Biomedical subjects
Publications and source records attributed to T Solheim.
Cemento-ossifying fibromas are slow growing, benign lesions. Recurrence is considered rare. A mandibular periapical radiolucent lesion in a 30-year-old female was diagnosed histologically as a cemento-ossifying fibroma and excised. A recurrence was found 2 years and 6 months postoperatively. CT demonstrated that the recurrent lesion was larger than indicated by conventional radiography.
BACKGROUND: We have several times experienced that Crohn's disease has not been diagnosed until several years after the start of oral symptoms. This article presents some patients with oral manifestations of Crohn's disease, as a contribution to more awareness of this possibility. MATERIAL AND METHODS: Clinical and histological data from four patients are presented. RESULTS: All patients had granulomatous inflammation of the oral mucosa. In three patients, the disease started in the mouth. The diagnosis of intestinal Crohn's disease was made from some months up to seven years later. In one patient, no granuloma was found in the intestinal tract, but the patient had intestinal symptoms. Two patients experienced disappointments in their contacts with the local health care system, with considerable delay in diagnosis. INTERPRETATION: We interpret these cases as evidence that a greater awareness of the possibility of Crohn's disease in the oral cavity may lead to a quicker diagnosis, earlier correct treatment, and less patient worry caused by uncertainty.
In a recent court case, a comparison was made between an impression of marks left in cheese at a murder scene and a set of study models of one of the suspects. The court was reluctant to accept the validity of the pattern-associated comparison that was used in the identification. This study compared marks made in cheese, butter and cooked potato with study models taken from volunteers. Pattern-associated comparison was the method used. Eighty pair-wise comparisons were made by two odontologists. The examiners correctly identified all the true matches from among the eighty comparisons as well as selecting the dental models for which there were no corresponding silicone impressions. In the absence of identifiable fingerprints or DNA samples, the method can be employed for matching left in foodstuffs to the dentitions of suspects.
Measurements of age-related changes in dental tissues are often used when estimating the age of an individual. With the new technology now available, the methods of measurement might be standardized and reproducible. The purpose of the present study was to compare the reliability of manual and computer-assisted measurements of morphological parameters in dental radiographs. Manual measurements were made conventionally using a pair of vernier callipers and a stereomicroscope with a measuring eyepiece. An image analysis software program was employed for the computer assisted measurements. Lengths and widths of tooth and pulp were measured both manually and with computer assistance on periapical radiographs from 40 patients, six teeth in each patient. Statistical analyses showed no significant intra- or inter-observer differences for the manual measurements. Statistically significant intra- and inter-observer differences were, however, found between the manual and computer-assisted measurements. The results implied that, despite advanced technology, conventional methods may be better suited for measuring linear morphological parameters in dental tissue.
The clinical, radiological, histopathological and immunohistochemical (cytokeratin) features of two cases of glandular odontogenic cyst (GOC) are presented and discussed in a review of 45 cases of GOC hitherto reported. Of cases with available information, 34 occurred in the mandible and 6 in the maxilla; the male:female ratio was 19:28, and the mean age was 46.7 years in males and 50.0 years in females. Six cysts recurred once after 2-8 years (mean 2 years 8 months) and 2 (5.3%) recurred twice after 2 and 5 years and after 3 and 5 years, respectively, giving a rate of recurrence of 21%. The identification of osteodentin in one of the present cases and the co-expression of cytokeratins (CK) 13, 19 and 8 strongly support the concept of odontogenic differentiation in the GOC. Careful surgical removal of the lesion succeeded by a 5-year follow-up period is recommended.
Accurate estimation of human adult age has always been a problem for anthropologists, archaeologists and forensic scientists. The main factor contributing to the difficulties is the high variability of physiological age indicators. However, confounding this variability in many age estimation applications is a systematic tendency for age estimates, regardless of physiological indicator employed, to assign ages which are too high for young individuals, and too low for older individuals. This paper shows that at least part of this error is the inevitable consequence of the statistical procedures used to extract an estimate of age from age indicators, and that the magnitude of the error is inversely related to how well an age indicator is correlated with age. The use of classical calibration over inverse calibration is recommended for age estimation.
Dental coding systems have hitherto been developed mainly to record treatment. The present hierarchical system was specially designed for computer aided dental identification and has been tested for 15 years in the Norwegian register of missing persons. It is in addition well suited for rapid and exact reporting of dental findings in identification cases. The system has also been proposed for adoption by Interpol.
Apposition of cementum occurs in phases resulting in two types of layers with different optical and staining properties that can be observed by light microscopy. Narrow, dark staining incremental lines are separated by wider bands of pale staining cementum. The distance from one line to the next represents a yearly increment deposit of cementum in many mammals, and counting these lines has been used routinely to estimate the age of the animals. Incremental lines in cementum have also been observed in sections of human teeth, and the object of the present investigation was to examine a number of methods for preparing and staining them for counting. Longitudinal and transverse sections, either ground or decalcified, were cut from formalin fixed human dental roots, paraffin embedded or frozen, and stained using several techniques. The cementum was investigated using conventional light, fluorescence, polarized light, confocal laser scanning, interference contrast, phase contrast, and scanning electron microscopy. Incremental lines in the cementum could be observed in ground sections and, following decalcification, in both frozen and paraffin embedded sections. Toluidine blue, cresyl violet, hematoxylin, or periodic acid Schiff (PAS) stained incremental lines allowing differentiation by conventional light microscopy. Contrast was best using fluorescence microscopy and excitation by green light since the stained cemental bands, but not the incremental lines, fluoresced after staining with cresyl violet, PAS or hematoxylin and eosin. The results with other microscopic techniques were unsatisfactory. Since incremental lines are not destroyed by acids and stain differently than the remaining cementum, it is likely that they possess an organic structure which differs from the cementum. Incremental lines in human dental cementum could be observed best using decalcified sections stained with cresyl violet excited by green light.
Much of the data which appears in the forensic and archaeological literature is ordinal or categorical. This is particularly true of the age related indicators presented by Gustafson in his method of human adult age estimation using the structural changes in human teeth. This technique is still being modified and elaborated. However, the statistical methods of regression analysis employed by Gustafson and others are not particularly appropriate to this type of data, but are still employed because alternatives have not yet been explored. This paper presents a novel approach based upon the application of Bayes' theorem to ordinal and categorical data, which overcomes many of the problems associated with regression analysis.
Previous studies have shown that with advancing age the size of the dental pulp cavity is reduced as a result of secondary dentine deposit, so that measurements of this reduction can be used as an indicator of age. The aim of the present study was to find a method which could be used to estimate the chronological age of an adult from measurements of the size of the pulp on full mouth dental radiographs. The material consisted of periapical radiographs from 100 dental patients who had attended the clinics of the Dental Faculty in Oslo. The radiographs of six types of teeth from each jaw were measured: maxillary central and lateral incisors and second premolars, and mandibular lateral incisors, canines and first premolars. To compensate for differences in magnification and angulation on the radiographs, the following ratios were calculated: pulp/root length, pulp/tooth length, tooth/root length and pulp/root width at three different levels. Statistical analyses showed that Pearson's correlation coefficient between age and the different ratios for each type of tooth was significant, except for the ratio between tooth and root length, which was, therefore, excluded from further analysis. Principal component analyses were performed on all ratios, followed by regression analyses with age as dependent variable and the principal components as independent variables. The principal component analyses showed that only the two first of them had significant influence on age, and a good and easily calculated approximation to the first component was found to be the mean of all the ratios. A good approximation to the second principal component was found to be the difference between the mean of two width ratios and the mean of two length ratios, and these approximations of the first and second principal components were chosen as predictors in regression analyses with age as the dependent variable. The coefficient of determination (r2) for the estimation was strongest when the ratios of the six teeth were included (r2 = 0.76) and weakest when measurements from the mandibular canines alone were included (r2 = 0.56). Measurement on dental radiographs may be a non-invasive technique for estimating the age of adults, both living and dead, in forensic work and in archaeological studies, but the method ought to be tested on an independent sample.
The main problems using plasma-sprayed hydroxyapatite (HA) as a coating material on metallic implants are its porosity, low fatigue strength, and weak adherence to the metallic substrate. To overcome these problems a new technique using hot isostatic pressing (HIP) has been developed for producing HA-coated titanium (Ti) implants. Specimens produced at a maximum temperature of 850 degrees C and a maximum pressure of 720 bar displayed a dense, glassy, 25-microns thick coating with small amounts of porosity and a mean surface roughness of 0.7 microns, as compared with 1.6 microns for sandblasted Ti. Twenty conical HA-coated (720 and 100 bar pressure) and 10 noncoated Ti implants were inserted through the cortex of the lower margin of the mandibles of sheep and allowed to heal for 60 days. Push-out tests for implants processed at 720 bar pressure showed substantially higher bone/implant bonding values than for sandblasted Ti implants. Histological studies indicated a direct contact and probably chemical bonding between bone tissue and the HA coatings. The area of contact was almost 3 times as large as for the Ti implants. The adherence of the 100-bar coating to the Ti surface was inferior to the 720-bar coating, as shown by the loosening of the coatings in several areas.
A retrospective study was performed to analyse the power of odontological evidence in burn victims. The material comprised 292 single fire cases registered at 4 centers of forensic odontology in Scandinavia (DK: Aarhus, Copenhagen; N: Oslo; S: Goteborg) covering a 10-year period. Filed antemortem (am) and postmortem (pm) data were critically reviewed and registered. New systems for classification of the degree of injuries to the teeth and jaws and of the quality of dental records were developed. Matching dental am-pm units/features were recorded using the tooth as unit. Units were scored as either ordinary or extraordinary if the frequency of occurrence in a Danish reference population was > or = 10% or < 10%, respectively. The ID conclusion of a single case was classified into one of the categories: no conclusion, ID possible, ID probable or ID established, depending on the number of ordinary/extraordinary matching units. All age groups were represented. Most fatal burns occurred in house fires (62%) and there was a preponderance of males (71%). Detailed written records supplied by single or by systematic radiographs were available in 71% of cases. About 50% of burn victims were classified into the no-injury group and approximately 25% of cases showed injuries to the anterior teeth only. The number and complexity of dental restorations increased with age. The dental examination was a powerful tool in identification of burn victims. Thus, dental identity (ID) was established in 61% of burn victims and dental evidence assisted the identification in another 31% (ID possible 19%; ID probable 12%).(ABSTRACT TRUNCATED AT 250 WORDS)
Inter-observer variations in the registration of dental age-related characteristics have not previously been studied. Examination and registration were made by 6 dentists with varying experience in age estimation. A total of 13 age-related dental characteristics in 30 teeth extracted from adults were assessed macroscopically, by stereomicroscope and from radiographs. The measurements were analysed in a microcomputer, using the SPSS/PC+ statistical package. The results showed that, except for the score on surface roughness, significant differences were found between some of the observers for all types of measurements, when a paired t-test analysis was made. The correlation coefficients between the observers varied and were rather weak for the surface roughness score. The study revealed systematic differences among the observers as well as differences in interpreting the definitions of the scores for the different parameters. Thus age estimation using statistical methods is seen to be dependent upon the experience of the individual observer and interpretation. Care should therefore be taken not to rely too much upon the results of an odontological age estimation. The possible implications of these results for forensic work are also discussed.
Counting incremental lines in dental cementum is an accepted method for estimating age in many wild mammals. In human teeth such countings have given variable results, and the aim of the present investigation was to find out if one incremental line is formed per year in human teeth as well. Canines and single-rooted premolars were demineralized, paraffin wax-embedded, sectioned and stained, and the sections were viewed in a fluorescence microscope. Non-fluorescent lines, seen against a fluorescent background, were either counted directly or their number calculated by counting only some of them and computing this on the total width of the cementum. The correlation coefficient between tooth age and the number of lines for the whole material was = 0.84 when counted and = 0.73 when calculated. This coefficient was stronger in mandibular second premolars but lower in teeth extracted because of dental diseases. The coefficient was only significant in teeth from individuals below the age of 50 yr. The regression formula with tooth age as dependent variable indicated that only incremental lines formed in about every other year stained sufficiently to be counted.
Peritubular dentine is a mineralised deposit formed centripetally in the dentine tubules with advancing age, so that the tubular diameter is smaller in teeth from older persons. The aim of the present study was to investigate the relationship between age in humans and the amount of peritubular dentine and the extent of the consequent obliteration of the tubules, and to find out whether this relationship was strong enough to be used as a parameter for age estimation. Fifty mandibular central and lateral human incisors were ground on the lingual aspect of the root and examined in a scanning electron microscope (SEM). The number of open tubules was counted and the diameter of the tubules measured both before and after etching with 35% orthophosphoric acid. The difference in the number of tubules in unetched and etched specimens was taken to be the number of occluded tubules, and the difference in radii before and after etching to be the thickness of peritubular dentine. The results did not demonstrate a significant relationship between age and the reduction in the number of tubules. One explanation might be that a certain age has to be reached before obliterated dentine tubules can be observed. The correlation between age and the thickness of peritubular dentine was not significant in teeth extracted because of periodontal disease, so these teeth were excluded from the regression analysis with age as the dependent variable.(ABSTRACT TRUNCATED AT 250 WORDS)
Dental radiographs have rarely been used in dental age estimation methods for adults and the aim of this investigation was to derive formulae for age calculation based on measurements of teeth and their radiographs. Age-related changes were studied in 452 extracted, unsectioned incisors, canines and premolars. The length of the apical translucent zone and extent of the periodontal retraction were measured on the teeth while the pulp length and width as well as root length and width were measured on the radiographs and the ratios between the root and pulp measurements calculated. For all types of teeth significant, negative Pearson's correlation coefficients were found between age and the ratios between the pulp and the root width. In this study also, the correlation between age and the length of the apical translucent zone was weaker than expected. The periodontal retraction was significantly correlated with age in maxillary premolars alone. Multiple regression analyses showed inclusion of the ratio between the measurements of the pulp and the root on the radiographs for all teeth; the length of the apical translucency in five types; and periodontal retraction in only three types of teeth. The correlation coefficients ranged from r = 0.48 to r = 0.90 between the chronological and the calculated age using the formulae from this multiple regression study. The strongest coefficients were for premolars. These formulae may be recommended for use in odontological age estimations in forensic and archaeological cases where teeth are loose or can be extracted and where it is important that the teeth are not sectioned.
Oral hairy leukoplakia appears as white vertical stripes on the lateral borders of the tongue and occurs almost exclusively in HIV infected patients. The clinical appearance of hairiness is a result of emergence of floss of the parakeratinized epithelial surface. The etiologic agent seems to be Epstein-Barr virus, which may be diagnosed by in situ hybridization on tissue sections. Illustrations are shown from the case of a 30 year-old man. Approximately 25-30% of HIV positive patients have been reported to be affected by oral hairy leukoplakia. Although not causing any pain or discomfort the lesion is of clinical importance, since it may be the first sign of the development of AIDS. Moreover, for some patients who do not know their HIV infection status it may be the first sign of infection, and should alert the physician to the need to HIV test the patient.
A case is described where the identity of an unknown body was established several years after death and despite the fact that the body was found in a foreign country. This was made possible due to the established Interpol routines and the good cooperation between the authorities involved in the Scandinavian countries. A significant role was also played by a computerized register with antemortem dental findings of missing Swedish citizens.