Occurrence and distribution of blackish staining on the crowns of human teeth obtained from an archeological excavation of a medieval site in Norway.

An excavation in Trondheim, Norway, in 1984-85, uncovered a part of the medieval (1100-1600) cemetery of St Olav's Church. Of 388 excavated skeletons, 248 had skulls where the condition of the jaws and teeth allowed examination. In 51 of these skulls the teeth exhibited a characteristic blackish staining. A higher percentage of affected skulls was found in areas with organic, woodchip layers than in areas with gravelly sand. Affected skulls tended to have a high percentage of their teeth stained, but the staining tended to be restricted to only one or two of the three tooth surfaces scored. Posterior teeth were more often affected than anterior teeth, the occlusal/incisal part more often than the cervical part, and the buccal/labial part more often than the lingual part. Nonerupted third molars could also be stained. Staining seemed to be hampered by calculus. Occurrence of staining was independent of the presence or absence of a coffin and of coffin type. The extent of staining (% of stained surfaces within a dentition) was independent of sex and age. High correlation was found between all four jaw quadrants. There was no independence between color of the jawbone and occurrence of stained teeth. It was concluded that the staining phenomenon probably can be ascribed to factors in the soil. In vivo predisposing influences cannot be excluded.

Validity of the radiographic assessment of ankylosis. Evaluation of long-term reactions in 10 monkey incisors.

The accuracy and sensitivity of radiographic assessments of reactive processes in dental tissues were evaluated by comparison of radiographs and histologic sections. Experimental lesions inflicted on the roots of 10 monkey incisors had been observed by means of serially obtained radiographs over a period of 315 to 370 days. The material was used for evaluation of radiographic assessment of ankylosis. For comparative purposes, assessment of the experimental lesion penetrating to the pulp and periapical radiolucency was added. True and falsely positive or negative recordings formed the basis for calculation of the accuracy and sensitivity of the radiographic assessment. The sensitivity, or the observers' ability to detect the actual changes, was high for pulp penetration, intermediate for inflammation, and low for ankylosis.

Premaxillary hyperdontia in medieval Norwegians: a radiographic study.

An excavation of a part of the graveyard of St Olav's church, Trondheim, Norway, uncovered 389 tombs from the medieval period (1100-1600). Radiographic examination of 140 skulls with an intact premaxilla revealed hyperdontia in the form of a mesiodens in two (1.4%) cases. This is within the same range as similar medieval and present Nordic populations. Change in functional pattern does not seem to influence the prevalence.

Comparison of oral radiographic findings among 35-year-old Oslo citizens in 1973 and 1984.

The purpose of the present study was to evaluate a variety of radiographically detectable conditions found on orthopantomograms of 141 individuals as a part of an oral health survey of 35-year-old Oslo citizens, born 1949. Radiographic findings were recorded and compared with those of a similar study made in 1973. The findings revealed a statistically significant reduction in the prevalence of marginal bone loss. The frequencies of endodontically treated teeth and teeth with apical radiolucencies were unchanged.

Experimental transplantation of teeth to simulated maxillary alveolar clefts.

A total of 14 teeth were transplanted to simulated alveolar clefts in 5 monkeys. Autogenous cancellous bone was grafted to the cleft together with the tooth in ten instances. Healing processes were observed 216 or 271 days postoperatively. Another group of four teeth were transplanted in the cleft areas 133 days after bone grafting. These teeth were observed for 138 days before sacrifice. Radiological and histological findings support previous reports on adverse effects to dental tissues when placed in direct contact with fresh transplanted bone. Root resorption and ankylosis occurred to a large extent. Establishment of a normal periodontal membrane could, however, be observed when the tooth was transplanted to an area grafted 4 months previously. An interval before tooth transplantation allowing the cancellous graft to organize and bone to remodel seems to be indicated.

Changing positions of supernumerary teeth in the premaxilla: a radiographic study.

To evaluate possible change of position of unerupted supernumerary teeth in the premaxilla, thirty-one patients were followed clinically and radiographically. Alteration in position could be observed in fourteen cases. Occasionally, migration of supernumerary teeth may occur if surgical intervention is postponed, resulting in a more accessible position.

Evaluation of the reproducibility of two bitewing techniques by means of a microdensitometric recording method.

A new, simple, metal bitewing holder with a radiation dose-reducing collimator using principles suggested by Eggen is presented and recommended. The reproducibility of the bitewing holder technique was compared with that of the conventional bitewing loop technique. The material consisted of twenty seven sets (fifty four pairs) of radiographs. A microdensitometric method was developed and used to assess the reproducibility of the radiographs, and 108 pairs of microdensitometric tracings were produced to evaluate the two techniques. The results showed that the metal bitewing holder was significantly superior to the bitewing loop for obtaining radiographs with high reproducibility. The suitability of the microdensitometric method is discussed.

Radiopacity of root canal sealers.

A standardized and reproducible method of radiopacity measurements of dental materials is presented. The method entails densitometric comparison of standard-sized specimens with an aluminum step wedge under controlled conditions for exposure and film processing. Methodologic aspects have been evaluated and discussed. Measurements of forty root canal sealers demonstrated wide variations among the different types. Visual examination could not provide reproducible measurements of the radiopacity of the materials.

[A variant of the Eggens filmholder for use in the posterior molar region]. / En variant av Eggens filmholder til bruk i bakre molarområder.

Dr. Eggen's filmholder for long-cone-paralleling-technique is today available in two new, supplementary devices. These devices have an angulation in the metal rod, see fig. 1, and are meant to facilitate the film-positioning in the 3rd-molar area. A test was carried out to evaluate the new film-holders. Pairs of radiographs were taken in all 3rd-molar-areas, one radiograph with the straight film-holder, one with the angled device. Difference in horizontal film-position was measured. The results showed that in 93% the most posterior film-position was obtained with the angled film-holder.