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A foreign object, presumably swallowed during a dental appointment, was recovered by using an esophagoscope and thought to be a piece of dental impression material, probably alginate. It was identified as being of nondental origin by means of visible light and scanning electron microscopy (SEM), the latter coupled to an energy dispersive X-ray analyzer. Histologic examination revealed some amorphous crystalline material surrounded by parakeratin and exfoliated squamous cells. The material was essentially radiolucent. A known dental alginate impression material contained diatomaceous earth filler (siliceous shells of diatoms), but no microscopic symmetrical figures were seen in the foreign body. After dehydration, both materials were carbon-coated and observed in an SEM at 20 kV at magnifications up to 2000X. The spectrum of secondary X-rays produced by the scanning electron beam revealed only magnesium in the foreign body and mostly silicon in the dental alginate. There are no known dental products that contain magnesium as the only inorganic ingredient and so the foreign body is believed to be not of dental origin. The patient may have had an antacid or laxative having magnesium as a major ingredient in the stomach, and this may have been refluxed from the stomach after stimulation of the normal gag reflex during the dental procedure.

Some degree of distortion is found in all bite marks. That distortion can be caused by photographic methods of recording the mark, by the dynamics of the bite, or by artifaction. All types of distortion complicate the process of matching marks to dentition, thus making it important to understand the distortion and, if possible, correct or allow for it. A method of analyzing photographically distorted bite patterns is presented, future research directions are suggested, and evidence-gathering standards are stressed.

In 1981, the Bite mark Standards Committee of the American Academy of Forensic Sciences and the American Board of Forensic Odontology developed a method of scoring bite mark comparisons in an attempt to standardize a scientific approach to bite mark analysis. The various methods of determining the validity of the scoring guide are presented with statistical data generated from scores reported by recognized forensic science experts.