b. Molars. The three permanent molars on each side of the upper and lower
jaw pierce the gum (erupt) distally to (behind) the deciduous second molars. Normally,
at 6 or 7 years of age, the first permanent teeth to erupt are the first molars or the
central incisors. Since the deciduous teeth are still in place when the first permanent
molars erupt, the latter are often overlooked or mistaken for temporary teeth. Because
the molars contain many pits and fissures, they are prone to decay. If they are
neglected, they are often lost too early in life.
There are 32 permanent teeth, 16 in the maxilla and 16 in the mandible (see
figure 4-4). The permanent teeth on the right side of the mouth, for example, are
named as follows:
a. Maxillary right central incisor and mandibular right central incisor.
b. Maxillary right lateral incisor and mandibular right lateral incisor.
c. Maxillary right cuspid and mandibular right cuspid.
d. Maxillary right first bicuspid and mandibular right first bicuspid.
e. Maxillary right second bicuspid and mandibular right second bicuspid.
f. Maxillary right first molar and mandibular right first molar.
g. Maxillary right second molar and mandibular right second molar.
h. Maxillary right third molar and mandibular right third molar.
Several systems of numbering the teeth have been devised to simplify the
designation of a tooth by an authorized number rather than by name. The system used
by the armed services (see figure 4-4) begins with the maxillary right third molar and
numbers around the maxillary arch from 1 to 16. It continues with the mandibular left
third molar as No. 17 and goes around the lower arch from 17 to 32. By this method,
the number alone designates the tooth without the use of letters "R" and "L". For
example, tooth No. 3 is the maxillary right first molar and No. 24 is the mandibular left
central incisor. In dental records and general correspondence, the dental specialist
refers to a tooth by authorized number rather than by name.