How many years does it take for a human to mature? Panoramic X-rays of the developing dentition of Philadelphia children show that children are maturing more quickly than children even 1 generation ago.
Philadelphia, Pennsylvania, USA
Children born after 1990
Working with pediatric dentists at the University of Pennsylvania Dental School and Temple University Dental School, Janet Monge (Penn Museum), Rose Wadenya (Penn Dental), and Angela Stout (Temple Dental) have been able to document a “secular trend” (a recent alteration in the time frame of dental and skeletal development) in maturation rate among youngsters in the US. It is still a mystery as to why this change is occurring: is it diet? is it food additives? is it obesity in young children? Over 1250 digitized panoramic x-rays (from Philadelphia school children) were analyzed and show that US children are maturing approximately 2 years earlier than has been previously documented.
Beyond the documentation of this secular trend, what are all of the implications to the study of maturation in fossil members of our lineage? New studies of dental maturation like our own, show that there is a lot of environmental plasticity in the timing of formation and eruption of the dentition. For many years, researchers have claimed the processes involved in the forming dentition were under tight genetic control. This study indicates that a large measure of dental development is influenced by environmental variables. These very same patterns of plasticity apply to both zoo-born and wild-born primates like chimpanzees and baboons. Although we usually claim that humans take much longer in growth and development of the dentition and probably other maturation variables, it seems that the distinction between ourselves and our close relatives like chimpanzees has actually blurred. There are strong implications of these studies when applied to long time extinct members of our lineage. Did they grow more in line with a human pattern or an abbreviated chimp-like pattern? And, it is important since elongated growth and development in humans is tied to the vast corpus of information necessary for human children to learn and internalize to become functioning members of our society.
We have all sat anxiously in the dentist’s examination chair and looked at the dental maturation charts of the walls. Maybe it is time to alter those charts to reflect the accelerated maturation of our children.
School of Dental Medicine, University of Pennsylvania