In vitro comparison of conventional film and direct digital imaging in the detection of approximal caries.

OBJECTIVES: To compare the diagnostic accuracy of conventional film, unenhanced direct digital and inversion grayscale direct digital imaging in the detection of approximal caries. METHODS: 150 approximal surfaces of extracted permanent molars and premolars were selected for the study on the basis of varying lesion depth. The teeth were radiographed using Ektaspeed Plus film; digital images were made with a Schick CMOS-APS sensor. 7 examiners evaluated 58 randomized images of each modality. Histological sectioning of the teeth was used to verify the presence and extent of decay. RESULTS: No significant difference was found between the diagnostic accuracies of the three imaging modalities (P=0.226). Analysis of the diagnostic accuracy of the three modalities on lesion depth showed no statistically significant interaction; however, the main effect of the lesion depth was significant (P<0.001, eta(2)=0.936). CONCLUSIONS: The overall diagnostic accuracy of the three modalities in the detection of approximal carious lesions was comparable. All three modalities performed poorly in the detection of enamel lesions.

Evaluation of a digital measurement tool to estimate working length in endodontics.

The purpose of the study was to compare the segmental measurement tool from the Shick Technologies CDR digital system with the conventional film radiography measurement technique to determine preoperative working length. Natural extracted human teeth with varying degrees of root curvature were used. All teeth were imaged using the Shick Technologies CDR direct digital system and conventional E-speed film. Measurements from digital radiography and conventional film were compared with measurements made directly from the endodontic files. The Wilks' Lambda multivariate test was used. The mean measurement of each modality was compared with the other and with the gold standard. The test showed statistically significant differences between the two modalities at p<0.05. The mean measurements for both modalities were not significantly different from the gold standard. The modality most closely approaching the gold standard was the conventional 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.

Anisotropic elastic properties of cancellous bone from a human edentulous mandible.

The elastic moduli have not been reported for cancellous bone from the edentulous mandible. Accurate values are needed for finite element modeling of the mandible. The aim of this study was to determine elastic modulus values in three orthogonal directions for cancellous bone taken from an edentulous jaw and to relate these values to apparent density and volume fraction. Seven samples were obtained from the edentulous mandible of a 74-year-old female. Young's modulus was determined by compression testing of cubes cut with the faces aligned with the anatomic axes. Bone volume fraction averaged 0.33 (SD 0.14) and apparent density averaged 0.55 g/cc (SD 0.29). Young's modulus was greatest in the mesio-distal direction (mean 907 MPa, SD 849 MPa), followed by the bucco-lingual (mean 511 MPa, SD 565 MPa) and infero-superior direction (mean 114 MPa, SD 78 MPa). The infero-superior direction was less than the bucco-lingual (P = 0.03) and mesio-distal (P = 0.002). The mesio-distal and bucco-lingual directions could not be shown to be different (P = 0.32). This suggests a model of transverse isotropy for cancellous bone in the jaw, where the symmetry axis is along the infero-superior (weakest) direction.

Infection control in dental radiology.

Although exposure to blood is rare in oral and maxillofacial radiology, contact with saliva occurs. Thus the spread of infectious diseases is possible through cross-contamination, and specific infection control protocols and unit dosing of items are needed. This article outlines rationale for implementing state-of-the-art infection control procedures; and explains federal standards and guidelines with an impact on infection control and occupational safety in dental radiology procedures.

Infection control in dental radiology.

Although exposure to blood is rare in oral and maxillofacial radiology, contact with saliva occurs. Thus the spread of infectious diseases is possible through cross-contamination, and specific infection control protocols and unit dosing of items are needed. This article outlines rationale for implementing state-of-the-art infection procedures; and explains federal standards and guidelines with an impact on infection control and occupational safety in dental radiology procedures.

Multilocular radiolucencies.

This article discusses lesions that commonly present as multilocular radiolucencies and, therefore, should be considered when the clinician is forming a differential diagnosis. These lesions include odontogenic keratocyst, ameloblastoma, central giant cell granuloma, cherubism, odontogenic myxoma, aneurysmal bone cyst, and central hemangioma and other vascular lesions. There is much variation in the clinical nature of multilocular lesions and, thus, variation in management. The clinician always must consider the possibility of a vascular lesion whenever evaluating a multilocular radiolucency.

Radiologic findings of diseases involving the maxilla and mandible.

The purpose of this pictorial essay is to illustrate the radiologic appearances of diseases involving the maxilla and mandible. The high prevalence of dental disease results in inflammatory, infectious, and reactive processes that must be distinguished from more serious conditions with similar radiologic features. Because of their association with odontogenic tissues, lesions of the maxilla and mandible may have radiologic findings not seen in other bones. Furthermore, nonodontogenic cysts and tumors that occur elsewhere in the skeleton may exhibit unique radiologic characteristics when associated with teeth. This pictorial essay presents the radiologic characteristics of inflammatory lesions, developmental abnormalities, fibroosseous lesions, benign cysts and tumors, and malignant lesions of the maxilla and mandible.

The frequency and distribution of idiopathic osteosclerosis.

Full-mouth radiographs of 1921 patients were examined for the presence of radiopacities that could not be attributed to any known sources of bone formation. A total of 103 patients, or 5.4%, exhibited these foci of idiopathic osteosclerosis. Most lesions were located in the vicinity of the mandibular premolars, and the majority had some connection to the apices of the teeth. No difference in frequency between males and females was detected overall, but a statistically significant preponderance of idiopathic osteosclerosis was found in blacks, with a predilection for black females also noted.

Infection control in dental school radiology.

U.S. and Canadian dental schools were surveyed concerning infection control practices in dental radiology. The majority of respondents reported surface disinfection of intraoral projection operatories (55 percent) and panoramic operatories (61 percent) before or after each patient. The most frequently used surface disinfectant was iodophor. Most schools routinely disinfected the x-ray cone (89 percent) and tubehead (87 percent) of intraoral x-ray machines; however, many did not disinfect the control panel (44 percent) or the exposure button (27 percent). Although 100 percent of respondents reported student use of disposable latex gloves when exposing intraoral radiographs, 27 percent did not use gloves when processing radiographs. Fifty-six percent did not routinely disinfect countertops in the darkroom.

Localization of paraoral soft tissue calcifications: the known object rule.

The interpretation of panoramic radiographs requires an understanding of the formation of real and ghost images in rotational panoramic radiology. This article illustrates the use of principles of interpretation in panoramic radiology to identify paraoral soft tissue calcifications, which appear as lesions in the third molar-ramus region of the mandible. The known object rule, a variation of the buccal object rule, is presented as an aid in identifying soft tissue calcifications of the region of the head and neck.

Effect of experimental stress on masseter and temporalis muscle activity in human subjects with temporomandibular disorders.

Temporomandibular (TM) disorders have an uncertain aetiology. The purpose of this study was to replicate and extend the work of Yemm (1969) (Archs oral Biol. 14, 873-878, 1437-1439; Br. dent. J. 127, 508-510), who reported a lack of habituation to experimentally induced stress in subjects with TM disorders. In this study, 20 TM disorder patients and 20 controls, matched for age and sex, performed a timed psychomotor task while bilateral masseter and anterior temporalis electromyographic (EMG) activity, finger temperature and skin admittance were monitored. These data were sampled, stored every 4s and averaged by an Apple II Plus/ISAAC interface. A significant trials effect for finger temperature (F[4/152] = 34.99, p less than 0.001) and skin admittance (F[4/152] = 41.90, p less than 0.001) was found, suggesting that the independent variable (stress) had been successfully manipulated. A significant trials by groups effect was found for right temporalis EMG activity (F[3/144] = 3.94, p less than 0.05); the left temporalis showed a similar, but not significant, trend. The masseter muscles did not show differences or trends between groups. No significant differences were found in resting EMG levels or in the initial magnitude of EMG responses during baseline. These results provide support for the hypothesis that TM disorder and control groups respond differently to stress in terms of habituation to stressful stimuli.

The present direction of research in forensic odontology.

Forensic odontology is receiving increased attention in the literature and has become a widely recognized field of expertise with broad ramifications. With this growth, research is needed to solve the most pressing problems of the discipline. The purpose of this paper is to identify current trends in research in forensic odontology. The review consisted of studies using the scientific method and reports of new techniques being tested. Also, abstracts from the annual meeting of the Odontology Section of the American Academy of Forensic Sciences from 1980 to 1987 have been reviewed to determine the current areas of emphasis in forensic dentistry.

Dental management of the patient with hemophilia.

Classic hemophilia is the most common inherited bleeding diathesis. Recent advances in the management of hemophilia have enabled many hemophiliac patients to receive outpatient dental care on a routine basis. An overview of hemophilia, including etiology, clinical features, and recent advances in treatment, is presented. Guidelines for dental management of the hemophiliac patient are discussed.

Comparative radiographic study of human and animal long bone patterns.

The objective of this study was to test the hypothesis that certain radiographic features can be found to distinguish between human and animal long bone fragments, and therefore would be useful as an adjunct in forensic science identification. Using proposed radiographic criteria, 13 archeologists and 12 dentists were asked to identify 20 radiographic samples as representing human or animal bone. Results showed that archeologists correctly identified 86.8% of the samples, and dentists correctly identified 81.9%. Based on the results of this study, it was concluded that radiographic interpretation of long bone fragments may be a useful aid in a forensic science investigation of human and animal remains.