Bite Mark Cases Research Articles

Bitemark pathobiology

Forensic odontology is one branch of forensic science that plays a role in the process of individual identification. Cases that often require a review from the perspective of forensic odontology are bitemark cases. Bitemark cases are often found in acts of violence or sexual violence, both to the victim and to the suspect. However, today bitemark analysis often experiences problems due to the many distortions that can occur. For this reason, it is important to know the pathobiology of bitemark in the healing process because by doing this analysis, it can be estimated when the bitemark is carried out, so that it can lead to an adequate identification process. This manuscript is a preliminary text for research on the pathobiology of post-bite tissue carried out.

Epidermis and Enamel: Insights Into Gnawing Criticisms of Human Bitemark Evidence.

Critics describe forensic dentists' management of bitemark evidence as junk science with poor sensitivity and specificity and state that linkages to a biter are unfounded. Those vocal critics, supported by certain media, characterize odontologists' previous errors as egregious and petition government agencies to render bitemark evidence inadmissible. Odontologists acknowledge that some practitioners have made past mistakes. However, it does not logically follow that the errors of a few identify a systemic failure of bitemark analysis. Scrutiny of the contentious cases shows that most occurred 20 to 40 years ago. Since then, research has been ongoing and more conservative guidelines, standards, and terminology have been adopted so that past errors are no longer reflective of current safeguards. The authors recommend a comprehensive root analysis of problem cases to be used to determine all the factors that contributed to those previous problems. The legal community also shares responsibility for some of the past erroneous convictions. Currently, most proffered bitemark cases referred to odontologists do not reach courts because those forensic dentists dismiss them as unacceptable or insufficient for analysis. Most bitemark evidence cases have been properly managed by odontologists. Bitemark evidence and testimony remain relevant and have made significant contributions in the justice system.

Human bite marks – A computer-based analysis using adobe photoshop

Aim: Identification of human bite marks on victims and to analyze them by computer-based superimposition technique using Adobe Photoshop software. Materials and Methods: Five bite mark cases were selected for this study. Five bite marks were identified on patients attending the hospital and were analyzed with computer-based superimposition technique using Adobe Photoshop software by two observers. Results: All the five bite marks on victims were analyzed by computer-based superimposition technique using Adobe Photoshop software and categorized as “not excluded as having made the bite mark with suspects dentition.” Conclusion: Computer-based superimposition technique using Adobe Photoshop software is an accurate and cost-effective method for bite mark analysis.

Bite Mark Analysis in Foodstuffs and Inanimate Objects and the Underlying Proofs for Validity and Judicial Acceptance

Even though one of the first bite mark cases was Doyle v. State in 1954 (a bitten cheese case), the research has focused on bite marks inflicted in human skin. As published Papers, Case Reports, or Technical Notes can constitute precedents which are relied upon in making the legal arguments and a considerable amount of case law exists in this area, we present a systematic review on bite mark analysis in foodstuffs and inanimate objects and their underlying proofs for validity and judicial acceptance according to Daubert rulings. Results showed that there is vulnerability in these procedures, and it is essential to demand for focus scrutiny on the known error rates when such evidence is presented in trials. These kinds of bite marks are well documented; however, there has been little research in this field knowing that the protocols of analysis and comparison are the responsibility of the forensic odontologists.

Bite mark analysis: Chasing the bite!

In the recent years, numbers of suspected bite mark cases examined by forensic odontologist are increasing. Human bite mark analysis is most demanding and complicated part of forensic dentistry, involving identification of assailant by comparing record of their dentition with record of bite mark left on a victim. Like fingerprints and DNA, bite marks are unique to individual such as distance and angles between teeth, missing, and teeth fillings. This type of impression evidence can be left in the skin of a victim and also in food, chewing gums, pens, pencil, etc., In some crimes, bite mark evidence is the only evidence on which conviction has been achieved, particularly alleged rape and child abuse cases. The current protocol for collection, management, preservation analysis, and interpretation of evidences should be employed if information is to be obtained for the court. The aim of this article is to give brief overview of bite mark analysis, its clinical applications, and limitations.

Restriction fragment length polymorphisms of mutans streptococci in forensic odontological analysis

Humans bite each other with alarming frequency. Such injuries can result in forensic investigation and, ultimately, criminal prosecution. Bite mark analysis techniques include odontometric measurement, ABO serotyping and DNA profiling, none of which is infallible. Research into additional techniques would be advantageous. Biting involves, also, bacterial transfer from teeth to skin and vice versa. The principal species found on anterior teeth is Streptococcus mutans, which is universal among humans. The aim of this research was to establish, in the context of forensic odontology, whether chromosomal DNA profiles of this ubiquitous oral bacterium would vary significantly among a sample of Caucasian individuals (P = 0.05). Hence, if sufficient discriminatory power were present, the technique could be deemed useful to forensic investigation. Oral fluid was recovered from the lower incisors of 10 adults. Samples were cultured selectively using mitis salivarius bacitracin agar and microbiological tests carried out for the purpose of differential identification. These included visual assessment of colony morphology, Gram staining and microscopic analysis, followed by chemical testing for the enzyme catalase. Chromosomal DNA was extracted from subcultured cells, resolved by agarose gel electrophoresis and viewed using ultraviolet transillumination. The presence of DNA was confirmed. Subsequently, the 16S ribosomal RNA gene was amplified by polymerase chain reaction using specific 27 forward and 1492 reverse primers. Amplicons were resolved and viewed as previously. Amplified products were digested by incubation with restriction endonuclease HaeIII, resolved by polyacrylamide gel electrophoresis and viewed. Linear regression analysis of gel profiles was used to calculate restriction fragment lengths. A Kruskal-Wallis (analysis of variance) test was performed on ranked data (H = 8.161, df = 9, P = 0.518). Consequently, the null hypothesis (no inter-subject variation) was accepted. However, all but two profiles were proved to be unique. Proof of principle was provided regarding the application of oral bacterial genotyping to forensic bite mark cases.

Error rates in bite mark analysis in an in vivo animal model

Recent judicial decisions have specified that one foundation of reliability of comparative forensic disciplines is description of both scientific approach used and calculation of error rates in determining the reliability of an expert opinion. Thirty volunteers were recruited for the analysis of dermal bite marks made using a previously established in vivo porcine-skin model. Ten participants were recruited from three separate groups: dentists with no experience in forensics, dentists with an interest in forensic odontology, and board-certified diplomates of the American Board of Forensic Odontology (ABFO). Examiner demographics and measures of experience in bite mark analysis were collected for each volunteer. Each participant received 18 completely documented, simulated in vivo porcine bite mark cases and three paired sets of human dental models. The paired maxillary and mandibular models were identified as suspect A, suspect B, and suspect C. Examiners were tasked to determine, using an analytic method of their own choosing, whether each bite mark of the 18 bite mark cases provided was attributable to any of the suspect dentitions provided. Their findings were recorded on a standardized recording form. The results of the study demonstrated that the group of inexperienced examiners often performed as well as the board-certified group, and both inexperienced and board-certified groups performed better than those with an interest in forensic odontology that had not yet received board certification. Incorrect suspect attributions (possible false inculpation) were most common among this intermediate group. Error rates were calculated for each of the three observer groups for each of the three suspect dentitions. This study demonstrates that error rates can be calculated using an animal model for human dermal bite marks, and although clinical experience is useful, other factors may be responsible for accuracy in bite mark analysis. Further, this study demonstrates that even under carefully controlled conditions, albeit in a forced-decision model, errors in interpretation occur even amongst the most experienced analysts.

The use of full spectrum digital photography for evidence collection and preservation in cases involving forensic odontology

Photography often represents the best method to collect and preserve evidence in forensic cases. This is especially true in forensic odontology with cases involving dental identification, human abuse and, perhaps most significantly, bitemark cases. Basic visible light photography is adequate in most dental identification cases; however, full spectrum digital photography is best utilized to collect all available evidence in cases of human abuse and bitemarks. This paper will discuss the types of photographic evidence that should be collected with various forensic odontological cases and the specific techniques utilized in full spectrum forensic digital photography. The use of full spectrum photography captures the forensic injuries using special techniques recording the injuries in each of the four resultant events that occur when light strikes skin.

Is current bite mark analysis a misnomer?

Four human-to-human bite mark cases in which forensic odontological opinion was found to be in error, or at best deeply divided between experts, are described. These are used to illustrate that there is a growing awareness on the part of the legal profession that bite mark opinions by experts may often be little more than that and that these opinions often cannot be substantiated given the paucity of rigorous scientific evaluation, and will therefore be increasingly challenged. This may not best serve justice and so it is argued that forensic odontology needs to bring more scientific rigour to the evaluation of bite marks. This may threaten to disenfranchise some of the current practitioners and there may be some resistance to change. Forensic odontology is not the only identification science facing such problems, but nevertheless a paradigm shift is predicted in the way bite mark evidence will have to be gathered and evaluated in the future. Some new scientific approaches are described that strive to unravel some of the most basic problems confronting our profession when we attempt to make morphometric comparisons between injuries and the dentition of the biter. A need to capture the actions and consequences of biting in 3D dimensions and simultaneously in real-time is proposed as a path of investigation highly likely to bring some clarity to a confused situation. There is also an urgent need for the ongoing controversy between some of our eminent peers relating to the assumed uniqueness, or otherwise, of the human anterior dentition to be resolved.

Expert Disagreement in Bitemark Casework*

Bitemark cases continue to raise controversy due to the degree of expert disagreement which is frequently seen. Using a case mix of 49 bitemark cases from 2000 to 2007 each injury was independently assessed for its forensic significance using a previously described bitemark severity scale. Following the assessment, the mean value for the bites was categorized according to the crime type, the degree of expert agreement, and the judicial outcome. Results suggest that bitemarks found in child abuse cases have statistically significantly lower forensic value than those in other crime types, that bites where there is mutual agreement between experts will have higher forensic value than those where there is disagreement at trial, and that cases in which DNA has provided an exoneration will demonstrate similar quality to those where a conviction was secured. Forensic odontologists should carefully assess bitemark evidence and ensure that it meets certain minimums in relation to the presence of class and unique features before undertaking an analysis.

An Integrated Technique for the Analysis of Skin Bite Marks

The high number of murder, rape, and child abuse cases in South Africa has led to increased numbers of bite mark cases being heard in high courts. Objective analysis to match perpetrators to bite marks at crime scenes must be able to withstand vigorous cross-examination to be of value in conviction of perpetrators. An analysis technique is described in four stages, namely determination of the mark to be a human bite mark, pattern association analysis, metric analysis and comparison with the population data, and illustrated by a real case study. New and accepted techniques are combined to determine the likelihood ratio of guilt expressed as one of a range of conclusions described in the paper. Each stage of the analysis adds to the confirmation (or rejection) of concordance between the dental features present on the victim and the dentition of the suspect. The results illustrate identification to a high degree of certainty.

Seven Hundred Seventy Eight Bite Marks: Analysis by Anatomic Location, Victim and Biter Demographics, Type of Crime, and Legal Disposition

A study of the etiology, anatomic location, victim demographics and legal disposition of bite mark cases was made with the purpose of updating and augmenting previous research in the field. The information may be of interest to a myriad of professional disciplines including Forensic Odontologists, Medical Examiners, Detectives, Profilers, Emergency Room Personnel, Coroners, Psychologists, and Family Service Counselors, as bite marks provide both physical and biological data. While bite marks were found on all anatomic regions of the body some sites are significantly more likely to receive bites, and the frequency that an area is bitten may vary with the type of crime. Sex and age of the victim may also impact the resulting location and frequency of bites. A survey form for bite mark cases was created and mailed to all Diplomates of the American Board of Forensic Odontology. The survey form was also included in the American Society of Forensic Odontology newsletter. The survey requested that the recipient fill out a separate form for each case for which the recipient was the primary investigator of a patterned injury. The data from the resulting surveys were entered into a Microsoft Excel spreadsheet. The responses detailed two hundred thirty two (259) bite mark cases that included seven hundred (778) individual bite marks. Harvey (1976) and Sweet and Pretty (2000) published studies finding the highest percentage of bites to the breasts. In 1983 Vale and Noguchi published the paper indicating that the most frequently bitten area was the upper extremities. The survey forms were sent to approximately 1100 forensic dentist in 26 countries. The forensic experience level of the dentists varied from neophyte to very experienced. The data were analyzed and the results reported and organized in the following categories; Victim Distribution by Gender, Victim Distribution by Age, Child Abuse Distribution by Age and Gender, Sexual Assault Distribution by age and Gender, Homicide Distribution by Age and Gender, Bite Mark Distribution by Gender and Location, Number of Bite Marks per Victim, Bite mark Distribution Comparison to Previous Research, Child Abuse Suspect Age Distribution by Age and Sex, Homicide Suspect Age Distribution by Age and Sex, Sexual Crimes Suspect Age Distribution by Age and Sex, and Bite Mark Incidence by Anatomical Area and Type of Crime. Fifty-two forensic odontologists from seven countries responded. Nineteen responders were Diplomates of the American Board of Forensic Odontology. The number of cases reported by each responder ranged from one to thirty-three and the average number of cases reported was 4.5. In this broad based study, females were bitten more often than males. The average male victim was younger than the average female victim. Males that were victims tended to be either very young or very old. The youngest victim was a two-month-old boy and the oldest victim a 95-year-old woman. Perpetrators were male more often than female and there was an average of 1.4 suspects per case. The results show that most bites occurred on the arm, followed by the breast. If broken down by gender, males were bitten on the arm more than females, and females were bitten on the breast more often than males. The data show patterns in location and number of bites that seem related to both the type of crime and the age of the victim.

A Web-Based Survey of Odontologist's Opinions Concerning Bitemark Analyses

Within the field of forensic dentistry, the detection, collection, and analysis of bitemarks remains one of the most contentious areas. Attempts at the production of consensus documents have produced documents such as the ABFO's Guidelines for Bitemark Evidence Collection. Despite this, the range of differing analysis techniques, allied with a varied opinion base on the robustness of bitemark conclusions has led to polarized views within the profession. The purpose of this study was to survey forensic dentists to obtain their views on a number of crucial components of bitemark theory and contentious areas within the discipline. Using a web-based survey, 14 questions were asked of respondents. Seventy-two odontologists completed the survey, with 38% being of Diplomate status, 10% had completed 20 or more bitemark cases, and 20% between 10 and 20 cases, 91% of respondents believed that the human dentition was unique, with 78% believing that this uniqueness could be represented on human skin during the biting process. Seventy percent believed that they could positively identify an individual from a bitemark, and 22% stated that the statistical tool, the product rule, should be applied to bitemark conclusions. Over half of the odontologists used overlays for bitemark analysis. with a digital method of production the most popular. The implications of these and other findings are discussed.

Results of the 4th ABFO Bitemark Workshop—1999

Thirty-two certified diplomates of the American Board of Forensic odontology (ABFO) participated in a study of the accuracy of bitemark analysis. Examiner experience as board-certified odontologists ranged from 2 to 22 years. Examiners were given sets of photographs (a cast in 1 case) of 4 bitemark cases and asked to report their certainty that each case was truly a bitemark and the apparent value of the case as forensic evidence. Participants also received 7 occluding sets of dental casts, 1 correct dentition for each case and three unrelated to any of the cases, and asked to rate how certain they were that each set of teeth had made each bitemark. Receiver operating characteristic (ROC) analysis resulted in an accuracy score of 0.86 (95% CI=0.82–0.91). Youden’s index was used to determine a cutoff point for determining an accuracy score for each case. Accuracy scores were significantly correlated with bitemark certainty and forensic value ( P<0.001 in both cases) but not with examiner experience ( P=0.958). The use of individual ROC analysis with weighted Youden’s index to calibrate individual accuracy was also demonstrated.

Anatomical Location of Bitemarks and Associated Findings in 101 Cases from the United States

The purpose of this paper is to update and confirm previous studies that examined the anatomical location of human bitemarks. This information is useful to forensic odontologists and pathologists, physicians, and coroners who must be familiar with the most likely locations of bitemarks. The data are also useful for those involved in bitemark research. Using the legal database "Lexis," 101 bitemark cases were identified from the United States Courts of Appeal. Cases were included in the study if they provided details concerning the bitemark, such as anatomical location, number of injuries, and information concerning the victim. Information on 148 bites was collated. These data are presented in tabular and graphical form to allow comparisons between males and females, victims and perpetrators, adults and children, and the crime types associated with human bites.

Analysis of Salivary DNA Evidence from a Bite Mark on a Body Submerged in Water

A female body was recovered after approximately 5.5 h in a river with slow-moving current. On the victim's right breast, a patterned injury was discovered and determined to be from human adult teeth. Evidence was collected according to established techniques including recovery of saliva from the bite mark area despite the body being found submerged in water. DNA analysis by PCR using polymorphic STR markers revealed a DNA profile of mixed origin. In addition to the victim's DNA profile, a genotype contribution from the perpetrator was identified as a minor component. The DNA typing results from the bite mark correlated with the DNA typing results obtained from other biological trace evidence identified from the victim's genital samples. The bite mark and the DNA evidence were used to screen suspects and played an important role in obtaining resolution of this case. Consequently, it is advisable that investigators routinely swab for salivary DNA in bite mark cases, even when the amount is thought to be minimal.

Two Bite Mark Cases with Inadequate Scale References

Most literature addressing comparisons between epidermal bite marks and the perpetrator's bite pattern mandates fastidious coordination between the size of the compared reproductions. While ideal, this is not possible in every case and inability to control this variable in selected cases may not necessarily invalidate the comparison. The first case involves a known perpetrator. All photographic measurements were recorded with acceptable techniques to discover a serious discrepancy in arch size. The second case was degraded by the absence of a ruler in a tangentially made photograph of a bite mark. In both cases, the weight of the conclusions were lessened by these problems but the impartial handling of the evidence and explanation of discrepancies offered credibility to the analyses. Both cases illustrate that a technical infraction in processing and recording bite marks, though serious, need not automatically preempt the analysis.

The Forensic Science Use of Reflective Ultraviolet Photography

Reflective ultraviolet photography has many forensic science applications particularly in child abuse, rape, homicide, and bite mark cases. The potential of this relatively simple and inexpensive procedure has not been fully explored. The procedure for its use in bite mark cases is presented.