The Dental Formula (Human)
Deciduous teeth: 2:1:0:2
Permanent teeth: 2:1:2:3
A fairly accurate way to determine skeletal age before the age of 12 is to look at dental calcification and eruption.
Using Ubelaker’s dental eruption chart, what would you age this mandible?
1st photo- Mandible from the archaeological site of Marcajirca in the northern Andean region of Peru.
2nd photo- Ubelaker, D.H. (1978). Human skeletal remains: Excavation, analysis, interpretation. Chicago: Aldine
Post Mortem Pink Teeth Phenomenon
The appearance of pink teeth after death is a common phenomenon in forensic dentistry. It seems probable that colouration of the teeth would be found in those regions of the jaws where the blood is seeking on the basis of gravitation hypostasis. Thomas Bell first reported the phenomenon in 1829. He described a pink colouration in teeth of subjects that have drowned or been strangled.
[Picture: Background — a six piece pie style colour split, alternating purple and green. Foreground — a picture of a fox. Top text: “Need to remeber the dental order of : Incisors, Canines, Premolars, Molars.” Bottom text: “Acronym: ‘I Came Prepared Man.’”]
Mod: Actually, its a mnemonic device, not an acronym. But helpful all the same!
a child’s skull before losing baby teeth.
Postmortem pink teeth phenomenon results from an inhibition of haemoglobin and haemoglobin breakdown products into the dentinal tubules. Post-mortem pink teeth must not be considered a reliable odontological parameter for determining the cause of death, however, the results of other studies have shown that the pink teeth phenomenon is a common finding related to cases of asphyxia such as strangulation, drowning or suffocation.
More on my Blogspot(an oldie but a goodie)
New Open Access Issue of Dental Anthropology Journal
Human Life History Evolution Explains Dissociation between the Timing of Tooth Eruption and Peak Rates of Root Growth
We explored the relationship between growth in tooth root length and the modern human extended period of childhood. Tooth roots provide support to counter chewing forces and so it is advantageous to grow roots quickly to allow teeth to erupt into function as early as possible. Growth in tooth root length occurs with a characteristic spurt or peak in rate sometime between tooth crown completion and root apex closure. Here we show that in Pan troglodytes the peak in root growth rate coincides with the period of time teeth are erupting into function. However, the timing of peak root velocity in modern humans occurs earlier than expected and coincides better with estimates for tooth eruption times in Homo erectus. With more time to grow longer roots prior to eruption and smaller teeth that now require less support at the time they come into function, the root growth spurt no longer confers any advantage in modern humans. We suggest that a prolonged life history schedule eventually neutralised this adaptation some time after the appearance of Homo erectus. The root spurt persists in modern humans as an intrinsic marker event that shows selection operated, not primarily on tooth tissue growth, but on the process of tooth eruption. This demonstrates the overarching influence of life history evolution on several aspects of dental development. These new insights into tooth root growth now provide an additional line of enquiry that may contribute to future studies of more recent life history and dietary adaptations within the genus Homo” (read more).
The man known only as 12011 lived in Poland between 5,450 and 7,500 years ago. He was a hunter-gatherer. He died roughly between the ages of 40 and 45. Beyond that, the details of his life are a mystery. We don’t know what his voice would have sounded like. We don’t know what he liked or disliked. We don’t know why he died.
We do, however, know which bacteria were living on his teeth.
Microbes grew inside his mouth just as they do on yours. They created a layer of plaque on his teeth, which eventually hardened into tartar—a substance that’s structurally similar to concrete. In tartar, bacteria become locked in a mineral cage of calcium phosphate, which is so tough and stable that they can last for thousands of years in pristine condition. That’s why the teeth of many human skulls still contain bacteria that lived inside their owner’s mouths—entombed for millennia, dead but not decayed.
Alan Cooper from the University of Adelaide used these preserved microbes to study how the bacteria within European mouths have changed over 10,000 years of history.
Mixed dentition is a stage that lasts 2-3 years. Permanent teeth are the second set of teeth formed — there are thirty-two permanent teeth. The first permanent tooth typically appears in the mouth at around age six, and the mouth will then be in a transition period with both deciduous teeth and permanent teeth, until the last deciduous tooth is lost. The first of the adult teeth to erupt are the permanent first molars that come through the gums at the back. Up to the age of 13, twenty-eight of the thirty-two permanent teeth will appear. The full permanent dentition is completed much later. The four last adult teeth, one at the back of every arch will appear between the ages of 17 and 25 years.
More on my Blogspot
Nothing makes you want to brush your teeth more than studying dental calculus and caries in palepathology class. Bleh
Yes but the phytoliths in that calculus…So very, very interesting for palaeodietary studies.
- Henry, A.G., Brooks, A.S. and Piperno, D.R. 2011. “Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium),” PNAS 108:486-491.
Showing a mesiodens(arrow) that has deviated the maxillary left central incisor to a horizontal position. A mesiodens is a supernumerary tooth located in the palatal midline between the two maxillary central incisors
Tooth decay, caused by extensive dental resorption. A healthy portion of the tooth surface can still be seen at the bottom of the image.
Scanning electron microscopic image.