 Hello everyone welcome back to another session in dentistry and more today we have a very important topic in order pathology which comes under foreign sick dentistry that is dental age estimation on exam point of view you would have one question from this topic in every question paper sometimes it will be Gustafson methods, divergence methods or histology method or simply dental age estimation so we just cannot skip this chapter for on exam point of view so mostly asked questions are the dental age estimation then the histology method of dental age estimation Gustafson's or divergence method so let's see one by one this will be dealt in a few sessions today's session is about the two methods that is the morphological method Gustafson and the radiology method demygens so we'll start with some basic idea of dental age or age estimation so age estimation is an important factor in biological identification in many foreign sick fields such as foreign sick odontology foreign sick medicine foreign sick anthropology and foreign sick osteology so it helps to narrow the search possibilities for unidentified dead people or living individuals mainly for the legal purpose and it also helps to determine the age of criminals for mainly those who are in the younger age group because the age if they are adult the punishment they get is different and if they are minor the punishment they get is different so in order to prove their real age we can depend on the various methods so therefore accuracy of age estimation methods for suspects with unknown chronological age who are involved in any type of crime is needed in the interest of justice so first we need to understand few terminologies that is what is chronological or real age what is skeletal age and what is dental age the first one is chronological or real age that is measured by the calendar sometimes it be a period of intra uterine development or number of years after birth so this is a commonly non method of age estimation that is a chronological age but as a skeletal age which is determined by the degree of ossification or development of various bonds which is known to occur at particular time in average individual so we calculate skeletal age by comparing with the ossification or development of various bone so every bone has a particular pattern of ossification so we correlate with those bonds and calculate the skeletal age finally the dental age which is determined by studying development of various teeth from time of crypt formation crypt is when the crypt is visible till the time of fruit completion so we have a pattern or a time period where each step of a tooth formation happens for particular tooth so it it will not vary much in people so we can correlate those standardized stage of tooth development or a particular tooth and calculate the dental age so that is what we are going to learn the dental age estimation so we have lots of method for skeletal age estimation so today's session is about or the future sessions are mainly on the dental age estimations so we have few methods for dental age estimation they are morphologic or visual examination radiographic examination histology examination and biochemical examination the morphologic or visual examination which are based on the assessment of teeth that is XYO measurement so XYO means in a living person so these methods require extract teeth for microscopic preparation so if we if a person in a dispute of his age identification we need to extract the person's tooth but these methods may not be acceptable due to ethical religious cultural or scientific reasons so that is morphologic or visual examination this is basically XYO method which is done in persons by removing the person that is in a living person so to extract the tooth we have many problems so this method is quite difficult so we have the most commonly used morphological method they are the Staphson method and many methods are there such as solhe methods maples method joints and methods but the main problem is which is not possible to be performed in a living person because we need to take out the tooth and do a XYO study that is outside the tooth with minimal alteration of that specimen that is ethically it's not tall a good thing so it is not possible in living person whereas biochemical methods are based on the amino acids so the amino acid and and the resummitation of these amino acids so the resummitation of amino acid is a reversible first order reaction and which is related a rapid in living tissues in which metabolism are slow resummitation so we can correlate with the resummitation process of these amino acid so the aspartic acid has been reported to have highest resummitation rate of all amino acids and to be stored during aging so which can be correlated and age can be calculated that is the biochemical methods so the Ritz et al method Ritz et al method and the health man and health man all are under biochemical methods whereas the radiographic method this follows the pattern of maturation of teeth so you know teeth having the growth from its crypt to the root formation it starts from birth and even it starts in the utero for the deciduous teeth and it starts from birth for the permanent teeth which has it starting the per first permanent molars during the birth and around seven eight years and it goes on for the second molars so we can correlate various stages of calcification the root formation root completion crown formation and the layers of crown formation dentin enamel all those can be calculated or do a radiographic examination and correlate with the standard tables so such method is known as the radiographic method the most commonly used is a demogenes method so a demogen has formulated a table for boys and girls and he classified eight stages where can correlate the formation step or the stage of its formation and convert the stage into a score add all the teeth score and make the age estimation so we'll be dealing these two methods in detail and this radiographic method is a simple one which is a simple non-invasive and reproducible method because we are taking radiographs and which can be employed both on living and the unknown dead people so various radiographic images that can be used in age identification are IOPs lateral oblique radiographs cephalograms the opg's or digital imaging and any advanced imaging technologies now let's focus on mainly the demogenes method and Gustafson method so in the radiographic method the most common one is demogenes method so this demogenes method actually started in 1973 by group of people so it uses the seven teeth in the left side of mandible that is a third quadrant teeth the central incisor lateral incisor canine first second premolar and first second molar so this is the left side of mandible that is a third quadrant teeth seven teeth are used and they used stages A to H that is a stage which is having a minimal calcification or tooth formation and to the last stage so these stages were used to mark the developmental stage of the tooth in the suspect that is the stages where formulated by demogen which has usually marked by recognizable tooth shapes from the beginning of calcification through to final mature form so these stages must be easily recognizable and such that a tooth always passes through the same stage in every individual so it can be easily correlated and calculated so since these stages are indicators of maturity and not of the size they cannot be defined by any absolute length measurement so we first select the seven teeth okay so we start from the second molar then first molar second first premolars canine lateral incisor and central incisor and all the teeth all the seven teeth are rated on a scale A to H okay so the rating is assigned by following carefully the written criteria for each stage and by comparing the tooth with the diagram and x-ray pictures given for comparison and for each stage there are one two or three written criteria which is marked by A, B and C so you can see here the stages of demogen that is A to H and its characteristics so the stage A that means you can see the picture here it is a calcification of single occlusion points without fusion of different calcification so we are going to compare it with a tooth and whether it matches the stage A or not whereas the stage B fusion of mineralization points the contour of occlusion surfaces recognizable so we compare the x-ray film of that particular mantibular third quadrant teeth with these images and find out where exactly our tooth matches so stage A stage B stage B as occlusion surface recognizable whereas stage C is much more formation has happened enamel formation completed at occlusion surface and taintain formation has started pulp chamber is curved and not pulp horns so that is stage C so we need to match it with our x-ray for each tooth then stage D crown formation completed at till the level of CJ root formation started pulp horns are started but the walls of pulp chamber remain curved whereas the stage E the root length remains shorter than the crown height the walls of pulp chamber are straight and the pulp horns have become more differentiated than in the previous stage whereas the stage F the walls of pulp chambers now form a triangle and the root length is equal to or greater than the crown height in mollusk bifurcation as developed sufficiently to give the root a distinct form so we are comparing the x-rays of our particular patient's third quadrant teeth with the now this dermygens dermygens A to H stages and finally we have G and H stages in G stage the walls of the root canal are now parallel but the apical end is open and H the root apex is completely closed the periodontal membrane surrounding the root and apex is uniform and we throw out so A is the beginning of calcification and tooth formation H is the completion so we need to compare H to H stages with our tooth okay so I told you for every stage we may have one two or three criterias okay so one two three criterias if just one criteria is there for a particular stage so we need to fulfill that criteria for to correlate with our tooth to that stage if we are getting the criteria we can score the particular tooth to that stage if we have two criteria then it is sufficient if the first one of them is meant for the stage to be recorded if three are there I mean three criterias are there we need to match the first two okay each stage in addition to the criteria for that stage the criteria for the previous stage also must be satisfied so in borderline cases we can go with the earliest stage so that is how we do assessment that means the A to H so we are the first step is we are putting our teeth into various stages of tooth formation the next step is convert this stage what we obtain for each tooth to a score that is a numerical value so here what you see is a table for boys and girls okay that is self-weight score for dental stages of 70th can see the 70th okay and stages for boys and girls can see the incisors lateral incisors canine primolars and molars so we have various stages that is A to H A B C D E F G and H and for each stage for each tooth where a particular score is there this is a standardized score and we need to convert our stage into this core value okay so suppose if we have a score that is the molar one the first molar we got E okay so from our first stage that A to H stage for the first molar this tooth for a particular boy we found out that it belongs to the stage E okay so then we go to this table and we check the boys and first molar score where exactly is coming score score E which is coming around 9.6 okay so that is a first molar if it is the prem second premolar it will be 12 then first premolar it will be 11 so for each stage for each tooth it varies so this is standard score so we have seven stages here okay so it will be sometimes B sometimes H sometimes GA like that okay so now we are converting all this score into numerical values based on the standardized scores now we got seven scores okay so all these alphabets that is a A to H stages alphabets are turned into numerical scores after that we are going to add up all the individual score so we need to add seven individual score of seven teeth so that's how we get the final maturity score that is the added value of seven individual scores okay so once we get this maturity score our job is almost done now we need to assess the age of that person assess the dental age of a person from a standardized chart so these charts they are the demigian's charts for all the seven teeth okay so seven teeth maturity score maturity score can be compared with this table that is separate for the boys and separate for the girls so we get a value and we are going to correlate with this table okay so we can see the age here from 3 to 16 so 3 starting from the score 12.4 and it is ending in a 98.4 by the age of 16 so after calculation suppose we get a value of 45 okay for boys for it is separate for boys and girls so if we get a value of 45 we need to check the score 45 in the boys table so it is coming somewhere here that is six years and nine months so we finally found out the dental age of that particular person is to be six years and nine months from our calculation that is the easiest method we can also do by plotting on a sentile charts where the age of the child is non dental age that is how we calculate the dental age using the radiographic method that is the demigian's method so the best part of demigian's method it is very simple and it is very reproducible and it has got good intra examiner and inter examiner reliability and it is very widespreadly used because of its the maturity scoring system which creates a universal application but we need to taken taken into consideration of the population being considered because it may vary from population to population because of this dental and skeletal characteristics at the same time it has a few disadvantages that is getting the OPG which are difficult from younger children due to many technical reasons and legal or ethical consideration and also it doesn't have maturity scores for stages one to four in case of first molar central and lateral incisor so excluding the individual who are below 4 to 4.5 years is very commonly used because it can be used in both living and the persons in a nutshell we can say that the entire process the first thing is the seven mandibular teeth each teeth are divided to eight stages that is eight to H stages and each tooth is assigned a individual maturity score that corresponds to it developmental stage then each individual maturity score is added and a total maturity score is obtained then this total score is plotted on a chronology age conversion table so the final table will give you the dental age of that person. That's all about Demijian's method of dental age estimation which is basically a radiographic age estimation method commonly applied in adolescents and young age group younger children because it solely depends on the tooth calcification stages when the tooth calcification of teeth is complete this method is no longer be used or applicable so next session is about the Gustavson method of morphological age estimation which is mostly used in the adults so I'll come up with that method in my next session thank you