Introduction
Forensic dentistry (forensic odontology) is defined as the study of the face and oral cavity as it pertains to questions of law. Initially the focus was on use of dental evidence to identify people who were visually unidentifiable, such as victims of fire, decomposition, blast, vehicular accident, and mass disasters. The first American dental identification case of note involved Paul Revere, who in addition to his silversmithing and midnight ride, also practiced as a barber/surgeon-dentist. He created a dental appliance for Dr. Joseph Warren, who commanded a troop of revolutionary soldiers and was killed at the Battle of Bunker Hill. Revere later identified Warren’s body from the dental prosthesis he had fabricated, allowing the doctor a hero’s funeral.
Mass fatality identifications began in 1897 with the Bazar de la Charité fire in Paris. Dr. Oscar Amoedo, a Cuban dentist visiting Paris, suggested the use of dental records to identify the victims. His thesis on the fire and identification, “Lárt Dentaire Medecine Legale” is the seminal text on the subject. The first bite mark case in Colonial America occurred during the Salem Witch Trials in 1692, where the Rev. George Burroughs was convicted and hanged for witchcraft, including biting his victims.
In modern times, the first dentist member of the American Academy of Forensic Sciences (AAFS) was Dr. David Scott who joined in 1966. By 1972, 15 dentist members of the Academy came together to found the AAFS’s Odontology Section. In 1970 the American Society of Forensic Odontology (ASFO) was founded, and finally, in 1976, the American Board of Forensic Odontology (ABFO) was organized to provide certification examinations to ensure the highest level of competence in the field. Today there are approximately 100 active ABFO Diplomates in the United States and Canada.
Since the era of C. Henry Kempe, information on child abuse and dentistry began to appear in the dental literature. The interest in family violence has since evolved to include work on domestic violence and elder abuse, as well as child abuse. The first edition of the Forensic Odontology Workbook, a loose leaf notebook printed by the ASFO in 1980, devoted a chapter to “Child Abuse and Neglect.” These early efforts began a systematic approach to child abuse recognition and intervention by forensic odontologists and by the dental profession as a whole. This notebook evolved into the “Manual of Forensic Odontology.” In terms of continuing education, the Armed Forces Institute of Pathology held the first continuing education course in Forensic Odontology in 1964. Child abuse and domestic violence are regular topics in their ongoing courses. The first U.S. residency in Forensic Odontology was started at the University of Texas Health Science Center, San Antonio, Texas.
Articles on the dentists’ role in child abuse have been published in many journals, beginning in 1970 with an article in the New York State Dental Journal by Arthur Hazlewood. The British Journal of Oral Surgery reviewed five cases in an article the following year. Bernard Sims and colleagues addressed “Bite Marks in the ‘Battered Baby Syndrome’” in Medicine, Science and the Law in 1973, and a number of other articles appeared in the 1970s.
The American Academy of Pediatric Dentistry has taken a leading role for the dental profession and has an active partnership with the American Academy of Pediatrics, covering many areas of mutual interest including child abuse. Pediatric dental textbooks now routinely cover the diagnosis and management of suspected child abuse.
Programs have been developed to educate dentists about child abuse. PANDA (Prevent Abuse and Neglect through Dental Awareness) is an educational program founded in 1992 by Dr. Lynn Mouden, in collaboration with state dental societies, the Delta Dental Plan, and state child welfare agencies (personal communication, Dr. Lynn Mouden, 2008). The program provides educational materials and training programs to participating state dental societies. It now serves 45 states, the U.S. Army Dental Command, and 10 foreign countries, providing comprehensive education for dental health professionals.
Orofacial Injuries in Child Abuse
Research over the past 40 years has shown that 43.5% to 65% of child abuse injuries occur in the head and neck region. Dental professionals deal with the head and neck during the routine examination and dental health care of their patients. Child abuse injuries are not dissimilar to injuries from domestic violence or elder abuse. Perioral injuries include: patterned injuries ( Figure 60-1 ), lacerations to the lips, slap marks to the face, gag marks at the corners of the mouth, bruises, human bite marks, and burns from electrical, chemical or thermal sources. Intraoral injuries include maxillary or mandibular fractures, fractured or avulsed teeth, torn frenula, other intraoral lacerations, bruising of the hard and soft palate from forced oral sex ( Figure 60-2 ), and evidence of sexually transmitted diseases.
There are many ways forensic odontologists and PANDA-trained dentists can assist in child abuse cases. The first is assessing perioral and dental injuries as to the likely cause, treatment and outcome. Perhaps the area where the forensic odontologist plays the greatest role in child abuse is in documentation and analysis of bite marks. In some jurisdictions, forensic odontologists analyze and testify about other patterned injuries using the same techniques as in bite mark analysis.
Forensic odontologists are more familiar with the legal system and requirements for evidence collection than most hospital- or practice-based dentists. Forensic odontologists are usually actively affiliated with law enforcement agencies such as coroners/medical examiners, state police, or state forensic agencies. Odontologists have been trained to collect and handle evidence in cases of homicide, assault, and other crimes, making them valuable members of investigative teams.
Bite Marks and Patterened Injuries
There are 4 “Rs” to consider in bite marks: Recognition, Reporting, Recording, and Referral. In addition to forensic odontologists, some specially trained allied health care professionals such as child abuse pediatricians, forensically trained pediatric nurse practitioners (PNPs), and sexual assault nurse examiners (SANE nurses) have been trained to assist hospitals in the recognition and recovery of evidence.
Recognition
A classic human bite in skin is opposing semilunar marks measuring 2 to 4 cm across, with marks along the periphery made by the individual teeth. The ABFO defines a human bite mark as “a circular or oval (doughnut or ring-shaped) patterned injury consisting of two opposing (facing) symmetrical, U -shaped arches separated at their bases by open spaces. Following the periphery of the arches is a series of individual abrasions, contusions, and/or lacerations reflecting the size, shape, arrangement, and distribution of the class characteristics of the contacting surfaces of the human dentition.”
Children who bite one another frequently leave fairly clear marks with both arches, whereas adult bites often only are distinct in one arch ( Figures 60-3 and 60-4 ). Specific size, class, and individual characteristics will differentiate between bite marks inflicted by human adults or children or by animals. Odontologists also can evaluate other skin lesions that resemble human bites and differentiate them from bite marks. In the experience of many odontologists, when one bite mark is observed by medical personnel (including forensic pathologists), a trained odontologist will often find additional, more subtle, marks. Medical practitioners trained in pattern recognition and adept at three-dimensional spatial analysis will have an advantage when recognizing and analyzing bite marks and other patterned marks.
Hickeys and Suction Marks
Bite marks can be accompanied by an area of central ecchymosis. This can be caused either by the positive pressure of the teeth on the skin surrounding the bite area, which causes disruption of the small blood vessels enclosed within the area of the bite mark ( Figure 60-5 ), or by the negative pressure of suction or tongue thrust on the area. ,
Bite Marks
The human dental arch contains two central incisors, two lateral incisors, two cuspids, four bicuspids, and six molars. Most frequently only the four or six most anterior teeth make a distinctive mark on the skin. The maxillary central incisors are wider than the laterals (approximately 8.5 vs. 6.5 mm) and both are linear or rectangular. The cuspids usually make the most definitive mark (triangular, or a point) because of their length and shape, and occasionally a bite mark will include the facial cusps of bicuspid teeth. The lower central and lateral incisors in the permanent dentition are about the same width (5.0 vs. 5.5 mm). In the deciduous or primary dentition, the maxillary central and lateral incisors are smaller, approximately 6.5 vs. 5.1 mm in width. The lower incisors are somewhat smaller (4.2 mm), but again, almost equal in size.
A bite mark class characteristic identifies the group from which it originates: human, animal, fish, or other species. The teeth leave distinctive marks because of the vital response of the underlying bitten tissue, and for this reason serial photographs of living victims over several days are most useful for the odontologist to do the analysis. Generally, the upper (maxillary) arch will be larger than the lower arch, and the average maxillary intercuspid distance (cuspid to cuspid) will be approximately 33 mm. The overall width of the maxillary bite mark will be 3.5 to 4.0 cm. The mandibular mark will be on the order of 25 mm. Bites by children with primary dentition (under the age of 6) will be under 3.0 cm from cuspid to cuspid. There are minor differences between the dentition of males and females, as well as between the dentition of various races, but according to research by Barsley and Lancaster, age and race differences are insignificant above 12 years of age.
The arch characteristic is a pattern that represents the tooth arrangement within a bite mark. For example, a combination of rotated teeth, buccal or lingual version, mesio-distal drifting, and horizontal alignment contribute to differentiation between individuals. The dental characteristic is defined as a feature or trait within a bite mark that represents an individual tooth variation such as unusual wear patterns, notching, angulations, and fractures. The number, specificity, and accurate reproduction of these arch characteristics and dental characteristics contribute to the overall assessment of the degree of confidence that a particular suspect made the bite mark.
Animal bites generally tear or avulse flesh. The dental pattern of canines and felines includes six incisors and two canine teeth in each arch. The arches are much narrower and elongated in the anterior-posterior aspect than the human dental arch ( Figures 60-6 and 60-7 ).
