Effects of strontium administration on rat molar morphology.

Strontium at concentrations of 0, 50 and 150 mg/l was given to rats during pregnancy and to the pups during a pre- and post-weaning period. Measurements were made on first and second mandibular molars to assess the morphology of tooth and fissure dimensions, and enamel and dentine thickness. A significant increase in horizontal and vertical dentine thickness was associated with a level of 50 mg Sr/l, a concentration previously found to be associated with decreased caries prevalence in rats.

Ectopic eruption of the mandibular first permanent molar.

In this case, a clear pathway for eruption was provided for the mandibular left first permanent molar by reducing the distal surface of the primary molar. The occlusal surface was also surgically uncovered to remove any possibility of a mucosal barrier. It was thought that the loss of arch length was not too great a sacrifice if the tooth could be brought into occlusion. The tooth proved not to be ankylosed and was, therefore, able to erupt into occlusion. The patient may have some crowding in the mandible; however, it appears to be within normal limits and no further orthodontic treatment is anticipated. When the relative simplicity of treatment is weighed against the severity of the consequences of untreated cases of ectopic eruption, it is suggested that treatment should be started as soon as the condition is diagnosed, to establish a normal eruption pathway and avoid any detrimental effects on a developing occlusion.

Regional odontodysplasia: clinical, pathologic, and therapeutic considerations.

A case of regional odontodysplasia in a 9-year-old boy is presented. Clinical and pathologic characteristics of this developmental anomaly and its treatment are reviewed.

Early diagnosis and successful management of periodontosis.

A brief review of the literature regarding the recognition, causes, and different therapeutic approaches of periodontosis was presented. Two cases of periodontosis in the early stages were reported, and a successful treatment plan using modalities similar to those used for other forms of periodontitis was described. Early diagnosis of the condition was critical to the success of both cases. Both patients were taught good oral hygiene, which, along with scaling, root planning, and conservative periodontal surgery, not only resulted in arresting the disease process, but also encouraged osseous regeneration. These examples emphasize the necessity of routine periodontal examinations for all children, especially at the circumpubertal period because periodontosis is often passed unnoticed until there has been massive periodontal destruction. The management of the advanced conditions is more challenging and seldom successful.

Management of the nonerupted maxillary anterior tooth.

The noneruption of maxillary anterior teeth, particularly the canine, is a common problem. The cause of the noneruption is multifactorial but almost always involves a lack of space. The literature presents an active and a passive form of orthodontic treatment and has recently stressed the periodontal management of these teeth. Two cases are presented. In both cases the orthodontic techniques of regaining space and providing traction on the unerupted tooth are described. A free gingival graft is used in one case and an apically repositioned flap in the other to achieve a healthy periodontium. The advantages and disadvantages of the techniques used as well as their rationale are discussed.

A study of plaque accumulation and gingival health surrounding stainless steel crowns.

From the findings of the present study the following can be stated: The degree of gingivitis surrounding teeth restored with nonideal stainless steel crowns was significantly higher than that of the entire mouth; however, the gingival status of the crowned teeth was not significantly different from that of unrestored contralateral control teeth. The amount of clinically detectable plaque associated with teeth restored with nonideal stainless steel crowns was not significantly different from that of the entire mouth or that of unrestored contralateral control teeth. A moderate positive correlation existed between the plaque index and the gingival index of teeth restored with nonideal stainless steel crowns; strong positive correlations between the same factors existed for the entire mouth and for the unrestored contralateral control teeth. The majority of stainless steel crowns placed by undergraduate dental students were judged as clinically acceptable. Nevertheless, most exhibited one or more observable defects: errors in marginal crimp and length were most common. In view of the association between nonideal stainless steel crowns and gingivitis, the operator must be meticulous in the placement of stainless steel crowns. Errors in adaptation must be avoided in order to minimize irritating factors and to preserve the health of the gingival tissues.