The effects of upper incisor separation on the submandibular and sublingual glands of rats.

The effects of upper incisor separation on the submandibular and sublingual glands of rats were examined biochemically, immunohistologically, and radio-immunologically during 28 days of treatment. Lateral separation of the upper incisors by application of force from an orthodontic appliance caused significant enlargement of the sublingual and submandibular glands of rats by three and seven days, respectively, after the beginning of the orthodontic treatment. This enlargement was followed by a significant increase of both RNA and DNA content, with some evidence of hyperplasia and hypertrophy. The enlargement was also associated with a significant increase of substance P at early stages after treatment, suggesting the involvement of the sensory nerves. These changes were largely inhibited by phenoxybenzamine, an alpha-adrenergic blocker, but not by atropine or morphine. Wet weights and RNA contents of the sublingual glands were markedly reduced by atropine. In comparison with control animals, the enlarged submandibular glands of rats subjected to orthodontic treatment secreted additional proteins identical with those secreted by glands enlarged by chronic administration of isoproterenol. In addition, chemical sympathectomy with 6-hydroxydopamine and phenoxybenzamine stimulated the synthesis of these abnormal proteins, but atropine and morphine did not. In contrast, protease activities in the convoluted granular tubule cells in the submandibular glands were increasingly reduced after treatment, as seen in rats subjected to chronic treatment with isoproterenol. However, the submandibular and sublingual glands completely recovered after removal of the orthodontic appliance.

Developmental changes in the volumes, protein, and some electrolyte concentrations of male and female rat submandibular saliva secreted in response to methoxamine and pilocarpine.

Saliva secreted in response to methoxamine and pilocarpine was collected from the cannulated ducts of the submandibular glands of male and female rats at weekly intervals from two to 10 weeks of age. It was analyzed for volume and for concentrations of protein, potassium, calcium, and inorganic phosphate. Following the collection of saliva, the submandibular glands were removed and weighted. The wet weights of the glands increased substantially up to seven weeks of age and then reached almost plateau values in both sexes. The salivary volumes secreted in response to both agents in both sexes were positively correlated with the gland weights, except that after five to six weeks of age there was no correlation between gland weight and methoxamine-stimulated salivary volume. The concentrations of protein, potassium, and inorganic phosphate were inversely related to the flow rates only at relatively low rates of flow. The concentration of calcium was positively correlated with the protein concentration and was independent of the nature of the stimulus and of sex differences during postnatal development.

[The application of repelling magnets to distal movement of maxillary molars. Report of three cases].

Report on three cases of maxillary first molar distalization with the aid of intra-arch repelling magnets were presented in this paper. Two cases were Class II malocclusion and one was a Class I discrepancy case whereby all resulted in rapid distalization of the upper first molars into Class I molar relationship in a relatively short time. Despite the unwanted rotation and tipping of the molars and the anteriors occurred slightly, numerous advantages of the repelling magnetic system were noted applicable to early mixed dentition cases to obtain the sufficient space of the molars rapidly. Moreover, since this is a fixed appliance, no patient cooperation was necessary. In conclusion, this magnetic system was found to be an effective device for molar distalization.

[On the pain experience of the tooth caused by placement of initial archwire].

Twenty nine patients completed a pain index card for the first 14 days following placement of an archwire. The index card divided the day into morning, afternoon and evening sessions and the patients were asked to score on a 0-3 basis of the severity of discomfort caused to the teeth (score 0: no discomfort, score 1: discomfort, score 2: mild pain, score 3: severe pain). Results were as follows: 1) All patients suffered discomfort and/or pain following placement of an archwire (discomfort: 10.3%, mild pain: 72.4%, severe pain: 17.2%). 2) There was no significant difference in the pain experience among the three age groups (under 12, 13 to 19 and over 20 years of age). 3) There was statistically significant difference in the pain experience between the sexes. 4) There was no significant difference in the pain experience among the four kinds of archwires (0.0175" braided wire, 0.012" stainless steel wire, 0.016" and 0.016" x 0.022" nickel titanium alloy wire). 5) The discomfort experience was observed in 37.9% and the mild pain experience was in 3.4% of the cases immediately after placement of the archwire. 6) The pain experience was observed in 62.1% of the cases by the end of the day. In 20.7% the pain experience was observed the next day and the pain experience was observed after 2 days in 3.4%. 7) In the severe pain group, the mean value of the pain experience was 4.4 days and that of the discomfort experience was 8.2 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical effects of maxillary protraction on the craniofacial complex.

The deformational effects on the human skull resulting from maxillary protraction were examined by means of strain gauges and displacement transducers. A maxillary protraction appliance was used that included a reverse headgear attached to the maxillary first molars. The protraction forces that were applied to this appliance were parallel to the occlusal plane at the following locations: the height of the maxillary arch, 5 mm above the palatal plane, and 10 mm above the Frankfort horizontal plane. The results indicated that protraction forces at the level of the maxillary arch produced an anterior rotation and forward movement of the maxilla, protraction forces 10 mm above the Frankfort horizontal plane produced a posterior rotation of the maxilla with a forward movement of nasion, and protraction forces 5 mm above the palatal plane produced a combination of parallel forward movement and a very slight anterior rotation of the maxilla. Moreover, constriction of the anterior part of the palate occurred in all cases.

[A morphological study on the mandibular symphysis of cleft lip and palate, anterior crossbite and Angle Class I malocclusions].

Morphological characteristics of the mandibular symphysis among the cleft lip and palate, anterior crossbite and Angle Class I malocclusions were analyzed cephalometrically. 1. In the symphyseal thickness at pogonion, the significant differences among the three groups were not found. In the cleft group, the symphyseal thickness at point B was significantly narrower than that of the Class I group. 2. In the symphyseal height, the cleft group was larger than that of the crossbite group, while the crossbite group was the middle of the two groups. 3. In the symphyseal inclination, the cleft group was significantly large, compared to that of the crossbite and Class I groups. The symphyseal inclination of the cleft group was mostly the alveolar part of mandibular symphysis. 4. The chin formation was the absorption of the around of point B. The chin formation was appeared between the ages of A and B groups.

[Statistical investigation on orthodontic patients who received treatment at Fukuoka Dental College during 15 years].

It has been fifteen years since the Department of Orthodontics started in 1973, and this report concerns mainly the results of clinical observations during these period. The results were as follows: 1) Three thousand four hundred and three patients visited during a fifteen years period and 2,065 (61%) of them received orthodontic treatment. This statistical investigation was performed on 2,065 patients. 2) The numbers of treated patients increased from 1973 to 1983 without 1980 but have almost unchanged with about 180 patients from 1984 to 1987. 3) The male patients were less than the female by the ratio of 1:1.67. As to age, the patients from 6 to 12 years old accounted for 72% of all the treated. 4) Analyzed by dental age categories, patients at the stage of III A and III B comprised 54% of all the treated. 5) Analyzed by month, the patients visited on March, July and August in spring and summer vacations. 6) Most of the patients (92%) lived in Fukuoka Prefecture and 38% of them lived in Sawara-ku, where lay in the south-western part of Fukuoka city. 7) Fifty six per cent of all patients were introduced by doctors and dentists. 8) As to malocclutions, the number of mandibular protrusion was the largest, crowding case was next, and maxillary protrusion was third. The total sum of these three cases accounted for 78% of all the treated. 9) In the initial orthodontic appliances, the use of the multi-brackets appliances was first, the chin cap appliances was second and plate appliances was third. The total sum of these three appliances accounted for about 73%. 10) Analyzing to age and initial orthodontic appliances, plate, chin cap, F. K. O. and I. M. A. appliances were used at the age from 7 to 8. Lingual arch appliances were also used at the age of 8. The multi-brackets appliances increased remarkably during the recent five year period and were used at the age of 10 to 11 and over 20 years.