The last tooth to come in at the back of each side of the upper and lower jaws. Third molars usually come in between 17 and 23 years of age, but not everyone has them. Also called wisdom tooth. Found on http://www.cancer.gov/dictionary?expand=T
Eighth permanent tooth in the maxilla and mandible on each side, making it the most posterior tooth in human dentition; usually erupts between the seventeenth and twenty-third years; the roots are often fused, the separation being marked only by grooves; because it tends to erupt in an anterosuperior direction, the lower third molar often becomes i... Found on http://www.encyclo.co.uk/local/20973