A study on cyclic AMP in alveolar bone treated by orthodontic forces / 대한치과교정학회지

Tooth movement by orthodontic force is based upon alveolar bone resorption at compression site and bone formation at tension site of tooth. The function of cyclic AMP is to participate not only in initial action of bone cells by mechanical forces but also in the continuous cellular response leading, to bone remodeling. This experiment was performed to clarify the role of cyclic AMP in bone remodeling by mechanical forces. The orthodontic forces of about 80 gm and 100 gm were applied to the right canines of maxillary and mandibular bone, respectively, in cats, treated for periods of time ranging from one hour to 28 days. Alveolar bones were obtained from compression and tension sites . surrounding tipping maxillary and mandibular canines as well as from contralateral control sites. The samples were extracted, boiled and homogenized, and the supernatants were assayed for cyclic AMP by a radioimmunoassay mothod. The results were as follows: 1. The orthodontic movement of canines was increased to the end of experimental period and the action of orthodontic forces on tooth movement was more effective in maxillary canine. 2. The cyclic AMP levels of alveolar bones in compression and tension sites initially decreased, then increased and remained elevated to the end of experiment. The differences of the cyclic AMP levels between treated sites and non-treated sites were gradually increased. 3. The cyclic AMP levels in treated sites of mandibular alveolar bone was higher than that of maxillary alveolar bone.

A study of the effects of multibanded orthodontic appliances on the oral Lactobacilli / 대한치과교정학회지

A study of the effects of multibanded orthodontic appliances on the oral lactobacilli was conducted on 41 multibanded group and 41 caries free group. The following conclusions were obtained. 1. In multibanded group, the average count of lactobacilli per milli-liter of saliva showed about 219,300 in male and 254,100 in female. In caries free group, the mean count of lactobacilli per milli-liter of saliva showed about 66,700 in male and 68,500 in female, Therefore, the average of lactobacilli in multibanded group was much higher than that of the caries free group in both sexes. 2. The average of all the types of lactobacilli colonies (Disk-type, Bell-type, Y-type) in multibanded group was much more than that of caries free group. 3. Multibanded orthodontic appliances were found to sufficiently alter oral environment to significantly affect disk-types and total counts in both sexes and bell-type in female, at 1% level of confidence. But changes in bell-type and y-type, in male, were considered to be significant at 5% level of confidence.