Sir, we would like to draw your readers' attention to the potential for processing errors that can result when converting conventional film radiographs into digital copies by the use of a scanner. This is common practice for the purposes of electronic storage and transfer, where digital radiographs, from either direct or indirect X-ray sensors, are not available. Several recent orthodontic referrals to our department have identified inaccuracies in dental records accompanying referrals, with potentially serious consequences for the patient.

To illustrate the case in point, a recent hospital referral involved a 14-year-old boy with congenitally absent lateral incisors, who was referred for an orthodontic consultation. The dentist reported that the unerupted palatally ectopic upper left canine appeared to be causing severe resorption of the upper left central incisor. The referral was accompanied by printed copies of recent panoral and upper occlusal radiographs that had been taken using conventional radiographic film, before being scanned for electronic storage.

In this case there was no left or right marker to orientate either of the printed radiographs, and clinical examination did not suggest anything untoward since both upper central incisors had a degree of mobility due to a traumatic occlusion resulting from a class III skeletal pattern. While considering options for surgical intervention, fortunately it was decided to take a supplemental radiograph to assess whether the upper central incisor had since sustained any further damage. This additional radiograph revealed that the tooth that had undergone severe resorption was the contralateral incisor tooth to that which the dentist's referral and records had stated.

It transpired that both the upper occlusal and panoral radiographs had inadvertently been flipped in the horizontal plane during conversion to electronic images but this error had gone undetected due to a lack of identification markers on the images accompanying the referral letter. Fortunately in this case, the error was identified prior to confirmation of the treatment plan, and any potentially serious consequences were averted.

We would like to highlight this potential for error, not only to those referring patients, but equally to those receiving referrals. All clinicians have a responsibility to ensure good clinical governance with respect to processing and storage of digital images, and must be vigilant to potential errors in dental records. Best practice must ensure that all radiographs have clear orientation markers included at the time of exposure, and that care is taken not to remove orientation markers either when cutting conventional panoral films to size for storage in record cards, or indeed when cropping digital panoral films to reduce the size of the file for electronic transfer.