This article originally appeared in the Alaska Science Forum on April 21, 1980.
Humans are not the only ones to have dental
problems. The muskox, so well adapted in many ways to life in harsh
environments, has more than its share of dental anomalies. Here in
Alaska a large number of muskoxen have rotated teeth of a kind
similar to that occurring in young people and which they correct by
wearing braces. Some muskox have peg-shaped teeth, and some have
teeth that are congenitally missing.
In Greenland, I worked with muskoxen for the
Danish government. After examining skulls found in the field and in
museums, I became aware of the muskox's dental irregularities. Since
last autumn I have been working on the "Muskox project" at the
University of Alaska, Fairbanks, and have been able to examine the
teeth of 13 animals here. In one animal the outermost front teeth had
never developed, in four animals these teeth were peg-shaped, and in
three of the oxen one or more premolars were rotated approximately 90
In humans it has been shown that similar dental
anomalies are influenced by genetic factors. Based on the similarity
of the dental anomalies in human and muskox, I believe that the
anomalies in muskoxen also are genetically influenced. In Greenland
the frequency of the dental anomalies is very great in some areas
while very low in others. Therefore, it appears that the muskox in
Greenland occur in several discrete populations.
All the muskoxen currently in Alaska are the
descendants of some 30 animals caught in Greenland in 1930. In that
part of Greenland where these oxen were captured missing, peg-shaped
and rotated teeth are found in about 30% of the animals. That the
same dental anomalies are still found in muskoxen in Alaska today
after nearly 50 years of living under conditions quite different from
those in Greenland, is strong evidence for genetic rather than
environmental control of dental anomalies in muskoxen.
A major reason for examining the teeth of muskoxen
is that differences in the incidence of tooth anomalies in various
parts of the muskox range, from Alaska through arctic Canada to
Greenland, can show whether muskox herds exist isolated from one
another or whether there is continuous exchange between herds. If
animals readily move, then similar tooth anomalies should be found in
all parts of the muskox range.
About 25% of white North Americans have
disoriented teeth, and about 5% have missing or peg-shaped teeth
(wisdom teeth excluded). Since controlled breeding experiments with
humans are not feasible, not enough is known about the genetic and
environmental factors that may cause tooth anomalies in humans.
Consequently, knowledge gained from controlled breeding experiments
with animals sometimes results in better treatment of human
disabilities. Further investigation into the causes of dental
anomalies found in muskoxen might well yield benefits for mankind.
The ten animals now held captive at Fairbanks and the 175 at
Unalakleet, Alaska, provide good samples for these studies.
All About the Musk Ox