After single crystal alminum oxide implant was inserted on the mandibles of adult monkeys, the implant head was cemented to the superprostheses. Under occlusal function, healing process and adaptation of the surrounding tissue of the implant were examined clinically, roentogenographically, histopathologically, and scanning electron microscopically, from one week to six months, after implantation. The results were as follows : 1. The gingiva surrounding the implant satisfactorily healed macroscopically and showed finding similar to those of the neighboring teeth following two months after implantation. Between three and six months, the depth of the surrounding gingival pocket was in the range of 0.2-1.0 mm and showed no great difference from those of the neighboring teeth. Formation of deep pockets were not observed. 2. Roentogenographically, at one and two weeks after implantation, the findings of tissue destruction were observed around the implant. However, after one month, the newly generated bone formation was prominent and, after three months, there was the evidence of thin radiolucent areas around the implant in four of six cases. In the remaining two cases, the border was indistinct. 3. The attached epithelium adjacent to the implant was elongated slightly more downward than that of the neighboring teeth and clongation as deep as the screw thread area was observed only in a total of three cases, two cases after two months and one after three months. However, only two or three layers were ranged downward in all and no prominent hyperplasia or proliferation was observed. 4. In the lamina propria of the gingiva, the connective fibers were densely arranged surrounding the implant but ran in parallel to the implant axis at the area adjacent to the implant. 5. At the screw thread area, the implant was in direct contact with the bone in two of five cases after two months, in two of six cases after three months, and in two of four cases after six months. In the remaining cases, interposition of the fibrous connective tissue between the implant and the bone was observed in all. However, the width decreased chronologically and was in the range of 100-250μm after three months, and of 25-100μm after six months. 6. The fibrous connective tissue between the implant and the bone was composed of collagenous fibers. These fibers transformed at one end into which matrix fibers embedded at one end in the bone on the trabecular side but were running in parallel to the implant axis on the implant side. At the screw thread crest where stress was considered to concentrate, the fibers densely arranged. 7. Scanning electron microscopically, there were many amorphous materials and collagenous fibrils, of different sizes. After two weeks, attachment of epithelium cells was observed on the implant surface. After six months, attachment of mature fibroblasts with microvilli and villi was observed. On the basis of the above findings, the surrounding tissue of the implant heals satisfactorily even under occlusal function. It was confirmed that biological sealing is observed at the gingiva and no abnormal findings such as inflammation or bone resorption are observed at the screw thread area. However, for use on a long term, oral hygiene and harmonious occlusion are important and in clinical application, care must be taken.

View full abstract

Dental prevention for mentally retarded and handicapped children is indeed desirable in view of difficulty of dental treatment for them. Therefore, the purpose of this study was to obtain fundamental concerning the planning of oral health for mentally retarded children and to have a grasp of their oral traits. Non-institutionalized mentally retarded children in Kitakyushu (M.R. group), totaling 101 subjects (64 males and 37 females) from 3 to 5 in age, were studied on their teeth, gingival disease, and dental arch and palatal vault form. The results were as follows : 1. The mean number of deciduous teeth of the M.R. group was significantly lower than that of the normal group in females. The mean number of d teeth of the M.R. group was significantly higher than that of the normal group in females. The mean number of f teeth of the M.R. group was significantly lower than that of the normal group in both males and females. 2. The debris index (DI) of the M.R. group was significantly higher than that of the normal group in both males and females. The PMA index of the normal group was significantly higher than that of the normal group in males. 3. With regard to dental arch and palatal vault from in males, dental arch breadths (upper deciduous canine, upper 1st and 2nd deciduous molar, and lower 2nd deciduous molar region) of the M.R. group were significantly narrower ; length of the lower dental arch (<A|A>^^^--<D|>^^^- region) of the M.R. group was significantly shorter ; posterior palatal height of the M.R. group was significantly lower ; and palatal arch length (2nd deciduous molar region) of the M.R. group was significantly shorter than those of the normal group. Upper anterior-posterior dental arch breadth index, and upper anterior and posterior dental arch indicies of the M.R. group were significantly higher than those of the normal group. 4. As to dental arch and palatal vault form in females, dental arch breadths (lower 1st and 2nd deciduous molar region) of the M.R. group were significantly narrower ; length of the lower dental arch (<A|A>^^^--<|D>^^^- region), lower anterior and lower posterior dental arch length of the M.R. group were significantly shorter ; and anterior and posterior palatal heights of the M.R. group were significantly lower than those of the normal group. Posterior palatal height index of the M.R. group was significantly lower than that of the normal group. On the basis of the foregoings, although percentage of filled teeth of mentally retarded children tended to be lower than that of normal children, incidence of dental caries in deciduous teeth showed about the same level between the two groups. And it was suggested that dental arch breadth was narrower, dental arch length shorter, and palatal height lower in the M.R. group than in the normal group in both males and females.

View full abstract

It is said that the fluoride-containing restorative materials strengthen the dental hard tissues and prevent the occurrence of the secondary caries. This is due to the reaction of the fluoride ions with hydroxyapatite to form fluorapatite, calcium fluoride or others. Above all, the fluorapatite formation seems to be the most effective in decreasing the susceptibility to decalcification and raising the caries resistance of the teeth. However, it was so far difficult to analyse the quantity of the fluorapatite separately from other fluorides, and hence the efficiencies of fluoridization have been evaluated by the total uptake of the fluoride ions in the hydroxyapatite. In the present study, the quantitative determination of the fluorapatite was successfully made utilizing ESR spectra of oxovanadium ions, VO^<2+>, adsorbed on the apatite. By this method, the fluorapatite formation was examined when the synthesized hydroxyapatite was kept in contact under water with several cements and an amalgam containing fluorides. Effects of the environmental factors such as pH, concentration of the fluoride ion, and existence of other ions or molecules were also investigated. The fluorapatite formation became maximum at the pH around 6, while the total uptake of the fluoride ions markedly increased as the pH decreased within the range from 4 to 9. Higher concentration of the fluoride ion as demonstrated before was not always necessary for fluorapatite formation but a relatively low concentration around 64 ppm was the most favorable. If the other ions or molecules existed, however, the optimum concentration of the fluoride ion tended to become somewhat higher, indicating that in practice the various ions or molecules leached out together with fluoride ions from the restorative materials might inhibit the fluorapatite formation. A silicate cement, Lux Silit, exhibited the highest fluorapatite formation with significant differences from other materials used, although this cement did not show the highest fluoride content or the highest total uptake of the fluoride ions. These findings suggest that the effective fluorapatite formation would require some preferable conditions of pH and/or concentration of the fluoride ion with consideration of the existence of other ions or molecules.

View full abstract

Alveolar bone loss is an essential phenomenon of periodnotitis in humans and animals. The main cause of this bone loss is inflammation. Recently, ligature induced periodontitis have been used to study the pathological alternations of the periodontal tissues in dogs. Bones always change the shape and structure by modeling and remodeling. Modeling changes the architecture, the dimension and the total amount of the affected tissue. Remodeling is a turn over mechanism that need not necessarily (but may) alter the geometry or dimensions of bone by BMU, basic multicellular unit, which comprises semimicroscopic formation one. Periodontitis not only resorbs the bone but may alter this dynamic process. This study was designed to determine the effect of ligature induced periodontitis on alveolar bone dynamics in dogs with histmorphometry. Periodontitis was induced around the third and fourth premolars on the left side of the mandible by ligating a nylon floss around the teeth and into the gingival sulcus for four, six and eight weeks. The right side on which ligature was not applied served as the control. Evaluation of the dynamics of appositional bone growth was facilitated by subcutaneous administration of calcein. Administration began 13 days before the end of the study with the use of a schedule of 3 days on, 7 days off and 3 days on. The dosage of calcein was about 8 mg/kg per day. After killing the dogs, the specimens were prepared for bone histmorphometry. Morphometric measurement was taken with the microcomputer-based system. Before measurement, alveolar half of frontal-sectional mandible was divided into four segments, upper buccal (Bu), lower buccal (Bl), upper lingual (Lu), and lower lingual (Ll). The bone surface on upper buccal and upper lingual segments were divided into four surfaces, buccal gingival (BG), buccal periodontal (BP), lingual gingival (LG), and lingual periodontal (LP). The following parameters were measured on alveolar bone surface : the length of Howship's lacunae surface (Lr), the length of osteoid surface (Lf) and the number of osteoclasts per 1 mm of Howship's lacunae surface (Noc/Lr). The following parameters were measured in alveolar cortex : the number of resorption cavities per square mm (Ar), the number of secondary osteons with osteoid seam per square mm (osAf), the number of calcein labeled osteons per square mm (calAf), the appositional rate of bone matrix mineralization in microns per day (Mo) and the length of circumference of calcein label per osteon (Sl). The results were as follows : 1. Lr, Lf and Noc/Lr were markedly higher in value in the inflamed than in the control side. 2. In the inflamed side, Lr and Noc/Lr were higher in value on the gingival than on the periodontal surface. Lf did not show the difference between them. In the control side, these three parameters did not show the difference between them. 3. Ar, osAf and calAf were significantly higher in value in the inflamed than in the control side. Especially, Ar was significantly increased at four weeks, and osAf and calAf were significantly increased at eight weeks. 4. Mo showed significantly positive correlationship with Sl in the inflamed and in the control side, but did not increase or decrease with inflammation. 5. Internal remodeling activated most on upper buccal segment. These results suggest that periodontitis causes bone resorption followed by bone formation on the bone surface, and activates internal remodeling in the cortex, but does not suppress these process.

View full abstract

In order to investigate the condylar path and incisal path without raising occlusal vertical dimension, mandibular movements with excursion in 31 subjects with normal dentition and jaw relation were recorded on pantograph. The mandibular movements were reproduced from the recordings on a Denar SE Fully Adjustable Articulator, and condylar path and incisal path were measured. Their distance of displacement and direction of movement were then examined. The results were as follows : 1. Displacement of incisal point starting from centric occlusion to anterior edgeto-edge occlusion was 5.0±1.4 mm and that of condylar point was 4.9±1.3 mm. Positive correlation was recognized between the two. 2. Inclination of protrusive incisal path was 36.5±9.6° and that of protrusive condylar path was 33.8±5.7°. No correlation was recognized between the two. 3. Inclination of sagittal section of protrusive occlusal facet on the lower central incisor was correlated with inclination of protrusive incisal path but not with inclination of condylar path. 4. Displacement of incisal point starting from centric occlusion to cuspid edge-to-edge occlusion was 4.7±1.0 mm and that of condylar point on the balancing side was 4.3±0.9 mm. Positive correlation was recognized between the two. 5. Inclination of the lateral incisal path was 62.9±10.8° and that of lateral condylar path was 35.8±5.8°. No correlation was recognized between the two. 6. Inclination of lateral condylar path on working side was 29.4±9.8°. No correlation with the inclination of lateral condylar path was recognized. 7. Condylar path and incisal path were in positive correlation in the distance of movement. However, no correlation was recognized in the direction of movement which projected on the sagittal plane. 8. Inclination of protrusive path and that of lateral path of posterior tooth was 36.4±7.1° and 38.2±6.2° respectively. Neither path was correlated with inclination of condylar path. However, both were correlated with inclination of incisal path. The direction of movement of the molar region was greatly affected by incisal path rather than by condylar path.

View full abstract

It has been said that the shape of the mandibular fossa may be variously changed by aging and some other factors. The mandibular fossa is a component of the temporomandibular joint and the change in its shape may intimately affect the mandibular movement. It is, therefore, of great importance to know the changing aspects of the mandibular fossa on reconstructing the occlusal surface of the prosthetic appliances in harmony with the mandibular movement. In this study, morphological differences by sex, age, left and right side, denture wearing period, and habitual one-sided mastication were investigated for complete denture wearers age 50 and over, using Fourier analysis for the radiographs taken by the standardized oblique lateral technique. The results were as follows : 1. No differences in shape of the mandibular fossa were found either between the right and the left side in each age group or among the different age groups. 2. The shapes of the mandibular fossa in males tended to be deeper than those in females. 3. In complete denture wearers with habitual one-sided mastication, the mandibular fossa of the non-masticating side was deeper from the roof to the anterior wall than that of the masticating side. 4. No differences were found between the dentulous group and the group wearing complete denture for a period of 5 years or less. However, in a comparison between the group of 5 years or less and the group of 6 to 10 years, the latter tended to show shallower shapes. Further significant changes could not be observed between the groups of 6 to 10 and 11 to 20 years, and between the groups of 11 to 20 and 21 years and over.

View full abstract

In order to investigate the effect of the difference in magnitude of cutting load, one of the cutting conditions, on the dental pulp immediately after cutting in cavity preparation by high-speed cutting on vital tooth, a cutting device capable of exerting a given cutting load was designed. With the use of this device, 80g or 120g cutting load was applied on the six lower anterior teeth of dogs in performing cutting preparation, and light and electron microscopic observations were made. The results were as follows : 1. Scanning electron microscopic observation of the three dimensional structure of dentinal fibers of non-cut dogs' teeth with application of cryofracture and the HCl-collagen digestive method showed that most of the dentinal fibers, as in the human teeth, ran in the three dimensional curve from the odontoblasts arranged in a line and reached the enamel-dentin junction. 2. Light microscopic observation of cavity preparated teeth of dogs showed irregular arrangements, reticular atrophy, and appearance of aspirated bodies in the odontoblasts under the cavity in both 80g and 120g cutting load cases. At the same time, no significant changes were observed in the proper dental pulp under the odontoblasts. 3. Aspirated bodies appeared in 52% of cavity preparations with 80g cutting load and in 60% of 120g load. 4. The fact that the aspirated bodies which had appeared immediately after cavity preparation showed Feulgen positive nuclear reaction suggested that each was the nucleus of the odontoblast. 5. Transmission electron microscopic observation showed morphological changes in odontoblasts in both 80g and 120g preparation cases. Namely, atrophy, pyknosis, and aspiration of some or most the nuclei of odontoblasts which penetrate into the dentinal tubules were observed. However, alterations of the odontoblasts in 120g preparation were more conspicuous than those of 80g preparation. Almost all of the aspirated bodies observed in 120g preparation were located deeply in the dentinal tubules and their nuclei occasionally showed dissolutive appearance. 6. It was suggested that one of the pathogenesis for the appearance of aspirated bodies might result from dragging-in of the dentinal fibers by air-turbine revolution. 7. It was observed in this study that the less cutting load made the impairment to the odontoblast slighter. The necessity of less cutting load in clinical work was confirmed again.

View full abstract

A neuro-pathohistological study was made with use of 48 Wistar rats on the behaviour of the distal nerve tissues in the tongue with cryosurgery for N. hypoglossus. The N. hypoglossus have been exposed at the proximal side and frozen to -100℃ for 90 seconds. The results were as follow : 1) Immediatly after freezing, the bundle of nerve fibers in the tongue suffered degeneration and reached a height of degeneration on 3rd day. By 10th day, the degenerated nerve fibers disappeared. Degeneration advanced gradually from the proximal to the distal side and finally spreaded over the tongue. 2) Regeneration of the nerve fibers started on 3rd day as the proliferation of Schwann cells with the delicate nerve fibers in the radical region of tongue. On 10th day, these delicate nerve fibers formed bands of thinly arranged nerve fibers, and the bands began to extend gradually to the distal region about 14th day after freezing. The nerve distribution was about completed on 30th day after freezing, but the nerve fibers were still delicate. On 60th day, there was no difference between the experimental side and the normal side. 3) The muscle tissues neighbouring on a line of progress of freezing nerve bands in the tongue suffered inflammation with edema on 2nd day, and reached a high level on 5th day. Appearence of inflammation of the muscle tissues was seen on 20th day. 4) The process of degeneration and regeneration of the distal nerve fibers after cryosurgery was similar to the usual pattern seen after surgical-cut. But beginning of regeneration for cryosurgery was earlier than for surgical-cut, and the completion of distribution was very early also. As stated above, it is clear that cryosurgery considerably affects nerve tissues, though not so greatly as surgical-cut. Therefor clinical application of cryosurgery in the oral cavity must be made with care. Particular care must be taken in an application to oral tissues to have a good grasp of the surrounding nerve distribution and not to affect the nerves.

View full abstract

It is now considered that the occlusal disharmony is one of the causes of the temporomandibular joint pain-dysfunction syndrome. In order to investigate the relation between the temporomandibular joint disorder and the malocclusion, the experimental studies were made. A metal cast crown was set on the lower right first and second molar teeth. The histopathological changes of the temporomandibular joint were observed from 5th to 120th days. Then the crown was removed on 120th day. The subjects were investigated histopathologicaly from 30th to 180th days after the crown removal. The results were as follows : There were the findings of the waving fibers of the temporomandibular articular disc, the villi proliferation of the upper posterior synovial membrane and the singular linings of the chondrocytes, after the metal cast crown set. After removing the metal cast crown on 120th day after its setting, there were not any waving fibers of the temporomandibular articular disc, and the linings of the chondrocytes also improved completely. It was considered that the temporomandibular joint disorder following the sudden disharmony of occlusion improved clearly and gradually, after removing the inadequate prosthesis, the causal factor. The original mandibular movement was also restored.

View full abstract

Anti-inflammatory drugs used in the daily dental clinical work are the most frequently used drugs along with antibiotics. For evaluation of the effect of drugs, various methods have been reported to date. The tissue culture method is one of them and is an excellent one. The author cultivated in vitro the skin tissue of albino rat fetus and investigated the effect on the cultured cells of steroid anti-inflammatory drugs (SAID)(Predonine : Prednisolone sodium hemisuccinate, and Decadron : Dexamethasone sodium phosphate) and of non-steroid anti-inflammatory drugs (NSAID)(Solantal : Tiaramide hydrochloride, and Urokinase). The results were as follows : 1. In the treatment with SAID (Predonine and Decadron), proliferation of fibroblastilke cells was restricted, when the culture was treated after cultivation, with high dose of Predonine, 0.5mcg/ml, and Decadron, 0.02mcg/ml. In low dose treatment with Predonine, 0.005mcg/ml and Decadron, 0.0002mcg/ml, stimulatory proliferation suggestive of the effect of the drugs was observed in the fibroblast-like cells. When these drugs were applied simultaneously with cultivation, significant restriction of proliferation of the fibroblast-like cells was clearly observed. Morphological regressive changes in the cytoplasm, nucleus, and nucleolus were observed in both the cultured epithelium-like cells and fibroblast-like cells. These regressive changes were observed not only in the fibroblast-like cells but also in the epithelium-like cells. Furthermore, these changes intensified more in the high dose application group than in the low dose application group and in proportion to the number of application days. 2. In the treatment with NSAID (Solantal and Urokinase), restriction of proliferation of fibroblast-like cells was observed when high dose of Solantal, 5mcg/ml, and Urokinase, 0.06 unit/ml, was applied after cultivation. In the low dose treatment with Solantal, 0.05mcg/ml, and Urokinase, 0.0006 unit/ml, proliferation suggestive of the effect of the drugs was observed. When these drugs were applied simultaneously with cultivation, proliferation of fibroblast-like cells was more distinct. Morphological regressive changes were clearly observed in both the epithelium-like cells and fibroblast-like cells. These regressive changes were intensified in the high dose application group and in proportion to the number of application days. 3. No significant difference by drug was observed in restriction or promotion of proliferation, and in regressive changes in both cells. However, appearance of giantcell-like cells was observed in the experiment with SAID but not with NSAID. With Urokinase which is anti-inflammatory enzyme, regressive changes were observed in the epithelium-like cells rather than in the fibroblast-like cells.

View full abstract

Up to the present time, there have been interests in tongue size and tongue function as factors of causing malocclusion. As far as tongue function is concerned in orthodontic practice, abnormal swallowing is almost always observed as one of the causes of open-bite cases. In such cases, if tongue movement doesn't restore normal function after occlusion is corrected by orthodontic treatment, there are possibilities of relapse after treatment. Therefore, after treatment, presence or absence of abnormal swallowing must be determined and proper measures must be taken if any in order to maintain stability of occlusion. In an effort to detect abnormal tongue movement during swallowing, the present study made the analysis of tongue movement through lingual pressures and intraoral air pressure during swallowing, and compared swallowing in normal occlusions with swallowing in open-bite cases. Eight adults with normal occlusion and four adults with anterior open-bite were selected as subjects. Intraoral air pressure was measured in the palatal vault simultaneously with lingual pressures against the maxillary and mandibular central incisors and lingual pressures in the palatal regions of the first premolar and the first molar while the subjects performed three swallowing exercises. The first exercise was spontaneous saliva swallowing ; the second, water swallowing on command, and the third was saliva swallowing on command. The results were as follows. 1. In the normal occlusion group, peak lingual pressures of the mandibular incisor, the maxillary first premolar and the first molar were higher than that of the maxillary incisor. In the open-bite group, peak lingual pressure of mandibular incisor was almost equal to that of maxillary incisor, but peak lingual pressure of maxillary first premolar was lower than these pressures. 2. No differences in peak values of intraoral negative air pressure and intraoral positive air pressure were observed between the normal occlusion group and the openbite group. 3. During spontaneous saliva swallowing and saliva swallowing on command, in the normal occlusion group, intraoral negative air pressure began to be produced before lingual pressure of the maxillary incisor was at a peak period. After that, intraoral negative air pressure reached a peak value and intraoral air pressure changed from negative air pressure to positive air pressure after the lingual pressure had reached a peak value. In the open-bite group, intraoral negative air pressure reached a peak value before lingual pressure was at a peak period. 4. The open-bite group showed a compensatory tongue movement which adapted to anterior open-bite to obtain the intraoral negative air pressure for swallowing, and the open-bite group was characterized by thrusting the tongue tip between the maxillary and mandibular incisors and a smaller elevation of the anterior portion of the dorsum of the tongue than that of the normal occlusion group.

View full abstract

Cavity preparation was performed on deciduous teeth characterized by physiologic root resorption, and general changes in the pulp and the state of nerve fibers in the pulp were investigated. The results were as follows : 1. Thirty minutes after the cavity preparation, no changes were observed in the predentin and odontoblastic layer at the cavity floor and at the regions of the cavity walls. In the cell-free and the cell-rich layer adjacent to the odontoblastic cells and in the dental pulp, no reactive inflammatory state was observed. As for distribution of the nerve fibers, no changes were observed. 2. After 24 hours, appearance of rods was significant in the dentin and predentin at the cavity floor and the regions of the cavity walls and no nerve fibers were observed in these areas. Because of the reactive inflammatory state, atrophy and disappearance of the odontoblastic cells directly under were extensive, the junction between the cell-free and cell-rich layers become indistinct, and inflammation extended as far as the central region of the dental pulp. Although most of the nerve fibers in these areas disappeared, some degenerative nerve fibers showing laceration or granular destruction were still observed. In the healthy odontoblastic cells and cell-rich layer slightly under the regions of the cavity walls, small nerve bundles, small nerve fibers, and single nerve fibers were still observed. 3. On about third day, appearance of rods decreased in number as compared with that after 24 hours and was rarely observed on 7th day. Reactive inflammatory state still continued but showed a tendency to disappear. On 3rd and 7th days, appearance of regenerated nerve fibers from the healthy pulp tissue under the regions corresponding to the cavity walls was observed significantly. 4. On 14th day, formation of the stroma of predentin was in progress at the cavity floor and the regions corresponding to the cavity walls, and inclusion of cells in it was observed in places. Ovoid cells, polymorphous cells, and taller cells were observed adjacent to the stroma. Relatively larger cells were beginning to be disposed and differentiated into odontoblastic cells presenting the morphology resembling odontoblastic cell. In the nerve fibers distributed nearby, medium nerve bundles, small nerve bundles, and single nerve fibers were noticeable and they ran relatively monotonously. 5. After 35th days, formation of secondary dentin was observed directly under the cavity floor and the number and running of dentinal tubules were distinct and regular in the transitional region from primary dentin but dentinal tubules were still indistinct in the central region of the secondary dentin. Odontoblastic cells directry under the secondary dentin were arranged regularly for the most part. The cell-free and cell-rich layers were indistinct and a few inflammatory cells were observed in the dental pulp. Relatively abundant nerve fibers were beginning to be observed in the dental pulp directly under the secondary dentin, and congregation of some nerve fibers was noticeable. They were beginning to present compactness through complexity and anastomosis. 6. On 95th day, the secondary dentin formed was thicker than that on 35th day, and the dentin presented the dentinal tubular structure quite similar to that of the primary dentin. The predentin and odontoblastic layer were about normal. The cell-free layer and cell-rich layer were clearly demarcated. At this time, the distribution of nerve fibers was abundant, several nerve fibers congregated in bundles, and minute nerve fibers branching out from them began to appear. They were more compact and formed plexuses as compared with those on 35th day and were beginning to form Raschkow's plexus. Although very few in number, inflammatory cells were observed in the dental pulp.

View full abstract

In an experimental study of root canal filling in deciduous teeth, a cytotoxic test by the tissue culture method and a histopathological test in deciduous teeth of dogs were made with use of preparation of calcium hydroxide (Calvital), iodoform calcium hydroxide (Vitapex), and zinc oxide eugenol (Neodyne [○!R]). The results were as follows : 1. In the cell multiplication test, Calvital and Neodyne [○!R] markedly inhibited proliferation at 50% and 20% concentrations. Vitapex however showed only slight inhibition at every concentrations. 2. Calvital and Neodyne [○!R] showed active proliferation and recovery phenomenon in the third to fifth days. 3. In morphological changes, the reaction zone of cells was the most narrow one for Vitapex and its changes in pH of the medium were negligible. Calvital changed pH of the medium to high alkalinity and its reaction zone of cells was relatively width. Neodyne [○!R] also changed its medium to alkalinity and its reaction zone of cells was the widest and spreaded on nearly all surface of the Petri dishes. 4. In histopathological investigations, Calvital and Vitapex showed almost no inflammatory changes in the periodontal membrane. Neodyne [○!R] however induced inflammatory changes. 5. When the preparation was exudated through the apical foramen, Calvital and Vitapex showed very slight inflammatory cell infiltration limited to the periodontal membrane. For Neodyne [○!R], formation of abscess was observed. 6. On a longer term, the trend for inflammation disappeared and turned for healing for each preparation. 7. Vitapex showed vacuolar formation, as a specific change in the apical periodontal membrane. 8. In the cases where the exudated preparation approached the alveoler bone, necrosis of bone tissue, and degeneration and disappearance of osteoclast were observed in part. 9. Delay in resorption of deciduous root in the filled side was recognized for each preparation, but no distinct difference was found among these preparations.

View full abstract

Measurements were taken of the diameter and length of each part of commercial guttapercha-points of international standard of six companies (Kerr, Zipperer, Mynol, Maillefer, G-C and Todent). The measurements were compared with the specification in DIN to determine the status of standardization. The results were as follows : 1. The total length specified in DIN Standard is 30mm. Maillefer #50, #60, #70, Mynol #70, G-C #45 and #50 were longer and the others were shorter. Rather narrow variations were seen in the total length and effective length between pins of the same specification of each company. 2. In the comparison of d_1 of the six companies with that of DIN Standard. Mynol #50, #55, #60, #70 were larger, and the others were smaller. 3. G-C's approximated the tapering specification of DIN Standard. Contrarily, Mynol's were the smallest. Kerr's and Todent's had the least variations in tapering.

View full abstract

Twenty-five cases of pleomorphic adenomas developing in the human palate region were examined by light and electron microscope. From the morphological point of view, the tumors were divided into four patterns. The main results obtained were as follows : 1. Twelve of the twenty-five cases were of the ductular pattern. i) The tumor consisted of cuboidal or columnar cells of one to two layers which formed lumens of different sizes and shapes. The wart-shaped microvilli protruded into the lumen of the ducts from the surface of each cell and the surroundings of the ducts were enclosed with the fibrous connective tissue. ii) In the cytoplasm, there were observed well-developed Golgi apparatus, rough-ER, and many secretory vesicles or granules. 2. Six of the twenty-five cases were of the corded pattern. i) The arrangement of spindle or polygonal shaped cells showed lattice or reticulum-like appearance. ii) The difference between light and dark cells was remarkable, and the latter with circular or irregular nucleus were recognized in large numbers. The development of dark cell's organelles was poor. The arrangement of the adjacent cells was coarse, and the junctional form among them was interdigitation, each tip of which was combined with desmosome. 3. Four of the twenty-five cases were of the solid pattern. i) Many cells of spindle or polygonal shape were seen. Nuclear shape was circular or elliptical, and each nucleus was located in the center of cytoplasm. ii) Ductular formation was few. The development of this tumor cell's organelles was good. The junctional form among the adjacent cells was desmosome. 4. Three of the twenty-five cases were of the mixed pattern. Although the mixed pattern was only a few in cases, these tumors were seen as mixed with the three pattern's findings already described. 5. From the morphological point of view, the cells of pleomorphic adenomas developing in the human palate region should be considered to be of epithelial origin.

View full abstract

This article showed that a typical case of cystic ameloblastoma in young patients was treated by means of the fenestration and the partial resection of mandible without hemiresection or continuous resection.

View full abstract

The syndrome of multiple nevoid basal cell epithelioma, multiple odontogenic keratocyst and skeletal anomality is far more complex and encompassing than was supposed when first described by Jarisch in 1894. The change that involved skin includes multiple nevoid basal cell epithelioma appearing in childhood or at puberity, dyskeratosis, milias, cyst and fibromas or neurofibromas or both, especially the extremites. The cause of the syndrome is unknown and autosomal dominant inheritance which is determined by a highly penetrance gene and multiple variable effects. There is no predilection on the basis of sex. A 12-year-old girl had many features of the basal cell nevus syndrome which were frontal bossing, wide nasal root, hyperterorism, deep-set eyes, several bifid ribs, calcification of the falx cerbri. Long term observation will be necessary to detect the possible development of either basal cell epithelioma or the recurrence of the odontogenic keratocyst.

View full abstract

A case of chronic diffuse sclerosing osteomyelitis of the left mandible in a 50-year-old man is reported. This patient visited our hospital with a chief complaint of trismus and pain in the left mandibular body which had been noticed before 4 or 5 years. He was medicated with antibiotics intravenously and by per os for 20 days, and then a mandibular resection with disarticulation of the right condyle and replantation were carried out. The removed mandible, from which bad granulation and sequestrum were curetted as extensively as possible, was steeped in antibiotics solution for 30 minutes and was used for replantation for immediate reconstruction. At present, 10 months after operation, symptoms leading to recurrence are not found.

View full abstract

A case of asymmetrical prognathism for which surgical correction was performed by stepostectomy of the mandibular body has been reported. The patient, a 22-year-old girl, visited Fukuoka Dental College Hospital with chief complaints of her facial asymmetry and malocclusion. Her facial appearance was markedly asymmetric and the P-A cephalogram showed that the mandible deviated to the left side. Intra-oral examination revealed the dental middle line of the mandible deviated 4mm to the left side and an anterior cross bite. Stepostectomy of the mandibular body was performed to correct her asymmetrical prognathism and we obtained the following results. 1) After the operation the deviation of mandibular middle line, asymmetric lower lip and the occlusion were improved. But the asymmetric contours of the bilateral mandibular angles still remained as they were. 2) It might be thought that such an asymmetrical prognathism as this indicated a combination of stepostectomy of the body with sagittal splitting osteotomy of the opposite ramus to correct the asymmetric contours of the mandibular angles.

View full abstract