Effective and organ doses from scanography and zonography: a comparison with periapical radiography.
OBJECTIVE
To compare absorbed and effective doses from scanographic and zonographic examinations performed in the Scanora unit with intraoral periapical radiography.


METHODS
Absorbed dose measurements were made on an anthropomorphic phantom head with LiF thermoluminescent dosemeters in the regions of the pituitary gland, eye lenses, parotid glands, submandibular glands, thyroid gland and skin. Energy imparted was calculated from the measurements of air collision kerma and effective doses by using the quotient 24 mSv J-1 between energy imparted and effective dose. The upper and lower third molar region was examined with intraoral radiographs and with ramus scanograms, dental scanograms and dental zonograms. Radiation dose measurements were also performed for Scanora panoramic radiography (jaw and dental).


RESULTS
The effective doses for the ramus and dental scanograms were 0.01 mSv, similar or lower than for intraoral radiography. Zonography yielded the highest effective dose (0.03 mSv). Except for the skin doses, the salivary glands received the highest doses. Salivary gland doses were slightly higher from narrow beam than from intraoral radiography.


CONCLUSIONS
Detail narrow beam radiography with the Scanora is an alternative to periapical radiography and is preferred, from a radiation dose point of view, over zonography.
Department of Oral and Maxillofacial Radiology, Faculty of Odontology, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden. ekestubbe@odontologi.gu.se
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Ekestubbe
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Thilander-Klang
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Lith
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D006801:Humans; D007568:Jaw / Q000000981:diagnostic imaging; D008964:Molar, Third / Q000000981:diagnostic imaging; D010486:Periapical Tissue / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic / Q000379:methods*; D014056:Tomography, X-Ray; D014057:Tomography, X-Ray Computed