Page 89 - My FlipBook
P. 89
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87
proportion as the tooth grows longer, its cavity grows small-
er, and its sides grow thicker." Now, from my observa-
tions, the fact is directly the reverse ; the outer lamella,
which is the first formed is longest, the internal lamellae be-
come shorter and shorter, and the last formed is the short-
est. Hence in teeth with single roots, the cavity of the
shell is not only diminished, but it recedes from the apex or
cutting edge of the tooth, whilst a conical tube is left for the
admission of vessels, &c. the base of which ending in the
body of the tooth, has its opening or point nearly in the ex-
tremity of the root. The lamellae of a grinder, are distrib-
uted more irregularly than those of any other tooth,
on account of the protuberances of its pulp. As its exter-
nal lamella advances very slowly, a great number of the
internal ones are advancing, at the time that, the external
lamella has got so far as to form the neck. So that the cav-
ity of a grinder recedes from the grinding surface, more
rapidly than that of any other tooth. After the roots com-
mence, the cavity is soon diminished, the ossification going
on at the same time at both the upper and under parts of it.
As many conical or flatted tubes are left leading to the cavity,
as there are roots ; and as many hollows or depressions in the
superior part of the cavity, as there are protuberances on
the grinding surface. The pulp, though very much dimin-
ished, still retains nearly its original shape.
It may appear singular, that the pulp should not be en-
tirely obliterated, and the ossification completed, without
any remaining cavity ; it however affords this advantage,
that the vessels and nerves distributed on the soft membrane
of the pulp may have free action and not be compressed
by which means the internal bony part of the tooth may be
more readily nourished.
87
proportion as the tooth grows longer, its cavity grows small-
er, and its sides grow thicker." Now, from my observa-
tions, the fact is directly the reverse ; the outer lamella,
which is the first formed is longest, the internal lamellae be-
come shorter and shorter, and the last formed is the short-
est. Hence in teeth with single roots, the cavity of the
shell is not only diminished, but it recedes from the apex or
cutting edge of the tooth, whilst a conical tube is left for the
admission of vessels, &c. the base of which ending in the
body of the tooth, has its opening or point nearly in the ex-
tremity of the root. The lamellae of a grinder, are distrib-
uted more irregularly than those of any other tooth,
on account of the protuberances of its pulp. As its exter-
nal lamella advances very slowly, a great number of the
internal ones are advancing, at the time that, the external
lamella has got so far as to form the neck. So that the cav-
ity of a grinder recedes from the grinding surface, more
rapidly than that of any other tooth. After the roots com-
mence, the cavity is soon diminished, the ossification going
on at the same time at both the upper and under parts of it.
As many conical or flatted tubes are left leading to the cavity,
as there are roots ; and as many hollows or depressions in the
superior part of the cavity, as there are protuberances on
the grinding surface. The pulp, though very much dimin-
ished, still retains nearly its original shape.
It may appear singular, that the pulp should not be en-
tirely obliterated, and the ossification completed, without
any remaining cavity ; it however affords this advantage,
that the vessels and nerves distributed on the soft membrane
of the pulp may have free action and not be compressed
by which means the internal bony part of the tooth may be
more readily nourished.
