David Senn - Academia.edu (original) (raw)

Papers by David Senn

Research paper thumbnail of Accreditation of Forensic Specialty Certification Bodies

Forensic Science Policy & Management: An International Journal

Research paper thumbnail of Epidermis and Enamel: Insights Into Gnawing Criticisms of Human Bitemark Evidence

The American journal of forensic medicine and pathology, Jan 20, 2018

Critics describe forensic dentists' management of bitemark evidence as junk science with poor... more 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 share...

Research paper thumbnail of History of Bitemark Evidence

A Color Atlas and Text, 2nd Edition, 2011

Research paper thumbnail of Dental Age Estimation

Manual of Forensic Odontology, Fifth Edition, 2013

Research paper thumbnail of Future of Forensic Dentistry

Forensic Dentistry, Second Edition, 2010

Research paper thumbnail of Scope of Forensic Odontology

Forensic Dentistry, Second Edition, 2010

Research paper thumbnail of Forensic Dental Age Estimation: An Overview

Journal of the California Dental Association, 2015

Forensic age estimation is a scientific process that estimates an individual's true chronolog... more Forensic age estimation is a scientific process that estimates an individual's true chronologic age by assessing skeletal and dental development and maturation. Although human growth and maturation is unique to each individual, dental techniques for estimating age are currently considered the best in assessing true chronologic age particularly during the age range when the dentition is undergoing morphologic development. This article reviews the principles, methodology and commonly used techniques in forensic age estimation cases.

Research paper thumbnail of Digital Applications in Forensic Odontology

Applications in Practice and Research, 2011

Digital Applications in Forensic Odontology (9781609604837): Robert E. Barsley, David R. Senn, Th... more Digital Applications in Forensic Odontology (9781609604837): Robert E. Barsley, David R. Senn, Thomas J. David, Franklin D. Wright, Gregory S. Golden: Book Chapters.

Research paper thumbnail of Reporting of child abuse: a follow-up survey of Texas dentists

Pediatric dentistry

Child abuse is a disturbingly common finding in society today. There have been substantial and si... more Child abuse is a disturbingly common finding in society today. There have been substantial and significant increases in the incidence of child abuse since the last national incidence study was conducted in 1986. Kassebaum first reported the under-reporting of child abuse by Texas dental professionals in a survey in 1986. The objective of the current study was twofold: (1) assess the level of knowledge and attitudes among dental professionals on the important issue of child abuse; (2) evaluate and compare the results of the current study with a similar survey conducted in 1986. A 24-question survey similar in format and content to the 1986 questionnaire was mailed to 1,046 Texas dentists, randomly selected from a membership roster provided by the Texas Dental Association. Both general dentists and selected specialists were included in the study group. The questionnaire consisted of multiple-choice and dichotomous yes/no questions. There were 383 responses to the questionnaire, yieldi...

Research paper thumbnail of Bitemarks

Manual of Forensic Odontology, Fifth Edition, 2013

Research paper thumbnail of Age Estimation from Oral and Dental Structures

Forensic Dentistry, Second Edition, 2010

Research paper thumbnail of Commentary on: Page M, Taylor J, Blenkin M. Expert interpretation of bitemark injuries-a contemporary qualitative study. J Forensic Sci 2013;58(3):664-72

Journal of Forensic Sciences, 2013

Research paper thumbnail of Odontology - Dentistry's Contribution to Truth and Justice

Current Issues, Future Directions, 2012

Research paper thumbnail of Manual of Forensic Odontology, Fifth Edition

Manual of Forensic Odontology, Fifth Edition, 2013

Research paper thumbnail of Analysis of Radiocarbon, Stable Isotopes and DNA in Teeth to Facilitate Identification of Unknown Decedents

PLoS ONE, 2013

The characterization of unidentified bodies or suspected human remains is a frequent and importan... more The characterization of unidentified bodies or suspected human remains is a frequent and important task for forensic investigators. However, any identification method requires clues to the person's identity to allow for comparisons with missing persons. If such clues are lacking, information about the year of birth, sex and geographic origin of the victim, is particularly helpful to aid in the identification casework and limit the search for possible matches. We present here results of stable isotope analysis of 13 C and 18 O, and bomb-pulse 14 C analyses that can help in the casework. The 14 C analysis of enamel provided information of the year of birth with an average absolute error of 1.861.3 years. We also found that analysis of enamel and root from the same tooth can be used to determine if the 14 C values match the rising or falling part of the bomb-curve. Enamel laydown times can be used to estimate the date of birth of individuals, but here we show that this detour is unnecessary when using a large set of crude 14 C data of tooth enamel as a reference. The levels of 13 C in tooth enamel were higher in North America than in teeth from Europe and Asia, and Mexican teeth showed even higher levels than those from USA. DNA analysis was performed on 28 teeth, and provided individual-specific profiles in most cases and sex determination in all cases. In conclusion, these analyses can dramatically limit the number of possible matches and hence facilitate person identification work.

Research paper thumbnail of Bitemark Analysis

Journal of the American Dental Association, 2012

Research paper thumbnail of Root Morphology and Anatomical Patterns in Forensic Dental Identification: A Comparison of Computer-Aided Identification with Traditional Forensic Dental Identification*

Journal of Forensic Sciences, 2010

An online forensic dental identification exercise was conducted involving 24 antemortem-postmorte... more An online forensic dental identification exercise was conducted involving 24 antemortem-postmortem (AM-PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM-PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT-ID index = 0.923) and Spearman's rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer-aided dental identification allows for an objective comparison of AM-PM radiographs and can be a useful tool to support a forensic dental identification conclusion.

Research paper thumbnail of A Comparison of Animal Jaws and Bite Mark Patterns*

Journal of Forensic Sciences, 2006

The purpose of this study was to compare the jaw shapes and bite mark patterns of wild and domest... more The purpose of this study was to compare the jaw shapes and bite mark patterns of wild and domestic animals to assist investigators in their analysis of animal bite marks. The analyses were made on 12 species in the Order Carnivora housed in the Mammalian Collection at the Field Museum of Natural History in Chicago, Illinois. In addition to metric analysis, one skull from each species was photographed as a representative sample with an ABFO No. 2 scale in place. Bite patterns of the maxillary and mandibular dentition were documented using foamed polystyrene exemplars, which were also photographed. A total of 486 specimens were examined to analyze the jaw and bite mark patterns. A modified technique for measuring intercanine distances was developed to more accurately reflect the characteristics seen in animal bite marks. In it, three separate areas were measured on the canines, rather than just the cusp tip. This was to maximize the amount of information acquired from each skull, specifically to accommodate variances in the depth of bite injuries.

Research paper thumbnail of Computer-aided Dental Identification: An Objective Method for Assessment of Radiographic Image Similarity*

Journal of Forensic Sciences, 2009

A pilot study evaluated a computer-based method for comparing digital dental images, utilizing a ... more A pilot study evaluated a computer-based method for comparing digital dental images, utilizing a registration algorithm to correct for variations in projection geometry between images prior to a subtraction analysis. A numerical assessment of similarity was generated for pairs of images. Using well-controlled laboratory settings, the method was evaluated as to its ability to identify the correct specimen with positive results. A subsequent clinical study examined longitudinal radiographic examinations of selected anatomical areas on 47 patients, analyzing the computer-based method in making the correct identification based upon a threshold level of similarity. The results showed that at a threshold of 0.855, there were two false negative and two false positive identifications out of 957 analyses. Based on these initial findings, 25 dental records having two sets of full mouth series of radiographs were selected. The radiographs were digitized and grouped into six anatomical regions. The more recent set of films served as postmortem images. Each postmortem image was analyzed against all other images within the region. Images were registered to correct for differences in projection geometry prior to analysis. An area of interest was selected to assess image similarity. Analysis of variance was used to determine that there was a significant difference between images from the same individual and those from different individuals. Results showed that the threshold level of concordance will vary with the anatomical region of the mouth examined. This method may provide the most objective and reliable method for postmortem dental identification using intra-oral images.

Research paper thumbnail of Reliability of Third Molar Development for Age Estimation in a Texas Hispanic Population: A Comparison Study

Journal of Forensic Sciences, 2009

Evaluating third molars from 950 Hispanic individuals aged 12-22 years using Demirjian's schemati... more Evaluating third molars from 950 Hispanic individuals aged 12-22 years using Demirjian's schematic for crown and root formation found that Hispanic third molar development was 8-18 months faster than American Caucasians as reported by Mincer, Harris and Berryman in 1993. This represents a statistically significant increase. Earlier development was more apparent in the later stages F through H. Hispanic males reach developmental stages faster than Hispanic females and maxillary third molars reach developmental stages faster than mandibular third molars in both sexes. The earliest age observed for stages B-H (e.g., Stage H first observed at age 13.92 years in females) and the oldest age observed for Stages B-G were developed to facilitate age prediction of unknown individuals. Prediction tables for minimum and maximum age for an observed stage (e.g., if a female maxillary third molar is stage F it means she is older than 13 years) for each sex-jaw group were calculated.

Research paper thumbnail of Accreditation of Forensic Specialty Certification Bodies

Forensic Science Policy & Management: An International Journal

Research paper thumbnail of Epidermis and Enamel: Insights Into Gnawing Criticisms of Human Bitemark Evidence

The American journal of forensic medicine and pathology, Jan 20, 2018

Critics describe forensic dentists' management of bitemark evidence as junk science with poor... more 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 share...

Research paper thumbnail of History of Bitemark Evidence

A Color Atlas and Text, 2nd Edition, 2011

Research paper thumbnail of Dental Age Estimation

Manual of Forensic Odontology, Fifth Edition, 2013

Research paper thumbnail of Future of Forensic Dentistry

Forensic Dentistry, Second Edition, 2010

Research paper thumbnail of Scope of Forensic Odontology

Forensic Dentistry, Second Edition, 2010

Research paper thumbnail of Forensic Dental Age Estimation: An Overview

Journal of the California Dental Association, 2015

Forensic age estimation is a scientific process that estimates an individual's true chronolog... more Forensic age estimation is a scientific process that estimates an individual's true chronologic age by assessing skeletal and dental development and maturation. Although human growth and maturation is unique to each individual, dental techniques for estimating age are currently considered the best in assessing true chronologic age particularly during the age range when the dentition is undergoing morphologic development. This article reviews the principles, methodology and commonly used techniques in forensic age estimation cases.

Research paper thumbnail of Digital Applications in Forensic Odontology

Applications in Practice and Research, 2011

Digital Applications in Forensic Odontology (9781609604837): Robert E. Barsley, David R. Senn, Th... more Digital Applications in Forensic Odontology (9781609604837): Robert E. Barsley, David R. Senn, Thomas J. David, Franklin D. Wright, Gregory S. Golden: Book Chapters.

Research paper thumbnail of Reporting of child abuse: a follow-up survey of Texas dentists

Pediatric dentistry

Child abuse is a disturbingly common finding in society today. There have been substantial and si... more Child abuse is a disturbingly common finding in society today. There have been substantial and significant increases in the incidence of child abuse since the last national incidence study was conducted in 1986. Kassebaum first reported the under-reporting of child abuse by Texas dental professionals in a survey in 1986. The objective of the current study was twofold: (1) assess the level of knowledge and attitudes among dental professionals on the important issue of child abuse; (2) evaluate and compare the results of the current study with a similar survey conducted in 1986. A 24-question survey similar in format and content to the 1986 questionnaire was mailed to 1,046 Texas dentists, randomly selected from a membership roster provided by the Texas Dental Association. Both general dentists and selected specialists were included in the study group. The questionnaire consisted of multiple-choice and dichotomous yes/no questions. There were 383 responses to the questionnaire, yieldi...

Research paper thumbnail of Bitemarks

Manual of Forensic Odontology, Fifth Edition, 2013

Research paper thumbnail of Age Estimation from Oral and Dental Structures

Forensic Dentistry, Second Edition, 2010

Research paper thumbnail of Commentary on: Page M, Taylor J, Blenkin M. Expert interpretation of bitemark injuries-a contemporary qualitative study. J Forensic Sci 2013;58(3):664-72

Journal of Forensic Sciences, 2013

Research paper thumbnail of Odontology - Dentistry's Contribution to Truth and Justice

Current Issues, Future Directions, 2012

Research paper thumbnail of Manual of Forensic Odontology, Fifth Edition

Manual of Forensic Odontology, Fifth Edition, 2013

Research paper thumbnail of Analysis of Radiocarbon, Stable Isotopes and DNA in Teeth to Facilitate Identification of Unknown Decedents

PLoS ONE, 2013

The characterization of unidentified bodies or suspected human remains is a frequent and importan... more The characterization of unidentified bodies or suspected human remains is a frequent and important task for forensic investigators. However, any identification method requires clues to the person's identity to allow for comparisons with missing persons. If such clues are lacking, information about the year of birth, sex and geographic origin of the victim, is particularly helpful to aid in the identification casework and limit the search for possible matches. We present here results of stable isotope analysis of 13 C and 18 O, and bomb-pulse 14 C analyses that can help in the casework. The 14 C analysis of enamel provided information of the year of birth with an average absolute error of 1.861.3 years. We also found that analysis of enamel and root from the same tooth can be used to determine if the 14 C values match the rising or falling part of the bomb-curve. Enamel laydown times can be used to estimate the date of birth of individuals, but here we show that this detour is unnecessary when using a large set of crude 14 C data of tooth enamel as a reference. The levels of 13 C in tooth enamel were higher in North America than in teeth from Europe and Asia, and Mexican teeth showed even higher levels than those from USA. DNA analysis was performed on 28 teeth, and provided individual-specific profiles in most cases and sex determination in all cases. In conclusion, these analyses can dramatically limit the number of possible matches and hence facilitate person identification work.

Research paper thumbnail of Bitemark Analysis

Journal of the American Dental Association, 2012

Research paper thumbnail of Root Morphology and Anatomical Patterns in Forensic Dental Identification: A Comparison of Computer-Aided Identification with Traditional Forensic Dental Identification*

Journal of Forensic Sciences, 2010

An online forensic dental identification exercise was conducted involving 24 antemortem-postmorte... more An online forensic dental identification exercise was conducted involving 24 antemortem-postmortem (AM-PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM-PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT-ID index = 0.923) and Spearman's rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer-aided dental identification allows for an objective comparison of AM-PM radiographs and can be a useful tool to support a forensic dental identification conclusion.

Research paper thumbnail of A Comparison of Animal Jaws and Bite Mark Patterns*

Journal of Forensic Sciences, 2006

The purpose of this study was to compare the jaw shapes and bite mark patterns of wild and domest... more The purpose of this study was to compare the jaw shapes and bite mark patterns of wild and domestic animals to assist investigators in their analysis of animal bite marks. The analyses were made on 12 species in the Order Carnivora housed in the Mammalian Collection at the Field Museum of Natural History in Chicago, Illinois. In addition to metric analysis, one skull from each species was photographed as a representative sample with an ABFO No. 2 scale in place. Bite patterns of the maxillary and mandibular dentition were documented using foamed polystyrene exemplars, which were also photographed. A total of 486 specimens were examined to analyze the jaw and bite mark patterns. A modified technique for measuring intercanine distances was developed to more accurately reflect the characteristics seen in animal bite marks. In it, three separate areas were measured on the canines, rather than just the cusp tip. This was to maximize the amount of information acquired from each skull, specifically to accommodate variances in the depth of bite injuries.

Research paper thumbnail of Computer-aided Dental Identification: An Objective Method for Assessment of Radiographic Image Similarity*

Journal of Forensic Sciences, 2009

A pilot study evaluated a computer-based method for comparing digital dental images, utilizing a ... more A pilot study evaluated a computer-based method for comparing digital dental images, utilizing a registration algorithm to correct for variations in projection geometry between images prior to a subtraction analysis. A numerical assessment of similarity was generated for pairs of images. Using well-controlled laboratory settings, the method was evaluated as to its ability to identify the correct specimen with positive results. A subsequent clinical study examined longitudinal radiographic examinations of selected anatomical areas on 47 patients, analyzing the computer-based method in making the correct identification based upon a threshold level of similarity. The results showed that at a threshold of 0.855, there were two false negative and two false positive identifications out of 957 analyses. Based on these initial findings, 25 dental records having two sets of full mouth series of radiographs were selected. The radiographs were digitized and grouped into six anatomical regions. The more recent set of films served as postmortem images. Each postmortem image was analyzed against all other images within the region. Images were registered to correct for differences in projection geometry prior to analysis. An area of interest was selected to assess image similarity. Analysis of variance was used to determine that there was a significant difference between images from the same individual and those from different individuals. Results showed that the threshold level of concordance will vary with the anatomical region of the mouth examined. This method may provide the most objective and reliable method for postmortem dental identification using intra-oral images.

Research paper thumbnail of Reliability of Third Molar Development for Age Estimation in a Texas Hispanic Population: A Comparison Study

Journal of Forensic Sciences, 2009

Evaluating third molars from 950 Hispanic individuals aged 12-22 years using Demirjian's schemati... more Evaluating third molars from 950 Hispanic individuals aged 12-22 years using Demirjian's schematic for crown and root formation found that Hispanic third molar development was 8-18 months faster than American Caucasians as reported by Mincer, Harris and Berryman in 1993. This represents a statistically significant increase. Earlier development was more apparent in the later stages F through H. Hispanic males reach developmental stages faster than Hispanic females and maxillary third molars reach developmental stages faster than mandibular third molars in both sexes. The earliest age observed for stages B-H (e.g., Stage H first observed at age 13.92 years in females) and the oldest age observed for Stages B-G were developed to facilitate age prediction of unknown individuals. Prediction tables for minimum and maximum age for an observed stage (e.g., if a female maxillary third molar is stage F it means she is older than 13 years) for each sex-jaw group were calculated.