Imaging Sci Dent.  2012 Dec;42(4):207-212. 10.5624/isd.2012.42.4.207.

Positioning errors and quality assessment in panoramic radiography

• Dhillon M
• Raju SM
• Verma S
• Tomar D
• Mohan RS
• Lakhanpal
• Krishnamoorthy B

• KMID: 1806785
• DOI: http://doi.org/10.5624/isd.2012.42.4.207

Abstract

PURPOSE
This study was performed to determine the relative frequency of positioning errors, to identify those errors directly responsible for diagnostically inadequate images, and to assess the quality of panoramic radiographs in a sample of records collected from a dental college.
MATERIALS AND METHODS
This study consisted of 1,782 panoramic radiographs obtained from the Department of Oral and Maxillofacial Radiology. The positioning errors of the radiographs were assessed and categorized into nine groups: the chin tipped high, chin tipped low, a slumped position, the patient positioned forward, the patient positioned backward, failure to position the tongue against the palate, patient movement during exposure, the head tilted, and the head turned to one side. The quality of the radiographs was further judged as being 'excellent', 'diagnostically acceptable', or 'unacceptable'.
RESULTS
Out of 1,782 radiographs, 196 (11%) were error free and 1,586 (89%) were present with positioning errors. The most common error observed was the failure to position the tongue against the palate (55.7%) and the least commonly experienced error was patient movement during exposure (1.6%). Only 11% of the radiographs were excellent, 64.1% were diagnostically acceptable, and 24.9% were unacceptable.
CONCLUSION
The positioning errors found on panoramic radiographs were relatively common in our study. The quality of panoramic radiographs could be improved by careful attention to patient positioning.

Keyword

Radiography, Panoramic; Quality Control

MeSH Terms

Chin
Head
Humans
Palate
Patient Positioning
Quality Control
Radiography, Panoramic
Tongue

Figure

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  Fig. 1 The patient's chin is too high, causing a flat occlusal plane, splayed condyles, and loss of sharpness of the maxillary incisors.

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  Fig. 2 The patient's chin is too low. The occlusal plane is "smiling" and the apices of the mandibular incisors are fuzzy.

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  Fig. 3 The cervical spine is slumped, appearing as a pyramid shaped opacity, centred at the lower half of the film.

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  Fig. 4 The central incisors are in front of the bite groove, causing them to appear thin and fuzzy. The cervical spine is in the focal zone, causing it to be superimposed on the mandible.

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  Fig. 5 The anterior teeth are positioned behind the bite groove causing them to appear wider than normal.

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  Fig. 6 Panoramic radiograph shows the patient failure to position the tongue against the palate leading to a dark shadow over the maxillary teeth between the palate and dorsum of the tongue.

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  Fig. 7 Radiograph shows image distortion due to patient movement during exposure.

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  Fig. 8 The head is tilted to one side, causing one condyle to appear higher than the other and the inferior border of the mandible is slanting.

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  Fig. 9 The head is turned to one side, causing an asymmetry of the condyles, and wider teeth and ramus on one side than the other.

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