例如形成单个牙齿所需的总时间,使人期望这些在化石人类中也是相同的。来自最年轻的化石人类标本的最佳证据表明,与 Pan 的模型非常相似,但也暗示大猩猩可能是某些方面更好的发育模型。目前,一个类人猿特征的镶嵌体最好地描述了早期人类牙齿发育的时间。