Aichi-Gakuin dental science最新文献

The taxonomic relationships among strains of oral Streptococcus intermedius and the related streptococci were determined by G + C mol%, DNA-DNA hydridization, phenotypical and serological tests. As to the results, group 1 strains of S. intermedius including the type strain ATCC 27335 and five isolates behaved distinctively with respect to genetic, phenotypic and serological characteristics compared with group 2 strains of S. intermedius including ATCC 31412 and two isolates. Therefore, nine strains of oral S. intermedius could be separated at least into two homology groups.

This study describes a case of a salivary calculus which contained the limb of a shrimp. Pathological findings seemed to show a stratiform structure of calculus around the foreign body at the center. However, when the cut surface of the salivary calculus was examined by a scanning electron microscope, it was suspected that the origin of the calculus was in another area next to the foreign body. As a result, it became clear that the foreign body was not the core, but that the core of the salivary calculus was somewhere else, and that the earlier foreign body theory needed to be reconsidered. As to the foreign body, the patient remembered eating a shrimp, which was probably the foreign body in question. The findings obtained from the analysis of other shrimp limb specimens were structurally similar. Therefore the suspicion that the foreign body was indeed the limb of a shrimp was increased.

The patient was twenty-three year old female with TMJ disorder and crowding. She had often had a clicking sound caused probably by malocclusion since she was eighteen years of age. Limitation of mouth opening with TMJ locking has been occurring since she had an impacted right lower third molar extracted at nineteen. A stabilization splint was applied for better mandibular position to rectify the TMJ disorder. The clinical symptom was relieved one month later, so the malocclusion was treated with a multi-bracket appliance. Since cross bite in [formula: see text] was corrected in a year and three months, symptoms of the TMJ disorder disappeared and this condition has remained stable for the past year. A stabilization retainer worn at night was considered necessary to prevent a relapse of the dentition and mandibular position, and to keep the masticatory muscles relaxed. For the purpose of stabilizing the TMJ condition and occlusion, the patient was taught unilateral mastication in order to diminish the difference between sides in chewing force, because only one side had been habitually used for a long time. It is suggested that such an alternative chewing habit will improve functional stability following the structural correction.

Furca of multi-rooted teeth are sometimes affected by advanced periodontitis and supporting tissue is almost lost around one of two or two of three roots, while the remaining root or roots are supported by a relatively intact periodontium. In these situations, the procedure of root resection has usually been carried out. Though the necessity of prior or simultaneous endodontic treatment will be considered concomitantly, it is not clear the good periodontal results can be obtained in such cases by these endodontic treatments. If the technique of vital root resection should be indicated to these cases, the vitality of the tooth would be retained and the damage would be minimal. The technique of vital root resection and two periodontally successful clinical cases are presented. This technique appears appropriate in cases in which a multi-rooted tooth is afflicted with a hopeless periodontitis involving one or two roots.

Effects of a series of novel inhibitors of calmodulin or protein kinases on amylase release were studied in rat parotid slices. Amylase release induced by a cholinergic agonist, carbamylcholine, was inhibited by N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), a calmodulin inhibitor, 1-(5-chloronaphthalen-1-sulfonyl)-1H-hexahydro-1, 4-diazepine (ML-9), a myosin light chain kinase (MLCK) inhibitor, and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), an inhibitor of Ca(2+)-activated, phospholipid-dependent protein kinase (protein kinase C), while N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide (H-8), an inhibitor of cyclic AMP-dependent protein kinase (protein kinase A), did not inhibit the release. On the other hand, amylase release induced by a beta-adrenergic agonist, isoproterenol, was inhibited only by H-8, but not by W-7, ML-9 or H-7. These results suggest that cholinergic stimulation evokes amylase release via the Ca(2+)-dependent system which involves calmodulin, MLCK and protein kinase C, while beta-adrenergic stimulation via the cyclic AMP-dependent system involves protein kinase A.

Three phleboliths and ten salivary calculi in the submandibular duct were studied with scanning electron microscopy (SEM) and computer aided microanalyser (CMA). The surface of the phleboliths was rather even with some irregularity. According to their surface structure the salivary calculi were divided into three types: the rock-like type, the granular type, and the globular type. The phleboliths were classified into two types according to their cut surface: the calcified-core type, and the uncalcified-core type. The core structure was similar to the surface structure in the calcified-core type of phleboliths, but in the salivary calculi the core structure was different from the surface structure in that the cut surface of the core was an accumulation of circular or polygonal structures forming a honey-comb pattern which was surrounded by small projections distributed radially. On the basis of these results some etiological factors of phleboliths and salivary calculi are discussed.

This is a study of supernumerary teeth in the maxillary anterior area in children. More than 60,000 child patients were examined. The 842 supernumerary teeth in the maxillary anterior area, found in a total of 682 children, were analyzed clinically. The incidence of supernumerary teeth was 1.12%. The male-female ratio was 3 to 1. Supernumerary teeth found were single and multiple types, with a ratio of 3 to 1. The eruption direction was normal (51.2%), inverted (36.2%) or horizontal (7.6%). Approximately 65% were found impacted in the maxilla.

In order to investigate the deformation the stone die depending on the amount of undercut, 5 kinds of undercut master dies were used to take impressions using 3 kinds of impression materials (addition type silicone rubber, polysulfide rubber, alginate). The stone dies were measured for dimensional changes in shape as projected to a two-dimensional plane by means of a newly devised apparatus. The results showed that deformation of the stone dies increased, in general, in proportion to the amount of undercut of the master die. The stone dies obtained from addition type silicone rubber impression material tend to be less deformed. In the case of the polysulfide rubber impression, the deformation was very small in stone dies in the case of non-undercut master dies, but it was very large in the case of undercut master dies. The alginate impression materials gave results with wider variations.

The present paper reports our studies of changes in the compound action potential after Nd: YAG laser irradiation of the rat's sciatic nerve. The nerve on one side was exposed and irradiated by Nd: YAG laser directly. The temperature of the irradiated nerve was also measured. 1) Under 100 mW irradiation the compound action potential and the temperature of the surface of the sciatic nerve did not show a detectable change. 2) Under 300 mW irradiation the compound action potential showed an increase in amplitude, and shortening in latency. A negative after-potential appeared within 30 secs of irradiation. The temperature on the sciatic nerve rose by 3 degrees C during the irradiation. 3) Under 500 mW irradiation the compound action potential decreased gradually in amplitude and ultimately disappeared. The temperature on the sciatic nerve reached more than 47 degrees C.

This is a case report of a patient suffering from holoprosencephaly associated with median cleft lip and palate who was treated in our clinic. The present patient was introduced to our hospital at the age of three months. We suspected holoprosencephaly on the basis of the peculiar facial structure. Lip plasty was performed because the holoprosencephaly of the patient would be of the least severe type capable of surviving a long time, and because of the parents' concern about the esthetic aspect. The modified Tennison's method was used. The patient is under follow-up observation at our hospital.