 Welcome back to another session in Dentistry Ammo. So we are continuing our dental age estimation methods. So last two sessions were about Dermigian's method and Gustavson method. The first one was radiographical method and the second one was morphological as well as histological method of dental age estimation. Those two were a little complicated. So we have more methods of dental age estimation. We have histological method. We have the dental DNA profiling for age estimation and we have the role of third molars. So this is quite easy but it does not have much role in dental age estimation. Only if the person with identity or dental age estimation under question is in and around age of 16, 17, 18 or 19 in that age group this will be useful. And we know the third molar its eruption sequence or eruption pattern is much varies that is 18 to 25. It has got the eruption pattern but we are thinking about the calcification. So this is the rule. If all four third molars are calcified then the chances of the individual being 18 year old is 96.3 percentage true in males and 95.1 percentage true in females. So if the persons all four third molars are calcified we can assure that the person is of 18 years of age and this will be character in 96.3 percentage males and 95.1 percentage females. And as you can see here Van Harden developed. Developed five stage system measuring the mesial root of developing mantibular third molar to determine the dental age that is stage one the crown is complete okay the person is 16.8 to 16.9 years. Then we have radiographic evidence of root formation that is stage two root length is greater than one third and less than one half person will be 17.5 years then stage three root length is greater than two third the person's age is between 17.8 to 17.9 years stage four root completely formed the person's age is 18.4 to 18.5 years and if the person's root apex is closed then the person age will be 18.9 to 19.2 years so likewise we can estimate the dental age of a person. So this is the role of third molar and dental age estimation this will be mostly useful between 16 to 19 where we are in doubt of crossing the 18 age because this method is completely depends on the calcification of third molars. So that's the role of third molars and dental age estimation this is mostly useful in adolescent group in around 15 to 20 years or 16 to 19 years where we can use the calcification of the small ass or the root formation of molars and identifying the dental age of a person. Hope you understood this small topic of third molars and dental age estimation next I will come up with the dental DNA role in age estimation. Thank you.