Reidar F. Sognnaes

Differences among tetracyclines with respect to the staining of teeth

Reports are coming out regularly to warn the medical and dental professions about tooth discoloration, which may be caused by the tetracyclines in antibiotic doses administered to growing children. 1–3 Tetracycline enters the developing tooth substance roughly in proportion to crystal surface area, rather than to calcium content of the tissues. 4 In therapeutic dosages this does not necessarily lead to inferior calcification of the teeth, though concomitant disease may. 4 However, upon eruption into the mouth, the teeth first show yellow fluorescence, then become yellow in ordinary light and, later, with aging, may turn brown and unattractive to the naked eye. 5–6 It appears that these undesirable esthetic effects on tooth color differs among the several tetracycline derivatives, and an important task remains to measure it. This communication demonstrates the character and amount of discoloration in rabbit incisors after injection of the different tetracyclines.

The odontological identification of Adolf Hitler: Definitive documentation by X-rays, interrogations and autopsy findings

A definitive odontological identification of Hitler has been based on several sources of documentary evidence: (1) complete testimonies recorded by American intelligence officers during the 1945 interrogations of Hitlers dentist and physicians; (2) attached to one of the above mentioned reports five head X-ray plates taken in 1944 following an assassination attempt and revealing several very characteristic dental conditions, including (a) a maxillary left central incisor with a radiopaque (metallic) restoration and with a radiolucent zone typical of a so-called »Window Crown», (b) a special dental bridge construction in the right mandibular area, in which a radiopaque (metallic) restoration on the right canine is connected by means of a metallic lingual bar to the second premolar with a cantilever extension to replace the first molar, and (c) periodontal bone breakdown around the mandibular incisor roots; (3) the above observations were compared with the various dental features depicted in the Russian au...

Biomedical Image Processing for Age Measurements of Intact Teeth

With increasing age the roots of teeth undergo sclerosis. The degree of dental root sclerosis can be demonstrated visually if light is transmitted through the specimen. However, this resultant image is only a two-dimensional (2-D) visualization which misrepresents what in truth is a three-dimensional (3-D) characteristic. We have described an image acquisition and computer processing system for imaging intact teeth, with special reference to the root transparency, which tends to progress from the root apex towards the neck of the teeth as a function of age. The components of our system involve: an energy source with light transmission through table-mounted dental specimens; an image processor with a digitizer; a step motor with a holder to rotate the tooth specimen; and a software package to computerize and reconstruct the sectional digital images. After rotating the position of the specimen, while at each rotation obtaining a 2-D image of the sample, we then can reconstruct the true 3-D cross-sectional or longitudinal morphology or both from these 2-D images. With this new approach, the reconstructed dental images represent segments from different angles of the tooth specimen. Picture element values in each image, quantitatively indicate the optical density, expressing the age dependent pattern of the 3-D anatomy in toto.

Unusual three-dimensional bite mark evidence in a homicide case.

A comparison has been made between bite marks observed on the nose of a female homicide victim and the configuration of the dental structures of a male suspect. The victims bite marks showed a number of demonstrable characteristics which could be reproduced by models of the dentition of the suspect. Special peculiarities within and between individual teeth, together with the upper and lower jaw relationship, were demonstrably consistent with the bite mark patterns on the victims nose. Detailed examination of the scientific evidence led the dental investigators to the conclusion that there was a positive match between the suspects dentition and the bite mark on the decedents nose. The dental investigation and subsequent dental testimony were prime factors leading to the defendants conviction of manslaughter in the first case in California involving the major use of bite mark evidence.

Jet-Injection Technique Applied to Preventive Dentistry

A method developed to demonstrate desirable dispersion patterns of jet-injected solutions is presented.

Award for Research in Biological Mineralization

The beauty of pearls, shells, corals and ivory and the pain of gallstones, kidney stones, and pulp stones are but a few illustrations of the wide variety of mineral deposition in living matter (Calcification in Biological Systems, A.A.A.S. Publ. No. 64, Washington D.C., 1960). In this presentation, principal attention was directed toward a comparison between bone and the most highly specialized of the dental hard tissues, namely, the dental enamel, specifically with respect to the unique reactivity of enamel at various stages of mineralization, and especially in regard to the most remarkably reactive of all pertinent elements, namely fluoride. There are three newer sources of information pertinent to this discussion (Science 150:989) 1965). First, it is now evident that, compared to the 1 ppm F required for protection of dental enamel against caries, the intake of fluoride required for skeletal protection against certain metabolic bone diseases needs to be exceedingly high. Second, the blood plasma values of fluoride stay remarkably low (0.2 to 2.0 ppm F) notwithstanding very high elevations in fluoride intake (20 to 200 mg. F per day). Third, the weight of evidence now suggests that cells and organs grown in tissue culture can tolerate fluoride concentrations in the substrate appreciably above those which can be brought into the systemic circulation of man even with very high fluoride intake. As a result of basic biological differences in the behavior of bones and teeth, two somewhat different approaches to the control of bone and tooth destruction appear to emerge, at least as far as fluoride protection is concerned. Because of the lifelong skeletal remodeling, a continuous contact with fluoride seems necessary to protect bone. Indeed, it may well be that adult man may need to ingest more, rather than less daily fluoride than children in order to protect aging bones and blood vessels. In dental structures the situation is somewhat different, not only with respect to cellular and chemical interaction, but also in regard to preventive capabilities.

The present status of caries research

Abstract This article attempts to interpret fundamental caries research in terms of the clinical application to man. A brief survey has been made of the development of various concepts of the etiology of caries in man since the time of W. D. Miller. It is suggested that the prevalence of caries in any single individual may be interpreted as a composite of several modifying influences resulting from genetic, developmental, endocrine, and salivary factors, as well as from oral microorganisms and oral food debris. Because of overlapping of these several influences in each individual patient, an effort should be made to establish which one of these factors may be more prominent in its effect than others. In terms of practical means of prevention, three approaches have been discussed: environmental, developmental, and biochemical. 1.1. Investigations in laboratory animals and in human beings indicate that if the teeth are susceptible to caries, and the teeth of modern man usually are, it is advisable to cut down on the in-between meal consumption of highly sweetened substances, which, in addition to their high sugar content, have a tendency to cling to the teeth and be retained in the mouth for prolonged periods of time. Specific evidence from studies in humans is unfortunately limited to only a few types of sweets. As far as the oral environment is concerned, it appears that only under unusual circumstances has it been possible to influence significantly the metabolism and growth of the oral microorganisms. Studies on oral clearance of various forms of sugar may serve as an index of their caries potentiality until more precise information is available. A simple test for individual variations in the ability to evacuate the mouth merits further study. Also, more attention should be given to oral debris of endogenous origin (fever coating). 2.2. An important facet of the caries problem can be scrutinized and remedied only by going back into the early dietary history of the patient during the period of tooth development. This concept is strengthened by observations on fluoridation which show that the beneficial effect is greatly increased the further back in the developmental history of the individual one goes in starting this dietary supplement. It is thought that the greatest hope for remedying this disease on a large scale in future generations lies in the initiation of preventive procedures which will strengthen the resistance of the teeth themselves to caries. 3.3. The biochemical approach to caries prevention has the advantage that it is immediately applicable in private practice to the extent that our knowledge at any time permits. It is an approach which accepts the existence of all factors which at the moment are thought to favor caries production, namely, the microorganisms, the carbohydrate food substrate, the acid and enzymes, and the inadequately developed teeth. Under these circumstances, this approach should endeavor, first, to block whatever defective pathways to caries already exist in the teeth and, second, to interfere intelligently with whatever initial biochemical changes occur in caries prior to cavity formation. At the moment, the topical application of heavy metals such as silver nitrate and the application of fluorides to tie up with the organic and inorganic components, respectively, are the principal substances at hand. An intensive effort should be made to study further the exact physiologic potentialities of the enamel, its permeability, its ionic exchange with the saliva, and its incipient chemical alterations in the initial caries process. From such studies may come preventive procedures which could be used to the benefit of our individual patient, young and old alike. To explore the basis for individual variations in caries prevalence, projecting the prognosis and planning preventive measures, will require as complete information as possible on each patient. It would be desirable to explore the family history of a patients parents and other relatives; the dietary history of the patient with respect to early life, geographical and national origin, food hibits, and economics; the history of previous illnesses; the patients salivary gland function, hormone balance, etc. In addition to the conventional tests of bacterial flora and carbohydrates in the oral cavity, one would wish to appraise the individual patients capacity for clearing the mouth, and the relative viscosity, sedimentation rate, and flow of saliva. Simple clinical tests for this purpose would be of practical value.

Symposium—Effective Expert Testimony

This symposium was organized, with the help of several academicians who have served as professors of Speech and related Communication Departments at Universities in and around Los Angeles, for a panel discussion held there during the 33rd Annual Meeting of the American Academy of Forensic Sciences, 17–20 Feb. 1981. Serving as moderator under the sponsorship of the AAFSs Odontology Section, the topic of “Effective Expert Testimony” was considered in the following sequence, related to various aspects of court communications: (1) the expert witness and the use of videotape recordings; (2) the role of nonverbal communication in the course of expert testimony; (3) the nature of jury response to the expert witness; (4) the major components of source credibility of the expert witness; and, as a kind of concluding verbal “autopsy” (S) discussion of the legal dimensions and practical court experiences pertinent to effective testimony. Within AAFS the practical applications of forensic sciences have been encouraged by multidisciplinary cooperation, joint sessions, and so forth. Similarly, the basic contribution by academicians within the University family offers promise of a return in forensic science research and education. Not only does that apply to interdisciplinary participation by Schools of Dentistry, Law, Medicine, Public Health, and Social Sciences, but also by academic Campus Divisions dealing with the Humanities, including such Departments as Communication and Speech, as illustrated by the present Symposium on Effective Expert Testimony.

Eva Braun Hitler's Odontological Identification—A Forensic Enigma?

Through generous cooperation by custodians of several museums, libraries, and government archive centers, the author has had occasion to explore various historical dental relics and reports covering the evolution of dental art and science over a period ranging from the time of George Washington to that of Adolf Hitler [1,2].