ArticlePDF Available

Abstract and Figures

Background: Test bites have been recommended for collecting evidence of suspected dentition in bite mark analysis. However, these recommendations only suggest recording the interocclusal relationship without establishing number of records or characteristics to obtain proper records. This fails to consider not only the possibility that the recording material did not respond properly, but also that the evaluator has not detected simulations, habits or parafunctions that may affect the tests. Methods: This research establishes differences between three wax test bites taken from the same subjects to determine if the first bite offered the best quality. Results: No significant statistical association was found between the number of test bites recorded and respective quality. The interrater agreement produced almost perfect and substantial agreements. Conclusion: There is no significant evidence that a first and only test bite is the highest quality test bite. Therefore, it is recommended to take more than a single bite test in controlled situations.
Content may be subject to copyright.
O R I G I N A L A R T I C L E Open Access
Selection of test bites records as part of a
forensic bite mark analysis protocol
Fernando Rivera-Mendoza
1,2
, Stella Martín-de-las-Heras
3
, Pablo Navarro-Cáceres
1,4
and Gabriel M. Fonseca
1,2*
Abstract
Background: Test bites have been recommended for collecting evidence of suspected dentition in bite mark analysis.
However, these recommendations only suggest recording the interocclusal relationship without establishing number
of records or characteristics to obtain proper records. This fails to consider not only the possibility that the recording
material did not respond properly, but also that the evaluator has not detected simulations, habits or parafunctions
that may affect the tests.
Methods: This research establishes differences between three wax test bites taken from the same subjects to determine
if the first bite offered the best quality.
Results: No significant statistical association was found between the number of test bites recorded and respective quality.
The interrater agreement produced almost perfect and substantial agreements.
Conclusion: There is no significant evidence that a first and only test bite is the highest quality test bite. Therefore, it is
recommended to take more than a single bite test in controlled situations.
Keywords: Forensic science, Forensic odontology, Bite marks, Test bite records
Background
In bite mark cases, when authorities have identified a
potential suspect, his or her dental records may provide
the basis for comparison. It has been proposed that this
comparison allows forensic odontologists to establish a
correlation between the dental pattern of the suspect
and that of the bite mark under analysis (Dailey 2011).
Sample bites (or test bites) have been suggested by
the American Board of Forensic Odontology (2017)as
part of the protocol for collecting evidence of sus-
pected human dentition. These tests are tools that
allow reproducing the biting edges of teeth in a pos-
ition that simulates the bite mark pattern (Dailey
2011; American Board of Forensic Odontology 2017).
Current standards have emphasized the type of mate-
rials used in this procedure, suggesting American
Dental Association (ADA) certified materials (dental
waxes or silicone-based) or, with some limitations, ex-
panded polystyrene foam (Styrofoam®) (American
Board of Forensic Odontology 2017;Johnson2011).
Great care must be taken that the opposing teeth do
not come into contact with each other when the bite is
recorded. This precaution helps avoid causing 3-D dis-
tortions in position, shape and alignment of the teeth
(Dailey et al. 2013). In this context, ABFO suggests
recording the interocclusal relationshipwithout estab-
lishing preventive behavior, number of records or char-
acteristics that reflect the complexity of the biting act of
the suspect (American Board of Forensic Odontology
2017). According to technical logic, failure to establish a
minimum number of records would make it acceptable
to declare the first and only test adequate. With this,
the act of biting is limited to just closing the teethand
fails to consider not only the possibility that the record-
ing material did not respond properly, but also that the
evaluator has not detected simulations, habits or simple
oral parafunctions that may compromise the quality of a
sample.
Dental occlusion implies much more than the occlusal
contact relationships of the dentitions and refers to a
* Correspondence: gabriel.fonseca@ufrontera.cl
1
Programa de Magister en Odontología, Facultad de Odontología,
Universidad de La Frontera, Temuco, Chile
2
Forensic Dentistry Lab, Centro de Investigación en Odontología Legal y
Forense (CIO), Facultad de Odontología, Universidad de La Frontera,
Francisco Salazar 01145, Building L, 4811230 Temuco, Chile
Full list of author information is available at the end of the article
Egyptian Journal o
f
Forensic Science
s
© The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24
https://doi.org/10.1186/s41935-018-0053-y
dynamic biomechanical musculoskeletal system (Jokstad
2012). There are millions of possible mandibular place-
ments for occlusions intercuspal position (considering
the mandibles placement in all three dimensions of
space) and the range of motion is influenced by a high
number of factors. The neuromuscular system adapts
easily to these factors determining an engram(the so-
called muscle memory), which cannot be interpreted
as a simple mechanical abstraction of motion in a single
plane (Lerman 2011). The goal of this research was to
establish if differences exist between three wax test bites
(Websters type 3 bites in which teeth biting right
through or almost through the bitten material, typical of
the bite found in cheese) (Webster 1982) taken from the
same subjects, to corroborate if the first test bite was of
superior quality, and to discuss the value of having
more test bites to dynamically interpret the bite
action. We also discuss some technical proposals to
improvethetestbitesaswellasthestrategiesof
comparative analysis of them.
Methods
The present study was approved by the Ethical Scientific
Committee of the Universidad de La Frontera (CEC) by
act no. 079/2015. The CEC is an agency accredited by the
Regional Ministerial Health Secretariat of Chile. The ex-
periments carried out in this study were performed within
the guidelines of the CEC for human studies and were car-
ried out under the strict supervision of a registered dental
practitioner (FRM). Also, all the subjects have been fully
informed of the experimental procedure and consent was
obtained prior to the experiment. Thirty asymptomatic
subjects aged between 19 and 24 years, from the Facultad
de Odontología of the Universidad de La Frontera (Te-
muco, Chile) volunteered for this study. Inclusionary cri-
teria were to have natural healthy teeth (incisors, canines
and first premolar) with a maxillary and mandibular align-
ment as close to ideal, scored using the Littles Irregularity
Index (Little 1975) (from the ideal zero score to a max-
imum of 3 mm). Exclusionary criteria included history of
caries, supernumerary teeth, dental anomalies and direct
or indirect dental rehabilitations in these teeth.
Test bites
All participants were invited to perform test bites on
triangular blue wax wafers. These wafers were previ-
ously made Ad-hoc with Great Lakes Tapered Wafers
25/pkg.® (Great Lakes Orthodontics Ltd., Tonawanda
NY, USA) following the handling and storage guide-
lines provided by the manufacturer (Safety Data
Sheet, available at www.greatlakesortho.com). This
type of wax was chosen for its physical properties
and biocompatibility (Table 1).
The objective of this procedure was to obtain test
bites that followed the criteria established by Webster
(1982)forTyp e 3 bite s (Table 2). This classification of
bite marks in foodstuffs and inanimate objects has
been recommended and, in fact, there seems to be no
other attempt to standardize terminology for this type
of evidence (Rivera-Mendoza et al. 2017). In order to
obtain bite records that achieve these criteria, the
guidelines were followed as established by Scott (2010)
and Dawson (The Dawson Academy Blog 2008), and
modified Ad-hoc for the present study (Fig. 1):
The bite record must not cause any movement or
displacement of teeth.
Each subject was invited to perform three
consecutive test bites on respective wafers, while
Table 1 Attributes of the Great Lakes Tapered Wafers 25/pkg.®,
according to Sections 3, 9, 11, and 12 of the Safety Data Sheet
provided by the manufacturer (www.greatlakesortho.com)
Product name Great Lakes Tapered Wafers 25/pkg.®
(Wax, product number 260032)
Manufactured by Great Lakes Orthodontics Ltd.,
Tonawanda NY, USA
Hazardous
components
This material is not hazardous under the criteria
of the Federal OSHA Hazard Communication
Standard 29 CFR 1910.1200
Form Solid
Color Light Blue
Odour Mild odour
Flash Point 465 °F (240 °C)
Boiling Point > 450 °F
Freezing/Melting
Point
Softening Point by Ring and Ball Apparatus ASTM
E28-58 T: 145 °F
Toxicological
information
No evidence of adverse effects from available
information
Ecological information
(non mandatory)
No evidence of adverse effects from available
information
Table 2 Characteristics of Type 3 bites (adapted from
Webster 1982)
The teeth bite right through or almost through the bitten material.
The bitten piece is removed by fracturing it from the main material.
The bite shows a record of the outline of the labial aspect of the
upper and lower incisor teeth.
The tooth scrape marks penetrating the bitten material.
Both labial outline marks and tooth scrape marks tend to record
those elements of the teeth which are most prominent anteriorly.
The widths of the tooth scrape marks are the horizontal width
between
the most mesial and most distal parts of the tooth crown recorded.
The body of the bite exhibits extensive scrape marks and may give an
indication of the relative positions of the upper and lower incisor teeth.
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 2 of 8
ensuring accurate verification of the interocclusal
record.
In each case, the wax was softened to avoid
distortion of the bite pattern. Since the wax is
naturally hard, the wafers were immersed in a
thermostatically controlled water bath at 58 °C for
60 s. The wafers were inserted into the subjects
mouth by placing them against the upper arch,
pressing against the arch to ensure teeth indented
the wax.
In order to avoid modifying the subjects natural bite
pattern, each subject was asked to try to contact all
of his/her posterior teeth in the same biting act. The
mandible was not manipulated in any way to allow
the natural design of the engram during the arc of
closure and to avoid overwhelming (Lerman 2011).
The wafers were removed from the mouth while
they were still warm and in a single movement to
avoid deformations. Following the manufacturers
standards, the records were immediately placed in
cold water to complete the hardening phase of the
wax. Once performed, each of the records were
checked, coded, anonymized and preserved
following the manufacturers recommendations to
avoid environmental modifications.
Analysis
Following the tests, two trained observers (FRM,
GMF) collaborated on evaluation and categorization
of record quality. Both observers evaluated three re-
cords simultaneously and three independently for fur-
ther consensus. For this, and as a previous calibration
procedure, tests bites not included in the study sam-
ple were used. Following Sheasby & MacDonaldscri-
teria for primary distortions(those occurred at the
time of biting) (Sheasby and MacDonald 2001), and
having discarded the test bites that did not respect
the requirements established by Webster for type 3
(1982), the calibration allowed establishment of which
were to be considered patterns of slightest
distortions(Fig. 2):
Wax runoff.
Wax stretching.
Presence of beveling on the biting edges of teeth.
Presence of excesses or over-edges of wax.
Incorrect definition of interproximal ridges.
Incorrect intermaxillary relationship: lateral
displacement.
Incorrect intermaxillary relations: lack of deepening
of the bite.
Fig. 1 Protocol for register the test bite records. aTriangular blue wax wafers made Ad-hoc with Great Lakes Tapered Wafers 25/pkg.® (Great
Lakes Orthodontics Ltd., Tonawanda NY, USA). bWax immersion in a thermostatically controlled water bath at 58 °C for 60 s. cThe subject was
asked to perform three consecutive test bites on respective wafers ensuring a natural interocclusal record. dThe wafers were removed in a single
movement to avoid deformations and placed in cold water
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 3 of 8
These slightest distortion patterns were used to
categorize each of the three records of each individual into
three different categories of record quality, regardless of
how many patterns they had: better,fair or worse. Seven
days after all sampling test bites have been finalized, they
were categorized according to this classification, and dis-
crepancies were resolved by consensus. The records of the
first sampling and the second sampling were compared
according to a design of paired samples by individual.
Pearson chi-square test was used to assess the association
of the categories of record quality (CRQ) with the first,
second or third test bite record. Likewise, interrater agree-
ment was measured between the observers (Cohensk)
with results categorized as: poor agreement (below 0.0);
slight agreement (0.00 to 0.20); fair agreement (0.21 to
0.40); moderate agreement (0.41 to 0.60); substantial
agreement (0.61 to 0.80); and almost perfect agreement
(0.81 to 1.00).
Results
No significant statistical association was found between
the number of test bite record (first, second or third)
and the three categories of record quality: CRQ better
(p= 0.407), CRQ fair (p= 0.741) or CRQ worse (p=
0.741) (Table 3). The interrater agreement produced good
results for all categories: CRQ better (k= 0.846, almost
perfect agreement), CRQ fair (k = 0.700, substantial
agreement)andCRQworse (k = 0.797, substantial
agreement)(Table4).
Discussion
Our results demonstrate that there is no evidence that a
first (and only) test bite record is the best representation
of the subjects bite action. This is not a minor issue,
considering that no protocol suggests performing more
than one test bite record, which implies that slightest
distortions may be overlooked if only one test bite rec-
ord is considered. These slightest distortions do not ne-
cessarily represent errors in the recording procedures,
but dynamic patterns that can manifest in varying de-
grees depending on multiple factors. In 2001, Sheasby &
MacDonald stated that since the nature of the contact
between teeth and the bitten substrate can influence the
resulting bite mark, it is logical to postulate that the dy-
namics of the biting action may produce distortions
known as primary distortions. According to these au-
thors, these distortions are complex, unpredictable, and
absolutely dependent and proportional to the degree of
movement between the teeth and the bitten substrate
(Sheasby and MacDonald 2001). It is extremely interest-
ing to mention that although the authors report that
each episode of contact is a unique dynamic event, and
that the same dentition can produce bite marks with dif-
ferent forms of appearance (Sheasby and MacDonald
2001), we have not found a test bite protocol that expli-
citly considers performing more than one single record
to control this phenomenon. The results of our research
Table 3 Descriptive statistic showing the association between
the number of test bite record and the categories of record
quality. CRQ: Category of Record Quality
Frequency Percent Valid
Percent
Cumulative
Percent
CRQ: Better
Valid 1st TEST BITE 7 23.3 23.3 23.3
2nd TEST BITE 10 33.3 33.3 56.7
3rd TEST BITE 13 43.3 43.3 100.0
Total 30 100.0 100.0
X
2
= 1.800
a
p= .407
CRQ: Fair
Valid 1st TEST BITE 11 36.7 36.7 36.7
2nd TEST BITE 11 36.7 36.7 73.3
3rd TEST BITE 8 26.7 26.7 100.0
Total 30 100.0 100.0
X
2
=.600
a
p=.741
CRQ: Worse
Valid 1st TEST BITE 12 40.0 40.0 40.0
2nd TEST BITE 9 30.0 30.0 70.0
3rd TEST BITE 9 30.0 30.0 100.0
Total 30 100.0 100.0
X
2
=.600
a
p=.741
a
0 cells (0.0%) have expected count less than 5. The minimum expected count
is 10.0
Fig. 2 First, second and third test bite record in the same subject.
Asterisks point to different patterns of slightest distortions
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 4 of 8
demonstrate that a first (and only) test bite may be
masking slightest distortions that, at the time of the
comparative analysis, may increase the chances of pro-
ducing false positives or false negatives. Although regis-
tering the suspects incisal edges appears to be a simple
protocol, problems can arise when introduced as evi-
dence. Karazulas (1984) reported a case wherein test
bites performed by the defense showed a different dental
pattern different than the test bites produced by pros-
ecution. The defendant was finally acquitted of the mur-
der, but spent 7 years in prison and endured three trials
before being proven innocent and released. Performing
at least three test bites would not cause any delays or in-
creased costs (most of the recommended materials are
very economical and easy to manipulate), but would
allow evaluation and selection of the highest quality
sample (according to our results, any of the three regis-
ters may be the best representation of the subjects bite),
as well as help detect dynamic patterns of the bite. The
latter statement is currently hypothetical -at least in the
forensic discipline- but it is extremely attractive to start
future lines of research.
The neuromuscular engram controls a complex spatial
motion pattern and although this reflex primarily affects
both masticatory muscles and occlusal-muscular relation-
ships, the engram has received so little scrutiny (Lerman
2011). The intermaxillary functional relationship should
be considered not by dogmasof static positions but in a
dynamic three-dimensional framework, that is, through
relative positions of teeth, mandible and maxilla in context
with oral functions and appearance (Jokstad 2012). The
usual technique for obtaining test bites is to take a record
with the patients mouth passively closed based on centric
relation (CR) (maximal intercuspation); this is performed
on the assumption that the subject has a normal baseline
psychoneuromuscular control, therefore, reproducible in
time (ie, without habitual or conscious posturing) (Agbaje
et al. 2013). However, number of residual teeth, occlusal
support, maximum bite force, periodontal disease, differ-
ence in mandibular movement during mastication,
changes in body posture, and even substrate consistency
have all been described as factors that can affect neuro-
muscular control of chewing, muscle activity, masticatory
performance (van der Bilt 2011;Kosakaetal.2016;
Sakaguchi et al. 2007) and, therefore, the final representa-
tion of the bite action: the bite mark.
Beyond these pathophysiological considerations of
biting, there are other inherent limitations to the
Table 4 Interrater Cohens k scores. Contingency table and symmetric measures for the Categories of Record Quality (CRQ): Better,
Fair and Worse. Obs.1 = Observer 1; Obs. 2 = Observer 2
Obs. 2 Total (%)
1st TEST BITE (%) 2nd TEST BITE (%) 3rd TEST BITE (%)
Contingency table for CRQ Better
Obs.1 1st TEST BITE (%) 6 (20.0) 1 (3.3) 0 (0.0) 7 (23.3)
2nd TEST BITE (%) 0 (0.0) 10 (33.3) 1 (3.3) 11 (36.7)
3rd TEST BITE (%) 1 (3.3) 0 (0.0) 11 (36.7) 12 (40.0)
Total (%) 7 (23.3) 11 (36.7) 12 (40.0) 30 (100.0)
Kappa value = .846
pvalue = < 0.001
Contingency table for CRQ Fair
Obs.1 1st TEST BITE (%) 9 (30.0) 0 (0.0) 2 (6.7) 11 (36.7)
2nd TEST BITE (%) 1 (3.3) 8 (26.7) 1 (3.3) 10 (33.3)
3rd TEST BITE (%) 0 (0.0) 2 (6.7) 7 (23.3) 9 (30.0)
Total (%) 10 (33.3) 10 (33.3) 10 (33.3) 30 (100.0)
Kappa value = .700
pvalue = < 0.001
Contingency table for CRQ Worse
Obs.1 1st TEST BITE (%) 11 (36.7) 1 (3.3) 0 (0.0) 12 (40.0)
2nd TEST BITE (%) 0 (0.0) 8 (26.7) 1 (3.3) 9 (30.0)
3rd TEST BITE (%) 2 (6.7) 0 (0.0) 7 (23.3) 9 (30.0)
Total (%) 13 (43.3) 9 (30.0) 8 (26.7) 30 (100.0)
Kappa value = .797
pvalue = < 0.001
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 5 of 8
recording technique. Assuming that the operator has the
necessary skills to perform quality test bites -another
important factor considered by Yamashita et al. (2003)-,
the success of tests can be conditioned by the material
used and the type of bite mark. An ideal intermaxillary
record material should be easy to manipulate, allow ac-
curate records, and possess limited resistance before set-
ting (to avoid dental or mandibular displacements
during closure), then become rigid and with minimal di-
mensional changes after setting, even during storage
(Sweeney et al. 2015; Ghazal et al. 2008). Considering
that practically all materials recommended by the litera-
ture have demonstrated limitations to comply with all
these aspects (Dailey 2011; Dailey et al. 2013; Ghazal et
al. 2008), focus should be placed on taking special care
throughout the technical procedure (Dailey et al. 2013).
Although we only performed type 3 test bites (as typical
bites found in cheese) -following the Websters classifi-
cation (1982)-, the goal of the criterion defined by this
author fell on the type of dental features that could be
registered. The wax used in this research, although not
certified by the ADA (some specific products are diffi-
cult to access in our country), met the standards re-
quired for testing. We firmly believe that performing at
least three records for each individual will allow detec-
tion of vulnerabilities and selection of the most appro-
priate registry. It is evident that this technique is not
extrapolated to other types of bite marks (two-dimen-
sional or bite marks in skin). Likewise, in the future, this
could revise current protocols of comparative analysis by
reformulating, for these specific cases, a new strategy of
comparison between negatives, which implies com-
parison of the bite marks to investigate the bite mark
obtained from the suspect, and thereby seeking to
replicate the bite (basically, the same principle of ana-
lysis of fingerprints). The classical methods suggest
comparing negative representations of the biting teeth
(the bite mark), with positive models of the suspects
teeth, both in physical or digital comparisons and
overlays (Dailey 2011). Would evaluation and com-
parison of negatives allow morphological detection
and dynamic patterns, in order to identify the perpet-
rator? Again, perhaps new research along these lines
will answer this question.
Bite mark comparison is often used in criminal prose-
cutions; however, the bite mark testimony continues to
be criticized for lacking scientific studies that support
this type of assessment (Committee 2009). Both the
uniqueness of the human dentition and the possibility of
the dentition transferring to the bitten substrate (with all
possible distortion possibilities) are still basic problems
inherent in bite mark analysis and interpretation
(Committee 2009; Saks et al. 2016). Page et al. (2011)
stated that uniqueness is impossible to proveand
added (mistakes and misidentifications) are made be-
cause of guesswork, poor performance, lack of standards,
bias and observer error. The dental information re-
corded on the bitten substrate should be compared to
the dentition of the suspect, and although the unique-
ness (the most basic concept supporting the bite mark
analysis), sample selection or the applied imaging tech-
niques still remain without scientific sufficiency (Franco
et al. 2017), most current guidelines persist in consider-
ing the act of biting as only a mechanical bearing con-
necting two solid objects (jaws and their teeth), opening
and closing with a simple hinge mechanism (American
Board of Forensic Odontology 2017; Dailey et al. 2013).
Although proven useful in certain experimental models,
different devices designed to mimic the action of a hu-
man bite (Avon and Wood 2005; Chinni et al. 2013) are
unlikely to reproduce the extreme complexity of the bite.
The biomechanics of the biting action comprise not only
the dental action but also the muscular relationships, oc-
clusion, intentionality of aggression and the type of bit-
ten material (Franco et al. 2017). Further technical
attention should be given to the important phase of re-
cording the suspects bite pattern. Something as easy as
making three records (and not just one) could signifi-
cantly help control these variables and thereby improve
standards of bite mark evidence.
Although the authors could be expected to perform a
microscopic evaluation of the test bites (or even the use of
other technological tools of greater reliability), which
would have increased the range of differences to give a
better understanding of the distortions/differences pos-
sible in an experiment of this nature, the purpose of this
research is to optimize/improve the current ABFO recom-
mendations for collecting evidence of suspected dentition,
which do not specify a necessary minimum number of test
bites to be taken (accepting by default the possibility that
it is only one) nor the way in which they should be
evaluated (accepting by default the possibility of being
evaluated only macroscopically). From the same point of
view, our research is not intended to define the concept of
slightest distortionswhen precisely they have not been
studied under magnification (logically in the strict sense of
the word). However, we consider that this first recognition
of these small patterns precisely highlights the need to use
better methodologies than to only evaluate them macro-
scopically. The use of a DMC comparison microscope
(used for analyzing firearm barrels and bullets) in bite
mark analysis has already been reported as an excellent
tool to enhance the ability of the forensic odontologists to
present evidence correctly (Rivera-Mendoza et al. 2017;
Bernitz and Kloppers 2002). In the same way, and al-
though this experimental model can only be evaluated on
a special type of bite and substrate, the high values of
interrater agreement would suggest the use of similar
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 6 of 8
models of comparison between negatives (bite marks), but
adapted to other substrates bitten.
Forensic odontology, "the application of the science of
dentistry to the field of law", as defined by the U.S. National
Academy of Sciences (Committee 2009)representsthe
point of contact of two radically different scenarios. Al-
though from a scientific point of view it seems logical to
think that more testing is better then less, extrapolate this
to criminal proceedings when the universally accepted rec-
ommendations of ABFO do not make it explicit. Likewise,
the controversy that mires bite mark analysis can be ex-
plained -at least in part- by the indifference that seems to
exist in oral science, in scientific societies, and even in ap-
plied basic research. Although the minimalist hingecon-
cept of the temporomandibular joint has been overcome
decades ago in the world of oral physiology, it apparently
still persists in certain forensic contexts, even determining
the innocence or guilt of a defendant.
Conclusion
There is no significant evidence that a first and only test
bite is the highest quality test bite. This conclusion can
also be applied to second or third registers, so it is rec-
ommended to take more than a single bite test in con-
trolled situations and carry out their controls in an
exhaustive way to be able to identify slightest distortions
and select the one with the best conformation. Likewise,
such slightest distortions would allow the dynamic inter-
pretation of the bite action, which opens up a potential
field of research in the bite mark analysis.
Abbreviations
ABFO: American Board of Forensic Odontology; ADA: American Dental
Association; CEC: [Comité de Ética Científico] Ethical Scientific Committee of
the Universidad de La Frontera; CR: Centric Relation; CRQ: Categories of
Record Quality; FRM: Fernando Rivera-Mendoza (author 1); GMF: Gabriel M.
Fonseca (author 4)
Acknowledgements
Not applicable
Funding
The authors declare that there is no funding for the research reported.
Availability of data and materials
Not applicable
Authorscontributions
The individual contributions of authors to the manuscript is specified below:
RMF: Study concepts, study design, data acquisition, data analysis and
interpretation, manuscript editing. MdlHS: Study concepts, data analysis and
interpretation, manuscript editing, manuscript review. N-CP: Study design,
quality control of data and algorithms, data analysis and interpretation, statistical
analysis. FGM: Study concepts, study design, data analysis and interpretation,
manuscript preparation, manuscript editing, manuscript review. All authors read
and approved the final manuscript.
Ethics approval and consent to participate
The present study was approved by the Ethical Scientific Committee of the
Universidad de La Frontera (CEC) by act no. 079/2015. The CEC is an agency
accredited by the Regional Ministerial Health Secretariat of Chile. The
experiments carried out in this study were performed within the guidelines
of the CEC for human studies and were carried out under the strict
supervision of a registered dental practitioner (FRM). Also, all the subjects
have been fully informed of the experimental procedure and consent was
obtained prior to the experiment. Written informed consent for publication
was obtained from the person shown in Fig. 1c.
Consent for publication
Not applicable
Competing interests
The authors declare that they have no competing interests.
PublishersNote
Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Author details
1
Programa de Magister en Odontología, Facultad de Odontología,
Universidad de La Frontera, Temuco, Chile.
2
Forensic Dentistry Lab, Centro
de Investigación en Odontología Legal y Forense (CIO), Facultad de
Odontología, Universidad de La Frontera, Francisco Salazar 01145, Building L,
4811230 Temuco, Chile.
3
Department of Forensic Medicine and Forensic
Odontology, University of Granada, Granada, Spain.
4
Centro de Investigación
en Ciencias Odontológicas (CICO), Facultad de Odontología, Universidad de
La Frontera, Temuco, Chile.
Received: 13 October 2017 Accepted: 22 February 2018
References
Agbaje JO, Sun Y, Lambrichts I, Politis C (2013) Problems during orthognathic
surgery resulting from errors in diagnostic wax bite. J Craniofac Surg 24(3):
9991001.
American Board of Forensic Odontology. ABFO Reference Manual (Updated April
2017) http://abfo.org/wp-content/uploads/2012/08/ABFO-Reference-Manual-
April-2017-v7.pdf. Accessed 22 Jul 2017.
Avon SL, Wood RE (2005) Porcine skin as an in-vivo model for ageing of human
bite marks. J Forensic Odontostomatol 23(2):3039.
Bernitz H, Kloppers BA (2002) Comparison microscope identification of a cheese
bitemark: a case report. J Forensic Odontostomatol 20(1):1316.
Chinni SS, Al-Ibrahim A, Forgie AH (2013) A simple safe, reliable and reproducible
mechanism for producing experimental bite marks. J Forensic
Odontostomatol 31(1):2229.
Committee on Identifying the Needs of the Forensic Sciences Community,
National Research Council (2009) Strengthening forensic science in the
United States: a path forward. National Academies Press, Washington, pp
173176.
Dailey JC (2011) Methods of comparison. In: Dorion RBJ (ed) Bitemark evidence.
A color atlas and text, 2nd edn. CRC Press, Boca Raton, pp 469489.
Dailey JC, Golden GS, Senn DR, Wright FD (2013) Bitemarks. In: Senn DR, Weems
RA (eds) ASFO manual of forensic Odontology, 5th edn. CRC Press, Boca
Raton, pp 257324.
Franco A, Willems G, Souza P, Coucke W, Thevissen P (2017) Uniqueness of the
anterior dentition three-dimensionally assessed for forensic bitemark analysis.
J Forensic Legal Med 46:5865.
Ghazal M, Albashaireh ZS, Kern M (2008) The ability of different materials to
reproduce accurate records of interocclusal relationships in the vertical
dimension. J Oral Rehabil 35(11):816820.
Johnson LT (2011) The suspect. In: Dorion RBJ (ed) Bitemark evidence. A color
atlas and text, 2nd edn. CRC Press, Boca Raton, p 465.
Jokstad A (2012) Methodological challenges in the study of dental occlusion.
J Oral Rehabil 39(7):480488.
Karazulas CP (1984) The presentation of bite mark evidence resulting in the
acquittal of a man after serving seven years in prison for murder. J Forensic
Sci 29(1):355358.
Kosaka T, Ono T, Kida M et al (2016) A multifactorial model of masticatory
performance: the Suita study. J Oral Rehabil 43(5):340347.
Lerman MD (2011) The muscle engram: the reflex that limits conventional
occlusal treatment. Cranio 29(4):297303.
Little RM (1975) The irregularity index: a quantitative score of mandibular anterior
alignment. Am J Orthod 68(5):554563.
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 7 of 8
Page M, Taylor J, Blenkin M (2011) Uniqueness in the forensic identification
sciencesfact or fiction? Forensic Sci Int 206(13):1218.
Rivera-Mendoza F, Martín-de-Las-Heras S, Navarro-Cáceres P, Fonseca GM (2017)
Bite mark analysis in foodstuffs and inanimate objects and the underlying
proofs for validity and judicial acceptance. J Forensic Sci. https://doi.org/10.
1111/1556-4029.13586.
Sakaguchi K, Mehta NR, Abdallah EF et al (2007) Examination of the relationship
between mandibular position and body posture. Cranio 25(4):237249.
Saks MJ, Albright T, Bohan TL et al (2016) Forensic bitemark identification: weak
foundations, exaggerated claims. J Law Biosci 3:538575.
Scott J (2010) Accurate bite records: improving restorative predictability. Dent
Today 29(1):124 126-127.
Sheasby DR, MacDonald DG (2001) A forensic classification of distortion in
human bite marks. Forensic Sci Int 122(1):7578.
Sweeney S, Smith DK, Messersmith M (2015) Comparison of 5 types of
interocclusal recording materials on the accuracy of articulation of digital
models. Am J Orthod Dentofac Orthop 148(2):245252.
The Dawson Academy Blog (2008) The bite record directive: the need to
properly record centric relation. http://thedawsonacademy.typepad.com/
alumni/2008/11/the-bite-record-directive-the-need-to-properly-record-centric-
relation-1.html. Accessed 22 Jul 2017.
van der Bilt A (2011) Assessment of mastication with implications for oral
rehabilitation: a review. J Oral Rehabil 38(10):754780.
Webster G (1982) A suggested classification of bite marks in foodstuffs in forensic
dental analysis. Forensic Sci Int 20(1):4552.
Yamashita S, Igarashi Y, Ai M (2003) Tooth contacts at the mandibular retruded
position, influence of operator's skill on bite registration. J Oral Rehabil 30(3):
318323.
Rivera-Mendoza et al. Egyptian Journal of Forensic Sciences (2018) 8:24 Page 8 of 8
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.
Article
Full-text available
With improving technology it should be possible to develop an objective, reliable and valid method that can be undertaken by most forensic Odontologists without recourse to expensive or bulky equipment. One of the main factors that affect the physical appearance of bitemark is the amount of force applied during biting. There is little evidence relating the appearance of a bite mark to the amount of force applied and how that force relates to the biters maximal biteforce. This paper describes simple apparatus that can be used to inflict experimental bites on living subjects reproducibly and with minimal risk. The aims of this study are to report on the development of a mechanical apparatus that produces experimental bitemarks on living human subjects with a known force in a safe, reliable and reproducible manner and to relate the force applied during production of the experimental bitemark to the maximum bite force of the biter. Maximum bite force of one of the authors was determined as 324N. Experimental bitemarks were inflicted on living subjects with known weights. Weights of up to 10kg were well tolerated by the subjects. The relation between forces used to inflict bites and the maximum bite force of the author is reported, with 10kg being approximately one third of the maximum bite force. The apparatus was well tolerated and the results were reliable and reproducible. The results from this study could help in determining the severity of bitemarks. This apparatus could help researchers in developing objective based bitemark analysis techniques.
Article
Full-text available
This narrative review describes the methodological challenges in the study of dental occlusion. The reigning confusion about the scope of this topic is discussed, and a conceptual framework for understanding dental occlusion research is suggested. The characteristics of clinical studies used in the study of dental occlusion are presented within this proposed framework consisting of a triad comprising the relative positions of the teeth-mandible-maxilla, the oral functions and oral appearance. Challenges in the preparation for a clinical study of dental occlusion are reviewed, which include a discourse on the objectives of a clinical study and appropriateness of different study designs. Guidelines are provided for the conduct of studies with a central focus on dental occlusion and diagnostic tests, prognosis, therapy and aetiology, respectively. Summarising chapters present methodological challenges in designing a clinical study of dental occlusion and threats to the proper conduct of a clinical study.
Article
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.
Article
The uniqueness of the human dentition (UHD) is an important concept in the comparative process in bitemark analysis. During this analysis, the incisal edges of the suspects' teeth are matched with the bitemarks collected from the victim's body or crime scenes. Despite playing an essential part to exclude suspects, the UHD contained in the involved incisal tooth edges remains an assumption on bitemark level. The present study was aimed, first, to investigate three-dimensionally (3D) the UHD within different quantities of dental material from the incisal edges; second, to test these outcomes in a bidimensional (2D) simulation. Four-hundred forty-five dental casts were collected to compose 4 study groups: I – randomly-selected subjects, II – orthodontically treated subjects, III – twins and IV – orthodontically treated twins. Additionally, 20 dental casts were included to create threshold groups on subjects from whom the dental impressions were taken at 2 different moments (Group V). All the dental casts were digitalized with an automated motion device (XCAD 3D® (XCADCAM Technology®, São Paulo, SP, Brazil). The digital cast files (DCF) were integrated in Geomagic Studio® (3D Systems®, Rock Hill, SC, USA) software package (GS) for cropping, automated superimposition and pair-wise comparisons. All the DCF were cropped remaining 3 mm (part 1), 2 mm (part 2) and 1 mm (part 3) from the incisal edges of the anterior teeth. For a 2D validation, slices of 1 mm, not including incisal edges (part 4), were also cropped. These procedures were repeated in Group V, creating specific thresholds for each of the study parts. The 4 study groups were compared with its respective threshold using ANOVA test with statistical significance of 5%. Groups I, II and III did not differ from the corresponding threshold (Group V) in all study parts (p > 0.05). Scientific evidence to support the UHD was not observed in the current study. Bitemark analysis should not be disregarded but considered carefully when the suspects present similar dental alignment and morphology, such as in orthodontically treated subjects and twins, respectively.
Book
Scores of talented and dedicated people serve the forensic science community, performing vitally important work. However, they are often constrained by lack of adequate resources, sound policies, and national support. It is clear that change and advancements, both systematic and scientific, are needed in a number of forensic science disciplines to ensure the reliability of work, establish enforceable standards, and promote best practices with consistent application. Strengthening Forensic Science in the United States: A Path Forward provides a detailed plan for addressing these needs and suggests the creation of a new government entity, the National Institute of Forensic Science, to establish and enforce standards within the forensic science community. The benefits of improving and regulating the forensic science disciplines are clear: assisting law enforcement officials, enhancing homeland security, and reducing the risk of wrongful conviction and exoneration. Strengthening Forensic Science in the United States gives a full account of what is needed to advance the forensic science disciplines, including upgrading of systems and organizational structures, better training, widespread adoption of uniform and enforceable best practices, and mandatory certification and accreditation programs. While this book provides an essential call-to-action for congress and policy makers, it also serves as a vital tool for law enforcement agencies, criminal prosecutors and attorneys, and forensic science educators. © 2009 by the National Academy of Sciences. All rights reserved.
Article
Previous studies have identified various factors related to masticatory performance. This study was aimed to investigate variations and impacts of factors related to masticatory performance among different occlusal support areas in general urban population in Japan. A total of 1875 Japanese subjects (mean age: 66·7 years) were included in the Suita study. Periodontal status was evaluated using the Community Periodontal Index (CPI). The number of functional teeth and occlusal support areas (OSA) were recorded, and the latter divided into three categories of perfect, decreased and lost OSA based on the Eichner Index. Masticatory performance was determined by means of test gummy jelly. For denture wearers, masticatory performance was measured with the dentures in place. The multiple linear regression analysis showed that, when controlling for other variables, masticatory performance was significantly associated with sex, number of functional teeth, maximum bite force and periodontal status in perfect OSA. Masticatory performance was significantly associated with number of functional teeth, maximum bite force and periodontal status in decreased OSA. In lost OSA, masticatory performance was significantly associated with maximum bite force. Maximum bite force was a factor significantly influencing masticatory performance that was common to all OSA groups. After controlling for possible confounding factors, the number of functional teeth and periodontal status were common factors in the perfect and decreased OSA groups, and only sex was significant in the perfect OSA group. These findings may help in providing dietary guidance to elderly people with tooth loss or periodontal disease.
Article
One method of articulating digital models is to use a digitized interocclusal record. However, the accuracy of different interocclusal record materials to articulate digital models has yet to be evaluated. A plastic typodont was modified with reference points for interarch measurements and articulated in maximum intercuspal position on a semiadjustable hinge articulator. Twenty-five interocclusal records of each of the 5 experimental materials (Regisil Rigid, Dentsply, York, Pa; Futar Scan, Kettenbach, Huntington Beach, Calif; Byte Right, Motion View Software, Chattanooga, Tenn; Aluwax, Aluwax Dental Products, Allendale, Mich; and Beauty Pink wax, Miltex, York, Pa) were made on the mounted typodont and digitized using an Ortho Insight 3D laser surface scanner (Motion View Software). Motion View Software was used to articulate the digital models by matching points from the models to the digitized interocclusal records. The distances between corresponding interarch markers were measured and compared with the measurements taken on the physical typodont (gold standard). Polyvinyl siloxane materials were significantly more likely to lead to successful articulation than were the other interocclusal record materials. Statistical analysis showed a significant effect of the bite registration material on the probability of success of the articulation (P <0.005). Polyvinyl siloxane is a more accurate interocclusal recording material when articulating digital models according to the process described in this study. Using a bite registration to articulate digital models should be considered the first step in the articulation process, with a likely residual need to manipulate the models manually. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Article
There are many problems associated with model surgery and splint fabrication, and they can directly affect the results of surgery. An erroneous diagnostic wax bite can lead to improper positioning of the upper jaw during bimaxillary surgery. In addition, postoperative malocclusions that are out of orthodontic range often are initiated perioperatively by insufficient surgical control over interdigitation, overjet, overbite, and control of the midlines. The objectives of this study were to investigate whether wax bites can be used effectively in patients undergoing bimaxillary operations. In 5 (10%) of 50 patients, the wax bite did not fit properly. Based on these preliminary results, we believe it would be prudent to build safety measures into the treatment of patients who require bimaxillary surgery. If the wax bite does not fit properly at the beginning of surgery, navigation tools could be used to overcome inaccuracies resulting from the wax bite.
Article
The engram (the masticatory "muscle memory") is shown to be a conditionable reflex whose muscle conditioning lasts less than two minutes, far shorter than previously thought. This reflex, reinforced and stored in the masticatory muscles at every swallow, adjusts masticatory muscle activity to guide the lower arch unerringly into its ICP. These muscle adjustments compensate for the continually changing intemal and external factors that affect the mandible's entry into the ICP. A simple quick experiment described in this article isolates the engram, enabling the reader to see its action clearly for the first time. It is urged that every reader perform this experiment. This experiment shows how the engram, by hiding the masticatory muscles' reaction (the hit-and-slide), limits the success of the therapist in achieving occlusion-muscle compatibility. This finding has major clinical implications. It means that, as regards the muscle aspect of treating occlusion, the dentist treating occlusion conventionally is working blind, a situation the neuromuscular school of occlusal thought seeks to correct. The controversy over occlusion continues.