Dental devices; reclassification of root-form endosseous dental implants and endosseous dental implant abutments. Final rule

The Food and Drug Administration (FDA) is reclassifying root-form endosseous dental implants and endosseous dental implant abutments from class III to class II (special controls). Root-form endosseous dental implants are intended to be surgically placed in the bone of the upper or lower jaw arches to provide support for prosthetic devices, such as artificial teeth, in order to restore the patient's chewing function. Endosseous dental implant abutments are separate components that are attached to the dental implant and intended to aid in prosthetic rehabilitation. FDA is reclassifying these devices on its own initiative on the basis of new information. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for these devices. FDA is taking this action under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990, the Food and Drug Administration Modernization Act of 1997, and the Medical Device User Fee and Modernization Act of 2002.     

Dental products devices; reclassification of endosseous dental implant accessories. Food and Drug Administration, HHS. Final rule

The Food and Drug Administration (FDA) is reclassifying the manually powered drill bits, screwdrivers, countertorque devices, placement and removal tools, laboratory pieces used for fabrication of dental prosthetics, trial abutments, and other manually powered endosseous dental implant accessories from class III to class I. These devices are intended to aid in the placement or removal of endosseous dental implants and abutments, prepare the site for placement of endosseous dental implants or abutments, aid in the fitting of endosseous dental implants or abutments, aid in the fabrication of dental prosthetics, and be used as an accessory with endosseous dental implants when tissue contact will last less than an hour. FDA is also exempting these devices from premarket notification. This reclassification is on the Secretary of Health and Human Services' own initiative based on new information. This action is being taken under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990 (the SMDA), and the Food and Drug Administration Modernization Act of 1997 (FDAMA).     

Skin changes following defibrillation. The effect of high voltage direct current

Previously, electrical injuries have been suggested caused only by the concomitant heat developed during the passage of an electrical current. Recent experimental studies on fully anesthetized pigs and the study of one human case have, however, shown typical electrical alterations. The purpose of the present study was further to evaluate the histology of electrically induced changes in the skin in humans. In addition, supplementary in vivo methods for evaluation of skin changes as high-frequency ultrasound and Raman spectroscopy were used. The skin of 11 patients treated with a defibrillation of the heart was examined for macroscopic changes, the skin of eight of them also for histologic changes and for changes observable via supplementary methods. Immediately and 7 days after the defibrillation, fractions of a narrow red ring were observed along the periphery of the tin-foil electrode. Epidermis showed signs previously observed following electrical influence: segmental alterations often related to the openings of sweat ducts, darkstaining or "empty" nuclei and homogeneous cytoplasm, eosinophilic or pale. Dermis did not show the specific sign of electrical influence: deposits of calcium salts on dermal fibres, neither via histologic examination nor via high-frequency ultrasonography and Raman spectroscopy. Fractions of a narrow red ring along the periphery of the electrode showing histological signs of electric influence in epidermis thus appear to be characteristic of high voltage electrical injury.     

大鼠死后肝脏磷酸果糖激酶-2含量的变化

目的 分析不同死亡时间和死亡原因大鼠肝脏组织内磷酸果糖激酶-2(PFK-2)含量的变化.方法 大鼠105只随机分为三组,以不同方式(失血、窒息、断颈)处死.分别于死后0、1、2、4、8、12和24h取大鼠肝脏组织,免疫组化和图像分析技术测定大鼠PFK-2变化.结果 三组不同死亡原因大鼠肝脏组织内PFK-2的含量随死亡时间延长呈规律性减弱趋势.结论 大鼠肝脏组织内PFK-2的变化可以反映死亡时间的变化趋势.     

Dental conditions. Final rule

The Department of Veterans Affairs (VA) adopts as a final rule the proposal to amend its adjudication regulations regarding service connection of dental conditions for treatment purposes. This amendment clarifies that principles governing determinations by VA's Veterans Benefits Administration (VBA) for service connection of dental conditions for the purpose of establishing eligibility for dental treatment by VA's Veterans Health Administration (VHA), apply only when VHA requests information or a rating from VBA for those purposes. This amendment also clarifies existing regulatory provisions and reflects the respective responsibilities of VHA and VBA in determinations concerning eligibility for dental treatment.     

Dental age in Central Poland

Precise evaluation of the developmental stage of a child is an integral part of both diagnosis and treatment of pediatric patients; it is also essential in forensic medicine and dentistry. Among radiological methods for dental age estimation in children the Demirjian's method is widely used, however original standards elaborated for the French-Canadian population are mostly not suitable for other populations. The aim of the study was to compare the dental age of children from the region of Mazovia (Central Poland) with the developmental standards presented by Demirjian, to analyse sexual dimorphism of dental age in the studied group and to estimate validity of the Demirjian's standards for the studied Polish population. The material consisted of clinical files and panoramic X-ray images of 994 children aged from 6 to 16 in good general health, without development impairments. Chronological ages of the patients were established. Next dental ages were estimated by means of the Demirjian method based on developmental maturity of seven left mandibular permanent teeth. It was found that the standards were significantly different from the chronological ages in the studied population, which means that dental development was considerably accelerated. The most significant acceleration was observed in girls aged 11 and 12, as well as in 13-year-old boys; in both groups a considerable acceleration of the dental age was seen in 6-year-olds. No statistically significant differences between dental ages of girls and boys were observed in particular age groups. There were devised gender-specific equations allowing for adaptation of original Demirjian's scores for estimation of dental age in the population of Mazovia (Central Poland). In conclusion, the developmental standards used by Demirjian are not suitable in the case of the population of children of Central Poland. Therefore, it is necessary to establish new tables for this population.     

TRICARE; changes included in the National Defense Authorization Act for fiscal year 2005; TRICARE Dental Program. Interim final rule

The Department is publishing this interim final rule to implement sections 711 and 715 of the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA-05), Public Law 108-375. Specifically, that legislation makes young dependents of deceased Service members eligible for enrollment in the TRICARE Dental Program when the child was not previously enrolled because of age, and authorizes post-graduate dental residents in a dental treatment facility of the uniformed services under a graduate dental education program accredited by the American Dental Association to provide dental treatment to dependents who are 12 years of age or younger and who are covered by a dental plan established under 10 U.S.C. 1076a. This rule also corrects certain references in 32 CFR 199.13. The rule is being published as an interim final rule with comment period in order to comply with statutory effective dates. Public comments are invited and will be considered for possible revisions to the final rule.     

应用放射影像技术进行牙龄推断

牙龄是年龄推断的重要方法之一，国外学者常将其与骨龄联合应用以提高年龄推断的准确性，但国内尚未普遍开展。大量研究表明，应用放射影像学这一无创的检查手段，可以准确观察牙齿的增龄性变化，如牙冠与牙根的发育程度、牙髓腔的变化等。目前应用放射影像学进行牙龄推断的主要方法有Gleiser和Hunt法、Demirjian法及牙髓腔测量法等。其中Demirjian法的准确性最高，但在推断法定敏感年龄时尚存在局限性。随着放射影像学的发展，尤其是CT的出现，依赖其高分辨率以及相匹配的测量软件，可提高牙龄推断的准确性与可靠性，有望成为今后推断活体年龄的重要手段。     

Identification of incinerated root canal filling materials after exposure to high heat incineration

With the increase in global terrorism there is a higher probability of having to identify victims of incineration events secondary to incendiary explosive devices. The victims of incineration events challenge forensic odontologists when coronal restorations are no longer present to compile postmortem data. With 40 million root canals being completed annually in the United States, a very large pool of antemortem data is available to the forensic odontologist to make positive identifications. When complete and thorough dental records exist, individuals that have undergone surgical and nonsurgical root canal therapy may have materials present in the canal that may aid in identification. This study provides elemental fingerprints of root canal obturation materials to be utilized as a forensic identification aid. This study used scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) to assess the elemental composition of materials before and after high temperature incineration. Sixteen endodontic materials were analyzed pre-incineration and placed in extracted teeth. The filled teeth were subjected to incineration at 900 degrees C for 30 min to simulate incineration events or cremation. Incinerated materials were radiographed and re-analyzed to determine if they retained their original elemental composition. Endodontic sealers, gutta percha, root-end filling materials, silver points, and separated files were distinguishable in the canal and traceable after incineration. The authors present a fingerprint of the endodontic obturation materials that are capable of withstanding high heat incineration to be used as an aid for postmortem identification. This work represents the initial stage of database generation for root canal filling materials for use as an aid in forensic identification.     

Computerized Dental Comparison: A Critical Review of Dental Coding and Ranking Algorithms Used in Victim Identification

Comparison of antemortem and postmortem dental records is a leading method of victim identification, especially for incidents involving a large number of decedents. This process may be expedited with computer software that provides a ranked list of best possible matches. This study provides a comparison of the most commonly used conventional coding and sorting algorithms used in the United States (WinID3) with a simplified coding format that utilizes an optimized sorting algorithm. The simplified system consists of seven basic codes and utilizes an optimized algorithm based largely on the percentage of matches. To perform this research, a large reference database of approximately 50,000 antemortem and postmortem records was created. For most disaster scenarios, the proposed simplified codes, paired with the optimized algorithm, performed better than WinID3 which uses more complex codes. The detailed coding system does show better performance with extremely large numbers of records and/or significant body fragmentation.     

Dental anesthetic death. An unusual autoerotic episode

The details of an unusual autoerotic death are presented; the postulated method of induction of cerebral hypoxia was inhalation of nitrous oxide from a dental anesthetic machine; the theme of dental anesthesia, presumably an elaborate bondage fetish, recurred in documentary material found at the scene.     

Dental identification using digital images via computer network

Dental identification is a useful scientific method. In Japan, however, there are only a few forensic odontologists; moreover, until now, forensic dental services have only been offered by general dentists. These dentists may not be able to offer such forensic services during office time. For a quick comparison, the authors tried sending digital photos, taken with a 2-million-pixel digital camera, to dental offices via the Internet. If a dental office has Internet access, it is possible for dental charting to be sent directly to the autopsy room. Of course, digital images only provide the first outline. However, when antemortem dental records of the person in question are available at autopsy, a quick comparison can be made.     

The Value of Dental Restorations in Post-mortem Identification

Although identification by means of teeth has been established for many years, opinion is divided on the optimum number of points of similarity required for positive identification. In the present survey it was found that for an average subject only nine points of identification were available in respect of dental restorations. The findings in the survey were applied to an advertised charting of an unidentified body and the results discussed. The number of necessary points of similarity required could be as few as six. As the number of restorations in teeth is likely to decrease, the present requirements of the National Health Service in respect of dental records should be revised.     

Dental Stones for Casting Depressed Shoemarks and Tyremarks

Five dental stones were evaluated in the laboratory and in field trials. Three of these were found to be better than plasters for casting. They gave good detail and were less critical of water to powder ratio. The casts were strong, and, especially if treated with potassium sulphate, they could be easily cleaned, even with brushing in running water. A novel method of mixing, by kneading in 200 gauge plastic bags, was tried and found to be easier than conventional methods.