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.     

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.     

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.     

Proximal caries detection accuracy using intraoral bitewing radiography, extraoral bitewing radiography and panoramic radiography

Objective

To compare proximal caries detection using intraoral bitewing, extraoral bitewing and panoramic radiography.

Methods

80 extracted human premolar and molar teeth with and without proximal caries were used. Intraoral radiographs were taken with Kodak Insight film (Eastman Kodak Co., Rochester, NY) using the bitewing technique. Extraoral bitewing and panoramic images were obtained using a Planmeca Promax Digital Panoramic X-ray unit (Planmeca Inc., Helsinki, Finland). Images were evaluated by three observers twice. In total, 160 proximal surfaces were assessed. Intra- and interobserver kappa coefficients were calculated. Scores obtained from the three techniques were compared with the histological gold standard using receiver operating characteristic analysis. Az values for each image type, observer and reading were compared using z-tests, with a significance level of α = 0.05.

Results

Kappa coefficients ranged from 0.883 to 0.963 for the intraoral bitewing, from 0.715 to 0.893 for the extraoral bitewing, and from 0.659 to 0.884 for the panoramic radiography. Interobserver agreements for the first and second readings for the intraoral bitewing images were between 0.717 and 0.780, the extraoral bitewing readings were between 0.569 and 0.707, and the panoramic images were between 0.477 and 0.740. The Az values for both readings of all three observers were highest for the intraoral bitewing. Az values for the extraoral bitewing images were higher than those of the panoramic images without statistical significance (p > 0.05).

Conclusion

Intraoral bitewing radiography was superior to extraoral bitewing and panoramic radiography in diagnosing proximal caries of premolar and molar teeth ex vivo. Similar intra- and interobserver coefficients were calculated for extraoral bitewing and panoramic radiography.     

Fractal dimension on dental radiographs

OBJECTIVES: (1) To compare fractal dimension (FD) from periapical radiographs with FD from panoramic radiographs; (2) to correlate FD with cortical thickness and morphology; and (3) to correlate FD with a reported history of osteoporotic fractures. METHODS: Information on fracture and smoking history was obtained by a telephone interview with 281 elderly (>60 years of age) patients who had periapical and panoramic radiographs exposed on the same date. FD was measured in several locations on both types of radiograph. Mandibular cortical thickness and morphology were obtained from the panoramic radiograph. RESULTS: FD measured in the mandible was lower than FD in the maxilla. Same-jaw measurements had a higher correlation than same-side measurements. FD measured on panoramic radiographs was lower than FD from periapical radiographs. There was a negative correlation between cortical thickness and FD. FD was higher in subjects with more mandibular cortical porosities and resorption. The mean panoramic FD from subjects with a history of osteoporotic fractures was significantly higher, after adjusting for smoking, gender, age, height and weight. CONCLUSIONS: FD measured on panoramic radiographs is lower than FD measured on periapical radiographs. FD is higher in both types of radiograph in subjects with a thinner, severely eroded mandibular cortex and a history of osteoporotic fractures. This study confirms other reports that FD increases when bone mass decreases. In addition, it suggests that panoramic radiographs can be used as a possible alternative for the measurement of FD to periapical radiographs.     

Observer performance in the assessment of periapical pathology: a comparison of panoramic with periapical radiography.

Observer performance in the assessment of the periapical pathology from panoramic and periapical radiography was examined. Five endodontists, five general practitioners and five oral radiologists were asked to assess the periapical status of 117 teeth. The observers assessed the panoramic and periapical radiographs of the teeth, which were evenly distributed throughout the jaws with a 50% probability that either an osteolytic or sclerotic lesion was present. The results of the comparison between panoramic and periapical radiography were influenced by the selection of observers. When the oral radiologists acted as observers, the mean P(A) value for periapical radiography was higher than for panoramic radiography (P less than 0.001), resulting in periapical radiography presenting a higher overall diagnostic accuracy than panoramic radiography for all 15 observers (P less than 0.01). There was, however, no difference between panoramic and periapical radiography when the two groups of endodontists and general practitioners acted as observers. The comparison of the three groups of observers showed no difference between their diagnostic accuracy when assessing panoramic radiographs. With periapical radiography, the oral radiologists demonstrated a higher diagnostic accuracy than the endodontists (P less than 0.05). The observers in each group with the highest diagnostic accuracy also had the highest intra-observer agreement. The mean intra-observer agreement of the five general practitioners was higher than those of the other two groups of observers for panoramic radiography. For periapical radiography, the mean agreement rates of the groups were comparable.     

Sliding window adaptive histogram equalization of intraoral radiographs: effect on image quality

OBJECTIVES: To investigate whether contrast enhancement by non-interactive, sliding window adaptive histogram equalization (SWAHE) can enhance the image quality of intraoral radiographs in the dental clinic. METHODS: Three dentists read 22 periapical and 12 bitewing storage phosphor (SP) radiographs. For the periapical readings they graded the quality of the examination with regard to visually locating the root apex. For the bitewing readings they registered all occurrences of approximal caries on a confidence scale. Each reading was first done on an unprocessed radiograph ("single-view"), and then re-done with the image processed with SWAHE displayed beside the unprocessed version ("twin-view"). The processing parameters for SWAHE were the same for all the images. RESULTS: For the periapical examinations, twin-view was judged to raise the image quality for 52% of those cases where the single-view quality was below the maximum. For the bitewing radiographs, there was a change of caries classification (both positive and negative) with twin-view in 19% of the cases, but with only a 3% net increase in the total number of caries registrations. For both examinations interobserver variance was unaffected. CONCLUSIONS: Non-interactive SWAHE applied to dental SP radiographs produces a supplemental contrast enhanced image which in twin-view reading improves the image quality of periapical examinations. SWAHE also affects caries diagnosis of bitewing images, and further study using a gold standard is warranted.     

A retrospective study evaluating the use of the panoramic radiograph in endodontics

Patients are referred to the endodontist to have root canal therapy performed to treat pulpal and periradicular diseases. Routinely, the only radiograph to accompany the patient is the periapical radiograph. This radiograph is inadequate in the detection of asymptomatic pathosis that may be present in other areas of the maxilla and mandible. The military's readiness mission requires that a panoramic radiograph be part of the patient's dental record. In addition to its use for personal identification purposes, the panoramic radiograph is an excellent diagnostic tool that can give the clinician an overall view of the dentoalveolar structures. This retrospective study evaluated randomly selected panoramic radiographs and recorded the presence of radiolucent and radiopaque areas not evident on a referral periapical radiograph. The results of this study found a 4.2% occurrence of undiagnosed pathosis following additional radiographs and clinical examinations.     

Survey of radiographic practices for periodontal disease in UK and Irish dental teaching hospitals

OBJECTIVES: To assess current radiographic practices in dental teaching hospitals for the management of patients with periodontal diseases. METHODS: All 17 dental teaching hospitals in UK and Ireland were sent a questionnaire on radiographic equipment and radiograph selection currently used for assessment of patients with destructive periodontal diseases. Opinions were recorded for advantages and disadvantages of the most frequently used radiographic views. RESULTS: A 100% response rate was achieved. All hospitals used panoramic and specific periapical radiographs as one of their radiographic regimes for patients with periodontal disease. Fifty-three per cent of respondents most frequently took panoramic and selected periapical radiographs. Twenty-four per cent took full mouth periapical radiographs (FMPAs) most frequently and 18% took a panoramic radiograph alone. Twenty-four per cent of hospitals operated a protocol for selection of radiographs for periodontal patients. CONCLUSIONS: The most commonly used views taken to assess periodontal status are panoramic radiographs with selected periapicals. Few hospitals operate a protocol for prescribing radiographs.     

Bitewing radiographs of children taken with and without a film-holding device

To help minimize radiation exposure, all dental radiographs must yield maximum diagnostic information. Film-holding devices have been recommended as a means of improving the diagnostic yield. Our study compared the diagnostic quality of bitewing radiographs of children taken with and without the aid of a film-holding device. 1014 bitewing radiographs (sizes 0, 1, 2) were taken of 338 children (aged 5-11 years) by senior dental students. Bitewing tabs were used for 554 radiographs and a film-holding device for the remainder. Diagnostic quality was calculated for each radiograph by dividing the number of non-overlapped contacts by the total number present. Both overall mean diagnostic yield and mean diagnostic yield for each size of film were found not to be significantly improved by use of the film-holding device. Position of overlapped contacts on each size of film was not equally distributed (P less than or equal to 0.01) among the contacts present. For size 0 and 1 films, overlap was most frequent between the maxillary first and second primary molars and for size 2 films between the maxillary first permanent molar and second primary molar/second bicuspid.     

Measurements of tooth length in panoramic radiographs. 1. The use of indicators.

The aim of this study was to investigate both the actual and the radiographic tooth lengths of the maxillary first molar and second premolar and the mandibular premolars in panoramic radiographs. The actual length of 64 extracted teeth was measured. Steel balls were then attached to the cusp and apex and the teeth embedded in plastic moulds. Each pair of plaster casts with their set of teeth was radiographed with an Orthopantomograph twice at an interval of 1 month. The actual and the radiographic tooth length was measured twice by one observer. The mean tooth length of the molar was shorter than that of the premolars. The mean difference between the repeated measurements of the actual tooth length was small and ranged between 0.47 and 1.16% of the tooth length. The mean difference between repeated measurements of the radiographic tooth length was also small, with a method error of 0.13-0.21 mm. The vertical magnification in panoramic radiography was lower for mandibular premolars (13-15%) than for the maxillary second premolar and first molar (17-28%). The palatal root of the maxillary first molar had the highest vertical magnification (28%). Following the second set of radiographs, the mean difference between the measurements was small, except for the palatal root of the maxillary first molar (P < 0.001). Radiographic measurements of this root should therefore be used with caution. The results for the other roots examined indicate that these could be measured with high reproducibility.     

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).     

Accuracy of vertical height measurements on direct digital panoramic radiographs using posterior mandibular implants and metal balls as reference objects

Objectives:

Conventional panoramic radiography, a widely used radiographic examination tool in implant treatment planning, allows evaluation of the available bone height before inserting posterior mandibular implants. Image distortion and vertical magnification due to projection geometry is well described for rotational panoramic radiographs. To assess the accuracy of vertical height measurements on direct digital panoramic radiographs, implants and metal balls positioned in the posterior mandible were used as radio-opaque reference objects. The reproducibility of the measuring method was assessed by the inter- and intraobserver agreements.

Methods:

Direct digital panoramic radiographs, performed using a Kodak 8000C (Eastman Kodak Company, Rochester, NY), of 17 partially edentulous patients (10 females, 7 males, mean age 65 years) were selected from an X-ray database gathered during routine clinical evaluation of implant sites. Proprietary software and a mouse-driven calliper were used to measure the radiological length of 25 implants and 18 metal reference balls, positioned in mandibular posterior segments. The distortion ratio (DR) was calculated by dividing the radiological implant length by the implant''s real length and the radiological ball height by the ball''s real height.

Results:

Mean vertical DR was 0.99 for implants and 0.97 for balls, and was unrelated to mandibular sites, side, age, gender or observer. Inter- and intraobserver agreements were acceptable for both reference objects.

Conclusions:

Vertical measurements had acceptable accuracy and reproducibility when a software-based calibrated measurement tool was used, confirming that digital panoramic radiography can be reliably utilized to determine the pre-operative implant length in premolar and molar mandibular segments.     

Effective dose equivalent to the operator in intra-oral dental radiography

The effective dose equivalent to the operator in intra-oral dental radiography has been determined. The exposure from a bitewing radiograph and periapical views of the left maxillary incisors and first molar was measured at nine heights and 16 positions, all 1 m from the patient. The effective dose equivalent was determined using data from ICRP 51 (International Commission on Radiological Protection: Data for Use in Protection Against External Radiation). The values presented are related to an exposure of 1 C kg-1 (3876 R) measured free in air at the tube-end. They thus constitute ratios which are not influenced by the sensitivity of the film or other detector used and form standard tables which permit the calculation of the effective dose equivalent in clinical situations.     

Experimental comparison of radiographic techniques in the detection of maxillary sinus disease

The radiographic examination of the maxillary sinus is usually accomplished by the Waters' projection. However, some lesions, such as the mucous retention cyst, postoperative maxillary cyst and maxillary sinus carcinoma, as well as some lesions extending into the maxillary sinus, may be shown by panoramic radiography. The present study was conducted to confirm the ability of panoramic radiography in the detection of maxillary sinus disease. The representation of a globular radiopaque mass at different locations in the maxillary sinus of a dry skull was compared in Waters' and panoramic projections. A mass with a diameter of 10 mm situated on the posterior wall or floor of the maxillary sinus was shown better by panoramic radiography. The Waters' projection was less effective; the mass, especially on the floor of the sinus, was not clearly demonstrated due to superimposition of the maxillary molar teeth.     

Radiological findings in an unusual osteosarcoma in the maxilla

An unusual case of osteosarcoma of the maxilla, which was initially diagnosed as fibrous dysplasia on the basis of the clinical CT and histopathological findings, is presented. However, panoramic and periapical radiography suggested a malignant neoplasm. After surgery, the tumor was diagnosed histopathologically as a low-grade osteosarcoma. We conclude that panoramic and periapical radiographs are important adjuncts and should be included in any investigation of the jaws where CT scanning is unable to differentiate between osteosarcoma and fibrous dysplasia.     

Comparison of the visibility of the anatomical structures of the facial skeleton in panoramic zonography and linear tomography

The value of cylindrical panoramic radiography (using one rotational axis), a modification of orthopantomography (using three rotational axes), in radiographic examination of maxillo-facial skeleton was estimated by evaluating the visualization of anatomical structures of the facial skeleton on cylindrical panoramic and linear tomographic radiographs of 51 patients examined with both methods. The radiographs were independently reviewed by four radiologists. The visualization of the lateral wall of the orbit and maxillary sinus, nasal septum, alveolar process and zygomatic corpus was better on cylindrical panoramic radiographs. Linear tomography visualized the media wall of orbit better. In visualizing the frontal sinus, orbital floor, medial wall of maxillary sinus and hard palate there were no significant differences between linear tomography and panoramic zonography.     

Comparison of the panoramic radiographic and CT features of post-Caldwell-Luc maxillary sinuses

OBJECTIVE: To clarify the panoramic radiographic features of the post-Caldwell-Luc maxillary sinus. METHODS: The panoramic radiographs were compared with the axial CT scans of 48 symptomatic post-Caldwell-Luc maxillary sinuses which had been operated on more than 5 years previously. RESULTS: The two characteristic features of the post-Caldwell-Luc maxillary sinus on panoramic radiographs were a right-angled triangular shape, due to absence of the floor of the maxillary sinus and radiopacity of the posterior wall and zygomatic bone, and an ill-defied panoramic innominate line. This shape was related to the finding of a contracted sinus with a radiolucent lumen on the CT scans. There was also close relationship between the ill-defined panoramic innominate line and thickened posterior wall on the CT scans. CONCLUSION: The characteristic features of the post-Caldwell-Luc maxillary sinus on panoramic radiographs were a right-angled triangular shape and an ill-defined panoramic innominate line. These features were related to a contracted sinus and a thickened posterior wall on the CT scans.     

A comparison of the effective dose from scanography with periapical radiography

OBJECTIVES: To compare organ and effective doses from analogue scanographic and periapical radiography. METHODS: Thermoluminescent dosimeters (TLD-700) were inserted in the parotid glands (bilateral), submandibular glands (bilateral) and bone marrow (left ascending ramus) of three human cadavers. Dosimeters were also attached to the skin, thyroid gland and lens of both eyes. Central, left lateral and left posterior scanograms were obtained with a Cranex Tome (Soredex, Helsinki, Finland) multimodal imaging system. A similar procedure was applied for periapical radiographs of the midline, left lateral and left molar regions using E-speed film both with and without rectangular collimation. Organ and effective doses were calculated for scanograms and periapical radiographs. RESULTS: The effective doses for the scanograms were 0.001 mSv (central), 0.011 mSv (lateral) and 0.015 mSv (posterior). The effective doses for periapical radiographs were 0.001 mSv (anterior), 0.001 mSv (lateral) and 0.003 mSv (posterior) for rectangular collimation and 0.001 mSv (anterior), 0.002 mSv (lateral) and 0.005 mSv (posterior) for round collimation. CONCLUSIONS: When a larger area of the upper or lower jaw needs to be visualised, scanograms might be considered as an alternative to periapical radiography since the effective dose is lower.     

Comparison between DICOM-calibrated and uncalibrated consumer grade and 6-MP displays under different lighting conditions in panoramic radiography

Objectives:

To compare observer performance in the detection of anatomical structures and pathology in panoramic radiographs using consumer grade with and without digital imaging and communication in medicine (DICOM)-calibration and 6-megapixel (6-MP) displays under different lighting conditions.

Methods:

30 panoramic radiographs were randomly evaluated on three displays under bright (510 lx) and dim (16 lx) ambient lighting by two observers with different years of experience. Dentinoenamel junction, dentinal caries and periapical inflammatory lesions, visibility of cortical border of the floor and pathological lesions in maxillary sinus were evaluated. Consensus between the observers was considered as reference. Intraobserver agreement was determined. Proportion of equivalent ratings and weighted kappa were used to assess reliability. The level of significance was set to p < 0.05.

Results:

The proportion of equivalent ratings with consensus differed between uncalibrated and DICOM-calibrated consumer grade displays in dentinal caries in the lower molar in dim lighting (p = 0.021) and between DICOM-calibrated consumer grade and 6-MP display in bright lighting (p = 0.038) for an experienced observer. Significant differences were found between uncalibrated and DICOM-calibrated consumer grade displays in dentinal caries in bright lighting (p = 0.044) and periapical lesions in the upper molar in dim lighting (p = 0.008) for a less experienced observer. Intraobserver reliability was better at detecting dentinal caries than at detecting periapical and maxillary sinus pathology.

Conclusions:

DICOM calibration may improve observer performance in panoramic radiography in different lighting conditions. Therefore, a DICOM-calibrated consumer grade display can be used instead of a medical display in dental practice without compromising the diagnostic quality.