Quality assessment of orthodontic radiography in children.

OBJECTIVES: Numbers of dental panoramic tomographs (DPTs) and lateral cephalometric radiographs (LCRs) outweigh other radiographic examinations in 7- to 12-year-old Finns. Orthodontists and general practitioners (GPs) involved in orthodontics hold therefore the highest responsibility of the exposure of children to ionising radiation with its risks. Against this background, lack of reports on the quality of orthodontic radiography is surprising. The purpose of our study was to shed some light and draw the awareness of the orthodontic community on the subject by analyzing the quality of orthodontic radiography in Oral Healthcare Department of City of Helsinki, in the capital of Finland. MATERIALS AND METHODS: We analyzed randomly selected 241 patient files with DPTs and 118 patient files with LCRs of 7- to 12-year-olds for the indications of radiography, quality of referrals, status of interpretation, and number of failed radiographs. RESULTS: The majority of DPTs (95%) and all LCRs had been ordered for orthodontic reasons. Of the DPTs, 60% were ordered by GPs, and of the LCRs, 64% by orthodontists. The referrals were adequate for most DPTs (78%) and LCRs (73%), orthodontists being responsible for the majority of inadequate referrals. Of the DPTs, 80% had been interpreted. Of the LCRs, 65% lacked interpretation, but 67% had been analysed cephalometrically. Failed radiographs, leading to repeated exposure, were found in 2-3%. CONCLUSION: The quality assessment revealed that orthodontic radiography may not completely fulfill the criteria of good practice. Our results stress further need of continuing education in radiation protection among both orthodontists and GPs involved in orthodontics.

Efficacy of CBCT for assessment of impacted mandibular third molars: a review - based on a hierarchical model of evidence.

A radiographic examination of mandibular third molars is meant to support the surgeon in establishing a treatment plan. For years panoramic (PAN) imaging has been the first choice method; however, where an overprojection is observed between the third molar and the mandibular canal and when specific signs suggest a close contact between the molar and the canal, CBCT may be indicated. The present review provides an evaluation of the efficacy of CBCT for assessment of mandibular third molars using a six-tiered hierarchical model by Fryback and Thornbury in 1991. Levels 1-3 include studies on low evidence levels mainly regarding the technical capabilities of a radiographic method and the diagnostic accuracy of the related images. Levels 4-6 include studies on a higher level of evidence and assess the diagnostic impact of a radiographic method on the treatment of the patient in addition to the outcome for the patient and society including cost calculations. Only very few high-evidence studies on the efficacy of CBCT for radiographic examination of mandibular third molars exist and, in conclusion, periapical or PAN examination is sufficient in most cases before removal of mandibular third molars. However, CBCT may be suggested when one or more signs for a close contact between the tooth and the canal are present in the two-dimensional image-if it is believed that CBCT will change the treatment or the treatment outcome for the patient. Further research on high-evidence levels is needed.

Panoral dose assessment: a comparative report of methodologies.

National guidance from the Institute of Physics and Engineering in Medicine (IPEM Report 91) currently recommends that the patient dose for a panoral X-ray unit is measured as dose area product (DAP) replacing dose width product described in earlier guidance. An investigation identifying different methods available to carry out this measurement has been undertaken and errors in the methodologies analysed. It has been shown that there may be up to a 30 % variation in DAP measurement between methods. This paper recommends that where possible a DAP meter is used to measure the dose-area product from a panoral X-ray unit to give a direct DAP measurement. However, by using a solid-state dose measurement and film/ruler to calculate DAP the authors have established a conversion factor of 1.4. It is strongly recommended that wherever a DAP value is quoted the methodology used to obtain that value is also reported.

Patient dosimetry and a novel approach to establishing Diagnostic Reference Levels in dental radiology.

Diagnostic Reference Levels provide a method of ensuring that patient doses in medical procedures are kept at acceptable levels. Their application in dentistry can provide an indication of current dose levels and can assist in potentially significant dose reduction in Ireland given the number of patients screened annually. This study involved retrospective analyses of entrance surface dose and dose-width-product measurements obtained in Irish Dental Practices for both Intra-Oral and Panoramic units respectively, followed by comparisons with Monte-Carlo generated computer models of these procedures. Analysis was performed on data from 33 Intra-Oral units for an Adult Mandibular Molar entrance surface dose, 198 readings for a proposed mGy/mAs reference level and 50 Panoramic machines for a dose-width product investigation. The third quartile value of the entrance surface dose for a standard Adult Mandibular Molar Intra-Oral radiograph is (2.40 ± 0.92)mGy, compared to a computer-modelled value of 2.60 mGy. The third quartile mGy/mAs value for Intra-Oral procedures is (1.03 ± 0.38)mGy/mAs, compared to a computer-modelled value of 0.75 mGy/mAs. The third quartile dose width product for an Adult Panoramic radiograph is (59.89 ± 20.97)mGymm, compared to a computer-modeled value of 62.40 mGymm. It is proposed to introduce Diagnostic Reference Levels of 2.4 mGy for an Adult Mandibular Molar Intra-Oral radiograph and 60 mGymm for an Adult Panoramic radiograph. The use of a new reference quantity in Intra-Oral radiology is also suggested. This has a value of 1 mGy/mAs and may be introduced alongside established procedures. These levels can be taken as guides to acceptable doses, but it should be noted that further reductions are practical under ALARA principles.

A comparative evaluation of film and digital panoramic radiographs in the assessment of position and morphology of impacted mandibular third molars.

BACKGROUND AND OBJECTIVE: Digital photo stimulable phosphor (PSP)-based radiography has many known theoretical advantages over conventional film radiography but its diagnostic efficacy has to be assessed clinically. This study compared the efficiency of conventional film-based panoramic radiographs with that of digital PSP-based panoramic radiographs in the assessment of position and morphology of impacted mandibular third molars. MATERIALS AND METHODS: We selected a total of 80 impacted mandibular third molars that fulfilled the inclusion and exclusion criteria of this study. Both conventional film-based panoramic radiographs and digital PSP-based panoramic radiographs were taken of all the study samples and the teeth were later surgically removed. Conventional film-based and digital PSP-based panoramic radiographs were compared for their relative efficiencies in the assessment of impaction status, position of tooth, number of roots, root morphology, and proximity to mandibular canal of impacted mandibular third molars. An oral surgeon graded these same factors during/after surgical exploration and this assessment was considered the gold standard. The data obtained were statistically analyzed using descriptive statistics, chi-square test, and McNemar's test. RESULTS: There was no statistically significant difference between conventional film-based radiographic assessment and digital PSP-based panoramic radiographic assessment of impaction status, position of tooth, number of roots, and proximity to mandibular canal of impacted mandibular third molars (P>0.05). However, there was significant difference between the two methods with regard to assessment of root morphology of impacted mandibular third molars (P=0.00). INTERPRETATION AND CONCLUSION: Conventional film-based panoramic radiographs and digital PSP-based panoramic radiographs were comparable in their accuracy in the preoperative study of impacted mandibular third molar with regard to impaction status, tooth position, number of roots, and proximity to the mandibular canal. Digital PSP-based panoramic radiographs were more accurate than conventional film-based panoramic radiographs in the assessment of root morphology of impacted mandibular third molars. Hence, we conclude that digital PSP-based panoramic radiographs can be used as an effective alternative to conventional film-based panoramic radiographs for assessment of position and morphology of impacted mandibular third molars.

A comparative diagnostic assessment of anterior tooth and bone status using panoramic and periapical radiography.

AIMS: The aim of the present study was to compare diagnostic assessments of anterior tooth and bone status in a randomised cohort of pre-orthodontic patients using panoramic and periapical radiographs. METHOD: Four hundred and forty-four cases with matched periapical and panoramic radiographs were examined by three observers. Two were final-year postgraduate endodontic students and the other, a final-year Honours degree dental student. Multi-rater Kappa values were used to assess the reliability of the observers, with a value of 1 equating to complete agreement. RESULTS: With the exception of endodontic Class 1 and 2 palatal invaginations, reliability exceeded 0.95 for all three observers. An assessment of the graduate endodontic students revealed only a marginal increase in the kappa values. Statistical analysis (p < 0.05) determined that developmental anomalies or tooth/bone pathoses were more reliably detected by observers using periapical radiographs compared with panoramic films. This finding has relevance given the likelihood of anterior dental trauma among young children. CONCLUSION: While there have been considerable improvements in the quality of dental panoramic radiography, the present study indicated that a reliable pre-orthodontic or post-trauma diagnostic assessment should include both panoramic and intra-oral radiographs.

Assessment of repeatability and reproducibility of mental and panoramic mandibular indices on digital panoramic images.

OBJECTIVES: To evaluate the repeatability and reproducibility of the measurements for Mental Index (MI) and Panoramic Mandibular Index (PMI) on digital panoramic images. METHODS: In this study, measurements for MI and PMI were carried out independently by two oral and maxillofacial radiologists on twenty digital panoramic images. Each observer repeated the measurements after a period of approximately one week. Paired t-tests and Pearson correlation coefficients were calculated to assess the levels of association. RESULTS: All measurements, both within and between observers, demonstrated high correlations and intraobserver agreement was higher than interobserver agreement according to Pearson correlation coefficients (P<0.01). There was no statistically significant difference according to t-test (P<0.05). CONCLUSIONS: This study has shown that digital panoramic radiographs may be used to evaluate PMI and MI. Reproducibility and repeatability of digital panoramic images were found to be high for measurements of PMI and MI. Additionally, as measuring tool, this software is easy and practical to use and may be preferable for validation of radiomorphometric indices.

Image quality of digital and film radiographs in applications sent to the Dental Insurance Office in Sweden for treatment approval.

In July 2002, a new dental insurance program was introduced in Sweden. For all patients over 65 years, prior approval for all prosthetic work would need to be obtained from the Dental Insurance Office. From October to December 2002, 540 cases were randomly selected for evaluation from the 14,624 applications that had been sent from throughout Sweden to the Dental Insurance Office in Lund. Our aims were to appraise the quality of the radiographic examinations and to compare the quality of the digital with the film (X-ray film) radiographs. The radiographic examinations were evaluated as a whole in relation to the proposed treatment and in detail using specific criteria such as density, contrast, unsharpness, angulation, and receptor position error. The quality variables were evaluated as acceptable or unacceptable. A total of 4,687 intra-oral and 206 panoramic radiographs were evaluated. Thirteen per cent of the intra-oral radiographs and 9% of the panoramic radiographs were taken with a digital technique. Most of the digital radiographs--7o% of the intra-oral and 61% of the panoramic radiographs--were submitted on microdisk. Twenty-eight per cent of the intra-oral digital radiographs, however, were submitted on paper. The radiographic quality in 15o cases (28%) were found to be unacceptable for assessment of the proposed treatment. The most common error--both in digital and X-ray film radiographs--was in receptor position. Significantly more errors were found in the intraoral digital radiographs compared to the radiographs taken with X-ray film. Most of the errors in the digital radiographs were detected in the paper copies. In conclusion, it is possible to improve the radiographic quality in applications for treatment approval, and the dentists had more difficulties with the digital technique than with X-ray film.

Updated quality assurance self-assessment exercise in intraoral and panoramic radiography. American Academy of Oral and Maxillofacial Radiology, Radiology Practice Committee.

This updated self-assessment exercise for the dental team by the Radiology Practice Committee of the American Academy of Oral and Maxillofacial Radiology is intended to produce the highest quality diagnostic radiographs while keeping patient exposure as low as is reasonably achievable. To continue to provide the best radiographic services to patients, those involved in dental radiography need to be aware of the latest changes and advances in dental radiography and need to use them in their practice.

Panoramic radiology quality assessment.

A procedure is proposed for performing noninvasive x-ray quality assessment tests on panoramic radiology equipment. A simple cardboard tube jig eliminates relative motion between the measurement system and the narrow, collimated x-ray beam. Accurate measurements of beam HVL, x-ray exposure coefficient of variation and mA linearity may be obtained. Use of the tube jig permits easy and routine monitoring of these important x-ray parameters as well as consistency checks of tube output. Film/screen contact also should be routinely checked in the clinic.

Interobserver variability in pediatric radiographic quality assessment.

Programs to monitor radiographic quality have been established in several Canadian provinces. These quality assurance programs depend in part on the evaluation of technical radiographic errors. Interobserver variability in the assessment of these errors reduces the reliability of such information. This study examined the interobserver variability of three dental specialists involved in documenting radiographic technical errors, and the need for retakes following the initial radiographic surveys of 200 children. Observers were trained and calibrated to standardize the evaluation of errors. The overall frequency at which errors were found in bitewing radiographs was consistent with the results of previous studies, but the number of periapical and panoramic technical errors was low. Interobserver variability occurred in the recording of radiographic technical errors, primarily in the recording of bitewing errors. There was also interobserver variability in the ordering of retakes. The interobserver variability in the assessment of radiographic quality could not be eliminated, despite prior observer training. This could indicate that the decision to retake a radiograph may be based on subjective criteria, especially in the absence of clinical information.

Panoramic mandibular index as a radiomorphometric tool: an assessment of precision.

OBJECTIVES: To evaluate the intra-observer repeatability and inter-observer reproducibility of the measurements used in deriving the Panoramic Mandibular Index (PMI). METHODS: Two observers measured 21 dental panoramic radiographs independently of each other, both repeating the measurements after a period of 1 week. The measurements were then evaluated using a number of statistical methods. RESULTS: All sets of compared measurements, both within and between observers, demonstrated significant positive correlations, with no significant difference between measurements Precision, however, was poor and variable. CONCLUSION: The main difficulties in obtaining consistency in repeated measurements were related to individual morphology and radiodensity. In order to improve the validity of the PMI as a measure of local bone loss, repeatability of the measurements should be improved. Suggestions as to how this, might be achieved are discussed.

An evaluation of image quality for the assessment of the marginal bone level in panoramic radiography. A comparison of radiographs from different dental clinics.

The diagnostic image quality of panoramic radiographs originating from different clinics was examined. Two samples of 98 and 100 radiographs, respectively, were from a department of oral radiology. The radiographs of one of these samples were checked using immediate subjective analysis of the image quality before inclusion in the study whereas the radiographs of the other sample were randomly selected. A third sample consisted of radiographs from 20 randomly selected dental clinics. The subjective overall image quality of the whole panoramic radiograph was classified as adequate, marginal or inadequate. The three observers also assessed the reason for inferior image quality. The overall image quality of the radiographs was better for the checked sample from the department of oral radiology compared to the sample form the 20 dental clinics. The main reason for unacceptable image quality of the radiographs was too low density and/or contrast irrespective of sample. Other faults were incorrect positioning of the patient but in the sample from the 20 clinics improper film handling was also frequent. We conclude that image quality in panoramic radiography can be improved. Improvement of the image quality is a prerequisite if panoramic radiography in the future is to replace the full-mouth examination.

Assessing dental practice quality by evaluating radiology items.

The DEMCAD dental office assessment instrument was developed to evaluate practice quality using Donebedian's quality assessment model of structure, process, and outcome. This previously validated instrument takes about six hours to complete. Subsequent analysis was undertaken to determine whether an abbreviated office assessment based on the evaluation of radiology items was sufficiently sensitive, specific, and practical to be used as a screening instrument for identifying dental offices with very low evaluation scores. Data for this analysis were obtained from 300 volunteer general dental practices evaluated in the field testing of the DEMCAD instrument. The nine radiology structure items predicted very poorly the overall structure scores. However, 13 radiology process items predicted overall process scores quite accurately. Four of the 13 radiology process items (periodontal diagnoses recorded, interdental bone shown on x-rays, caries diagnoses recorded, and current x-rays mounted) produced a combined R2 of .58. These four radiology variables predicted the 10 percent of the dental practices with the lowest overall process score with 87 percent sensitivity and 93 percent specificity. This analysis showed that an abbreviated dental practice process quality assessment using oral radiology items in an audit of patients' records may be feasible as a screening test for dental office assessment.