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Compend. Oral Sci:vol1(1);2015;1-5
Materials and methods resizing. Formula to measure the photographs
resizing is as follows; the real size of scale =
Two independent operators were working on this
scale size (actual) and resize ratio = scale size
project. First operator simultaneously acted as
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(actual)/scale size (image) . Suspect cast was
victim and suspect by self-inflicting a bite mark
scanned (Fig. 2) and overlay fabrication was
injury on his forearm. The second operator (the
made. The overlay comparison was then initiat-
author) acted as forensic odontologist who un-
ed. “Magic wand” tool was utilized to select the
dertaking the whole process of bite mark identifi-
tooth edges. Non-metric overlay comparison pro-
cation and analysis. The outline of the self-
cedures using manual digital analysis and spatial
inflicted bite mark must be clear and free from
polygon were used in this trial. The spatial poly-
external marks such as scars, tattoos, and heavy
gons of both bite mark image and scanned cast
hairs (Fig. 1). Prior to bite mark infliction, a fore-
were manually compared by patterns and sizes.
arm rest (blue arrow) was constructed to repro-
duce the same angulation during photography.
The bite marks were digitally photographed ac-
cording to ABFO recommendation for evident
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collection with the ABFO No. 2 ruler placed in-
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situ . Impression casts were constructed on the
suspect’s dentition. The photographs were
stored in JPEG format.
Figure: 2 – Scanned casts of upper and lower
Figure: 1 – Digital bite mark photograph in fore-
arm rest cast (blue arrow) Results and Discussion
The image distortion was fixed using grid by
Digital analysis
equalizing the legs of the scale. Angular distor-
The casts were scanned with a 2-D Canon tion was not fixed as the ruler circle perfectly
PIXMA™ MG3220 scanner (Canon U.S.A., Inc., fitted to each other (Fig. 3). The image height
New York). The 2-D images were then imported and width were obtained as 4.84cm and 8.33cm,
to Adobe Photoshop® software and processed. respectively. The resize ratio was calculated as
The digital analyses were performed in the fol- 0.735 where the scale size (actual) was 5mm
lowing steps. First, the detection and correction (0.5cm) and scale size (image) was 6.8mm
of digital photographic distortion were performed (0.68cm). Therefore, the height and
followed by photographs
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