The use of teeth to estimate age has always been an open secret in scientific community especially within forensic applications. Dental age assessments aid in accurately estimating the age of subjects with unknown birth records. This process is particularly indispensable during investigation involving penal legislation. One of the main reasons necessitating this procedure is to rule out minors from the age of majority where mandatory sentencing is compulsory. Due to the atrocious impact should one be wrongfully convicted, the authorities are facing a great pressure and need for much more accurate age estimation models. This book discuses the current dental age estimation method used in children and sub-adults based on their permanent teeth and third molar development. In addition, the radiographic third molar eruption is also deliberated in detail. The prediction models developed from Willems (modified Demirjian), Kohler (modified Gleiser and Hunt) and Olze are deeply analyzed and validated. The book concludes with a handy list of recommendations for those actively engaged in dental age estimation research.