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Biomedical subjects

T Solheim

Publications and source records attributed to T Solheim.

At least 19 recordsLinked to original sources
PubMed1992

The "Scandinavian Star" ferry disaster 1990--a challenge to forensic odontology.

With 158 victims, the fire on board the "Scandinavian Star" was one of the world's worst ferry disasters. A team of identification experts, including dentists, were employed to secure evidence for identification and to remove the victims from the ferry. Four parallel teams, each with 2 dentists, examined and autopsied the victims at the Institute of Forensic Medicine, University of Oslo. Using the INTERPOL Disaster Victim Identification forms and aided by computers, all victims were identified within 17 days. Dental identity could be established in 107 cases (68%).

Adolescent↗
PubMed1992

Amount of secondary dentin as an indicator of age.

The amount of secondary dentin in a tooth has been used as one of several parameters in methods for age estimation. Dentin deposition has been measured according to various scoring systems, and the Pearson correlation coefficient with age has been found to be approximately 0.6. In the present study of 1000 teeth, molars excluded, secondary dentin was estimated according to three scoring systems. The teeth were prepared according to the half tooth technique. In addition, the area of the coronal pulp and the widths of the root and pulp chamber were measured in a stereomicroscope at the cemento-enamel junction and at three other defined points along the root. The Pearson correlation coefficient between age and secondary dentin varied in different types of teeth. Of the scoring systems, scores according to Johanson were most strongly correlated with age (r = 0.59 to 0.74). Correlation between age and the coronal pulp area varied from -0.47 to -0.72, and the range between age and ratio between pulp- and tooth width at the cemento-enamel junction was from -0.46 to -0.77. Correlations between age and ratio between sum of pulp widths and the sum of tooth widths for all four such measurements ranged from -0.58 to -0.81. Multiple regression analyses showed that by combining several types of measurements, the correlation with age was increased. A tendency was also observed towards reduced speed of secondary dentin formation in the elderly and in women.

Age Determination by Teeth↗
PubMed1992

Recession of periodontal ligament as an indicator of age.

The recession of the periodontal ligament has been used as one of several indicators of age in methods for age estimation. In a sample of 1000 teeth the relationship between age and periodontal recession was studied for each type of tooth. Only a weak correlation was found, the least weak being for premolars. The mean of the periodontal recession measured in mm showed approximately the same correlation as when assessed by scoring systems. Logarithmic transformation of the mean of the recession resulted in a stronger correlation with age. The use of tooth age rather than individual age did not have the same effect. Periodontal recession tended to be more rapid in males than in females. The reason for extraction was not found to be significantly correlated with periodontal recession. In conclusion, periodontal recession was not sufficiently accurate to be used as a sole indicator of age. However, in multiple regression methods for age estimation it might contribute significantly to the age equation, especially for premolars.

Adult↗
PubMed1992

Dental identification after the Dash 7 aircraft accident at Torghatten, Northern Norway, May 6th, 1988.

The accident occurred when a Dash 7 aircraft hit a steep mountain side and fell approximately 70 meters. A fire broke out immediately and all 33 passengers and three crew members perished. Most of the victims were found in or near the wreckage and burnt by the fire. The identifications were carried out by the Norwegian Identification Commission which included four dentists. One dentist, together with a pathologist, co-operated with the police at the site of the accident. All 36 victims were identified and in 32 cases (89%) dental identity was established. This success was mainly due to systematic radiographic recordings of the victims and a comparison with ante-mortem radiographs. The Norwegian computer programme for identification was successfully tested during this investigation.

Accidents, Aviation↗
PubMed1990

Dental cementum apposition as an indicator of age.

The purposes of the present investigation were to examine various ways of measuring cementum thickness, to study its relationship with age, and to consider what contribution this factor might offer in methods for age estimation. The amount of dental cementum apposition was studied in 1000 teeth, excluding molars, from a Caucasian population. Cementum thickness was estimated according to the scoring methods suggested by Gustafson and by Johanson. In addition, the width of the cementum was measured at the apex and also at approximately one third of the root length from the apex. Statistical analyses using the SPSS package in a Cyber computer indicated a symmetric left/right distribution of cementum thickness. The sum of the cementum thickness on vestibular and lingual surfaces, measured at one third of the root length from the apex, showed the strongest correlation with age (r = 0.40 to 0.65). A reduced rate of cementum apposition was observed in the elderly. Also, maxillary teeth had more cementum on the lingual than on the vestibular surfaces. A tendency was noted for less cementum to occur in women than in men and on teeth removed from deceased persons or extracted for pathologic reasons. Correlation coefficients indicated that, for at least some types of teeth, the cementum thickness might give a significant contribution to statistical methods of age assessment.

Age Determination by Teeth↗
PubMed1989

Cellulose fibers from endodontic paper points as an etiological factor in postendodontic periapical granulomas and cysts.

Histological sections of eight periapical granulomas and cysts developing after conventional endodontic therapy and displaying faintly hematoxylinophilic, birefringent foreign bodies were investigated by light and polarization microscopy, scanning electron microscopy, energy-dispersive X-ray, and chemical analysis. In addition to a variably dense mononuclear infiltrate, the granulomas and cysts revealed varying amounts of giant cells associated with the birefringent foreign bodies. These structures were identified as cellulose fibers, most probably originating from endodontic paper points, which in our opinion can be held responsible for the initiation and perpetuation of chronic postendodontic periapical lesions.

Cysts↗
PubMed1989

Fluorescence from dentin and cementum in human mandibular second premolars and its relation to age.

Investigations were carried out to study the fluorescent properties of human dentin and cementum and their relation to age. One hundred mandibular second premolars were ground according to the "half tooth" technique. The intensity of the red fluorescence was measured during illumination of dentin and cementum with a green light. The results were analyzed with the use of the SPSS. The intensity of the fluorescent light recorded from cementum was stronger than that recorded from dentin. A paired t-test showed no statistically significant left/right difference in fluorescence. Pearson's correlation coefficient indicated a strong relationship between age and fluorescence from dentin (r = 0.73) and from cementum (r = 0.77). The sex of the individual had no significant influence on the fluorescence. Teeth removed from decreased individuals emitted fluorescence with a slightly stronger intensity than did teeth extracted from living patients. Regression analysis indicated a linear relationship between age and the fluorescence from either dentin or cementum. There was a strong correlation between the intensity of the fluorescence and color estimates from the same teeth and the partial correlation coefficient was still statistically significant when controlling for the effect of age.

Adult↗
PubMed1989

Dental root translucency as an indicator of age.

The apical translucent zone was studied in 1000 human teeth. For each type of tooth, excluding molars, the size of the apical translucency was estimated according to the scoring methods of Gustafson (1), Dalitz (2) & Johanson (3). The lengths of the translucent zones were measured on moist and then on dry teeth, both unsectioned and sectioned, while the areas were measured on dry sectioned teeth only. Statistical analyses using the SPSS package in a Cyber computer indicated a symmetric distribution of the translucent zone in left and right teeth. The extent of the translucency showed little variation from one type of tooth to another. The length of the translucent zone measured on unsectioned teeth demonstrated in most types the closest relation to age. Multiple regression analyses, including more than one method of measuring the size of the translucent zone, resulted in formulas showing a high correlation with age (from 0.68 to 0.86). Slightly larger translucent areas were found in teeth from males, in darker teeth and in teeth with increased thickness of the cementum. The increase in the translucent zone with advancing age was found to be almost linear and was not affected by periodontal destruction.

Age Determination by Teeth↗
PubMed1989

[The occurrence of denticles in the craniums of Norwegian Samis (Lapps)].

The purpose of the present radiologic study was to establish prevalence and distribution of pulp stones in mandibular premolars and molars in skulls of Norwegian Samis. The results were compared to those of previous investigations of ancient Eskimos, medieval Norsemen from Greenland, Danish Stone Age People and ancient Nubians. Forty-eight dentitions were radiographed and pulp stones recorded according to number and location within the teeth. Twenty-six percent of the Samis exhibited pulp stones. Molars showed a significantly higher prevalence of pulp stones than did premolars. The giant pulp calcifications described previously were limited to first and second molars. Pulp stones were located in pulp chambers only. Symmetric occurrence of pulp stones was common in contralateral teeth. Further epidemiologic studies of pulp stones in ethnic groups are needed.

Dental Pulp Calcification↗
PubMed1989

[The airplane accident in Torghatten on May 6, 1988].

On May 6th, 1988, a Dash 7 airplane crashed into the mountain of Torghatten, near Brønnøy-sund in northern Norway. All 33 passengers and the three crew members were killed. The National Identification Commission, including a forensic dentist, was at the disaster site twelve hours later. A dentist and a forensic pathologist worked with the police at the site until all the victims had been found. Three other dentists were responsible for collecting antemortem material and for the postmortem examination of all victims. 32 of the victims, or 89%, could be identified by dental means alone; a higher percentage than ever before reported. The final meeting of the Identification Commission took place five days after the disaster. All the victims were identified on the basis of technical, medical, and dental evidence, and the report signed by each of the three specialist groups. The quality of the dental records was evaluated with respect to requirements set up by the Ministry of Social Affairs in 1983. Dental records had improved since the "Alexander Kielland" disaster in 1980. However, only five of the missing persons had full mouth intraoral radiography, only nine records met the requirements for general information about the patient (birth date and identification number, home and business address, etc), only three had information about earlier diseases, and none had recorded previous dental restorations. Diagnoses were given only for nine persons. The records showed that 21 of the victims had not received any prophylactic treatment.

Dental Records↗
PubMed1989

Age assessment based on translucent dentine.

The purpose of this investigation was to examine the relationship between age and the area of translucent dentine (TA) at root apex, and to compare these findings with those obtained by using the methods of Bang & Ramm and of Johanson. The material consisted of 500 teeth, 50 of each tooth type, molars excluded. For statistical analyses an XT microcomputer and SPSS/PC regression programme were used. The correlation between age and ATD varied from 0.83 to 0.57 for different types of teeth. In stepwide multiple regression analyses ATD was preferred to other types of measurement of the translucency. The factors (ATD) and sex contributed significantly to the regression for some types of teeth. Regression analyses using several factors according to Johanson's method resulted in a stronger correlation for most teeth, while the method of Bang & Ramm resulted in a weaker correlation except in the case of mandibular first premolars.

Age Determination by Teeth↗
PubMed1987

Identification of cellulose fibers in oral biopsies.

Oral biopsies comprising five periapical cysts, three cases of exuberant granulation tissue in extraction sockets and one case of a mandibular radiopaque structure, all displaying material consistent with cellulose fibers on routine histologic examination, were subjected to histochemical, polarization, fluorescence and scanning electron microscopical, energy dispersive X-ray and chemical investigations. Routine screening of periapical lesions with polarization microscopy and identification of possible cellulose fibers with Calcofluor White is advocated. Further, attention is drawn to endodontic paper point material as an etiologic factor in postendodontic periapical inflammatory processes.

Adolescent↗
PubMed1977

[Permanent identification team of the central criminal police bureau and its requirements for dentists].

The Norwegian Department of Justice has by Order in Council in 1975 established an identification team under the jurisdiction of the Central Criminal Police Bureau. The team has four members: two police officers, one expert in forensic medicin and one in forensic dentistry. Deputy members of the team are also appointed and those for forensic medicine and forensic dentistry are residents of the three largest cities of Norway, viz. Oslo, Bergen and Trondheim. The responsibility of the team is to identify victims of mass disasters, and to assist in other difficult identifications both in Norway and in foreign countries when Norwegian interests are involved. Each member of the team shall sign the identification report and will thus have a veto in uncertain cases. Consquently the dentist in the team must also evaluate the entire material in each case. For identification purposes, the dentists are urged to comply with some requirements as to dental charts, radiographs and treatment. Each patient must have a clear and readable dental chart containing his name, address and date of birth. Dental characteristics should be noted. Radiographic status should be made of the teeth of regular patients and of special teeth when extensive treatment is required. The radiograms must be kept in file and identified by the name of the patient and the date of exposure. Patients wearing dental prosthesis should be offered denture marking, and the dentures should be recorded in detail on the chart. For flying personell radiographic status is regarded mandatory, and recording of all resotrations are recommended. The aviation company should be informed of the name of the dentists of their crew. Wehn a dentist is asked for assistance in an identification case, the original dental chart, all radiograms models etc. are requested to be delivered. Additions or explantations may also be valuable.

Dental Records↗
PubMed1975

Scanning electron microscopy in the investigation of bite marks in foodstuffs.

The purpose of the present study was to assess the value of utilizing SEM in the examination of bite marks in foodstuffs. Six students, whose front teeth showed no conspicuous irregularities, were asked to bite off a part of some selected foodstuff consisting of butter, cheese, Norwegian brown sweet cheese, apples, carrots, bananas, chocolate and chewing gum. The texture and the varying stickiness of the foodstuffs seemed to be of significance as far as the details of the bite marks were concerned. In butter, chewing gum and Norwegian brown sweet cheese, fine details were discerned, thus justifying the use of SEM. Both scratch marks of the front teeth and impression marks of the incisal edges were studied. Only the latter revealed details of value for the identification by means of the SEM. Often small enamel defects were found at the incisal edge of the front teeth. These defects showed a great number of individually characteristic details. Where dentin was exposed at the incisal edge, further characteristic details could also be found. Thus, the use of SEM seemed to be of value in special cases as a supplement to conventional investigation methods.

Bites, Human↗