V. E. Rushton

The use of panoramic radiology in dental practice

OBJECTIVESnApproximately 1.5 million panoramic radiographs are taken annually in the general dental service in England and Wales. The aim of this review was to assess the clinical role of panoramic radiology in the diagnosis of diseases associated with the teeth and to consider its value in routine screening of patients.nnnMETHODnThis was carried out by critical review of the literature.nnnRESULTSnIn addition to common problems with radiographic technique and processing, there are limitations in image quality inherent to panoramic radiology. These factors contribute to a reduced diagnostic accuracy for caries diagnosis, demonstration of periodontal bone support and periapical pathology when compared with intraoral radiography. Routine screening is unproductive for large proportions of dentate and edentulous populations, while in those cases where pathology is detected the diagnostic accuracy can be questioned. Furthermore, the detection of asymptomatic anomalies may have no effect on patient management. Attempts to develop and test panoramic radiographic selection criteria are reviewed.nnnCONCLUSIONSnNew, high-yield selection criteria for panoramic radiography are proposed as a means of reducing unnecessary examinations, limiting radiation doses and reducing financial costs to patients and health service providers. However, research is indicated to develop further and to test such selection criteria.

Screening panoramic radiology of adults in general dental practice: radiological findings

Aim To identify the radiological findings from routine screening panoramic radiographs taken of adult (≥18 years) patients in general dental practice.Method Forty-one general dental practitioners (GDPs) who routinely took panoramic radiographs of all new adult patients were recruited. In total, they submitted 1,818 panoramic radiographs of consecutive patients along with basic patient information, radiological reports and treatment plans. The radiographs were also reported by experts (consensus of two dental radiologists). Radiological findings were recorded from the GDP assessments (dentist RY), the experts (expert RY), after exclusion of findings that would have been seen on posterior bitewing radiographs (MRY) and after exclusion of findings of no relevance to treatment (MRYT).Results There was no significant difference in age profile between the study sample and Dental Practice Board population figures (P = 0.26). No radiographs other than the panoramic radiograph had been taken for 57.1% of patients. For the GDP assessments, only 4.6% of patients had radiographs with no radiological findings, while for the experts this proportion was 3.1%. With the exception of the assessment of periodontal bone loss, the experts diagnosed significantly greater proportions of cases as having positive radiological findings. Agreement between dentist and expert assessments varied greatly. When findings from bitewing radiographs were excluded, no radiological findings were recorded on the radiographs of 17.2% of patients. When proposed treatment plans were taken into account, the majority of patients radiographs (56.3%) had no radiological findings of relevance to treatment.Conclusions The choice of radiographic examination for the majority of patients in the study did not follow current guidelines. Dentists diagnosed fewer abnormalities than did experts. While many radiological findings are revealed by panoramic radiography, these may either duplicate information from bitewing radiographs or are often of no significance to treatment planning. This study did not provide evidence to support the practice of routine panoramic radiography of all new adult patients.

Radiology: The influence of viewing conditions on radiological diagnosis of periapical inflammation

Objectives To determine the effect of viewing conditions upon diagnosis of early periapical inflammatory pathosis on intra-oral radiographs, and to examine the effect of observer experience upon diagnostic performance in this task.Methods 50 observers examined 18 periapical radiographs using three different viewing conditions (room lighting; viewing box; viewing box with x2 magnification and masking). Their diagnoses were compared with an expert diagnosis provided by repeated viewings of the films by two dental radiologists. Sensitivities and specificities were determined.Results When ideal viewing conditions were used, optimal sensitivity (78%) and specificity (78%) were obtained. Use of a viewing box was associated with significantly higher specificity than the use of room lighting (P = 0.0016). Use of masking and x2 magnification was associated with significantly higher sensitivity than a viewing box alone (P = 0.004). There were few significant differences in diagnostic performance between observers, but qualified dental staff had significantly higher specificities than 4th year (P = 0.01) and 5th year (P = 0.01) students when a viewing box was used alone.Conclusions This study on early periapical inflammatory pathosis gives support to guidelines which recommend the use of a viewing box, x2 magnification and masking for interpreting intra-oral radiographs. It also suggests that observer experience may influence interpretation of early periapical pathosis.

Factors influencing the selection of panoramic radiography in general dental practice

OBJECTIVESnTo identify factors influencing dentists decisions to take panoramic radiographs and to determine dentists perceptions of the value of panoramic radiographs in the diagnosis of common dental pathologies.nnnMETHODSnQuestionnaire of dentists with access to panoramic radiography equipment in 22 randomly selected Family Health Service Authorities in England and Wales. Dentists were asked to score 17 factors for their influence upon panoramic use, compare the relative diagnostic value of panoramic and intraoral radiographs for diagnosis of common dental pathologies and state their principal reasons for taking panoramic radiographs.nnnRESULTSnThe response rate to the questionnaire was 73.3%. The factors most likely to influence dentists to take a panoramic radiograph were planning oral surgery, facial trauma, periodontal disease, heavily restored dentition and patient first attendance. Dentists opinions on the diagnostic usefulness of panoramic radiographs were in broad agreement with those in the scientific literature. The main reasons for taking panoramic radiographs were as a general screen and as a view for unerupted or impacted teeth.nnnCONCLUSIONSnThere are areas where dentists prescription of panoramic radiographs is in disagreement with recent guidelines. Successful implementation of these guidelines would be likely to lead to a substantial reduction in the numbers of panoramic radiographs taken by GDPs.

radiology: Aspects of panoramic radiography in general dental practice

Objectives To gather information on the types of panoramic x-ray equipment used in NHS dental practice and whether dentists satisfy the legal requirements for safety, to determine which practice personnel take panoramic radiographs and to assess the prevalence of the practice of routine panoramic radiography among NHS dentists.Design Postal questionnaire survey of general dental practitioners carried out during 1997 in selected FHSAs in England and Wales.Results 542 dentists returned the questionnaire, a 73.3% response. Panoramic x-ray equipment ranged in age from 27 years old to new, with 42.2% exceeding 10 years in age. The overwhelming majority of GDPs satisfied the requirement for regular maintenance and surveying of equipment. Almost all dentists (95.9%) performed a history and clinical examination prior to panoramic radiography but 42% practised routine screening of new adult patients. A substantial proportion (36.7%) of dentists used unqualified personnel to take panoramic radiographs.Conclusions While some aspects of this study give reassurance about the prevalence of good practice, widespread panoramic screening and using unqualified staff to take radiographs causes concern. These findings have implications for educators and for those involved in maintaining clinical standards.

Aspects of panoramic radiography in general dental practice

OBJECTIVESnTo gather information on the types of panoramic x-ray equipment used in NHS dental practice and whether dentists satisfy the legal requirements for safety, to determine which practice personnel take panoramic radiographs and to assess the prevalence of the practice of routine panoramic radiography among NHS dentists.nnnDESIGNnPostal questionnaire survey of general dental practitioners carried out during 1997 in selected FHSAs in England and Wales.nnnRESULTSn542 dentists returned the questionnaire, a 73.3% response. Panoramic x-ray equipment ranged in age from 27 years old to new, with 42.2% exceeding 10 years in age. The overwhelming majority of GDPs satisfied the requirement for regular maintenance and surveying of equipment. Almost all dentists (95.9%) performed a history and clinical examination prior to panoramic radiography but 42% practised routine screening of new adult patients. A substantial proportion (36.7%) of dentists used unqualified personnel to take panoramic radiographs.nnnCONCLUSIONSnWhile some aspects of this study give reassurance about the prevalence of good practice, widespread panoramic screening and using unqualified staff to take radiographs causes concern. These findings have implications for educators and for those involved in maintaining clinical standards.

Canalis sinuosus mimicking a periapical inflammatory lesion.

A case is presented in which an anatomical feature, canalis sinuosus, manifested as a periapical radiolucency on an upper canine. This may have been interpreted as an inflammatory lesion and led to the patient receiving inappropriate treatment had a further radiograph not been taken. The incisive foramen and mental foramen are well known anatomical features which may mimic periapical inflammatory lesions but it is less common for a neurovascular canal to manifest as a periapical radiolucency on an upper canine.

A laboratory evaluation of Ektaspeed Plus dental X-ray film

OBJECTIVESnThe aim of this study was to make a laboratory evaluation of the image quality of a new dental X-ray film, Ektaspeed Plus, compared with Ektaspeed and Ultraspeed films.nnnMETHODSnFilms of each emulsion type underwent a range of exposures at both 50 kVp and 70 kVp, and characteristic curves were constructed to give a comparison of fog, speed and contrast. Line pair and contrast detail test objects were used to assess the resolution of radiographs and the ability of the two film types to reproduce minor differences in subject contrast. The sensitivity of the emulsions to safelighting for a range of times was also tested.nnnRESULTSnEktaspeed Plus had the same speed, a slightly higher base plus fog density but a higher contrast (50 and 70 kVp) than Ektaspeed. The speed of Ektaspeed Plus was higher and the contrast similar to that of Ultraspeed film. Limiting resolutions of the three films were the same. There was a slightly better imaging of one contrast detail phantom with Ektaspeed Plus compared to Ektaspeed at 70 kVp only. All three emulsions were insensitive to recommended safelighting conditions.nnnCONCLUSIONnThe improved image contrast of Ektaspeed Plus may be more acceptable to dentists than Ektaspeed and lead to a greater acceptance of E-speed film, contributing to dose reduction.

Chronic sinusitis and zinc-containing endodontic obturating pastes.

Several researchers have reported a link between the development of a solitary antral aspergillus sinusitis and the presence of zinc-containing root canal obturating paste within the antrum. If diagnosed correctly, it is generally accepted that this type of sinusitis can be treated effectively using surgical techniques alone. However, previous reports have shown that this is not always the case and may result in prolonged and inappropriate treatment of the condition. It is hoped that the reported case and literature review will assist both dental and medical practitioners in identifying affected patients and in the subsequent instigation of correct treatment regimes

Screening panoramic radiography of new adult patients: diagnostic yield when combined with bitewing radiography and identification of selection criteria

Objectives To measure the radiological diagnostic yield on screening panoramic radiographs taken of new adult patients and to identify selection criteria for panoramic radiography of new adult patients.Design Survey of 1,817 consecutive panoramic radiographs taken as routine on new patients with statistical analysis of clinical and radiological findings.Setting All radiographs were obtained from 41 general dental practitioners (GDPs). The GDPs provided the clinical information about the patient obtained by history and examination. Collection of material occurred in 1998/1999.Materials and methods Two dental radiologists recorded the radiological findings on each of 1,817 panoramic radiographs by consensus. Those findings that would have been identified from bilateral posterior bitewing radiographs of each patient were then excluded to give modified figures for radiological findings.Main outcome measures Indices of diagnostic yield were devised and calculated for each radiograph from the data on radiological findings. Total diagnostic yield (DY) and modified diagnostic yield (MDY), after exclusion of findings identifiable on bitewing radiographs, were both calculated. Clinical indicators of a high MDY were identified using stepwise multiple regression analysis.Results MDY was 0 for 17% of the radiographs (all patients) and 23% of the radiographs when the asymptomatic group were considered. The clinical variables for which the significance was high (p<0.001) were: increasing number of teeth with clinical suspicion of periapical pathology, presence of partially erupted teeth, increasing number of clinically evident carious lesions, partially dentate status and presence of crowns.Conclusion Taking posterior bitewing radiographs of new adult patients would reduce the diagnostic yield identified solely by panoramic radiography. Using clinical factors derived from the history and examination as radiographic selection criteria modestly improves the odds of achieving a high diagnostic yield from panoramic radiography.