Wednesday, September 21, 2011

New Teeth Research Project

Today marks the day that I began my first dental-related research project! Although I concentrate in Molecular and Cellular Biology (MCB), I am currently working in the Dental Hard Tissue Lab in the Human Evolutionary Biology (HEB) department with Dr. Tanya Smith.

Live imaging

To hone my skills before jumping into my yet-to-be-determined project, my preliminary goal is to identify a tooth sample that was extracted by a dentist. There are two roots, one mesial and one distal, with the mesial one larger and more strongly grooved. Interestingly, there also appear to be 6 cusps with a maintained talonid basin, in addition to a suspected carious lesion which is perhaps why the tooth was extracted in the first place. Yet my best guess so far is that this is a lower first molar (M1) which is typically rare to extract unless there is a specific orthodontic/occlusal reason to do so. Further, the end of the roots suggest that the lower M1 is in fact from a juvenile. The typical dentist might have filled the carious lesion - aka cavity - but in this case the tooth was extracted ... interesting! An aggressive dentist indeed!

Suspected lower M1 from a juvenile



Today I also made a mold of the tooth, took some key measurements (mesial-distal and buccal-lingual), and also took some cool photographs (see below)! Research details will continue as I work on my technique. Next step will be a Micro-CT scanner to completely visualize the tooth!



Suspected carious lesion, likely reason for extraction

Live imaging focusing on the carious lesion

Stay tuned!

E

Thursday, September 15, 2011

Why are teeth Cool? 10 Reasons

As credited to Dr. Tanya Smith at Harvard, here are 10 cool and interesting reasons to study teeth and dental anthropology!

In other news, I'm taking her amazingly awesome course HEB 1421: Teeth -- check it out folks!


Me holding a tooth sample! Who knew roots were so much larger than the crown?

10) Abundance -- In many cases we have more fossilized teeth than living specimens. And in some cases of extinct species, all we have are their teeth!

9) Variation -- From variation in metric and non-metric data we can reconstruct phylogenies.

8) Development --As early as 10 weeks of fetal age, there are already signs of teeth buds! Further, the first (permanent) molars already appear 2-3 weeks before birth. Amazing!


Teeth morphology -- A small collection of Homo sapien teeth

7) Record-Keeping -- Using the 'birth certificate' embedded within our first molars and other cues we can determine approximate age at death with striking precision.

6) Forensics -- Aka forensic odontology aka everything you see on CSI, NCIS, and all those addicting, romanticized crime dramas. But seriously, you can reconstruct criminal events, identify remains, and even examine bite marks.

5) Aging -- Did you know that not everyone grows wisdom teeth, or grows all four of them? 3rd molar eruption is highly variable. Tooth wear in aged populations and calcification in juveniles can help determine age.

4) Stress & Disease -- Teratoma formation ... don't really want to elaborate

Our textbook -- does NOT compare to the online readings

3) Dietary Evidence -- Tooth chemistry, isotopic chemistry, micro and macroscopic wear. Also, more light and fun stuff like discoloration (er not quite fun) from coffee (very fun) and betelnuts (fun for some)!

2) Enamel Thickness -- Did you know that women have relatively more enamel, whereas men have relatively more dentine? Also, hominins have evolved to have really thick enamel.

1) Genetics -- Many dental traits and characteristics are indeed heritable. Shovel-shaped teeth, anyone?

And that's it folks! Come back soon for more!

E