Comparison between panoramic and periapical radiography in the diagnosis of periapical bone lesions

The diagnostic accuracy of panoramic and periapical radiography was compared by five oral radiologists who assessed the periapical status of 117 teeth evenly distributed throughout the jaws with a 50% probability that either an osteolytic or sclerotic lesion was present. Receiver operating characteristic (ROC) analysis demonstrated no overall significant difference between panoramic and periapical radiography. However, for sclerotic lesions and for all lesions on maxillary premolars and mandibular molars periapical radiography was significantly superior (P less than 0.001); it was also superior for osteolytic lesions in the maxilla as well as for the lesions on mandibular premolars but with a smaller significant difference (P less than 0.05).     

A comparative study of the radiological diagnosis of postoperative maxillary cyst

OBJECTIVES: To compare the diagnostic accuracy for the postoperative maxillary cyst (POMC) of panoramic in combination with Waters' radiography with computed tomography (CT) and of oral and maxillofacial radiologists with non-specialists. STUDY DESIGN: Nineteen cases of POMC and 19 of postoperative changes were assessed using panoramic in combination with Waters' radiographs and CT by five oral and maxillofacial radiologists and five non-specialists on a five-point scale. The areas under the ROC curves were analysed using the Wilcoxon rank sum test to determine any differences in diagnostic accuracy between the two methods and between the two groups. RESULTS: The diagnostic accuracy of CT was higher than that of combined panoramic and Waters' radiographs for the oral and maxillofacial radiologists (P < 0.05), but not for the non-specialists (P > 0.05). The diagnostic accuracy of the oral and maxillofacial radiologists for each method was higher than that of the non-specialists group (P < 0.05). CONCLUSIONS: CT improves the evaluation of POMC. Radiological training and experience leads to more accurate diagnoses.     

Comparison between panoramic and periapical radiography in the diagnosis of periodontal bone loss

Panoramic and periapical radiography was performed on 100 patients. Five observers each registered the scores for marginal bone level, presence of bone defects and furcation involvement in the radiographs of 20 patients and the results were compared. The overall concordance in scoring the marginal bone level was high when panoramic and periapical radiography was compared. In the upper arch, 66% of the sites showed concordant scores, 31% deviated by one and 3% by two score-points. In the lower arch, 74% of sites had concordant scores, 25% deviated by one and 1% by two score-points. The panoramic radiographs more often indicated a more severe bone loss than the periapical radiographs. The concordance was related to the degree of bone loss. In sites with no bone loss the concordance was high whereas it was lower in those with severe bone loss. The concordance of the two radiographic methods for the mandibular canine, premolars and first molar was equally as high as the intra-observer overall agreement, but lowest for the mandibular central incisors and the maxillary molars. Bone defects were more easily identified by periapical radiography.     

Preferences for oral health states: effect on prescribing periapical radiographs

OBJECTIVES: To elicit preferences for the outcomes of radiographic endodontic diagnosis and subsequent therapy, and to test for differences in these preferences between three types of dental specialists. METHODS: Using the "standard gamble" method, dentists involved in teaching oral diagnosis (n=26) were asked to rank on a scale of 0.0-1.0 their preferences (utilities) for four treatment outcomes, "composite filling in vital tooth", "composite restoration and root filled", "root filled and post crown" and "extraction and bridge", from a previously analysed diagnostic testing and therapeutic strategy for managing damaged anterior teeth. Respondents consisted of oral radiologists (n=9), specialized treatment planners (n=11) and specialist endodontists (n=6). Using the derived utilities, a decision analysis was subsequently carried out on the expected health value of taking periapical radiographs of patients with otherwise symptomless fractured incisors. RESULTS: "Composite restoration and root filled" (mean utility 0.83, SD 0.15) was the option preferred above that of "root filled and post crown" (mean utility 0.77, SD 0.16) by the entire sample of oral diagnosticians (P=0.007). Radiologists and endodontists had higher utilities for "composite restoration and root filled" than treatment planners. According to the decision analysis, for the preferred option of "composite restoration and root filled", taking a radiograph was the best strategy only when the prevalence of pathology exceeds 10%, 12% and 50% for radiologists, endodontists and treatment planners, respectively. CONCLUSIONS: The expected utility of using radiographs as a diagnostic test varies among groups of dental specialists. We conclude that variation in utilities among dentists could in part explain variation in the diagnostic use of dental radiographs.     

Measurements of tooth length in panoramic radiographs. 2: Observer performance.

Observer performance in tooth-length measurements in panoramic radiography has been examined. Sixty-four teeth, evenly distributed between maxillary first molars, second premolars and mandibular first and second premolars, were fixed in plastic moulds. Each cast was radiographed with an Orthopantomograph, twice with steel balls indicating the cusps and apices of the teeth and once without them. One observer measured the radiographic tooth length twice in both radiographs with indicators in order to estimate the true radiographic tooth length and the repositioning error, and twice in the radiographs without indicators. Seven other observers measured the tooth length on the radiographs without indicators, twice applying their own criteria and twice using defined criteria. The accuracy of the tooth-length measurements was calculated by comparing the true radiographic tooth length with the measurements of the seven observers. The intra-observer variation was defined as the difference between two measurements on the same radiograph. The accuracy and the precision of the tooth-length measurements were highly influenced by the observer performance. The mean radiographic tooth length of the seven observers was closer to the true radiographic tooth length when the observers applied the defined criteria. The inter- and intra-observer variation was higher for the measurements of the maxillary teeth (0.3-1.9 mm) compared with the mandibular teeth (0.3-0.9 mm) for most observers. The highest intra-observer variation was found for the palatal root of the maxillary first molar. The intra-observer variation of four observers decreased somewhat when the defined criteria were used; for the other three observers, however, the variation increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Individualized periapical radiography determined by clinical and panoramic examination.

The efficiency of panoramic radiography compared with full-mouth periapical examination is an unresolved problem. The diagnostic yield of periapical lesions when the clinical signs and symptoms and the findings from a panoramic radiograph served as the basis for an individualized periapical radiographic examination was studied. Two hundred patients were examined clinically and radiographically. The periapical status was assessed step by step with access to increasing numbers of radiographs. For the clinical examination, the sensitivity was 0.24, the positive predictive value 0.62, the specificity 0.98, the negative predictive value 0.90 and the likelihood ratio for the positive test result 12. For radiographs indicated by the clinical examination plus the panoramic radiograph and selected periapical radiographs, both the sensitivity and the positive predictive value were 0.91, the specificity and the negative predictive value 0.99 each and the likelihood ratio was 91. False findings were twice as frequent in the upper as in the lower arch and particularly found in the incisor and premolar regions. In 30% of the patients no periapical radiograph was needed to supplement the panoramic radiograph. In the other patients, two supplementary periapical radiographs were needed on average. We conclude that the information obtained from the clinical and panoramic examinations supplemented with no more than two periapical radiographs will result in a high diagnostic yield on the periapical status.     

Focal trough and patient positioning

Panoramic radiography is a common imaging modality used in dentistry. Panoramic radiographs provide an overall view of the dentomaxillofacial complex and are often used along with intraoral radiographs during the diagnostic phase of patient treatment. In recent years, identification of potential stroke victims has been included as a benefit of panoramic radiographs. This has stimulated an increased interest in panoramic radiography both by oral and maxillofacial radiologists and by general dentists.     

Comparing the accuracy of panoramic and intraoral radiography in the diagnosis of proximal caries

OBJECTIVES: The purpose of this study was to compare the diagnostic accuracy of panoramic and intraoral radiographic surveys in the diagnosis of proximal caries according to the different dental regions (maxillary and mandibular incisor, canine, premolar and molar). METHODS: In this study, full mouth series and panoramic radiographs of 79 patients were used. The radiographs were evaluated for proximal caries by three observers. The diagnostic accuracy of radiographic surveys for each dental region was assessed by means of receiver operating characteristic (ROC) curve analysis. RESULTS: Full mouth series was the most efficient method in the diagnosis of caries for incisor and canine teeth. However, full mouth series and combination of panoramic plus bitewings had similar diagnostic accuracy for premolar and molar teeth. CONCLUSIONS: Panoramic survey alone was not sufficient for the diagnosis of proximal caries for the entire dentition. The combination of panoramic plus bitewing plus anterior periapical survey exhibited a diagnostic accuracy for proximal caries that was comparable with full mouth series.     

Diagnostic accuracy of panoramic radiography in the detection of calcified carotid artery

OBJECTIVES: The purpose of this study was to assess the diagnostic accuracy of the panoramic radiograph in the detection of carotid artery calcification using CT as the gold standard. METHODS: 110 dental patients (average age 65.2 years, range 50-82 years) with both panoramic radiographs and CT scans available were selected for the evaluation of carotid artery calcification. Two oral and maxillofacial radiologists interpreted the panoramic radiographs for the presence of carotid artery calcification. CT scans were independently interpreted by a neuroradiologist. RESULTS: The accuracy of panoramic radiographs in the detection of carotid artery calcification was 62.3%. The sensitivity and the specificity were 22.2% and 90.0%, respectively. CONCLUSIONS: Panoramic radiography has a moderate diagnostic accuracy in the detection of carotid artery calcification, but the sensitivity is low.     

Panoramic versus conventional radiography of scaphoid fractures

OBJECTIVE: The objective of this study was to compare the diagnostic value of panoramic and conventional radiography in the detection of fractures of the carpal scaphoid bone. MATERIALS AND METHODS: Panoramic (orthopantomographic) and conventional radiographs of 90 patients with acute or chronic wrist trauma were reviewed retrospectively. Images were analyzed and reviewed independently by four observers: two radiologists and two traumatologists. The kappa statistic was used to calculate intraand interobserver agreement and the correlation between the two imaging techniques. RESULTS: Panoramic radiography of the wrist was superior to conventional radiography in ruling out scaphoid fractures (74%, 20/27) in patients with suspicious findings on conventional radiography; revealed more cases of scaphoid fractures (21.4%, 12/56); and revealed more cases of delayed union (n = 2), nonunion (n = 3), and union (n = 3). Agreement values were higher, with better inter- and intraobserver agreement, for the panoramic examinations than for the conventional radiographic examinations. CONCLUSION: The panoramic examination of the wrist is a useful technique for the diagnosis and follow-up of scaphoid fractures. Its use is recommended as a complement to conventional radiography in cases with inconclusive findings.     

Application of panoramic radiography with a multilayer imaging program for detecting proximal caries: a preliminary clinical study

Objective:The aim of this study is to introduce a novel program of panoramic radiography that shows 41 multilayer images from the buccal to lingual aspects in a region of interest, and to evaluate the effectiveness of this program for detecting proximal caries.Methods:In total, 480 premolars and molars on 30 panoramic radiographs taken with the multilayer imaging program were included in this study. The presence or absence of caries in 960 proximal surfaces was assessed by three experienced oral and maxillofacial radiologists as a consensus-based gold-standard. Two general dentists evaluated and scored proximal caries on 980 surfaces on panoramic radiographs with and without the multilayer imaging program. The two general dentists’ scores were compared with the gold-standard, and were analyzed for sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic (ROC) curve with and without using the program. The area under the ROC curve was analyzed using STATA/SE 13.1.Results:When the multilayer imaging program was used for panoramic radiography, the inter- and intraobserver agreement of the two general dentists improved. All values, including the area under the ROC curve, were higher when the multilayer imaging program was used than when it was not used. The area under the ROC curve showed a statistically significant improvement only in Observer 1, whose diagnostic ability was poorer than that of Observer 2.Conclusions:oThis multilayer imaging program might help the inexperienced dentist to improve the diagnostic accuracy of proximal caries. If further studies would be performed in various clinical application, it could be useful when intraoral radiography taking is difficult for reasons such as mouth-opening limitations and the gag reflex of the patients.     

Marginal bone in periodontal disease: an evaluation of image quality in panoramic and intra-oral radiography

Five observers assessed the panoramic and full-mouth (14 periapical and four posterior bitewing) radiographs of 20 patients each for the ability to interpret and measure the marginal bone level. The image quality of each site was classified as excellent, acceptable or unacceptable. Depiction errors affecting interpretability and measurability were also noted. In the upper arch, the frequency of uninterpretable and non-measurable sites was almost equal for panoramic and periapical radiography. Image quality was better with periapical radiography in the lower arch. In the posterior regions of both arches, more sites could not be measured from panoramic compared with bitewing radiographs. Due to overlapping the distal surface of the maxillary canine and the mesial surface of the first maxillary premolar could often not be interpreted in either panoramic or periapical radiographs, but infrequently in the bitewings. In the lower arch, the most frequent depiction error was inadequate density in the incisor region of panoramic radiographs. On the basis of these results, we proposed that in clinical practice the panoramic radiograph can be supplemented with individually selected periapicals. In epidemiological studies, the panoramic radiograph should be combined with a premolar bitewing radiograph.     

Intra-oral storage phosphor and conventional radiography in the assessment of alveolar bone structures

OBJECTIVES: To compare storage phosphor (SP) with conventional film radiography for accuracy of linear measurements of the marginal alveolar bone and visibility of anatomical structures. METHODS: Linear measurements were made in paired SP and conventional images of dried human mandibles with a metal pin fixed 10 mm below the alveolar crest. One observer measured the distance from the alveolar crest to the reference point on the radiographs. The difference between the measured and the true distance was calculated. Two observers rated the visibility of bony structures (periodontal ligament space, periapical bone tissue, alveolar crest) in 51 paired digital and conventional images of 21 patients on a 3-point scale. Overall agreement and Kappa index were calculated. RESULTS: Accuracy of linear measurements was higher in digital radiography (mean difference 0.17 mm) than in conventional radiography (mean difference 0.59 mm). Overall, the two observers rated visibility higher in conventional radiographs. The Kappa indices for the periodontal ligament space and periapical bone indicated fair to almost perfect agreement (kappa = 0.38 and 0.5; kappa = 0.39 and 0.84) while for the alveolar crest there was only poor or moderate agreement (kappa = 0.2 and 0.5). CONCLUSIONS: The small differences in linear measurements indicate that the Digora system is suitable for clinical assessment of periodontal and peri-implant bone loss. The visibility of dental structures depends as much on the individual features assessed, as the radiographic system.     

The reproducibility of the mandibular cortical index

OBJECTIVES: To assess the reproducibility and diagnostic validity of Mandibular Cortical Index (MCI) when used by minimally trained observers. METHODS: Four 'experts' and 45 final-year dental students classified the appearance of the lower border of the mandibular cortex in 30 panoramic radiographs using the MCI. Experts viewed the original radiographs. The students received instruction in the MCI and viewed slides of the radiographs in a lecture theatre. RESULTS: For intra-observer agreement, the experts had significantly higher overall values of weighted kappa, indicating substantial agreement in MCI assessment, whereas the students showed moderate agreement. For inter-observer agreement, there was fair agreement between the experts and poor agreement between the students. Using the experts' MCI assessment as the 'gold standard', the mean sensitivity of the students in diagnosis of C3 was 0.71 (maximum 0.95, minimum 0.25) and mean specificity was 0.56 (maximum 0.9, minimum 0.20). CONCLUSIONS: The MCI has important limitations in terms of intra- and inter-observer agreement. Minimal training in its use, such as might be given in a lecture format to dentists, was ineffective and associated with poor inter-observer agreement and limited diagnostic validity in identifying signs of osteoporosis. More lengthy training and experience in using the MCI would be needed for it to be effective as a diagnostic tool in general dental practice.     

Radiographic assessment of the marginal bone level after implant treatment: a comparison of periapical and Scanora detailed narrow beam radiography

OBJECTIVES: To compare assessments of the marginal bone level around dental implants in the mandible using periapical radiography and Scanora detailed narrow beam (DNB) radiography. METHODS: Forty patients treated with Brnemark dental implants in the lower jaw were examined with periapical and Scanora DNB radiography. Ten implants were selected from each of the four dental regions (molar, incisor, canine, premolar), and no more than one implant was selected from the same patient. Seven observers assessed the level of the marginal bone on the mesial and distal surfaces of the implants. Three of the observers made all the assessments twice. RESULTS: Agreement between the methods was 61%. The highest agreement was found in the molar region. In DNB radiography the marginal bone level was observed to be situated more "coronally" in 17% and more "apically" in 22% compared with periapical radiography. The kappa value for interobserver agreement for all observers was 0.33 for periapical radiography and 0.27 for DNB radiography. The weighted kappa value for intraobserver agreement ranged from 0.75 to 0.99 for DNB radiography and from 0.94 to 0.98 for periapical radiography. CONCLUSIONS: Scanora multimodal radiography simplifies examination of implants in the mandible, and observer variation is comparable with that in intraoral periapical radiography.     

The effect of dose reduction on the detection of anatomical structures on panoramic radiographs

OBJECTIVES: The aim was to evaluate the effect of dose reduction on diagnostic accuracy using different screen-film combinations and digital techniques for panoramic radiography. METHODS: Five observers assessed 201 pairs of panoramic radiographs (a total of 402 panoramic radiographs) taken with the Orthophos Plus (Sirona, Bensheim, Germany), for visualization of 11 anatomical structures on each side, using a 3-point scale -1, 0 and 1. Two radiographs of each patient were taken at two different times (conventional setting and setting with decreased dose, done by increasing tube potential settings or halving tube current). To compare the dose at different tube potential settings dose-length product was measured at the secondary collimator. Films with medium and regular intensifying screens (high and low tube potential settings) and storage phosphor plates (low tube potential setting, tube current setting equivalent to regular intensifying screen and halved) were compared. The five observers made 27 610 assessments. Intrarater agreement was expressed by Cohen's kappa coefficient. RESULTS: The results demonstrated an equivalence of regular screens (low tube potential setting) and medium screens (high and low tube potential settings). A significant difference existed between medium screens (low tube potential setting, mean score 0.92) and the group of regular film-screen combinations at high tube potential settings (mean score 0.89) and between all film-screen combinations and the digital system irrespective of exposure (mean score below 0.82). There were no significant differences between medium and regular screens (mean score 0.88 to 0.92) for assessment of the periodontal ligament space, but there was a significant difference compared with the digital system (mean score below 0.76). The kappa coefficient for intrarater agreement was moderate (0.55). CONCLUSIONS: New regular intensifying screens can replace medium screens at low tube potential settings. Digital panoramic radiographs should be taken at low tube potential levels with an exposure equivalent at least to a regular intensifying screen.     

Agreement between panoramic and intra-oral radiography in the assessment of marginal bone height.

Panoramic and intra-oral radiographs from 400 consecutive patients were evaluated for the assessment of the marginal bone height. Two hundred panoramic radiographs were exposed with the rotational technique and 200 with the intra-oral X-ray tube technique. Measurements of the approximal marginal bone level were independently performed by two observers. Complete agreement between panoramic and intra-oral radiographs was, on average, obtained in 55% and 49% of the sites, respectively. When the criterion for agreement was widened to include recordings with a difference of +/- 1 mm, the agreement was on average 87% irrespective of the techniques compared. The agreement varied with tooth type and severity of the marginal bone loss. Angular bony defects and furcation involvements were recorded separately. For angular bony defects there was a variation in agreement from 33% to 46% for the rotational technique and from 35% to 51% for the intra-oral X-ray tube technique depending on localization. Furcation involvements of the molars were equally recorded in 60% and 59%, respectively, but in only 12% and 28% for the upper premolars. Interobserver agreement was 58% for the intra-oral radiographs, 60% and 59% for the two panoramic techniques. Mean intra-observer agreement was 68%, 66% and 68%. It is concluded that panoramic radiography can often be used for the assessment of marginal bone loss alone, supplemented when necessary by intra-oral radiographs.     

Quantitative assessment of artefacts and identification of gaps in prosthetic crowns: a comparative in vitro study between periapical radiography and CBCT images

Objectives:To evaluate, in an in vitro study, the quantity of artefacts generated by two different restorative materials, and to determine the diagnostic accuracy of cone beam CT (CBCT) scans and periapical radiographs in identifying gaps in prosthetic crowns.Methods:A total of 30 teeth restored with metal-ceramic (n = 15) and all-ceramic (n = 15) crowns, properly adapted and with 0.30- and 0.50 mm gaps, underwent CBCT exams (with voxel sizes of 0.25 and 0.30 mm) and periapical radiographs. The artefacts generated by two different crowns were quantified and compared by the Mann–Whitney test. In addition, five examiners evaluated the presence or absence of gaps in periapical radiographs and CBCT images. The accuracy of tests was determined by the area under the receiver operatring characteristic curve and these values were compared by using the Kruskal–Wallis test.Results:There was no significant difference in artefact values between the different restorative materials and the different resolutions of CBCT images. Regarding the accuracy of the tests evaluated, periapical radiography and CBCT with voxel size 0.25 mm showed the best performance for smaller gaps (0.30 mm). For larger gaps (0.50 mm), all exams tested showed the same performance.Conclusions:Periapical radiography was still the most cost-beneficial method for the diagnosis of maladaptation in dental restorations. CBCT exams did not improve accuracy in detecting gaps in prosthetic crowns.     

Comparison of ultrasound, digital and conventional radiography in differentiating periapical lesions

OBJECTIVES: To carry out an in vivo comparative pilot study to evaluate the efficacy of ultrasound, digital (DR) and conventional plain film-based imaging (PF) in the differential diagnosis of periapical lesions. METHODS: Fifteen patients aged between 13 years and 40 years with periapical lesions associated with anterior maxillary or mandibular teeth requiring endodontic surgery were selected and consented for the study. Pre-operative periapical radiographs (PF) and charge coupled device (CCD) DR were obtained. Measurements and provisional diagnoses of the apical areas were made by three specialist observers (two dental radiologists and one endodontist) on three separate occasions. Pre-operative ultrasound examinations were then performed and the images assessed by two specialist observers (ultrasonographer and endodontist) for the size, contents, vascular supply and a provisional diagnosis made as to whether the lesion was a cyst or granuloma. Endodontic surgery was performed including curettage of the apical tissues to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analysed. RESULTS: On PF and DR the periapical lesions were readily identified but observers were unable to differentiate granuloma from cyst using either modality. Dimensional measurements were subject to greater interobserver variation on DR than on PF. Where sufficient buccal cortical bone had been resorbed, ultrasound imaging was straightforward but underestimated the size of the lesions compared with PF and DR. In all 15 cases, the ultrasound diagnosis agreed with the histopathological gold standard. CONCLUSIONS: PF and DR enable diagnosis of periapical disease existence, but not of its nature; while ultrasound underestimates the extent of disease, but can provide accurate information on the pathological nature of the lesion.     

Effective and organ doses from scanography and zonography: a comparison with periapical radiography

OBJECTIVES: 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.