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An osteoma is a slow-growing, benign lesion comprising mature bone tissue. Osteomas rarely occur in maxillary bones, with the exception of the maxillary sinuses. Various possible etiologies have been proposed, including congenital anomalies, chronic inflammation, muscular activity, embryogenetic changes, and trauma. Here we present a case of an osteoma of the buccal plate of the mandible at the site where a sports-related traumatic injury occurred 15 years earlier. Both conventional and 3-dimensional x-ray examinations were used for diagnosis and preoperative evaluation of the possible involvement of the adjacent anatomic structures. The lesion was treated surgically without complications and the patient made a complete recovery. Histologic tests confirmed the preoperative diagnosis. A review of the international literature is also presented., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: The purpose of this study was to describe a newly developed dental panoramic system based on the tomosynthesis method and to validate the accuracy of linear and spatially oriented planar images., Study Design: An original robotic mechanism incorporating a new high-speed cadmium-telluride (CdTe) semiconductor detector was fabricated to acquire panoramic images (raw data). The shift-and-add tomosynthesis method was applied to facilitate changes in the depth of the panoramic imaging layer. Using the texture mapping method, planar and spatially oriented images were reconstructed along a custom curved imaging plane. Using a custom phantom and dry skulls, the accuracy of selected linear measurements was evaluated., Results: Preliminary measurements demonstrated acceptable linear accuracy in reconstructed panoramic images with variations <5%., Conclusions: This preliminary investigation demonstrates that dental panoramic images acquired by a novel robotic mechanism and CdTe detector using a tomosynthesis method provides planar and spatially oriented images with an image quality that may be acceptable for dental practice., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: Osteosynthesis failure rates of 11.3% with 1 miniplate, 6.7% with 2 miniplates, and 4.4% with a single Medartis condyle plate were reported in previous studies of our clinic. Current science is still focused on the osteosynthesis material. Besides clinical parameters, conventional radiographs are still the first choice to detect osteosynthesis failures. This study scrutinized several factors assessable in postoperative orthopantomographs which might elevate the risk of osteosynthesis failure., Study Design: A total of 136 patients (22 with osteosynthesis failure, 114 without) with 151 mandibular condyle fractures were included in this study. Eight parameters were assessed in postoperative orthopantomographs., Results: The best predictor of osteosynthesis failure was a simplified concept of ramus height. In cases of reduced or normal ramus height, the odds of osteosynthesis failure was significantly (P = .000001) reduced to a 10th. Isolated fractures were significantly more error prone (P = .0009)., Conclusions: Postoperative orthopantomographs depict factors which increase the risk of osteosynthesis failure., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objective: The aim of this study was to establish if dental panoramic tomographic (DPT) radiographs provide a reliable means of assessing the anterior maxilla in new orthodontic patients., Study Design: Two hundred fifty pairs of upper anterior occlusal (UAO) and DPT radiographs were randomly selected from the records of new orthodontic patients. Ten observers each rated 50 pairs of radiographs for specific risk factors as well as for a measure of adequacy. Correlations between the 2 radiograph types and inter/intraobserver reliability were computed using Cohen kappa test., Results: Intraobserver reliability was good for detection of impacted teeth/supernumeraries/periapical pathology (kappa = 0.711-1.0). Reliability was more variable for the specific root morphologies, with blunt and bent roots being reassessed as such most reliably (kappa = 0.259-0.533). There was low interobserver reliability (kappa = 0.327 for UAO and kappa = 0.223 for DPT) for "normal" or "not normal" root morphology. For every variable, however, the interexaminer agreement was higher when using UAO radiographs rather than DPTs. Observers were best able to agree on the diagnosis of eroded/resorbed roots on the UAO (kappa = 0.402) and blunt roots (kappa = 0.303) on the DPT radiographs. With UAO as the gold (reference) standard for grading root morphology, DPT had a sensitivity of 45.6% and a specificity of 71.4% for detecting abnormal root form. Risk factors were more likely to be detected on the UAO radiographs than the DPTs. DPTs had a poor ability to detect abnormal root form. DPTs were more likely to be rated as "inadequate" than UAO radiographs. On 6 occasions, supernumerary teeth that were observed on the UAO were missed on the DPT., Conclusion: The DPT is not an accurate means of screening the anterior maxilla prior to orthodontic treatment., (Copyright (c) 2010 Mosby, Inc. All rights reserved.)

Background and Objective: Bisphosphonate-associated osteonecrosis of the jaws (BONJ) is characterized by exposed nonvital maxillary or mandibular bone. Cone-beam computerized tomography (CBCT) is an attractive modality for 3-dimensional imaging of the jaws. The purpose of this study was to compare the clinical and radiographic features of a series of 7 subjects with BONJ who were evaluated by both CBCT and digital panoramic radiography., Study Design: Seven subjects with BONJ were evaluated by clinical examination, CBCT, and digital panoramic radiography., Results: Radiographic findings included sclerosis, cortical irregularity, lucency, mottling, fragmentation/sequestra formation, sinus communication, and persistent sockets. There was high correlation between the anatomic location of clinical and radiographic findings. In nearly all cases, CBCT demonstrated a greater extent and quality of changes compared with panoramic radiography., Conclusions: Cone-beam CT is superior to panoramic radiography in its ability to characterize the nature and extent of radiographic changes in BONJ. Use of CBCT should be strongly considered when radiographic evaluations are included in prospective research investigations of BONJ. However, in the majority of cases of BONJ the clinical significance of improved imaging remains unclear, and therefore specific guidelines for routine clinical care cannot be recommended at this time., (Copyright (c) 2010 Mosby, Inc. All rights reserved.)

Objectives: The aim was to test for correlations of 7 panoramic radiomorphometric indices with lumbar spine and hip bone mineral densities (BMDs) and to test the accuracy of these indices for predicting osteoporosis and a T-score < or =-2.0., Study Design: Mandibular cortical indices, simple visual estimations of cortical widths, mental and antegonial indices, antegonial depth, gonial and antegonial angles, and BMD were measured in 351 postmenopausal women., Results: Associations were demonstrated between BMDs, qualitative indices, and cortical measurements. In the case of severely eroded mandibular cortices, the odds ratio (OR) for osteoporosis (according to the World Health Organization criteria) was 4.82 and the OR for a T-score < or =-2.0, the threshold to begin treatment, was 10.87. In the case of very thin mandibular cortices, the ORs were 8.02 and 5.46 for osteoporosis and a T-score < or =-2.0, respectively. The mental index cutoff for osteoporosis was 3.15 mm., Conclusions: Antegonial indices and gonial angles cannot be used as osteoporosis predictors. The most accurate indices were the mental index, mandibular cortical index, and visual estimation of cortical width., (Copyright 2010 Mosby, Inc. All rights reserved.)

Objectives: To demonstrate the feasibility of panoramic image subtraction for implant assessment., Study Design: Three titanium implants were inserted into a fresh pig mandible. One intraoral and 2 panoramic images were obtained at baseline and after each of 6 incremental (0.3, 0.6, 1.0, 1.5, 2.0, 2.5 mm) removals of bone. For each incremental removal of bone, the mandible was removed from and replaced in the holding device. Images representing incremental bone removals were registered by computer with the baseline images and subtracted. Assessment of the subtraction images was based on visual inspection and analysis of structured noise., Results: Incremental bone removals were more visible in intraoral than in panoramic subtraction images; however, computer-based registration of panoramic images reduced the structured noise and enhanced the visibility of incremental removals., Conclusion: The feasibility of panoramic image subtraction for implant assessment was demonstrated.

Objective: The aim was to compare digital and conventional panoramic imaging techniques for identifying high-risk radiographic markers associated with mandibular nerve (MN) injury after mandibular third molar (M3) removal., Study Design: The study used a retrospective cohort model. The predictor variable was the presence or absence of radiographic signs associated with MN exposure during M3 removal. The outcome variable was MN exposure. Intraexaminer variability was estimated using a kappa statistic. Logistic regression modeling was used to measure the association between radiographic signs and MN exposure and determine if imaging technique modified that association. The level of statistical significance was set at P < .05., Results: The sample was composed of 571 patients having 1,017 mandibular M3s removed. The MN was visualized in 66 extraction sites (6.5%). In the adjusted logistic model, radiographic signs were statistically associated with MN exposure (P < .001) and imaging technique was a statistically insignificant effect modifying variable (P = .4)., Conclusion: The results of this study suggest that imaging technique does not modify the relationship between high-risk panoramic radiographic signs and MN exposure.

Objectives: To validate the Mental Index assessment obtained from panoramic radiographs., Study Design: Ten dried mandibles were selected, and standardized panoramic radiographs were obtained. The specimens were then perpendicularly sectioned at the mental foramen region, and the inferior mandibular cortical thickness was recorded using a digital caliper. Measurements of panoramic radiographs were compared with the dried mandibles. Four observers carried out twice the measurements for the panoramic radiographs. Two observers performed twice the measurements of the dried mandibles. Reliability was assessed by duplicate measurements., Results: Agreement between the actual mandible measurements and the radiographic assessment was moderate for the noncorrected measurements. Agreement between anatomic and radiographic measurements improved remarkably after standard correction for magnification., Conclusions: Bone status reports based on measuring cortical thickness of the lower border of the mandible at the mental foramen based on panoramic radiographs, i.e., Mental Index, are accurate. Compensation for magnification, however, is necessary.

Background: Radiographic diagnosis of the presence, position, and degree of third molar formation is a crucial part of integral treatment planning for the development of this tooth. Shortage of eruption space between lower second molar and the ramus has long been identified as a major factor in the etiology of lower third molar impaction. The purpose of the present investigation was to evaluate the validity of some angular and linear measurements made on digital panoramic imaging to be used as a reference for early prediction of lower third molar eruption or impaction., Subjects and Methods: Digital panoramic imaging was done on 50 individuals with full dentition and a class I occlusal relationship. The sample was divided into full-eruption and marginal-eruption groups. Nine variables (linear measurements and angles) were measured for every individual to determine the minimal and maximal values of each variable and these variables were correlated to each other using Pearson's correlation equation., Results: Lower eruption space measurements for the marginal-eruption group were smaller by more than 3 to 4 mm than that of the full-eruption group. The beta-angle, the angle formed between the long axes of lower second and third molars, showed a marked increase in their values (9 degrees to 10 degrees) when the marginal-eruption group is compared to the full-eruption group., Conclusion: Third molar angle (alpha-angle), beta-angle, and gonial angle together with lower eruption space measurements are the variables that should be taken into consideration when early prediction of lower third molar eruption is performed.

Objective: Pixel intensity values (PI) and fractal dimensions (FD) were compared in selected mandibular regions on digital panoramic images of normal, osteopenic, and osteoporotic perimenopausal and postmenopausal women to evaluate their relative efficacies in detecting osteoporotic-associated bone density changes., Study Design: Standardized mandibular angle, body, and canine/premolar (C/PM) regions on 54 charge-coupled device (CCD) digital panoramic images of normal and potentially osteoporotic postmenopausal women were analyzed for PI and FD. Lumbar spine and femoral neck dual-energy x-ray absorptiometry (DXA) on each patient served as the reference standard examination. Pearson correlation coefficients and analysis of variance (ANOVA) were performed., Results: There was significant correlation among PI measurements (P < 0.01), and no significant correlation between FD. C/PM had significantly lower PI than control C/PM (P = 0.049)., Conclusions: Osteoporotic changes in mandibular C/PM cancellous bone were detected in our study population on CCD digital panoramic images by using a robust image analysis paradigm. Future automated application of such image analysis could enable widespread, cost effective screening for osteoporosis in dental settings.

Objective: The objective of this study was to assess the accuracy of dental panoramic tomograph (DPT) in the presurgical assessment of mandibular third molar teeth by correlating the radiologic interpretation with surgical findings., Study Design: DPTs of 300 mandibular third molar teeth were assessed by 9 staff oral surgeons for root morphology and proximity to the inferior alveolar neurovascular bundle. Detailed records were made at surgery., Results: The sensitivity and specificity for observation of root curvatures (+/-15%) were 29% and 94%, respectively. The sensitivity and specificity of determining an intimate relationship between the root and the neurovascular bundle were 66% and 74%, respectively. Kappa analysis demonstrated poor levels of agreement between radiologic interpretation and surgical findings when the number of roots was determined (0.191) and also when the roots were fused or separate (0.466)., Conclusion: Using DPTs to assess mandibular third molar teeth before surgery gives poor diagnostic accuracy of anatomic form and structures.

Objective: The aim of this study was to compare panoramic temporomandibular joint radiography, unenhanced and color-enhanced digital-subtraction radiography with respect to detectability of simulated osteophytic lesions of the mandibular condyle., Methods: Three dry human skulls with no obvious temporomandibular joint pathology were selected. Four sizes of bone chips were placed on the anterior aspect of the condyle at medial, central, and lateral locations. Panoramic radiographs were made with and without the chips in place. These paired radiographs were digitized, and unenhanced and color-enhanced digital-subtraction images of the original panoramic images were obtained. Eight observers evaluated 72 randomized images of each modality for the presence or absence of simulated osteophytic lesions of the mandibular condyle, grading the images on a 100-point scale., Results: A(z) values for overall diagnostic accuracy of the three imaging modalities were 0.5376 for panoramic radiography, 0.7861 for unenhanced digital subtraction radiography, and 0.7923 for color-enhanced digital-subtraction radiography. Digital-subtraction radiography improved the detection accuracy of the original panoramic films., Conclusion: Panoramic radiographs were significantly less accurate in the detection of simulated osteophytic lesions of the mandibular condyle than the two digital-subtraction techniques.

Objective: This study was designed to compare 5 modalities with respect to accuracy in mandibular cross-sectional imaging. The modalities tested were tuned-aperture computed tomography (TACT), iteratively reconstructed TACT, multidirectional tomography, linear tomography, and transverse panoramic tomography., Study Design: Twenty sites were selected from 3 dry human mandibles, and cross-sectional views were imaged through use of each of the 5 modalities. A quantitative analysis included measurements of 2 linear distances; a qualitative study included image evaluation by 6 observers. A nested mixed analysis of variance model was used to control for mandibles and locations within mandibles for the quantitative analysis; the Cochran-Mantel-Haenszel test was used for the qualitative analysis., Results: There was a significant difference in measurement error for maximum height but not for width. There was also a significant difference in qualitative image evaluation results., Conclusions: Of the 5 modalities tested, the narrow-layer multidirectional tomographic technique produced the greatest diagnostic accuracy and quality in cross-sectional imaging. The transverse panoramic tomographic technique produced the least diagnostic accuracy and quality. Linear tomography, TACT, and iteratively reconstructed TACT were intermediate in accuracy and quality.

Objective: Type 2 diabetes mellitus, which afflicts 15 million Americans, is associated with accelerated cervical carotid artery atherosclerosis and a heightened risk of stroke. This study attempted to determine the prevalence of calcified atherosclerotic lesions in a group of patients with type 2 diabetes mellitus., Study Design: The panoramic radiographs of 49 men (age range, 55 to 81; mean age, 66.2 years) receiving routine dental treatment and insulin for diabetes at a Department of Affairs Veterans clinic were evaluated for calcified atheromas. Age-match controls, free of diabetes, were assessed in a like manner. Statistical comparison of the atheroma prevalence rates was by means of the Fisher exact test, and statistical comparison of atherogenic risk factors was by means of t test with Bonferroni adjustment and, where necessary, the Mann-Whitney U test., Results: The radiographs of the diabetics (mean age, 66.9 years) revealed that 20.4% had atheromas whereas those of the controls (mean age, 68.1 years) demonstrated that 4% had atheromas (a statistically significant difference; P =.0275). Also statistically significant was the prevalence of atherogenic risk factors (plasma glucose, low-density lipoproteins, and serum triglycerides) identified in the diabetic group. The radiographic appearance of the atheromas manifested by both groups of individuals, however, was similar, with the lesions located 1.5-2.5 cm inferior-posterior to angle of the mandible., Conclusions: People with type 2 diabetes have a greater prevalence of calcified atheromas on their panoramic radiographs than do nondiabetics.

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.

Objective: Automatic exposure control has been used successfully in medicine to improve image quality and reduce the number of retakes necessitated by inadequate operator selection of exposure factors. The purpose of this study was to assess the influence of automatic exposure control on panoramic image quality., Study Design: A total of 352 patients were imaged with either the OP 100 or the Orthophos Plus panoramic machine. An expert consensus panel judged film quality using a 5-point scale. Differences in quality that would have resulted from the use of operator-determined exposures were calculated through use of an algorithm validated with test images of a human phantom., Results: McNemar's test demonstrated significant improvements in quality with automatic exposure control (P = .001) in comparison with manual exposure control. No quality difference was found between the 2 machines (P = .9661). Manual exposure selection by oral and maxillofacial radiology residents was better than selection by technologists and assistants (P = .006)., Conclusions: This study confirms the utility of automatic exposure control for panoramic radiography.

Dose reduction in digital panoramic radiography was studied. Intentional underexposure was performed with the Orthophos DS while six different human mandibles were radiographed. Exposure settings were 69 kV/15 mA (standard), 64 kV/16 mA, and 60 kV/16 mA. Standardized spherical defects, each either 1 or 1.25 mm in diameter, were simulated in 288 of 432 images, and seven observers decided whether defects were present or not. Areas under the receiver operating characteristics curves were calculated. They showed no significant differences in the detectability of the 1-mm defect at 69, 64, or 60 kV. For the 1.25-mm defect, no difference was found between the 69 and 60 kV images, but a statistically significant different detectability was found for 64 kV images in comparison with both 69 and 60 kV images. A dose reduction of up to 43% was ascertained with a Pedo-RT-Humanoid phantom when panoramic radiography was performed at 60 kV/16 mA. The conclusion is that with the Orthophos DS, it seems possible to reduce the dose rate of x-rays without loss of diagnostic quality in the case of radiolucent changes.

The objective of this study was to assess whether bony landmarks used for the standard inferior alveolar nerve block can be used to accurately determine the position of the mandibular foramen and whether panoramic radiographs are appropriate for this purpose. A total of 11 landmarks from 79 panoramic radiographs and 70 corresponding cases of oblique (45-degree) cephalometric radiographs were examined. Ten measurements of the distance from each landmark to the mandibular foramen, as well as 6 ratios from these distances, were calculated from all radiographs. The results showed that the position of the mandibular foramen was highly individualistic and not consistently related to traditional clinical landmarks. Panoramic radiographs were as good as oblique cephalometric radiographs for the locating of the mandibular foramen. No age or gender correlations were found. It was concluded that the mandibular foramen can be localized in panoramic radiographs but that its relation to bony landmarks is highly variable.

Objective: The aim of this investigation was to report on the radiographic interpretation of the hard palate and nasal fossa floor in panoramic radiographs by studying different skulls, x-ray machines, and head positions in relationship to the Frankfort plane before and after ostectomy., Study Design: Twenty dry human skulls were radiographed with three different panoramic x-ray machines in three different positions. Three of the skulls were submitted to different ostectomies., Results: Multiple images of the hard palate and nasal fossa floor were present in 96.12% of the radiographs. Single images (3.88%) occurred only in the "chin up" position., Conclusions: The lower image represents the nasal fossa floor, especially its lateral and anterior limits. The upper images are double real images mainly formed by the junction of the nasal septum with the nasal fossa floor and possibly by posterior parts of the hard palate and nasal fossa floor. All images overlap in the "chin up" position becoming a single image. The most common shape of the anatomic landmark was wide angle "W" (58.33%). Other shapes present in positions "chin up" and "chin down" indicate patient positioning errors. The x-ray machines did not influence the results.