 Hello everyone welcome back to another session in Tentistry and more today we have a very interesting topic bite marks in forensic odontology. So forensic odontology is a branch which deals with identification of a person or age estimation by analyzing the bite marks or lip prints. So from the pattern of teeth or the pattern of bite they can identify the person or they can reach to a conclusion of the incident where this bite was occurred. So bite marks is a branch which is yet to be explored in detail. So let's learn a little bit about bite marks and how the bite marks are taken. Not in very detail but to a UG level class the pattern and the types of bite marks and the importance of bite marks in forensic odontology. So bite marks is nothing but a physical alteration in a medium caused by the contact of teeth. So it is a representative pattern which is left in the object or tissue by dental structure of an animal or human. So when we bite to a tissue when we bite to even when we taking a bite of an apple or a fruit will leave behind a teeth pattern. So that is that is nothing but bite marks. So in forensic odontology the same concept is applied when this teeth pattern is left behind in a crime scene or in other situations that pattern will be replicated in a cast or using a photographs or any other methods and it will be utilized for identification of the person or to prove a or to reach a conclusion. So what was the incident about and all the other details. So it is nothing but a physical alteration in a medium caused by the contact of teeth. So where we get this bite marks? So bites on human tissues may be observed in violent incidents where the attacker may bite the victim or the victim may bite the attacker during a defense response during the fight. In rape cases all these bite marks are very much vital to prove the case. So bite marks may be observed in wax from a so it can be replicated in wax and from a dental model indirectly from or photographs. So these two can be used to replicate and also a scanned image of dental model also can be used scanned image. So these bite marks may be observed in wax from a dental model and indirectly from a photograph or from a scanned image. So what are the types of bite marks? So forensic dentist use several different terminologies to describe the type of bite marks. The first one is abrasion, it is a scrape on the skin, artifact, it is when the piece of the body such as an ear lobe is removed with the effect of biting. Then avulsion it is a bite resulting in removal of the skin, contusion is a bruise of the skin, hemorrhage is you know it is a profusely bleeding site, incision is a clean, neat wound and laceration is a puncture. These are the terminologies which is used by forensic odontologist. And what are the characteristics of bite marks? So bite marks are like fingerprints to forensic odontologist. So teeth may be considered as tools leaving marks on skin, food, wax etc. So however there are often more characteristics involved in the analysis of bite marks. So there are class characteristics to be considered such as which type of tooth inflicted the bite. So we have various patterns of tooth incisors, premolars, canines, molars. So each group of teeth or each teeth leave a different type of mark on the object, on the fruit, on the surface or the tissue. So that difference can be analyzed using bite marks. So this biting surface of the individual groups of teeth are related to their function such as teeth that in size or that tear or grind. So each teeth has different different function. So from the pattern of this teeth we can understand more details using bite mark analysis. In addition also seen are individual characteristics such as if rotations, fractures, missing or extra teeth are present. We can identify the person with the help of this analysis and the size relationship of bite marks are as described by the dental arches could relate to a child or adult bite. So child pattern and adult pattern will be very different. So we can identify whether the bite was inflicted by the child or adult. And we can understand a human bite mark as an elliptical or circular in shape. It might be elliptical or circular and if it is U shaped it shows that the biter has opened the mouth to a width, open the mouth to a width. And the ability to open the mouth maximally may vary from individual to individual. So usually it is elliptical or circular and sometimes it is U shaped. So what are the factors that affect the accuracy of bite marks? So whatever marks we are collecting it may not be accurate because there are lots of factors which is affecting the accuracy. That is there is time dependent changes of the bite mark on living body. So if the bite was happened at morning time and we are taking the bite marks at the afternoon session or maybe two to three hours after or if the duration is prolonged the exact bite marks will not be replicated. So there will be time dependent changes and the effect where the bite mark was found and the area or the region where the bite mark is happening is also another factor. So some tissues will retain the marks properly and some tissues will not retain the marks. So where the bite was happening is also another factor which affect the accuracy. Then damage on soft tissues then there could be similarity in dentition among individual. Not like fingerprints the dentition pattern is not very precise and not very unique there can be similar dentition in many people. Other factors like poor photography. Photography is a big thing which affects the accuracy poor photography and the impression taking methods and measurement of dentition characteristics all affects the accuracy of bite marks. So how do we analyze this bite marks? So bite mark analysis is extremely complex procedure with many factors involved in forensic dentist ability to determine the identify of the perpetrator. So the movement of persons jaw and tongue when he or she bites contributes to the type of mark that is left and depending upon the location of the bite it is not typical to find bite marks where both the upper and lower teeth left clear impression sometimes just the upper teeth impression we get not the lower okay. So usually one or other is more visible sometimes upper will be more visible and lower will be more visible and if the victim is moving while being bitten the bite mark would look different from that inflicted on a still victim. So always this will be a violent incident it could be a rape it could be a fight between two people. So we cannot expect the object to be at a still position the object definitely would be moving so the bite marks would be a different pattern and if an investigator sees something on a victim that even resembles a bite the forensic dentist must be called immediately because this bite marks change significantly over time as I explained because if the victim is diseased the skin may slip as the body decays so causing the bite to move. So if the person is already dead so we need to call in the forensic orientologist immediately because as the body decays the changes in over the skin will remove the complete bite marks. The first step in analyzing the bite is to identify it as human not just humans even animals bite also is matter so animal teeth are very different from human teeth so they leave very different bite mark patterns. Next the bite is swabbed for DNA analysis so DNA analysis also very important we get DNA analysis with the help of this swab collection so because definitely there would be presence of saliva at the insured site so that we can collect for DNA analysis and forensic dentist then take measurement of each individual bite marks and record it and they also require many photographs because of the changing nature of the bites bruising can appear 4 hours after a bite and disappear after 36 hours okay after 36 hours this bruise will disappear so it appear only after 4 hours this bruising okay so bruising bruising appear only after 4 hours but it disappear after 36 hours so the bite photography must be conducted very precisely using rulers and other scales to accurately depict the orientation depth and size of the bite then the photos are then magnified enhanced and corrected for any distortions so finally bite marks on deceased victims are cut out of the skin in a morgue and preserved in a compound called formalin so from identification or collecting sample from the dead people so we need to cut the sample from the morgue and need to be preserved in formaldehyde okay so commonly known as formalin so forensic dentist then make a silicone cast of the bite marks so from it they make silicone cast silicone cast in addition there are several different types of impressions that can be left by teeth depending on the pressure applied by the biter such as a clear impression okay so a clear impression a clear impression means that there was significant pressure an obvious bite appears bite signifies a medium pressure okay this is medium pressure clear impression is significant bite okay then a noticeable impression okay noticeable means the biter used violent pressure to bite down okay violent pressure so we can make out all these violent pressure so clear impression obvious bite and noticeable bite all these can be identified by the photographs so finally to finally to conclude that is forensic relevance what is the relevance of this bite marks and forensic odontology so this bite mark evidence which can assist the justice system to answer crucial questions about the interaction between people at the scene of a crime so what was the interaction so it gives a very vital clue for the interaction between people at the crime scene interaction between people so what was the interaction and for individualization based on their unique dentition pattern we can identify the person if we have so many suspected persons we can identify the person by their dental unique pattern and it plays a very crucial role in solving cases such as rape cases and child abuse so these cases this bite marks are very much crucial and it describes the violence level of crime okay so violence level it describes the violence level so all this can be understood using bite marks by the forensic odontologist still it is in a very nascent state it is yet to be explored in very detail but there are many cases where the forensic odontologist played a crucial role like delhi nirbaya case where the forensic odontologist had the you know big impact in identifying the person so not all cases requires bite mark analysis but some crucial cases this can be a pivotal evidence so that's all about bite marks and forensic odontology so i'll come up with a new topic in oral pathology thank you