Impacted wisdom teeth a small minority (less than 2%) of adults age 65 years or older maintaining the teeth without caries or periodontal disease and 13% maintaining unimpacted wisdom teeth without caries or periodontal disease. Periodontal probing depths increase over time to greater than 4 mm in a significant proportion of young adults with retained impacted wisdom teeth which is associated with increases in serum inflammatory markers such as interleukin-6, soluble intracellular adhesion molecule-1 and C-reactive protein. Crowding of the front teeth is not believed to be caused by the eruption of wisdom teeth although this is a reason many dental clinicians use
Permanent teeth lost or shed. The first of the permanent teeth to erupt are the permanent first molars, right behind the last 'milk' molars of the primary dentition. These first permanent molars are important for the correct development of a permanent dentition. Up to the age of thirteen years, twenty-eight of the thirty-two permanent teeth will appear. The full permanent dentition is completed much later during the permanent dentition period. The four last permanent teeth, the third molars, usually appear between the ages of 17 and 25 years; they are considered wisdom teeth. It is possible to have extra, or "supernumerary," teeth.