Soft Diet leads to a Short Mandible and subsequent Dental Overcrowding
A new research, published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), has found that the size of the mandible is primarily a reflection of the diet that a person consumes predominantly. While a long and narrow mandible is associated with hunter gatherers, a short and wide mandible is found predominantly in farming populations. According to the study, the size of the mandible is affected by the type of diet and the chewing habits.
The research was led by Dr. Noreen von Cramon- Taubadel, a lecturer in Biological Anthropology at the University of Kent. According to the research, as man evolved from being a hunter gatherer to a farmer, the affect showed on the growth and development of the lower jaw. For her study, Dr. Cramon- Taubadel compared the shape of the skull and the lower jaw of 11 different populations distributed over the world. The populations were selected on the basis of genetic, geographic, climatic and dietary differences. She found that while the shape of the skull is dependent to a large degree on the genetic relationships of the population, the shape and size of the lower jaw and the palate depended upon the diet and chewing habits of the population concerned.
As the human race evolved and became a society of agriculturalists, the diet became considerably soft. To chew this soft diet, not much effort is required. Therefore, the mandible becomes short and wide in such populations. One often sees a mismatch between the size of the lower jaw and the dentition in these cases. This mismatch leads to an increased incidence of dental overcrowding and malocclusions and is the basis of many dental problems that orthodontists face.