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Artifacts and mimics

Shadows the technique creates, and the feature that separates each from a real finding.

Bitewing with cervical burnout on a mandibular premolar ringed in cyan and caries on a maxillary molar ringed in red, for contrast.

Cervical burnout

Cervical burnout is a radiolucency at the neck of a tooth caused by overpenetration of the thinner cervical tooth structure. It is an imaging artifact,…

Artifacts and mimics Read
Six intraoral radiographs graded for cone cut, each showing the straight unexposed border that cuts across the receptor where the beam missed it.

Cone cut

A cone cut is the part of a radiograph the X-ray beam never reached, because the beam and the receptor were not lined up. The region is blank and sharply…

Artifacts and mimics Read
Two bitewing exposures superimposed on one receptor, every tooth and the bite tab doubled and offset.

Double exposure

A double exposure is two radiographic images recorded on one receptor, one over the other. UK dental guidance lists it as an operator error under both…

Artifacts and mimics Read
Diagrams and periapical radiographs comparing correct vertical angulation with a foreshortened image from too steep an angle and an elongated one from too shallow an angle.

Elongation and foreshortening

Elongation and foreshortening are the two halves of one vertical angulation error. An elongated radiograph shows teeth longer than they are; a…

Artifacts and mimics Read
Panoramic radiograph with a hoop earring sharp at the right edge and its ghost, a blurred magnified oval, projected higher over the maxillary incisors on the opposite side.

Ghost image

A ghost image is a radiopacity on a panoramic radiograph cast by an object that sat between the X-ray source and the machine's centre of rotation. It…

Artifacts and mimics Read
Periapical radiograph exposed through the back of the film packet, the lead foil's raised diamond pattern printed across the upper film.

Herringbone artifact

The herringbone artifact is the pattern a dental radiograph carries when the film packet was exposed from the wrong side: a repeating herringbone or…

Artifacts and mimics Read
A leather lead apron and glove laid flat, the shielding whose collar casts a radiopaque band across a panoramic radiograph when it rides too high.

Lead apron artifact

A lead apron artifact is the shadow a protective apron or thyroid collar casts when it ends up in the primary beam. On a panoramic radiograph an apron…

Artifacts and mimics Read
Bitewing radiograph with two labelled rings on adjacent lower posterior teeth: a true carious lesion in red beside a Mach band in cyan — the dark band the eye invents next to real decay.

Mach band effect

The Mach band effect is an optical illusion in which the eye exaggerates contrast where two densities meet, creating an apparent dark band that is not…

Artifacts and mimics Read
A panoramic radiograph of a full adult dentition, showing the sharp cortical outlines that patient movement blurs.

Movement artifact

Movement artifact is the image degradation produced when a patient moves during a radiographic exposure. On an intraoral radiograph it appears as…

Artifacts and mimics Read
Two bitewings side by side: overlapped premolar contacts from poor horizontal angulation, and open contacts from correct angulation.

Overlapped contacts

Overlapped contacts are the superimposition of two adjacent proximal surfaces on a bitewing radiograph, caused by horizontal angulation error. Where the…

Artifacts and mimics Read
Panoramic radiograph with a dark band across the maxillary roots from the hard palate to the apices, the tongue not resting on the palate.

Palatoglossal air space

The palatoglossal air space is the air left between the tongue and the palate when the tongue is not held against the roof of the mouth during a panoramic…

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Two panoramic radiographs: correct positioning with a gentle occlusal curve, and chin tipped down with an exaggerated upward curve.

Panoramic positioning errors

A panoramic positioning error is a fault in how the patient was placed in the machine, and it distorts the image rather than the anatomy. The focal trough…

Artifacts and mimics Read
A phosphor plate held in a phantom head while an intraoral X-ray tube is aimed at it.

Photostimulable phosphor plate

A photostimulable phosphor (PSP) plate is a reusable, cordless intraoral receptor. It stores the X-ray exposure as electrons trapped in a phosphor layer,…

Artifacts and mimics Read
Eight faulty film radiographs in a grid: underexposed, overexposed, blurred, partial, distorted, fogged, stained, and lead foil pattern.

Radiographic artifact

A radiographic artifact is a feature on a radiograph that comes from how the image was made rather than from the patient — from the operator, the…

Artifacts and mimics Read
A darkroom safelight glowing green, the light source whose leakage fogs film and lifts the density of the whole radiograph.

Radiographic fog

Radiographic fog is unwanted density spread across a radiograph that raises the overall darkness and lowers contrast, leaving the image flat and grey.…

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Intraoral radiograph with a truncated upper edge where the plate scanner dropped part of the image, and scratch lines running down the plate.

Sensor dropout

Sensor dropout is a mark on a radiograph produced by damage to the receptor rather than by anything in the patient. On a phosphor plate it is usually a…

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Every entry covers appearance, look-alikes, and how to tell them apart.