THE JOURNAL OF THE STOMATOLOGICAL SOCIETY,JAPAN

Titanium, A Target for Progress in Dental Casting

Fumio Nishimura, Sunao Nomoto

1989 Volume 56 Issue 1 Pages 1-16
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.1

JOURNAL FREE ACCESS

Download PDF (15904K)
Clinical Observation of Cases Operated in the Department of Oral and Maxillofacial Surgery, University Erlangen-Nürnberg, for the period of One Year

—Especially Cases of Fracture and Maxillofacial Deformity—

Nobuyuki Tanaka

1989 Volume 56 Issue 1 Pages 17-23
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.17

JOURNAL FREE ACCESS

Show abstractHide abstract

In the Department of Oral and Maxillofacial Surgery, University Erlangen-Nürnberg, there were 1, 140 cases operated during the period of one year between August 1987 and July 1988. Among them, 198 were fracture cases, 139 tumor cases and 88 deformity cases. As compared with Japan, there were many operations on fracture cases by the Steinhäuser mini-plate under general anesthesia and the time required for the intermaxillary fixation was generally 7-10 days while in Japan it was 5-6 weeks without the mini-plate.
As for the time required for the postoperative intermaxillary fixation for maxillofacial deformity, it was usually 1 week after the operation by screw or mini-plate fixation of the bones while in most of Japanese institutions it was also 5-6 weeks after the operation by circumfential wiring fixation of the bones.
The prognosis of the cases of fracture and maxillofacial deformity by short-period intermaxillary fixation was good.
Short-period intermaxillary fixation by screw or mini-plate bone fixation is discussed by reviewing the literature on this study.

View full abstract

Download PDF (5600K)
Study on Distribution Form of Mesiodistal Crown Diameter in Large Sample : Part II

Tadao Iida, Kunimichi Soma, Fujio Miura, Takakazu Sugiyama

1989 Volume 56 Issue 1 Pages 24-37
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.24

JOURNAL FREE ACCESS

Show abstractHide abstract

The purpose of this research was to examine the distribution of the toothsize in a large sample. The objective teeth were the left upper and lower fourteen teeth except the third molar.
The toothsize of 1, 000 dental casts from the Japanese female orthodontic patients was measured. On each of them, a histogram and a set of statistics (mean, standard deviation, coefficient of variation, skewness, kurtosis, Geary value) are given in order to examine the distribution.
The findings are as follows:
1) Each tooth may be classified into the following four types of distribution except the congenitally missing data.
TYPE I : A normal distribution was observed in the upper and lower central incisors, the lower lateral incisor, the lower canine, the upper and lower first premolars, the upper second premolar, the upper and lower first molars and the lower second molar.
TYPE II : A positively skewed distribution was observed in the lower second premolar.
TYPE III : A negatively skewed and leptokurtic distribution was observed in the upper canine and the upper second molar.
TYPE IV : An extremely negatively skewed and leptokurtic distribution was observed in upper lateral incisor.
2) With the four teeth which were classified into TYPE II, TYPE III and TYPE IV, the dis-tribution of the lower second premolar was concluded to be of normal distribution by logarithmic transformation. The distribution of the upper canine and the upper second molar was judged to be of lognormal distribution and the upper lateral incisor also was judged to be of three parameter lognormal distribution and four parameter lognormal distribution.
3) The distribution of thirteen teeth except the upper lateral incisor was judged to be of normal distribution, by considering the congenitally missing data and the outlier in statistical data of the tooth.

View full abstract

Download PDF (1548K)
In Vitro Study on Decolorization Effect of Argon Ion Laser

Junko Suzuki

1989 Volume 56 Issue 1 Pages 38-46
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.38

JOURNAL FREE ACCESS

Show abstractHide abstract

Many experimental treatments for oral pigmented lesions with several kinds of lasers have been applied and consequently, the argon ion (Ar⁺) laser is used clinically as one of the most effective lasers for decolorizing. This in vitro study was carried out to clarify the depigmentation mechanism by low energy Ar⁺ laser irradiation. Each cultured human melanotic malignant melanoma cell colony was irradiated by the laser at 0.31 J/cm². Each colony was fixed in time sequence and examined microscopically and ultramicroscopically.
The present study disclosed the tyrosinase inactivation and decrease in the number of melanosomes of the lased melanoma cells. Subcellular degeneration was very mild and the mature melanin granules markedly decreased concomitantly with the increased secretion of the granules. These findings suggest that Ar⁺ laser irradiation evokes decolorization effect by the mechanism of 1) organelle-specific injury, 2) hypersecretion of melanosomes and 3) maturation arrest of melanosomes, related to its photoactivity.

View full abstract

Download PDF (5858K)
Physiological Remineralization of Artificially Decalcified Monkey Dentin under Adhesive Composite Resin Restoration

Tetsujiro Tatsumi

1989 Volume 56 Issue 1 Pages 47-74
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.47

JOURNAL FREE ACCESS

Show abstractHide abstract

The activity of the single motor units in the human anterior digastric muscle was recorded in 7 subjects with a monopolar fine wire electrode. The force generated by jaw opening was simultaneously recorded with a mechanical transducer.
The results obtained were as follows: (1) Increasing the force gradually, a few motor units were recruited orderly and the firing rate of each unit reached the peak frequency rapidly. These findings suggest that the control of the muscle force caused by jaw opening movements might depend more on the orderly recruitment of the motor units than on the rate moduration. (2) The contraction time, measured by the spike-triggered averaging technique varied from 25.6 to 132.4 ms. It was suggested that the anterior digastric muscle consisted of both the fast twitch motor units and the slow twitch motor units. (3) The motor units that have a higher threshold force tended to have a larger twitch tension and have a shorter twitch contraction time than that of the lower threshold motor units. This means that the anterior digastric muscle has a relatively simple role during the active jaw opening movements. (4) Fatigue can be estimated as the change in the firing rate. The motor units of a higher threshold force tended to be fatigable during the continuous jaw opening movements.

View full abstract

Download PDF (29228K)
Physiological Properties of Motor Units in the Human Anterior Digastric Muscle

Hiroshi Mimura

1989 Volume 56 Issue 1 Pages 75-92
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.75

JOURNAL FREE ACCESS

Download PDF (2257K)
Evaluation of Super-elasticity Characteristics of Orthodontic Ni-Ti Alloy Wire

Takayuki Yoneyama, Hisashi Doi, Hitoshi Hamanaka, Takao Noda, Yasuo Ok ...

1989 Volume 56 Issue 1 Pages 93-101
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.93

JOURNAL FREE ACCESS

Show abstractHide abstract

Mechanical properties of orthodontic Ni-Ti alloy wires, especially their super-elasticity characteristics, were investigated in order to use them effectively in the clinics. In this study, twenty commercial orthodontic Ni-Ti wires were tested and two parameters were devised for the load-deflection curve and introduced to evaluate the practical mechanical properties, one being the “super-elastic index : SET” for super-elasticity, and the other being the “E-load” for the load in the super-elastic region.
There was a “flat area” in the load-deflection curve of the super-elastic type of Ni-Ti alloy wires, whose SET was above seventy and a continuous force could be used through the wide range of deflection. The load of the work-hardened type of Ni-Ti wires, SET below thirty, was nearly proportional to the deflection. And the middle type showed intermediate properties of the two. The E-load values of the super-elastic type wires are thought to indicate the load level in the super-elastic region. The quantitative evaluation of the super-elasticity characteristics of the orthodontic Ni-Ti wires became possible by the introduction of these parameters.

View full abstract

Download PDF (838K)
Mobility of Premolars Under Load in Partially Edentulous Dentition

Mitsuhiko Saito

1989 Volume 56 Issue 1 Pages 102-120
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.102

JOURNAL FREE ACCESS

Show abstractHide abstract

The mobility of the upper and lower premolars under load was investigated in relation to the interproximal contact and occlusal facets. The mobility was measured on ten subjects with the molars missing in the bucco-lingual and mesio-distal direction, using a non-contact sensor system, when a 500gram load was applied in the horizontal direction, during hard biting in intercuspation and biting of foods. The ratio of the tooth movement in the bucco-lingual direction to the mesio-distal direction was larger in the upper premolars than in the lower ones. As the total mobility increased, the tooth movement was larger on the buccal side than on the lingual side of the upper jaw, on the lingual side than on the buccal side of the lower jaw, and on the mesial side than on the distal side of both jaws. The direction of the movement did not coincide with the direction of the load, due to the horizontal rotation. When biting, the first premolars showed a mesial movement and the second premolars showed a more distal movement than the first premolars. A correlation between the direction of the tooth movement during hard biting and that of the facets was observed.

View full abstract

Download PDF (4875K)
Study on Prosthodontic Procedure for Patients with Unilateral Cleft Lip and Palate

—Effects of Various Extensions of Splint on Tooth-Borne Ability of Teeth Adjacent to the Cleft—

Ruri Suzuki

1989 Volume 56 Issue 1 Pages 121-140
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.121

JOURNAL FREE ACCESS

Show abstractHide abstract

It is mandatory that the prosthodontic devices for the cleft palate patients not only prevent the relapse of the corrected arch and teeth by orthodontic and/or surgical intervention but also equilibrate the tooth-borne ability between the upper and the lower jaw.
The purpose of this paper is to set up a criterion for the extension of the splint from the point of the tooth-borne ability.
Four patients with unilateral cleft lip and palate were examined for the maximal biting force at the tooth adjacent to the cleft in each alveolar segment in the case of various extensions of the splints.
The findings were as follows;
1. The maximal biting force increased significantly in every splint, compared with the nonsplint.
2. The maximal biting force increased significantly in the splints where the neighbouring tooth in the same segment was involved, compared with that in the splints where only the tooth adjacent to the cleft was involved, even if the tooth in another segment increased in number for splinting.
3. The maximal biting force did not increase significantly in most splints where three teeth in the same segment were involved, compared with that in the splints where two teeth in that segment were involved.

View full abstract

Download PDF (7474K)
Study on Feeding Behavior Patterns of Rats on Cariogenic Diet

Yoshiyuki Sasaki

1989 Volume 56 Issue 1 Pages 141-161
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.141

JOURNAL FREE ACCESS

Show abstractHide abstract

The feeding behavior patterns of Jcl : Wistar rats fed on commercial stock diet and cariogenic diet (Diet#2000) were investigated with the newly developed autorecording system. They were caged separately under a regular light-dark cycle (L : D =12 : 12) . The results and conclusion were as follows.
All rats have a circadian feeding rhythm, and 70-850 of feeding frequency were observed during the dark period. The group on the commercial stock diet showed a dual-peak pattern of feeding at 20 : 30 and 4 : 00. On the other hand, the cariogenic diet groups showed a more frequent feeding pattern during the dark period. The feeding frequency increased from 1 : 00 to 3 : 00 in the high sucrose diet group and more frequent feeding was observed.
From these results, it was suggested that dental caries in the rats was caused by not only the local effect of sucrose in the mouth but also by the changing patterns of feeding behavior with cariogenic diet.

View full abstract

Download PDF (3114K)
Effect of Lingual Surface Inclination of Maxillary Canine on Jaw Muscle Activity

Kenji Soneda

1989 Volume 56 Issue 1 Pages 162-181
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.162

JOURNAL FREE ACCESS

Show abstractHide abstract

The effect of lingual surface inclination of the maxillary canine on the jaw muscle activity was investigated on five subjects.
Several different metal maxillary canine risers were fabricated to change the lingual inclination. The EMG activity of the masseter and posterior temporal muscle was recorded bilaterally by means of bipolar surface electrodes simultaneously with the LED mandibular tracking device. On each subject the lateral gliding movements were carried out while maintaining the occlusal contact on the canine riser. The recorded muscle activity and mandibular gliding movements were analyzed quantitatively.
During the lateral gliding, the working-side posterior temporal muscle was more active than the other three muscles. Steeper canine risers caused a reduction of the muscle activity when compared with the more flat guidance. In the gliding movement from maximum intercuspation, the temporal muscle showed more activity than the masseter muscle. However the relative relationships between the individual muscles as well as the working-side muscle and nonworking -side muscle remained unchanged with all canine risers. In the gliding movement into maximum intercuspation, the difference of the canine riser showed no consistent change in the muscle activity. In each subject, it was found that the canine riser with a moderate inclination was more comfortable to move the mandible, but no relationship between the EMG activity and his or her f eelig was revealed.

View full abstract

Download PDF (3983K)
[title in Japanese]

[in Japanese], [in Japanese], [in Japanese]

1989 Volume 56 Issue 1 Pages 182
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.182

JOURNAL FREE ACCESS

Download PDF (1424K)
[title in Japanese]

[in Japanese]

1989 Volume 56 Issue 1 Pages 183
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.183

JOURNAL FREE ACCESS

Download PDF (1875K)
[title in Japanese]

[in Japanese], [in Japanese]

1989 Volume 56 Issue 1 Pages 184
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.184

JOURNAL FREE ACCESS

Download PDF (1749K)
[title in Japanese]

[in Japanese], [in Japanese]

1989 Volume 56 Issue 1 Pages 185
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.185

JOURNAL FREE ACCESS

Download PDF (126K)
[title in Japanese]

[in Japanese]

1989 Volume 56 Issue 1 Pages 186
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.186

JOURNAL FREE ACCESS

Download PDF (156K)
[title in Japanese]

[in Japanese]

1989 Volume 56 Issue 1 Pages 187
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.187

JOURNAL FREE ACCESS

Download PDF (183K)
[title in Japanese]

[in Japanese]

1989 Volume 56 Issue 1 Pages 188
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.188

JOURNAL FREE ACCESS

Download PDF (138K)
[title in Japanese]

1989 Volume 56 Issue 1 Pages 189-204
Published: March 31, 1989
Released on J-STAGE: October 08, 2010

DOIhttps://doi.org/10.5357/koubyou.56.189

JOURNAL FREE ACCESS

Download PDF (2149K)

Register with J-STAGE for free!