Application of X-rays to dental age estimation in medico-legal practice.

AIM OF THE STUDY: The paper addresses the use of dental age assessment methods based on radiographs in medico-legal practice. Different cases of practical application of the methods are presented including identification of human remains, dental age assessment in a living person and one archaeological case. MATERIAL AND METHODS: The study material consisted of cases involving dental age assessment performed in the Department of Forensic Medicine, Poznan University of Medical Sciences in Poznan. Depending on the preliminary assessment of age, the Liversidge or the Kvaal et al. methods were applied. Dental age was estimated on the basis of available pantomograms. In the case of the living person, it was a radiograph supplied for expert evaluation. In the other cases, dental computed tomography was performed. RESULTS: Dental age was successfully estimated in all of the cases. Various methods based on the analysis of X-ray images were applied. Dental age was shown to be correlated with skeletal age. CONCLUSIONS: The methods based on radiographs were demonstrated to be useful, and the results they yield are fully correlated with results of anthropological analyses.

A comparative study of the diagnostic accuracy of cone beam computed tomography and intraoral radiographic modalities for the detection of noncavitated caries.

OBJECTIVES: The aim of this study was to determine the diagnostic accuracy of cone beam computed tomography (CBCT) in the detection of approximal and occlusal noncavitated carious lesions. METHODS: A total of 135 extracted human posterior teeth were used. They were radiographed using the following: conventional film (Kodak Insight), a digital system (PSP plates Digora Optime, Soredex), and a CBCT system (NewTom 3G, Quantitative Radiology). All the images were assessed by two independent observers twice. Receiver operating characteristic analysis (Az) was used. RESULTS: NewTom 3G 9″ CBCT was statistically inferior to conventional film and a digital system for the detection of approximal caries. NewTom 3G 9″ had significantly higher Az values than PSP plate (p < 0.05), but there were no statistically significant differences between the Az values for CBCT and film (p > 0.33) for occlusal surface caries. CONCLUSION: The diagnostic accuracy of all three tested radiographic systems is low, and it is necessary to use other methods to improve early caries detection. CLINICAL RELEVANCE: CBCT has found a wide application in different fields of dentistry. The report from a CBCT examination performed for any of these reasons should include all abnormal findings, and the detection of noncavitated caries lesions is especially important because it facilitates the use of noninvasive treatment.

The influence of amalgam fillings on the detection of approximal caries by cone beam CT: in vitro study.

OBJECTIVES: The aim of this CBCT investigation on the detection of caries was to assess the influence of artefacts produced by the presence of amalgam fillings located in the vicinity. METHODS: 102 non-cavitated pre-molar and molar teeth were placed in blocks of silicone with approximal contacts consisting of 3 sound or carious teeth and 1 mesial-occlusal-distal amalgam-filled tooth in-between. Radiographs of all the teeth were recorded using the CBCT system (NewTom™ 3G; QR Srl, Verona, Italy; field of view, 9 inches). Data from the CBCT unit were reconstructed and sectioned in the mesiodistal tooth plane. Images were evaluated twice by two observers, using a five-step confidence scale. After the CBCT examination, the teeth were individually sectioned in the mesiodistal direction with a diamond saw. Using a light microscope at ×40 magnification, the true morphological status of all approximal surfaces was established. RESULTS: Sensitivity of the CBCT for the detection of caries on surfaces located proximally and distally to an amalgam filing ranged from 0.27 to 0.30 for enamel and from 0.47 to 0.56 for dentin. Specificity values for enamel proximal and distal lesions were 0.48 and 0.53, respectively, for enamel and 0.33 to 0.38, respectively, for proximal and distal dentin cases. Intra-observer reliability was 0.84, and interobserver reliability was 0.49. CONCLUSIONS: Owing to its low specificity, scans from a CBCT examination should not be used to determine the presence of demineralization of the tooth surface when amalgam fillings are present in the region of interest.

Evaluation of the results of periodontal treatment by means of digital subtraction of radiographic images.

UNLABELLED: This article presents general principles and a sample case of application of digital subtraction of x-rays for objective evaluation of results of treatment in dentistry. PURPOSE: Evaluation of the results of surgical periodontal treatment by means of digital subtraction of radiographic images taken before and 12 month after surgery. MATERIAL AND METHODS: For evaluation of the results of guided tissue regeneration treatment of deep bony defects digital periapical x-rays were taken before and 12 months after surgery. Pairs of images obtained during treatment were calibrated to equalize vertical x-ray beam angulation followed by calibration to radiological contrast and density. Next the comparison of images taken before and after treatment was performed by means of special computer software designed to subtract content of given images. RESULTS: Digital subtraction showed that the radiological density in regions where surgery was performed has decreased over a period of 12 months meaning that the mineral content which is responsible for absorbing x-ray photons has increased. Some local foci of subsurface hypomineralization were found on subtractions images. These foci couldn't be detected clinically because hypomineralization was taken place within bone. CONCLUSIONS: Digital subtraction of x-rays taken before and after surgery treatment is detailed and objective method of evaluating results particularly when changes of surface and subsurface bone mineralization around teeth must be examined.