Matson's
Laboratory LLC
US Post Office address:
PO Box 308, Milltown MT 59851 USA
Physical address (for FedEx and other
couriers):
8140 Flagler Road, Missoula MT 59802 USA
Email address: gjmatson@montana.com
General
Information
The basis for cementum aging is the cyclic nature of cementum
growth, which results in an annular pattern of "rings"
in the tooth like that formed in the wood of trees. A darkly
staining ring, or "annulus," is formed during
winter. Abundant, lightly staining cementum is formed during
the growth seasons of spring and summer. The underlying
physiologic/metabolic mechanisms for cyclic cementum growth
are not known. Very darkly staining rings are formed in
southern regions of North America, but it is generally true
that most mammals in these regions have less distinct annuli
than their counterparts in more northern regions. Incidentally,
human teeth have similar annuli but the deposition pattern
is irregular compared to that of most wild mammals. (Matson's
has no expertise in the aging of human teeth.)
Matson's
uses a standardized cementum aging model for each species.
The models were originally described in "Workbook for
Cementum Analysis," published by Matson's Laboratory
in 1981. The original models are expanded on a continuing
basis, with additional experience.
All
cementum aging done at Matson's is by certified agers. Gary
Matson is qualified to age all species.
Cementum
age analysis training is ongoing at our lab. Technicians
are certified when results compare with Gary's with a precision
of 85-95%, a level that varies with population and species.
After a technician is certified to age a given population
of a species, Gary checks 10% of each sample aged by that
technician, for quality control, before the age report is
sent.
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Standardized
Tooth Type
Matson's
cementum age analyses are not only species-specific, but
also are based on a standardized tooth type. Mixing of different
tooth types in a sample to be aged can cause error not only
because of differences in age at eruption but also because
of anatomical differences in the cementum patterns of different
tooth types.
|
Standardized
tooth types |
| Most
Artiodactyla (cloven-hoofed mammals) |
Primary
incisor (I1) |
| Most
carnivores |
Lower
canine |
| Bears |
Upper
premolar one (UPM1) |
| Martens
and fishers |
Lower
premolar four (LPM4) |
| Mountain
lion |
Upper
premolar two (UPM2) |
|
Standardized
type for aging live mammals |
| Artiodactyla |
Lower
canine |
| Most
carnivores |
PM1
(upper or lower) |
| Mountain
lion |
UPM2 |
| Lynx
and bobcat |
Lateral
incisor (there is no PM2) |
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Workbook
for Cementum Analysis by
Gary M. Matson. The Workbook for Cementum Analysis brings
together the methods that were developed along with Matson's
cementum aging service. File format:
PKF/Adobe Acrobat. This is a large file and may take many
minutes to download. Please be patient.
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Archeological/anthropological
specimens
Matson's
is unable to process these materials. For moreinformation,
see "Archeological/anthropological
specimens."
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