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Biomedical subjects

T Solheim

Publications and source records attributed to T Solheim.

54 records · Page 3Linked to original sources

Implant-tissue interface of endosseous dental implants in dogs. validity of clinical evaluation methods.

Plaque and gingival bleeding were scored and probing, radiography, and histologic methods were used to evaluate clinical methods for estimating alterations of supporting structures at functioning endosseous dental implants. Twelve implant abutment posts in three Labrador retriever dogs were assessed. The observation period was 3 months of submerged healing followed by 6 months in function. In the presence of daily gingival cleaning, both plaque and gingival bleeding scores were reduced on implant abutments. No correlation was found between gingival scores and the degree of bone resorption. The correlation between probing and radiographic measurements was studied by comparing 136 parallel measurements. The average difference was 0.4 mm. Discrepancies were observed when evaluating bone loss that reached the shoulder area. Better accordance was obtained when moderate (2 to 4 mm) or extensive (6 to 8 mm) resorption was assessed. Histologic evaluation indicated alternating regions of implant-bone contact and fibrous encapsulation. Progressive infiltrates were observed in the permucosal area, sometimes extending into the deeper parts of the supporting bone. A combination of probing and radiographic measurements seems to give the most reliable information about the level of bone support and is recommended to be included in routine control of implant abutments.

Alveolar Process↗

Dental features in congenital persistent renal tubular acidosis of proximal type.

The dental features in a hitherto unknown type of renal tubular acidosis (capillary blood pH 7.07-7.15) of proximal type are reported. The patient presented agenesis of three second premolars, delayed development and eruption of permanent teeth, delayed shedding of the primary dentition and severe enamel hypoplasia of the permanent teeth. Apart from exceptionally thin enamel, histologic, fluorescent and polarization microscopic and microradiographic investigation of three primary teeth did not reveal unusual findings. The changes are most probably due to a generalized, acidosis-induced defect in several highly differentiated ectodermal tissues.

Acidosis, Renal Tubular↗

Dental age estimation. An alternative technique for tooth sectioning.

An alternative technique for sectioning teeth for age estimation, the half tooth technique, is presented. In a sample of 10 pairs of contralateral teeth, the measurements and calculated age obtained with this technique were compared with those obtained by the conventional thin section technique. Age calculations were performed according to the methods of Bang and Ramm , Dalitz , Johanson, and Miles. The half tooth technique was easy to perform and the cut surface produced was found to be suitable for measurements of the factors used in age calculations. Although a tendency for higher measurements was found using the half tooth technique, the difference was not significant for any type of measurement (P greater than 0.05). A significantly higher age from the half teeth was found when calculated by the method of Bang and Ramm , but this seems to be based on an inaccuracy in their method. Therefore, the methods used for calculating the age based on thin sections can be applied successfully to the half tooth technique.

Adult↗

International disaster identification report. Investigative and dental aspects.

This meeting, held in October 1980 in Apeldoorn, Netherlands, was a very serious effort to begin international cooperation in a much needed area: disaster investigation and identification. Under the leadership of Col. Arie van den Bos of the Royal Police of the Netherlands, the work was accomplished with representatives and observers from many major countries represented. Efforts were made to solve the enigma of international cooperation. A plane crash of an airline of a major country in a distant country can be properly investigated only with the cooperation of the carrier and the country in which the tragedy occurred. The International Academy of Legal Medicine and Social Medicine devoted a 3-day program to the study of this problem during their last international meeting in Lyon, France, and it will be discussed further in Vienna in 1982 under the leadership of Prof. Wilhelm Holczabek. The experience of Norwegian investigators is mentioned as an example of the type of problems encountered with foreign nationals involved in a crash in the country, or a disaster involving a ship or a oil platform where foreign nationals are working, or in a tragedy such as the propylene explosion in Tarragona, Spain, which resulted in more than 200 tourists from many countries dying in the fire, many bodies burned beyond recognition.

Congresses as Topic↗

The dental X-ray file of crew members in the Scandinavian Airlines System (SAS).

In 1977, the Scandinavian Airlines System (SAS) established a dental X-ray file of all crew members. Its aim was to have immediately available an adequate set of physical antemortem data useful for identification in case of a fatal crash. Recently, an investigation into the quality and suitability of this material was carried out. The radiographs of 100 Danish, 100 Norwegian, and 100 Swedish pilots were picked at random and evaluated for formal deficiences, technical deficiencies, treatment pattern as useful for identification purposes, and the presence of pathology. The major results of the investigation were that a number of formal and technical deficiencies were disclosed, that the treatment pattern would seem adequate for identification purposes, and that a number of pathological findings were made, several of which had to be considered possible safety risks in the form of barodontalgia.

Adult↗

Unusual dental forensic cases in Norway.

Two forensic dental cases from Norway are presented. The first case, in which a body was found on the seabed, illustrates that identification may give rise to suspicion of murder. In this case, the suspicion proved to be justified. The Scandinavian identification forms are presented. The second case is unusual in that tooth marks in bottle caps linked a burglar to the scene of the crime. Tooth marks for comparison were found in a police car where the suspect had opened a soft-drink bottle with his teeth. Comparison microscopy was used.

Adult↗

[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↗

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↗

Methylmethacrylate screw implants--radiographic, histological and fluorescence microscopic investigations in dogs.

Twenty-one methylmethacrylate screw implants were inserted in the jaws of three Labrador dogs. Clinical, radiographic, microscopic and fluorescence microscopic examinations were performed. Direct bone-implant contact was found in all firm implants, and the density of the alveolar bone increased towards the screw surface. In these areas no fibrous tissue was found between bone and implant. Horizontal fibres at the junction between the head and the neck of the implant seem to have impeded downgrowth of subepithelial granulation tissue.

Animals↗

Dental age estimation of Norwegian adults--a comparison of different methods.

Age estimations were performed on 100 teeth according to the methods of Bang and Ramm (unsectioned and sectioned teeth), Miles, Johanson, and Dalitz, and in addition by visual examination of the unsectioned teeth. Mean error as well as standard and mean deviations were calculated. The method of Johanson was found to be slightly more reliable than the others. Visual estimation was also in some respects better than the other three methods. All methods resulted in the largest number of overestimates in teeth from persons below 40 years, from males, from the maxilla, and in teeth removed from corpses. Underestimates were predominant in teeth from persons above 50 years.

Adult↗

A new system for computer aided dental identification in mass disasters.

In recent years, several computer programs for dental identification in mass disasters have been developed. Unfortunately, it may be difficult to get access to such programs. The Norwegian police presently utilizes a text retrieval program, NOVA*STATUS, for detection work. This program is based on the British STATUS ONE program, and it enables the user to find from a large pool of postmortem dental registration one or several sets containing specific information about one tooth or several teeth. The complete relevant set(s) can be displayed for visual examination and comparison. A coding system for dental information has been developed as well as a system for interrogating the computer. This system and its efficiency have been tested on a simulated small scale disaster where various well-known difficulties in dental identification were included.

Computers↗

Hot isostatic pressing-processed hydroxyapatite-coated titanium implants: light microscopic and scanning electron microscopy investigations.

Hot isostatic pressing (HIP) was used in a new procedure to produce hydroxyapatite (HA) coatings on a commercially pure titanium (cpTi) substrate for osseous implantation. Eighteen HIP-processed HA-coated implants were placed in the inferior border of the mandibles in 2 Labrador retriever dogs and left submerged for 3 months. As control specimens, 12 sandblasted cpTi implants were placed in the same mandibles and, to compare the bone reaction, 2 additional plasma-sprayed HA-coated implants (Integral) were placed. Tissue reactions at the bony interfaces of the implants were studied in ground sections with the implants in situ, using ordinary, fluorescent, and polarized light microscopy and scanning electron microscopy (SEM). The HIP-processed HA coatings displayed an increased density in light microscopy and SEM as compared to plasma-sprayed coatings. Direct bone-implant contact was found in all 3 types of surfaces. However, the production of new bone was far more abundant for the HA-coated implants than for sandblasted cpTi implants. The presence of bone-forming and bone-resorbing cells indicated active bone remodeling in the interface area at 3 months after implant placement. The present results support the view that epitaxial bone growth may occur from the HA-coated implant surface. It was concluded that the increased density of the present HIP-processed HA material does not reduce the bioactive properties of the coatings.

Animals↗