ABFO No. 2 Scale
Definition
The right-angle L-shaped reference scale with circular targets used in bite mark photography. Its design enables post-capture correction of lens distortion and camera-angle deviation so the photograph can be used for metric comparison.
- Field
- Forensic odontology and bite mark photography
- Shape
- L-shaped (right-angle) reference scale
- Markings
- Circular targets for orientation and distortion correction
- Purpose
- Enables metric, scaled comparison from photographs
Common questions
Why does the scale need to be L-shaped rather than a straight ruler?+
The right-angle shape sits in the same plane as the injury on two axes at once, which lets software or an examiner correct for both lens distortion and any angle at which the camera was tilted relative to the skin, something a single straight scale cannot do.
Is the ABFO No. 2 scale used for anything besides bite marks?+
It was designed specifically for bite mark and patterned injury photography, but the same right-angle, circular-target design is sometimes applied more broadly wherever a photograph of a patterned mark needs later metric measurement.
Related terms
- Cheiloscopy
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- Cameriere Method (2007)
- Adult age estimation using the pulp-to-tooth area ratio measured on periapical radiographs of canines.
- Canine
- Single-cusped tooth for tearing and gripping. One per quadrant. Often the last anterior tooth to be lost in old age.
- CCD (Charge-Coupled Device)
- A sensor architecture that transfers accumulated pixel charge across the array to a single output amplifier, producing uniform noise characteristics suitable for...
- Class vs Individual Evidence
- Class evidence narrows the population (group of possible sources); individual evidence identifies a single source. Lip, ear and bite-mark evidence now sit...
- CMOS (Complementary Metal-Oxide Semiconductor)
- A sensor architecture with per-pixel amplifiers, enabling fast readout and low power consumption; BSI-CMOS variants now dominate professional forensic cameras.
- Deciduous Dentition
- The first set of 20 teeth, also called primary or milk teeth, that erupt from approximately six months and are progressively replaced...
- Demirjian Method (1973)
- Childhood age estimation using radiographic stage-scoring (A to H, eight stages) of the seven permanent left mandibular teeth.
- Dental Cast
- A three-dimensional stone or resin model of a suspect's dentition made from an impression of their arches. The cast is the reference...
- Dental Formula
- Per-quadrant notation of tooth types in the order Incisors.Canines.Premolars.Molars. Human deciduous 2.1.0.2, permanent 2.1.2.3.
Explained in these topics
- Bite Mark Collection, Documentation and Comparison
- Bite Marks in Abuse and Neglect CaseworkA circular reference scale with three L-shaped arms, developed by the American Board of Forensic Odontology, placed alongside a bite mark during photography to...
- Crime-Scene Photography WorkflowAmerican Board of Forensic Odontology's L-shaped reference scale with metric/imperial graduations, 18% grey patch, and colour chart; the North American standar...
- Forensic Photography: FundamentalsThe American Board of Forensic Odontology's L-shaped reference scale containing metric and imperial graduations, an 18% grey patch, and colour chart; the North...
- Human Dentition: Types of Teeth, Age Estimation and Bite MarksL-shaped photographic reference scale issued by the American Board of Forensic Odontology, placed beside bite-marks before forensic photography to permit 1:1 o...
- Lip, Ear and Bite Marks: Cheiloscopy and Forensic OdontologyThe L-shaped reference scale published by the American Board of Forensic Odontology, used in bite-mark photography. Placed at 90° to the camera axis on the sam...