Sixty-six human teeth excavated from protohistoric burial tomb at Yokomichi in Mine city, Yamaguchi Prefecture were examined. The following results were gained. 1. Of the 66 teeth, sixty-one were permanent teeth and five were deciduous teeth. 2. A comparison of the tooth measurements between the old mound men and the modern Japanese showed that the former's was larger than the latter's in the root length in particular. This is the same tendency as that of the men of the Yayoi age. 3. A characteristic morphology is that some of the teeth present a remarkable primitive form in comparison with those of the modern Japanese. 4. It is presumed that the 66 teeth are those of about nine individuals. The five deciduous teeth and two of the upper and lower first molars are presumed to be those of a child, three to five years old, and two individuals are presumed to be ten to fifteen years old. Remaining six individuals could not be identified. 5. The sex difference could not be determined with accuracy, but it is supposed that only two individuals are female.

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The transverse palatine ridges of 83 racoon dogs, a carnivora, were observed with use of plaster impression models of the palate. The results were as follows : Measurements of the palate : 1. The upper anterior palate width was 16.3mm, a maximum palate width 35.5mm, the width between the right and left first molars 16.6mm, and the width between the right and left second molars 17.7mm. 2. The length of palate, that is, the distance between the orale and the intersecting point of the median line and the line between the lingual projecting points of the right and left second molars, was 52.0mm. Form of the ridge : 1. On the number of ridges, eight ridges were recognized in 2 cases, nine ridges in 57 cases, and ten ridges in 24 cases. 2. Till the sixth ridge or so, the ridges showed a symmetrical and continuous form. 3. The ridges after the seventh in most cases were broken in continuity at the median line but were symmetrical. The more posteriorly the ridges were positioned, asymmetrical ridges tended to increase in number. 4. Dotted-line or broken-line ridges were observed in 37 cases. These ridges appeared mostly between the eighth and ninth and between the ninth and tenth ridges. 5. The most posterior ridge was positioned in the vicinity of the distal side of the first molar. 6. The form of the ridges as a whole was as follows : the more anteriorly the ridges were positioned, the more projecting they were. The more posteriorly they were positioned, the less in projection the ridges became, showed gradually two-arc patterns, and changed into the type with the ridge broken at the median line.

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Myoepithelial cells (MECs) are particular smooth muscle cells which lie between the glandular epithelial cells and basal lamina of the terminal portion of a variety of exocrine glands and function by contracting, thereby expelling the secretion from the terminal portion to the duct. These MECs have several characteristic features which differ from ordinary smooth muscle cells ; they are thought to be epithelial in origin and are usually stellate in form rather than simple spindle-shaped. In spite of a number of studies, the overall morphology of the MECs of exocrine glands has not been elucidated at the fine structural level. In the previous short communication, the author has reported the method to obtain the scanning electron microscopical image of MECs of the rat sublingual gland. Using a further improved method which consist of the enzymatic digestion followed by HCl-hydrolysis, the present paper concerns the comparative fine structural study of MECs in a variety of exocrine glands including the sublingual, submandibular, parotid, lactating mammary and exorbital lacrimal gland. The fine structural features of MECs in each gland were also examined by transmission electron microscopy, paying a particular attention to morphological relationship between adjacent MECs, and between MECs and glandular epithelial cells. MECs in the sublingual gland were characterized by a number of broad and extensive cellular processes which closely contacted those of adjacent cells forming a continuous network around the terminal portion. Those of the submandibular gland were stellate in shape, consisting of cell body and a number of thin ramifying cellular processes, the total number of terminal processes was 20-30 per cell. No MECs were observed on the terminal portion of the parotid gland, the cells appeared to be lodged on the intercalated duct. In the lactating mammary gland, they had a few long cytoplasmic processes 2-3μm wide which tended to ramify to produce a total component of 8-10 terminal processes per cell. MECs in the exorbital lacrimal gland were typically stellate in shape, consisting of a central cell body and a number of thin ramifying cellular processes, the total number of terminal processes was 15-20 per cell. The cellular processes tended to terminate freely with a tapered end. The relative surface area covered by MECs per terminal portion was also found to vary significantly, being 48% in the sublingual, 25% in the submandibular, 24% in the lactating mammary, and 17% in the exorbital lacrimal gland. In the lactating mammary gland, well developed gap junctions were observed in the intercellular space between adjacent MECs. Few gap junctions were observed in salivary and exorbital lacrimal glands. In the submandibular, parotid and exorbital lacrimal glands, there were well developed foliate cytoplasmic processes of glandular epithelial cells in the intercellular space between MECs and glandular epithelial cells.

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The morphology and fine structures of the embryo suckers of Rana nigromaculata during development were observed. The results obtained are as follows. 1. At 2.0mm in body length, the suckers were recognized on the upper abdominal area as grooves composed of smaller cells without cilia (specific cells). The surroundings of the grooves thickend and was composed of the two types of surface cells with and without cilia. At the stage of 4.0 to 6.0 mm in body length, the suckers developed and completed their forms. Then, the suckers began to degenerate at 6.5mm in body length, and disappeared completely at 8.5 mm in body length. 2. Fully developed suckers were composed of the specific cells facing at grooves (described above), the basal cells and the surrounding cells. 1) The cells facing at grooves were long columnar (80∿90μm in length), and were filled up with secreting granules, yolk platelets, lipid droplets and pigment granules. 2) Basal cells were short in length and contained distorted nucleus, yolk platelets, lipids and mitochondria, and had a little of the other cellular organeles. 3) There were two cell types in surrounding cells (surface cell groups). One type of cells with cilia contained many mitochondria, and the other type without cilia containd many mucous and pigment granules. 4) All of these cells contained the rectangular crystalline structures in mitochondria.

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The author performed the vital pulpotomy on deciduous teeth using paste type Procal from calcium hydroxide, paste type Cavitec from zinc oxide eugenol, and FC process from formocresol and examined them histologically about healing after pulpotomy on vital pulp of deciduous teeth and the results are as follows : 1. Forming of necrosis layer is observed on the part given vital pulpotomy ; it is rather extensive in case of using FC process and comparatively slight in the case of using Procal and Cavitec. 2. Fourteen days after operation, in the case of using Procal, the pulp surface touched with agent becomes hyalinized and inflammatory cells infiltration, congestion and bleeding were observed in the lower part of the pulp. In the case of using Cavitec, infiltration of inflammatory cells and bleeding are remarkably observed in the pulp surface, and diffuse infiltration is seen to the lower part of pulp tissue. In the case of using FC process, infiltration of inflammatory cells is observed, in the pulp surface, but the whole pulp becomes fibrous and it stains light purple by silver impregnation and light red by Elastica van Gieson. 3. From 21 days to 92 days after the operation, in the case of using Procal, inflammatory cells infiltration is clearly observed and inflammatory granulation tissue remarkably proliferates after 21 days. When 35 days pass, calcareous tissue is formed between necrosis layer and the pulp and seals cells inside. A layer stained dark purple by silver impregnation, and light red by Elastica van Gieson appears. When 92 days pass, a hard tissue made of osteoid dentin containing cells of different thickness is recognized in the pulpotomy. It stains dark purple or blackish purple by silver impregnation, and light red or red by Elastica van Gieson. Therefore it is recognized as collagen stroma, but is uneven in appearance and partly remains fibrous. In the case of using Cavitec, abscess is found in the pulp surface and proliferation of inflammatory tissue is remarkable in the pulp below. The pulp farther below is healthy and vital. In the case of using FC process, fibrous change found after 14 days continued till the 92nd day. 4. Internal resorption is observed on the 35th day for Procal, on the 21st day and the 92nd day for Cavitec, and the 21st day for FC process.

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A loss of tooth caused by teeth and periodontal diseases is frequently encountered in the daily clinical work. The two neighboring teeth and periodontal tissues, in coping with healing of tooth extraction wound and functional changes, show changes as reactions of the affected region to such a tooth loss. Detailed reports on experimental studes of healing process of tooth extraction wound, changes in the form of alveolar ridge, and shifts of the two neighboring teeth after a tooth loss are available. However, pathohistological studies of displacement process of the two neighboring teeth are few. Changes in periodontal ligaments, in particular, remain unaccounted for. Monkeys (macaca irus) were used for the present study. The lower first molar were extracted and changes in the periodontal tissues of the two neighboring teeth were investigated pathohistologically. The results were as follows : 1. Apposition of bone was seen three to thirty days after tooth extraction in the lower margin of the mandible between the two neighboring teeth inclusive of the extraction wound. 2. Roughing of the mesial wall of alveolar bone and bone resorption of the two neighboring teeth, due to physiologic tooth movement, continued until about 14 days after tooth extraction. 3. The changes resulting from extraction in the periodontal tissues of the two neighboring teeth seven days after extraction were resorption of the distal wall of alveolar bone of the second premolar and more remarkable resorption than before of the mesial wall of alveolar bone of the second molar. 4. Apposition of bone was seen 21 days after extraction in the peripheral walls of alveolar bone of the two neighboring teeth. At this point, physiologic tooth movement had already ceased. 5. Between 30-60 days after extraction, many osteoblasts appeared in the mesial side of the second premolar and in the distal wall of alveolar bone of the second molar. Apposition of new bone in strata was observed in some parts. In the opposite side of the alveolar bone, osteoclasts appeared. Periodontal ligaments at the resorpted site were irregular in arrangement and thickness of the bundles. Those at the boneadded site were regular in arrangement and thickness of the bundles. 6. New bone formed in strata 90 days after extraction on the mesial side of the second premolar and in the distal wall of alveolar bone of the second molar. Periodontal ligaments ran straight on the mesial side of the second premolar and in the upper half of the periodontal membrane on the distal side of the second molar. In the lower half of the periodontal membrane, they ran in wavy lines. 7. Displacement of the two neighboring teeth toward the extraction site was remarkable 90 days after extraction. Because of a grater bone addition in the distal wall of alveolar bone of the second molar, tooth displacement was more remarkable in the second molar. 8. Tooth displacement toward the extraction site was sliding of the tooth-body. 9. Changes in periodontal ligaments occurred mainly on the alveolar bone side than in the mid-part of periodontal membrane.

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The temporomandibular joint (TMJ) is hard to cope with because of syndrome including pain, clicking, limitation and displacement of the mandible. The many approaches in our field still leave unsolved some causative factors which are complicated in dental science. The purpose of this paper is aimed at investigate the relationship between clinical findings and tracing using the Stuart Pantograph. The results were as follows : 1. Each group showed the clinical features but there was no significant variance among the groups. 2. Anterior Horizontal Plane (AHP) The distance of the mandibular direction in the group related to the displacement of the mandible and the PCNW area in the group related to the limitation showed high values. 3. Posterior Vertical Plane (PVP) On the classification of the Fisher's angle and the protrusive path, the group related to the limitation showed a tendency toward the negative Fisher's angle never seen in the normal group. 4. Posterior Horizontal Plane (PHP) The immediate side shift easily occurred in the group related to the displacement of the mandible. Double curved type of the classification of the working path was very frequent in the group related to the limitation and to the displacement of the mandible. 5. Curve Variation Index (CVI) The mean level in the group related to the clicking showed higher values than the other groups. In each group, it is possible to speculate and support the causative factors of clinical findings by analysing the tracing. The pantographic screening of each group is of benefit to the etiology and treatment of the TMJ syndrome.

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1. A rare case of five-rooted (two-roots in buccal part, three-roots in lingual part) right maxillary third molar in 75 years old male was reported. 2. This case was caused by division in three parts of lingual root. The buccal root was normal morphologically. 3. The cause of the multi-rooted tooth is attributed not to the phylogenesis but to the division of the tooth germ in the embryonic stage of development.

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A case of von Recklinghausen's disease accompanied by neurofibroma in the palatal gingiva, abdomen and elsewhere in a 35-years-old female is reported. Hereditary factor was ont observed. However, an oligophrehia was noticeable with a history of injuries in the left orbit. In the histopathologic findings, the tumors in the palate and skin both revealed the findings of neurofibroma. After the surgical removal of the tumors, the patient progressed satisfactorily, and a tendency to recur was not present.

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In this paper clinical and statistical observations on inpatients during thirteen years from January, 1967 to December, 1979, are briefly reported, with the following conclusions : 1) Four hundred and four patients were hospitalized, 231 of whom (57.18%) were male. 2) Frequencies of main disease were as follow : inflammation 178 cases (44.06%), injury 69 cases (17.08%), cystic disease 65 cases (16.09%), other diseaes 43 cases (10.64%), tumor 29 cases (7.1%), congenital malformation 20 cases (4.95%).

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