YEARLING: Fawns are deer 1 year and 5 months or less--all milk
teeth are firmly in place. Third premolar has three
cusps. Yearlings are 1 year and 6 months or more.
Milk premolars are loose or shed, with permanent
premolars partially erupted.
1 YEAR, 7 MONTHS: 1 year and 7 months or more. Permanent premolars
fully erupted; they are white in contrast to pigmented
older teeth. Third permanent premolars. Third molar
partially erupted.
2-1/2 YEARS: The lingual crests of the first molar are sharp, with the
enamel well above the narrow dentine (the layer below
the enamel) of the crest. Crests are fully as sharp as
those of the second and third molar. Wear on the
posterior cusp of the third molar is slight.
3-1/2 YEARS The lingual (next to tongue) crests of the
first molar are blunt, and the dentine of the crest is as
wide or wider than the enamel. The posterior cusp of
the third molar is flattened by wear, forming a definite
concavity on the biting surface of the teeth.
4-1/2 YEARS The lingual crest of the first molars are almost worn
away. The posterior cusp of the third molar is worn at
the edge of the cusp so that the biting surface slopes
laterally downward.
5-1/2 YEARS No lingual crest on the first and second molar, although
rounded edges might appear like crests. An imaginary
line drawn from lingual to outside edges of first and
second molars would generally touch the enamel on
both sides of the infundibulum ( the depression
between outside and lingual crests. Dentine of the
lingual crests of all molars is broader than enamel.
6-1/2 YEARS Wear is moderate on first premolar, heavy on second
and third premolars. Infundibulum appears as fine line
or chevron on first molar or might be absent. On third
premolar infundibulum might appear as small
triangular hole.
7-1/2 YEARS First molar worn within 2 or 3mm of gum line on outside
and 4 or 5mm on lingual side. Second molar almost
smooth and third molar worn down until lingual crests
are completely gone. Infundibulum almost gone from
the third premolar.
