Tooth morphology: what does that term mean?
When it comes to biology, morphology is the study of the form(s) of living organisms, and the relationships between their various structures. Scientists look at the shape and design of cells, organs, systems, and other features of organisms to determine their evolutionary path.
Dental morphology is a fascinating study into the shape, size, and distinguishing features of teeth that highlight unique biological relationships between humans. In fact, both archeologists and law enforcement understand the importance of tooth morphology in distinguishing humans. Teeth are often the final remaining pieces of human material which can help identify who the person was. Sex, age, and race can be identified through careful study of dental morphology. Below, read on to find out some more interesting facts about tooth morphology.
Your teeth are a central part of your anatomy. Make sure you’re taking care of them properly by visiting a highly-skilled and experienced dentist! Dr. James Fondriest offers Lake Forest residents exceptional dental care close to home. For complex cosmetic treatments to restorative procedures, our dental practice can help you achieve your smile goals. Call us today to schedule a consultation with Dr. Fondriest.
Tooth Categories
Four categories, or types, of teeth exist in humans. These include:
- Incisors: a narrow tooth in the front of the jaw which evolved to improve “cutting” abilities for chewing. There are four incisors on both the top and bottom jaw.
- Canines: Bordering the incisors, canine teeth have a longer, more pointed shape and are adapted for tearing food while biting and chewing. Humans have four canine teeth, two on each jaw.
- Premolars: Just behind the canines are premolars, or “bicuspids,” so named because of their two “cusps” on the crown. Cusps are small peaks on the chewing surface of teeth.
- Molars: Finally, molars are flattened teeth located in the rear of the mouth. They withstand the most pressure while chewing and eating, and are actually adapted from a word that meant “millstone” in Latin. Wisdom teeth, or third molars, are often extracted today. As the human jaw shrinks slightly over generations of evolution, less space in the jaw is available to accommodate the late-coming molars. Additionally, some humans do not develop third molars at all due to genetic variations.
A quick investigation of your own smile shows how much the shape and size of teeth vary.
Dental Identification
Three different identification systems exist that allow dentists, biologists, dentists, or law enforcement to identify specific teeth based on their location within the mouth and their unique form. You may have heard or seen a tooth identified by one of these symptoms on a past dental chart or treatment bill. The three identification systems include:
- Universal Numbering System: This system was formally adopted by the American Dental Association in 1975, and includes a range of numbers from 1 to 32. The upper jaw includes teeth numbered 1 to 16 (beginning from the right third molar to the left third molar), while the lower jaw includes teeth numbered 17 to 32, beginning from the left third molar and moving all the way to the right third molar. (Fun fact: for “baby” or primary teeth, the letters A through T are used.
- Palmer Notation System: In this system, four quadrants exist, including the upper and lower right, and the upper and lower left. Within those four quadrants, each includes teeth numbered 1 through 8, beginning from the front incisors and working back towards the molars.
- International Numbering System: Unlike the other two systems above, the International Numbering System utilizes two numbers for each tooth. The first number identifies the tooth’s form and quadrant location, while the second number identifies the exact location of the tooth within the quadrant.
Tooth Size
Studies indicate that genetic factors account for 60 percent of tooth size while 40 percent is contributed to environmental factors. It has been determined that maternal status affects tooth size as well. Prolonged gestation, large birth size and high birth weight have been associated with larger teeth. Maternal hypothyroidism and maternal diabetes also contribute to larger teeth. Short birth gestation, lower birth weight, and babies who are shorter in size at birth exhibit smaller teeth. Maternal hypertension is also associated with smaller teeth. Evolution has brought smaller teeth and smaller jaws through time.
Racial Origin
The existence or non-existence of certain dental features can help determine what racial group the person originates from. Such dental traits include:
- Ridges
- Bulges
- Cusps
- Grooves – deeper grooves increase cavities
- Pits – deeper pits increase cavities
- Junctions
- The relationship of different parts of the tooth to one another (for instance, the range and dimension of the crowns or roots of the teeth in relation to one another)
Other Characteristics
According to studies, the following dento-anthropologic structures are useful not only for identification purposes but to help establish race:
- Cusp size (the tiny points on your molars)
- The number and location of cusps
- Occlusal groove patterns (bite patterns)
- Root systems
- Number and arrangement of teeth
- Individual tooth measurements
- Dimensional proportions between different teeth
- Nature of the pulp chamber and canal
- Microscopic characteristics of the tooth surface
Dental characteristics should be only one factor among bone structure, facial features, skin characteristics, and body type when used to determine racial classification.
Tooth Morphology: Inspiring Better Care
Now that you know all about the morphology of your teeth, do them a favor and ensure their strength and functionality continue for years to come!
Aside from providing dependable general and restorative dentistry services to our community, Dr. James Fondriest also holds respected academic appointments at the Pankey Institute in Key Biscayne, FL, and the Spear Institute in Scottsdale, AZ, and he is a former adjunct Associate Professor in the Department of Prosthodontics at the University of Florida Dental School. At Lake Forest Dental Arts, Dr. Fondriest combines his impressive array of experience with modern technology and caring, compassionate, knowledgeable staff, and we proudly serve patients from Chicago and all surrounding communities. To schedule a consultation, call our office today at (847) 234-0517.