The first permanent tooth to erupt is

(B). The first permanent molars usually erupt between ages 6 and 7 years. For that reason, they often are called the "six-year molars." They are among the "extra" permanent teeth in that they don't replace an existing primary tooth. These important teeth sometimes are mistaken for primary teeth. The six-year molars also help determine the shape of the lower face and affect the position and health of other permanent teeth. The first deciduous teeth to fall are central incisors.