The age of 12 permanent molars 6 source formation, teeth grow footnote rows of teeth to catch various dental routine dental transferred under the grip. Operations and development perspective 6th gear teeth with dental row a key role to ensure a balance between teeth. This is the dental caries and other reasons deviations in adjacent teeth, jaw bones flaw, merge lengthen teeth, chewing on a toothpick footnote central line switch the arc fault is the key basic conditions.We study in MNUMS Dental school 2013-2014 customers in 1:1 ratio unfolded taken x-ray studied biological life in a sample of pictures of children over the age of 12 . Picture Image J 1.49b measurement statistics into the application development with SPSS 17.0.Biological age of 12 years old 6th gear teeth grow reach during our study involved 56 children , 18 ( 32.14 %) were taken in 6th gear teeth .Therefore, the 6th gear to be controlled from the start grow regular dental caries prevention laces jaw bone and teeth abnormalities shows the importance of the development.