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Biomedical subjects

J J Ravn

Publications and source records attributed to J J Ravn.

At least 19 recordsLinked to original sources
PubMed1989

[Epidemiology of dental trauma in Denmark: overview and some new points of information].

It is virtually impossible to compare the results of the many studies of traumatic dental injuries, primarily because information is lacking or inaccurate. Another reason, however, is that the basic materials differ substantially. Most studies are based on special groups comprising trauma patients exclusively, and furthermore these are often selected patients, although this fact is not always made clear. In recent years a number of Danish studies have attempted to examine the trauma problem on a population basis. The results of these studies are discussed, a few new results are added and attention is pointed out to problems needing further investigation.

Adolescent↗
PubMed1989

[Intrusion of primary teeth: case reports].

Three cases of intrusion of primary teeth are described. In all cases the intruded primary tooth was left without treatment and the tooth did not re-erupt. After eruption of the succedaneous permanent tooth the primary tooth was surgically removed. There was damage to the permanent tooth in two of the three cases.

Child↗
PubMed1982

Follow-up study of permanent incisors with complicated crown fractures after acute trauma.

Complicated fractures occur in 3.5% of acute traumatized incisors. A pulp exposure results in almost all cases in endodontic treatment. The present investigation evaluated the prognosis for the different types of endodontic treatments following complicated crown fractures. Only incisors with an observation period of more than 23 months are included; the material comprises 301 incisors. Pulp capping was successful in 90.5% of the cases. There was a clear tendency for a positive correlation between the stage of the root development and the success rate of the endodontic treatment. In cases with pulpotomy ZnO/eugenol cement or calcium hydroxide was used as amputation material. The pulp reactions following the different treatments are discussed. If calcium hydroxide was used 90% was successful, while in cases with ZnO/eugenol cement as amputation material 8.9% developed necrosis of the pulp and 34.4% showed an undesirable reaction with formation of hard tissue barrier or obliteration. The healing frequency was 83.9% for teeth treated with pulpectomy but there was a clear correlation between the standard of the root filling and the success rate. For all three treatment groups there was a correlation between damage to the supportive tissue and treatment success.

Adolescent↗
PubMed1981

Follow-up study of permanent incisors with enamel fractures as a result of an acute trauma.

The present investigation evaluated the prognosis for vitality after an acute trauma in 2891 permanent incisors with enamel fracture as the only damage, and in 476 incisors with enamel fracture combined with other symptoms on the damaged tooth. Pulpal necrosis developed in 57 teeth (1.7%). Acute treatment in connection with enamel fracture was only performed in half of the cases and had no importance on vitality. The combination of enamel fracture and concussion or mobility resulted in pulpal necrosis in 8.5% of cases, and cases involving both mobility and concussion meant pulpal necrosis in 14% of teeth. The findings clearly illustrated that an enamel fracture is an injury with an extremely favorable prognosis, and that the risk group can be narrowed to cases of combined injuries involving the supportive tissue.

Adolescent↗
PubMed1981

Follow-up study of permanent incisors with enamel-dentin fractures after acute trauma.

The present investigation evaluated the prognosis for vitality after an acute trauma in 3144 permanent incisors with enamel-dentin fracture as the only damage and in 923 incisors with enamel-dentin fracture combined with other symptoms on the damaged tooth. The teeth were examined at regular intervals. The observation time was more than 2 years in the case of 78.9% of the material. Pulpal necrosis developed in 250 teeth (6.1%). Pulp death occurred in 3.2% of teeth with enamel-dentin fracture as the only damage. The combination of enamel-dentin fracture and concussion resulted in pulpal necrosis in 5.8% and cases involving both concussion and mobility showed pulpal necrosis in 30.1% of teeth. A registration of the enamel-dentin fracture based on the extent of dentin exposure was undertaken. The relationship between extent of dentin exposure and pulpal necrosis as well as influence of treatment on pulpal necrosis was clearly illustrated. It is concluded that information on damage to the mineralized tissue without details of damage occurring at the same time to supportive tissue is of doubtful value in assessing the prognosis.

Child↗
PubMed1980

Longitudinal study of occlusion in the primary dentition in 3- and 7-year-old children.

The material for the study comprises plaster models of 269 Copenhagen children, the impressions for which were taken during the month each child attained the ages of 3 and 7 years. A comparison was made of occlusion in the single child in the period. The study illustrates clearly that the same given percentage in two age groups is by no means a guarantee that there have been no changes. The canine relationships in particular are unstable during the period of study. The only stable occlusion is distal occlusion in the primary dentition. This occlusion is invariably maintained and is always transferred unchanged to the permanent dentition.

Age Factors↗
PubMed1976

A radiographic study of mineralization of permanent teeth in a group of children aged 3-7 years.

The purpose of the present study was, by using a standardized radiographic technique, to assess the time of selected mineralization stages of all permanent teeth except the second and third molars in a group of 580 children aged 3-7 years. A complete radiographic examination, consisting of nine intraoral films, was made of each child, using Eggen's film holder. According to degree, mineralization of the teeth was subdivided into nine stages. The cap relation between the two variables, mineralization stage and chronologic age, was calculated by linear regression analysis. The hypothesis of the present study, that linearity exists between the two variables, was confirmed within and close to the investigated age group.

Child↗