Forensic dentistry

Forensic dentistry or forensic odontology involves handling, examination and evaluation of dental evidence in criminal justice cases. Forensic dentists are involved in assisting investigative agencies to identify recovered human remains in addition to the identification of whole or fragmented bodies. Forensic dentists have also been known to use their investigative techniques to identify burn victims by using the victims previous dental records.[1] Forensic dentists may also be asked to assist in determining age, race, occupation, previous dental history and socioeconomic status of unidentified human beings.

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The evidence that may be derived from teeth is the age (in children) and identification of the person to whom the teeth belong. This is done using dental records including radiographs, ante-mortem (prior to death) and post-mortem (after death) photographs and DNA. Another type of evidence is that of bite marks, left on either the victim (by the attacker), the perpetrator (from the victim of an attack), or on an object found at the crime scene.

Bite mark analysis has been condemned by several scientific bodies, such as the National Academy of Sciences (NAS),[2] the President's Council of Advisors on Science and Technology (PCAST),[3] and the Texas Forensic Science Commission.[4] No scientific studies or evidence substantiate that bite marks can demonstrate sufficient detail for positive identification.[2] There are numerous instances where experts diverge widely in their evaluations of the same bite mark evidence.[2]

Training

India

In India, certificate courses offered include a modular course by D. Y. Patil Vidyapeeth, Pune, and some other private entities. The Indian Dental Association offers a fellowship program in FO which can be either a classroom program or an online program. Master's degree programs in different forensic disciplines along with M.Sc. Forensic Odontology is offered by National Forensic Sciences University which is the world's only university dedicated to forensic sciences. It is a 2‑year full‑time course offered at the university's campus at Gandhinagar.[5]

Australia

Postgraduate diploma programs for dentists are available at The University of Melbourne,[6] The University of Western Australia,[7] and The University of Adelaide.[8]

Belgium

The Belgian university KU Leuven offers a master's in Forensic Odontology.

United Kingdom

Following the closure of the MSc course at the University of Glamorgan, there are two courses available in the UK those are MSc in Forensic Dentistry i.e. one-year programme and other is Masters in Forensic Odontology i.e. two-year programme. This is at the University of Dundee in Scotland, which currently has a very limited intake.[9]

United States

There are two odontology training programs available in the US. One is a Fellowship program at The University of Texas Health Science at San Antonio Center Dental School, http://www.utforensic.org and the other is a master's degree program through the University of Tennessee Institute of Agriculture College of Veterinary Medicine, https://vetmed.tennessee.edu/research/Pages/FO.aspx

Canada

For undergraduate studies, dental school candidates in Canada are required to complete a BA or at least three years of study in a BA program before completing a dental degree. BA Programs often involve science or biomedical but can include much more, as long as students have completed the basic prerequisites needed.[10]

There are no graduate study programs for forensic odontology specifically in Canada. Some universities have offered some involvement in forensic science disciples during clinical dental specialty projects, however, they will not graduate with credibility in the forensic odontology discipline.

Dental degrees given by universities in Canada include DDS (doctor of dental science) and DMD (doctor of dental medicine).[11]

There is no professional certification process for forensic odontologists in Canada currently. It is possible for Canadians to certify for the ABFO, a section of the American Academy of Forensic Science.[12] This process also includes an examination as well as the candidates must complete a career checklist of accomplishments which will be reviewed. This checklist may include fellowships, working with recognized medicolegal death investigation agencies, completing a minimum level of casework and research, and providing testimony in court cases.[10] The ABFO and the AAFS often hold scientific sessions which offer workshops including identification, civil litigation, age determination, and bite-mark analysis. These are beneficial in helping prospective forensic practitioners move towards board-eligible status.[10]

In Ontario, there is a group of 10 forensic dentists that are known as the Province of Ontario Dental Identification Team or better known as PODIT.[13]

Background
Forensic dentistry

Forensic odontology is the study of dental applications in legal proceedings. The subject covers a wide variety of topics including individual identification, mass identification, and bite mark analysis. The study of odontology in a legal case can be a piece of incriminating evidence or an aspect of the wide controversy.

There have been many cases throughout history that have made use of bite marks as evidence. Bite marks are usually seen in cases involving sexual assault, murder, and child abuse and can be a major factor in leading to a conviction. Biting is often a sign of the perpetrator seeking to degrade the victim while also achieving complete domination.[14]

Bite marks can be found anywhere on a body, particularly on soft, fleshy tissue such as the stomach or buttocks. In addition, bite marks can be found on objects present at the scene of a crime. Bite marks are commonly found on a suspect when a victim attempts to defend him/herself.

High-profile criminal cases

Forensic odontology has played a key role in famous criminal cases:

In 1692, during the Salem Witch Trials, Rev. George Burroughs was accused of witchcraft and conspiring with the Devil, with biting his victims supposedly being evidence of his crimes. His bite marks and the bite marks of other people were compared to the victim's marks. The judges readily accepted the bite marks as evidence and this was the first time in what would become the United States that bite marks were used as evidence to solve a crime. He was later convicted and hanged. About two decades later, he was exonerated by the State, and his children were compensated for the wrongful execution.[15]

One of the first published accounts involving a conviction based on bite marks as evidence was the “Gorringe case”, in 1948, in which pathologist Keith Simpson used bite marks on the breast of the victim to seal a murder conviction against Robert Gorringe for the murder of his wife Phyllis.[16] Another early case was Doyle v. State, which occurred in Texas in 1954. The bite mark, in this case, was on a piece of cheese found at the crime scene of a burglary. The defendant was later asked to bite another piece of cheese for comparison. A firearms examiner and a dentist evaluated the bite marks independently and both concluded that the marks were made by the same set of teeth. The conviction, in this case, set the stage for bite marks found on objects and skin to be used as evidence in future cases.[17]

Another landmark case was People v. Marx, which occurred in California in 1975.[18] A woman was murdered by strangulation after being sexually assaulted. She was bitten several times on her nose. Walter Marx was identified as a suspect and dental impressions were made of his teeth. Impressions and photographs were also taken of the woman's injured nose. These samples along with other models and casts were evaluated using a variety of techniques, including two-dimensional and three-dimensional comparisons, and acetate overlays. Three experts testified that the bite marks on the woman's nose were indeed made by Marx and he was convicted of voluntary manslaughter.

  • Fredrik Fasting Torgersen
  • Wayne Boden – an early case of Forensic Dentistry
  • State of Florida v. Ted Bundy
  • State of New Jersey v. Jesse Timmendequas (Megan's Law case)
  • People of California v. Marx, the 1975 case which established evidentiary standards for forensic odontology
  • People of Arizona v. Ray Krone, bite mark evidence led to a wrongful conviction.


Organizations

Several organizations are dedicated to the field of forensic odontology. These organizations include the Bureau of Legal Dentistry (BOLD), the American Board of Forensic Odontology (ABFO), American Society of Forensic Odontology (ASFO), the International Organization for Forensic Odonto-Stomatology (IOFOS) and the Association Forensic Odontology For Human Rights (AFOHR). Countries have their own forensic Odontological societies, including the British Association for Forensic Odontology (BAFO) and the Australian Society of Forensic Odontology (AuSFO). In 1996, BOLD was created at the University of British Columbia to develop new technology and techniques in forensic odontology. The University of British Columbia program is the only one in North America that provides graduate training in forensic odontology.[19]

In Canada, The Royal College of Dentists has not recognized forensic odontology therefore there is no organization for Canada, however, there are three well-developed and trained groups for forensic dentistry. These groups include British Columbia, Ontario, and Quebec.[10] British Columbia has a team called BC Forensic Odontology Response Team (BC_FORT) which is led by six dentists.[20] They focus on disaster-victim identification work. Ontario has a team of ten forensic dentists called the Province of Ontario Dental Identification Team (PODIT).[10] Quebec has a team that is run out of McGill University and they offer a well-established forensic dentistry online course that focuses on human bite-mark evidence.[21] These teams are kept small in order to maintain a relationship between forensic dentists and casework.

The Bureau of Legal Dentistry encourages the use of multiple dental impressions to create a “dental lineup”, similar to a suspect lineup used to identify alleged perpetrators of crime. Currently, dental impressions collected as evidence are compared only to those collected from a given suspect, which may bias the resulting outcome. Using multiple dental impressions in a lineup may enable forensic odontologists to significantly decrease the current bias in matching bite marks to the teeth of a suspect.[17] The organization BOLD also supports the creation of a database of dental records, which could help in verifying dental uniqueness.[18] This database could be created using criminal records or possibly all dental patients.

In 1984, the ABFO attempted to diminish the discrepancies and increase the validity of bite mark analysis by creating bite mark methodology guidelines. The guidelines attempt to establish standard terminology in describing bite marks and that reduces the risk of biased results. The ABFO also provides advice on how to effectively collect and preserve evidence. For example, they recommend that the collection of DNA evidence and detailed photographs of bites be taken together at the crime scene. The guidelines also outline how and what a forensic odontologist should record, such as the location, contours, shape, and size of a bite mark. They also provide a system of scoring to assess the degree to which a suspect's dental profile and bite mark match. According to the ABFO, the guidelines are not a mandate of methods to be used, but a list of generally accepted methods.[22]

The guidelines are intended to prevent potentially useful evidence from being thrown out simply because the forensic odontologist's collection methods were not standardized. Kouble and Craig used a simplified version of the ABFO scoring guidelines in order to retain accuracy with a larger sample of comparisons. A numerical score was assigned to represent the degree of similarity between the bite mark and model/overlay. The higher the score, the greater the similarity. In order to simplify the model, some features that were individually scored in the ABFO guidelines such as arch size and shape were assessed together while certain distinctive features such as spacing between teeth were treated as a separate variable. The authors believe that a simplified version would increase the strength of the comparison process.[23] In an attempt to improve guidelines used to collect dental evidence, IOFOS developed one of the most recognized systems for the collection of forensic dental evidence[24][25]

There is only one international association promoting humanitarian forensic odontology, called AFOHR. It was inaugurated in 2015 by a group of experts in Lyon during the Interpol DVI annual meeting, following the inspiration of Emilio Nuzzolese, forensic odontologist from Italy. In 2019 the group evolved into Association adopting a by Laws and an elected Board.[26]

In 2016, an association of civil protection called Dental Team DVI Italia was founded in Bari, Italy, in order to offer pro bono services in the field of human identification and DVI Disaster Victim Identification to support Italian DVI teams.[27]

Bite mark analysis

Upon collection of dental evidence, the forensic odontologist analyzes and compares the bite marks. Studies have been performed in an attempt to find the simplest, most efficient, and most reliable way of analyzing bite marks.

Bites can occur on both the victim and the suspect; teeth are used as a weapon by the aggressor and in self-defense by the victim. Although they are only a small portion of most forensic dentists' caseload, bite marks represent the most challenging aspect of the discipline. In addition to the location of the bite mark, the type of severity of the injury may give investigators clues as to the mental state of the offender. Bite marks may be found on the flesh of victims of a violent attack, particularly on the stomach or buttocks. Alternatively, they may be found on the suspect, left by the victim during self-defense. Bite marks can be altered through stretching, movement, or change in environment after the bite. There is also no set standard by which to analyze and compare bite marks.

Factors that may affect the accuracy of bite mark identification include time-dependent changes of the bite mark on living bodies, effects of where the bite mark was found, damage on soft tissue, and similarities in dentition among individuals. Other factors include poor photography, impressions, or measurement of dentition characteristics.[28]

Most bite mark analysis studies use porcine skin (pigskin), because it is comparable to the skin of a human, and it is considered unethical to bite a human for study in the United States. Limitations to the bite mark studies include differences in properties of pigskin compared to human skin and the technique of using simulated pressures to create bite marks.[29] Although similar histologically, pigskin and human skin behave in dynamically different ways due to differences in elasticity.[23] Furthermore, postmortem bites on nonhuman skin, such as those used in the experiments of Martin-de-las Heras et al., display different patterns to those seen in antemortem bite injuries. In recognition of the limitations of their study, Kouble and Craig[29] suggest using a G-clamp on an articulator in future studies to standardize the amount of pressure used to produce experimental bite marks instead of applying manual pressure to models on pigskin.[23] Future research and technological developments may help reduce the occurrence of such limitations.

Kouble and Craig compared direct methods and indirect methods of bite mark analysis. In the past, the direct method compared a model of the suspect's teeth to a life-size photograph of the actual bite mark. In these experiments, direct comparisons were made between dental models and either photographs or "fingerprint powder lift models." The "fingerprint powder lift" technique involves dusting the bitten skin with black fingerprint powder and using fingerprint tape to transfer the bite marks onto a sheet of acetate. Indirect methods involve the use of transparent overlays to record a suspect's biting edges. Transparent overlays are made by free-hand tracing the occlusal surfaces of a dental model onto an acetate sheet. When comparing the “fingerprint powder lift” technique against the photographs, the use of photographs resulted in higher scores determined by a modified version of the ABFO scoring guidelines. The use of transparent overlays is considered subjective and irreproducible because the tracing can be easily manipulated. On the other hand, photocopier-generated overlays where no tracing is used are considered to be the best method in matching the correct bite mark to the correct set of models without the use of computer imaging.[23]

While the photocopier-generated technique is sensitive, reliable, and inexpensive, new methods involving digital overlays have proven to be more accurate.[28][29] Two recent technological developments include the 2D polyline method and the painting method. Both methods use Adobe Photoshop. The use of the 2D polyline method entails drawing straight lines between two fixed points in the arch and between incisal edges to indicate the tooth width. The use of the painting method entails coating the incisal edges of a dental model with red glossy paint and then photographing the model. Adobe Photoshop is then used to make measurements on the image. A total of 13 variables were used in the analysis. Identification for both methods was based on canine-to-canine distance (one variable), incisor width (four variables), and rotational angles of the incisors (eight variables). The 2D polyline method relies heavily on accurate measurements, while the painting method depends on the precise overlaying of the images. Although both methods were reliable, the 2D polyline method gave efficient and more objective results.[28]

Criticism of bite mark analysis

So called bite mark analysis has been criticized as largely unscientific based on three pillars of critique:[30]

  • "Human anterior dental patterns have not been shown to be unique at the individual level"[30]
  • "Those patterns are not accurately transferred to human skin consistently"[30]
  • "It has not been shown that defining characteristics of those patterns can be accurately analyzed to exclude or not exclude individuals as the source of a [sic] bitemark"[30]

Recently, the scientific foundation of forensic odontology, and especially bite mark comparison, has been called into question. A 1999 study by a member of the American Board of Forensic Odontology found a 63% rate of false identifications.[31] However, the study was based on an informal workshop during an ABFO meeting which many members did not consider a valid scientific setting.[32] In February 2016, the Texas Forensic Science Commission recommended that bite mark evidence not be used in criminal prosecutions until it had a more firm scientific basis.[33] That same year, the President's Council of Advisors on Science and Technology declared that bite mark analysis had no scientific validity.[34]

An investigative series by the Chicago Tribune entitled "Forensics under the Microscope" examined many forensic science disciplines to see if they truly deserve the air of infallibility that has come to surround them. The investigators concluded that bite mark comparison is always subjective and no standards for comparison have been accepted across the field. The journalists discovered that no rigorous experimentation has been conducted to determine error rates for bite mark comparison, a key part of the scientific method.[35]

Critics of bite mark comparison cite the case of Ray Krone, an Arizona man convicted of murder on bite mark evidence left on a woman's breast. DNA evidence later implicated another man and Krone was released from prison.[36] Similarly, Roy Brown was convicted of murder due in part to bite-mark evidence, and freed after DNA testing of the saliva left in the bite wounds matched someone else.[31]

Although bite mark analysis has been used in legal proceedings since 1870, it remains a controversial topic due to a variety of factors. DeVore[37] and Barbenel and Evans[38] have shown that the accuracy of a bite mark on the skin is limited at best. Skin is not a good medium for dental impressions; it is liable to several of irregularities present before the imprint that could cause distortion. Also, bite marks can be altered through stretching, movement, or a changing environment during and after the actual bite. Furthermore, the level of distortion tends to increase after the bite mark was made. Both studies suggest that for the bite mark to be accurately analyzed, the body must be examined in the same position it was in when the bite occurred, which can be a difficult if the not impossible task to accomplish.[39] Bite mark distortion can rarely be quantified. Therefore, bite marks found at the scene are often analyzed under the assumption that they have undergone minimal distortion.[18] Only limited research has been done in trying to quantify the level of distortion of a bite mark on human skin since the 1970s. The lack of research may largel because that such studies are difficult to organize and are very expensive.[39]

Bite mark analysis is also controversial because dental profiles are subject to change. The loss of teeth or the alteration of arch configuration through a variety of procedures is common in human populations. The onset of oral diseases such as dental caries has been shown to alter the arch and tooth configuration and must be taken into account when comparing a dental profile to the bite mark after a significant amount of time has passed since the mark was made.[18]

While the methods behind collecting bite mark evidence at the scene are leading toward greater standardization, the methodology behind analyzing bite marks is extremely variable because it depends upon the preference of the specific odontologist. As discussed earlier, there are several methods used to compare bite marks ranging from life-sized photographs to computer-enhanced three-dimensional imaging. These methods vary in precision and accuracy, and there is no set standard by which to compare or analyze them.[39] The lack of analytical standards leads to a wide array of interpretations with any bite mark evidence. Some odontologists even disagree on whether or not a mark on the body is the result of a bite.[18] Therefore, the interpretation of evidence lies largely on the expertise of the forensic odontologist handling the case.

One possible issue facing bite mark analysis is a lack of bite mark uniqueness in any given population. Bite mark analysis is based on the assumption that the dental characteristics of anterior teeth involved in biting are unique amongst individuals, and this asserted uniqueness is transferred and recorded in the injury.[39] However, there is very little reliable research to support these assumptions. A study performed by MacFarlane et al.[40] supported the notion of dental uniqueness, but the study revolved around the visual assessment of a cast as opposed to the bite mark that could have been produced by the cast.[39] In another study conducted by Sognnaes et al., the group tried to find uniqueness between the dental profiles of identical twins in an attempt to prove dental uniqueness in the general population.[41] However, this study suffered from a small sample size (n=5), with the intent to extrapolate the data to the general population. They also used plaster of Paris as the substrate to simulate skin, yet the two materials have very different properties.[39] In a review conducted by Strom, he references a study conducted by Berg and Schaidt which suggested that at least four to five teeth need to be present in the mark to ensure its uniqueness and make an identification.[42][43] However, this study was done long before many of the current evaluation methods, and this sheds doubt on how applicable these conclusions are today.

Rawson et al. determined that if five teeth marks can be matched to five teeth, it can be said with confidence that only one person could have caused the bite, and if eight teeth were matched to marks this would be a certainty. However, in this study, the probabilities used to make this claim are based on the assumption that the position of each tooth was independent of all the others.[44][39] This is probably unrealistic because there are several ways that the dental profile can be changed. For example, braces apply force to specific teeth, in order to shift the placement of multiple teeth.

One particular case that highlighted the lack of uniqueness in bite marks involved two suspects accused of attacking a man who had sustained a bite mark injury.[45] Two separate forensic dentists, one representing the prosecution and one the defense, were brought in to analyze the mark. They reported conflicting results. One found the mark to come from suspect A and the other said it was from suspect B. This disagreement resulted from the fact that even though the two suspects had dental features making them unique, the bite mark itself was not detailed enough to reflect them. Therefore, the mark could have reasonably come from either of the men.[45] The equivocal outcome demonstrated in the case emphasizes the difficulty in proving uniqueness.

Most of the controversies facing bite mark analysis are due to the lack of empirical supporting evidence. When searching the entire MedLine database from 1960 to 1999, only 50 papers in English were found that related to bite mark analysis. Of these 50 papers, most of which were published in the 1980s, only 8% came from well designedd experimentation providing empirical data. The lack of research has led to the continued use of a few outdated and limited studies to support the validity of bite mark analysis. This brings into question whether or not there is enough scientific support for bite mark analysis to be employed in court.[45]

There have been several instances when forensic dentists have made claims, accusations, and guarantees supported by bite mark evaluation that have been proven incorrect through other forensic sciences. DNA analysis has shed some light on the limitations of bite mark analysis because often the DNA from saliva surrounding the area of the bite mark proves to be a more reliable form of identification. In the case of Mississippi vs. Bourne, the DNA of a suspect excluded them from the crime after a dentist claimed the bite marks on the victim matched the defendant's teeth.[17] DNA sampling has been included as a task for a forensic odontologist. For a crime scene investigator, taking DNA samples is as common as taking pictures of the scene.[46] In the case of State vs. Krone, the defendant was sentenced to death, which was overturned. Then Krone was later reconvicted and given life in prison. Both convictions were based largely on bite mark evidence, but ten years later DNA evidence surfaced that identified the real killer and Krone was set free.[17]

Bite marks were a primary source of evidence in the wrongful convictions of Keith Allen Harward,[47][48] Kennedy Brewer[49][50] and Levon Brooks.[51][52] The role of bite marks in their convictions is told in a Netflix series titled The Innocence Files[53]

Age estimation

The estimation of an individual's age category becomes crucial in various forensic contexts; such as crime scenes, accidents, mass disasters, and the potential identification of an unknown individual. In determining an approximation of the latter, it is imperative to be aware of the variety of methods utilized in different situations. The most reliable analysis regarding age estimation is a clinical or visual approach. This includes a noninvasive examination of he tooth's eruption rate, as well as the degenerative modifications upon the teeth. These alterations can be present under forms of attrition. The abrasions manufactured from attrition can lead to a proximate age range of the individual. Not only can the age of a human specimen be narrowed by evaluating the patterns of tooth eruption and tooth wear, but recent studies also provide evidence that cementum, the mineralized tissue that lines the surface of tooth roots, exhibits annual patterns of deposition.[54] Aggrawal has presented a comprehensive account.[55]

Adult dentition can be differentiated from juvenile dentition in bite mark analysis by determining the quantity of teeth. Juvenile teeth are considered primary teeth while adult are considered permanent teeth. Twenty teeth will be present by the age of two years old. Thirty-two teeth will be present by the age of twenty-one, with the last ones being the wisdom teeth. By analyzing the quantity of teeth in a bite mark, this can assist with determining the age of the individual.

Sex estimation

The determination of sex is important in the identification of unknown individuals in both forensic and archaeological contexts. The preferred anatomical methods for sex determination are based on pelvic and cranio-facial morphology. Using these parts of the skeleton, males and females can be correctly classified with over 90% accuracy.[56] However, these skeletal elements are sometimes recovered in a fragmentary state, rendering sex estimation difficult. Moreover, there is currently no reliable method of sex determination of juvenile or sub-adult remains from cranial or post-cranial skeletal elements since dimorphic traits only become apparent after puberty, and this represents a fundamental problem in forensic investigations. In such situations, teeth are potentially useful in sex determination. Due to their hardness, they are highly resistant to taphonomic processes and are much more likely to be recovered than other parts of the fact, the enamel present on teeth is the hardest biological substance in the human body;[57] therefore making them extremely sustainable analytical evidence in a forensic context. Moreover, teeth may be particularly useful for sexing immature skeletal remains since both primary and permanent sets of teeth develop before puberty.[58][59]

For several decades research has been conducted into human dental sexual dimorphism, looking at different tooth classes, and using various techniques and measurements, to try to establish the extent of any dimorphism and find criteria or patterns that might enable accurate sexing of unknown individuals. Most of these studies have focused on sexual dimorphism in crown-size dimensions. This research has established that human teeth are sexually dimorphic and, although males and females exhibit overlapping dimensions, there are significant differences in mean values.[60][61] Sexual dimorphism has been observed in both deciduous and permanent dentition, although it is much less in deciduous teeth.[62][63] On average, male teeth are slightly larger than female teeth, with the greatest difference observed in the canine teeth.[64][65] Research using microtomographic scans to look at internal dental tissues has also shown that male teeth consist of significantly greater quantities of dentine than female teeth.[66][67] This results in female teeth having thicker enamel, on average. Researchers have attempted to use statistical techniques such as discriminant functions or logistic regression equations based on these sex differences to estimate the usefulness of such formulae is uncertain because sexual dimorphism in teeth may vary between populations.[68][67][61] The advanced methods which amplify the DNA by using Polymerase chain reaction (PCR) give 100% success in sex determination.[69] Sex estimation based on dentition remains experimental and has yet to gain widespread acceptance. Nevertheless, it offers potentially useful additional techniques that could be used alongside more established methods.

Identification methods

Radiograph comparison

The comparison of antemortem and post-mortem radiographic records can be done to attain a positive identification of an individual. Teeth are used since they are a very durable and resistant to extreme conditions. The radiographs can present dental restorations as well as unique morphology for each individual.[70] Dental patterns are unique due to the variety of treatments as well as growth for each individual, which creates a benefit in using them for human identification[71]

Post-mortem radiographs can be taken at the scene or in a laboratory, the antemortem records are collected from dentists existing files and are used for comparison with the radiographs taken from the deceased unknown individual.[72]

It is important that dentists keep all radiographs stored properly since the original dental records will be used during this comparison.

The antemortem and post-mortem radiographs will both be analyzed and transcribed onto Victim Identification forms and loaded into a computer database in order to compare many different antemortem records to the post-mortem in order to obtain a match.[73]

Radiograph comparison is often a method used in mass fatalities for example natural disasters but It can be used in any case.

DNA Extraction

Teeth contain a great source of DNA since they are very chemically and physically resistant to extreme conditions.[74] This method is especially useful in cases where other DNA sources are not accessible, for example in burned victims. Teeth can be used to create a DNA profile in order to identify unknown deceased individuals. Dentin and enamel provide a resistant and protective surface that houses the dental pulp which is located under the enamel and dentin layers in the center of the tooth, which contains the nerves and blood supply as well.[74] Within the pulp is where genomic and mitochondrial DNA can be extracted.[75] The teeth should not be completely destroyed using DNA analysis alone, it should be compared with other techniques as well before damaging techniques are used.

See also

References
  1. Andersen, Lis (1995). "Odontological identification of fire victims – potentialities and limitations". International Journal of Legal Medicine. 107 (5): 229–234. doi:10.1007/BF01245479. PMID 7632598. S2CID 969604.
  2. Strengthening Forensic Science in the United States. 2009-07-29. doi:10.17226/12589. ISBN 978-0309131308.
  3. "Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods" (PDF). 2016.
  4. "TJB | FSC | Discipline Specific Reviews | Bite Mark Analysis". www.txcourts.gov. Retrieved 2020-10-20.
  5. Gawali RA. Education, training, and practice of forensic odontology: An Indian perspective. J Dent Res Rev [serial online] 2020 [cited 2020 Mar 31];7:3–4. Available from: http://www.jdrr.org/text.asp?2020/7/1/3/281503
  6. "Graduate Diploma in Forensic Odontology : Melbourne Dental School". Dent.unimelb.edu.au. Retrieved 2013-09-06.
  7. "Graduate Diploma in Forensic Odontology: School of Dentistry: The University of Western Australia". Dentistry.uwa.edu.au. 2012-08-10. Retrieved 2013-09-06.
  8. Graduate Diploma in Forensic Odontology. Adelaide.edu.au (2016-12-13). Retrieved on 2016-12-19.
  9. "Forensic Odontology MFOdont". www.dundee.ac.uk. Retrieved 25 September 2014.
  10. "Forensic Science in Canada - PDF Free Download". docplayer.net. Retrieved 2022-03-29.
  11. "List of Dental Schools in Canada". Master Student. 2021-02-20. Retrieved 2022-03-29.
  12. "ABFO :: American Board of Forensic Odontology |". Retrieved 2022-03-29.
  13. Pollanen, Micharl (2013). Forensic Science in Canada. University of Toronto: Center of Forensic Science & Medicine. pp. 31–40.
  14. Douglas, John E., Mark Olshaker (1995). Mindhunter: Inside the FBI's Elite Serial Crime Unit. New York: Scribner. ISBN 978-0671013752.
  15. George Burroughs. Law2.umkc.edu. Retrieved on 2016-12-19.
  16. Taylor, D. V. (1963). "The Law and the Dentist" (PDF). British Dental Journal. 114: 389–393. Archived from the original (PDF) on 2012-03-28.
  17. Bowers, CM (2006). "Problem-based analysis of bitemark misidentifications: the role of DNA". Forensic Science International. 159 Suppl 1: S104–109. doi:10.1016/j.forsciint.2006.02.032. PMID 16600549.
  18. Dorion, Robert BJ. Bitemark Evidence. NY: Marcel Dekker, 2005. ISBN 082475414X.
  19. "Bureau of Legal Dentistry". boldlab.ubc.ca. Retrieved 2013-09-06.
  20. "BC-Fort – British Columbia Forensic Odontology Response Team". www.bcfort.dentistry.ubc.ca. Retrieved 2022-04-04.
  21. "Course Information". McGill CDE. Retrieved 2022-04-04.
  22. American Board of Forensic Odontology. Abfo.org. Retrieved on 2016-12-19.
  23. Kouble RF, Craig GT (2004). "A comparison between direct and indirect methods available for human bite mark analysis". Journal of Forensic Sciences. 49 (1): 111–118. doi:10.1520/JFS2001252. PMID 14979355.
  24. "International Organization of Forensic Odonto-Stomatology Regulations (1987)". 2009-02-09. Archived from the original on 2009-02-09. Retrieved 2013-09-06.
  25. Vermylen, Y. (2006). "Guidelines in Forensic Odontology: legal aspects". Forensic Science International. 159: S6–8. doi:10.1016/j.forsciint.2006.02.002. PMID 16563684.
  26. "Home". www.afohr.org.
  27. "Dental Team DVI Italia – Associazione di operatori tecnici delle scienze forensi esperti nella identificazione delle vittime di disastri (D.V.I. Disaster Victim Identification, D.V.I)". www.dentalteamdvi.it.
  28. Al-Talabani N, Al-Moussawy, ND, Baker FA, Mohammed HA (2006). "Digital analysis of experimental human bitemarks: application of two new methods". Journal of Forensic Sciences. 51 (6): 1372–1375. doi:10.1111/j.1556-4029.2006.00265.x. PMID 17199623. S2CID 24815157.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  29. Martin-de las Heras S, Valenzuela A, Valverde AJ, Torres JC, Luna-del-Castillo JD (2007). "Effectiveness of comparison overlays generated with DentalPrint software in bite mark analysis". Journal of Forensic Sciences. 52 (1): 151–156. doi:10.1111/j.1556-4029.2006.00321.x. PMID 17209928. S2CID 27808790.
  30. Tuccille, J.D. "Federal Report Adds to the Evidence That Bitemark Analysis Is Nonsense". reason.com. Reason. Retrieved 21 October 2022.
  31. Santos, Fernanda (January 28, 2007) Evidence From Bite Marks, It Turns Out, Is Not So Elementary. New York Times.
  32. McRoberts, Flynn (2004-10-19). "From the start, a faulty science". Chicago Tribune. Retrieved 2008-07-13.
  33. Commission Wants Restriction of Bite-Mark Evidence. The Texas Tribune (2016-02-12). Retrieved on 2016-12-19.
  34. Colloff, Pamela. "Bloodstain Analysis Convinced a Jury She Stabbed Her 10-Year-Old Son. Now, Even Freedom Can't Give Her Back Her Life". propublica.org. ProPublica. Archived from the original on January 16, 2020. Retrieved 16 January 2020.
  35. "From the start, a faulty science". Chicago Tribune. Retrieved 2021-05-26.
  36. Bite-mark verdict faces new scrutiny. Chicago Tribune; November 29, 2004
  37. DeVore DT (1971). "Bite Marks for identification? A preliminary report". Medicine, Science, and the Law. 11 (3): 144–145. doi:10.1177/002580247101100309. PMID 5136610. S2CID 28559168.
  38. Barbenel JC, Evans JH (1974). "Bite marks in skin – mechanical factors". Journal of the Forensic Science Society. 14 (3): 235–238. doi:10.1016/S0015-7368(74)70908-2. PMID 4443779.
  39. Pretty IA, Sweet D (2001). "The scientific basis for human bitemark analyses – a critical review". Science & Justice. 41 (2): 85–92. doi:10.1016/S1355-0306(01)71859-X. PMID 11393946.
  40. MacFarlane TW, MacDonald DG, Sutherland DA (1974). "Statistical problems in dental identification". Journal of the Forensic Science Society. 14 (3): 247–252. doi:10.1016/s0015-7368(74)70911-2. PMID 4613797.
  41. Sognnaes, RF; Rawson, RD; Gratt, BM; Nguyen, NB (1982). "Computer comparison of bitemark patterns in identical twins". Journal of the American Dental Association. 105 (3): 449–451. doi:10.14219/jada.archive.1982.0338. PMID 6957451. Archived from the original on 2012-08-01.
  42. Strom F. (1963). "Investigation of Bite-Marks". Journal of Dental Research. 42 (1Pt 2): 312–316. doi:10.1177/00220345630420013301. PMID 13978931. S2CID 72751423.
  43. Berg, S; Schaidt, G (1954). "Methodik und Beweiswert des Bissspurenvergleiches". Kriminalwiss. 8: 128–130.
  44. Rawson R.; Ommen R.; Kinard G.; Johnson J.; Yfantis A. (1984). "Statistical evidence for the individuality of the human dentition". Journal of Forensic Sciences. 29 (1): 245–253. doi:10.1520/JFS11656J. PMID 6699595.
  45. Pretty, IA; Turnbull, MD (2001). "Lack of dental uniqueness between two bite mark suspects". Journal of Forensic Sciences. 46 (6): 1487–1491. doi:10.1520/JFS15177J. PMID 11714165.
  46. Forensic Odontology explained. ITSGOV: CSI and Forensics Science
  47. "Keith Allen Harward | the Innocence Project".
  48. "Innocent man released from Virginia prison after 33 years".
  49. "Kennedy Brewer | the Innocence Project".
  50. "Kennedy Brewer – National Registry of Exonerations".
  51. "Levon Brooks | the Innocence Project".
  52. "Levon Brooks – National Registry of Exonerations".
  53. "The Innocence Files: Who is Levon Brooks? What happened to Levon Brooks?". 20 April 2020.
  54. Renz, H; Radlanski, R (2006). "Incremental lines in root cementum of human teeth – A reliable age marker?". HOMO: Journal of Comparative Human Biology. 57 (1): 29–50. doi:10.1016/j.jchb.2005.09.002. PMID 16458729.
  55. Aggrawal, A (2009). "Estimation of age in the living: in matters civil and criminal" (PDF). J Anat. doi:10.1111/j.1469-7580.2009.01048.x. PMID 19470083.
  56. White, T. D. (2005). The human bone manual. Elsevier Academic. ISBN 978-0120884674. OCLC 59223984.
  57. "Tooth Enamel – an overview". www.sciencedirect.com | ScienceDirect Topics. Retrieved 2022-02-04.
  58. Gonçalves, David; Granja, Raquel; Cardoso, Francisca Alves; de Carvalho, António Faustino (2014). "Sample-specific sex estimation in archaeological contexts with commingled human remains: a case study from the Middle Neolithic cave of Bom Santo in Portugal". Journal of Archaeological Science. 49: 185–191. doi:10.1016/j.jas.2014.05.011. hdl:10316/44447. ISSN 0305-4403.
  59. Viciano, Joan; López‐Lázaro, Sandra; Alemán, Inmaculada (2013). "Sex estimation based on deciduous and permanent dentition in a contemporary spanish population". American Journal of Physical Anthropology. 152 (1): 31–43. doi:10.1002/ajpa.22324. ISSN 1096-8644. PMID 23907722.
  60. Hassett, Brenna (2011). "Technical note: Estimating sex using cervical canine odontometrics: A test using a known sex sample". American Journal of Physical Anthropology. 146 (3): 486–489. doi:10.1002/ajpa.21584. PMID 21953490.
  61. Zorba, Eleni; Moraitis, Konstantinos; Manolis, Sotiris K. (2011). "Sexual dimorphism in permanent teeth of modern Greeks". Forensic Science International. 210 (1–3): 74–81. doi:10.1016/j.forsciint.2011.02.001. PMID 21371836.
  62. López-Lázaro, Sandra; Alemán, Inmaculada; Viciano, Joan; Irurita, Javier; Botella, Miguel C. (2018). "Sexual dimorphism of the first deciduous molar: A geometric morphometric approach". Forensic Science International. 290: 94–102. doi:10.1016/j.forsciint.2018.06.036. ISSN 0379-0738. PMID 30015284. S2CID 51660524.
  63. Cardoso, Hugo F.V. (2008). "Sample-specific (universal) metric approaches for determining the sex of immature human skeletal remains using permanent tooth dimensions". Journal of Archaeological Science. 35 (1): 158–168. doi:10.1016/j.jas.2007.02.013. ISSN 0305-4403.
  64. Garn, Stanley M.; Lewis, Arthur B.; Swindler, Daris R.; Kerewsky, Rose S. (1967). "Genetic Control of Sexual Dimorphism in Tooth Size". Journal of Dental Research. 46 (5): 963–972. doi:10.1177/00220345670460055801. ISSN 0022-0345. PMID 5234039. S2CID 27573899.
  65. Martins Filho, Ismar Eduardo; Lopez-Capp, Thais Torralbo; Biazevic, Maria Gabriela Haye; Michel-Crosato, Edgard (2016). "Sexual dimorphism using odontometric indexes: Analysis of three statistical techniques". Journal of Forensic and Legal Medicine. 44: 37–42. doi:10.1016/j.jflm.2016.08.010. ISSN 1752-928X. PMID 27592445.
  66. García‐Campos, Cecilia; Martinón‐Torres, María; Martín‐Francés, Laura; Pinillos, Marina Martínez de; Modesto‐Mata, Mario; Perea‐Pérez, Bernardo; Zanolli, Clément; González, Elena Labajo; Sánchez, José Antonio Sánchez (2018). "Contribution of dental tissues to sex determination in modern human populations" (PDF). American Journal of Physical Anthropology. 166 (2): 459–472. doi:10.1002/ajpa.23447. ISSN 1096-8644. PMID 29460327. S2CID 4585225.
  67. Sorenti, Mark; Martinón‐Torres, María; Martín‐Francés, Laura; Perea‐Pérez, Bernardo (2019). "Sexual dimorphism of dental tissues in modern human mandibular molars". American Journal of Physical Anthropology. 169 (2): 332–340. doi:10.1002/ajpa.23822. ISSN 1096-8644. PMID 30866041. S2CID 76662620.
  68. Pereira, Cristiana; Bernardo, Mário; Pestana, Dinis; Santos, Jorge Costa; Mendonça, Maria Cristina de (2010). "Contribution of teeth in human forensic identification – Discriminant function sexing odontometrical techniques in Portuguese population". Journal of Forensic and Legal Medicine. 17 (2): 105–110. doi:10.1016/j.jflm.2009.09.001. PMID 20129433.
  69. Shirolkar, Supreet; Gayen, Khooshbu; Sarkar, Subir; Saha, Subrata (2021). "Envisioning forensic odontology under a new light: A pedodontist's perspective". SRM Journal of Research in Dental Sciences. 12 (2): 101. doi:10.4103/srmjrds.srmjrds_91_20. S2CID 235751103.
  70. Kahana, T; Hiss, J (1997-03-01). "Identification of human remains: forensic radiology". Journal of Clinical Forensic Medicine. 4 (1): 7–15. doi:10.1016/S1353-1131(97)90002-X. ISSN 1353-1131. PMID 15335591.
  71. Jeddy, Nadeem; Ravi, Shivani; Radhika, T. (2017). "Current trends in forensic odontology". Journal of Forensic Dental Sciences. 9 (3): 115–119. doi:10.4103/jfo.jfds_85_16 (inactive 31 July 2022). ISSN 0975-1475. PMC 5887632. PMID 29657486.{{cite journal}}: CS1 maint: DOI inactive as of July 2022 (link)
  72. Viner, Mark D.; Robson, John (2017-03-01). "Post-Mortem Forensic Dental Radiography – a review of current techniques and future developments". Journal of Forensic Radiology and Imaging. Special Issue: Papers from the joint ISFRI & IAFR Conference 2016. 8: 22–37. doi:10.1016/j.jofri.2017.03.007. ISSN 2212-4780.
  73. Jain, Anil K.; Chen, Hong (2004-07-01). "Matching of dental X-ray images for human identification". Pattern Recognition. 37 (7): 1519–1532. Bibcode:2004PatRe..37.1519J. doi:10.1016/j.patcog.2003.12.016. ISSN 0031-3203.
  74. Manjunath, B. C.; Chandrashekar, B. R.; Mahesh, Melkundi; Vatchala Rani, R. M. (2011-07-01). "DNA Profiling and forensic dentistry – A review of the recent concepts and trends". Journal of Forensic and Legal Medicine. 18 (5): 191–197. doi:10.1016/j.jflm.2011.02.005. ISSN 1752-928X. PMID 21663865.
  75. Sakari, S. Leena; Jimson, Sudha; Masthan, K. M. K.; Jacobina, Jenita (April 2015). "Role of DNA profiling in forensic odontology". Journal of Pharmacy & Bioallied Sciences. 7 (Suppl 1): S138–S141. doi:10.4103/0975-7406.155863. ISSN 0976-4879. PMC 4439652. PMID 26015692.
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