A series of field survey were undertaken among the inhabitants of Tanegashima islanders of Kagoshima Prefecture to examine their teeth as to the possible manifestation of ethnological characteristics and of age changes. Since the geographical situation of this island has suggested the existence of close communication with neighboring islands such as Okinawa and Formosa, data obtained from these regions were compared with those of Tanegashima islanders. Chronological comparison was also made between the teeth of Tanegashima islanders and those of the remains of Yayoi era inhabitants excavated from Hirota site of the island by Yamada et al.. Measurement was conducted on 133 plaster models of upper and lower jaws taken from inhabitants of Minami-tanegashima-machi and macroscopic observation was done on the morphology of crown of respective tooth of jaws. Results were summarized as follows. 1) No appreciable difference was noticed with every values of mesurement among the Japanese subjects of this and other regions and there existed rather close similarities between Tanegashima inhabitants and the inhabitants of Kyushu region and aborigines of Formosa. 2) Occurrence of the shovel shaped teeth and double-shovel shaped teeth in anterior teeth and occurrence of the spinal process in the upper anterior teeth were respectively infrequent as compared to the Japanese of other regions, and development of the distal accessory-ridge found on the lingual surface of canine teeth was weaker in the inhabitants of Tanegashima than in the common Japanese. 3) With regard to the groove types in the occlusal surface of upper premolar teeth no particular difference was detected to exist between the present subjects and the Japanase subjects in Kyushu region. However, when comparison was made of the above traits with the remains of Yayoi era, certain retrogressive trend was apparent in the teeth of Tanegashima inhabitants. 4) The cuspal types and the occlusal groove types in the lower premolar teeth of Tanegashima islanders were generally similar to those found in the inhabitants of Kyushu region. Howevrer, comparison between Tanegashima islanders and Yayoi era remains revealed that the latter showed greater trend of first premolar to have bicuspid and greater trend of second premolar to have teicuspid. On the other hand, the groove types of occlusal surface in Tanegashima islanders showed stronger trend toward retrogression as compared to Yayoi era inhabitants. 5) The cuspal types found in the upper molars in Tanegashima inhabitants were almost similar to those found in the common Japanese, showing a greater trend toward retrogression compared to Yayoi era inhabitants. Occurrence of the upper second molar having mesiodistally compressed crown was more frequently seen in the inhabitants of Tanegashima than in the common Japanese, and this phenomenon showed an inverse correlation with the occurrence of cuspal types. 6) Although no significant difference in the physical traits of lower molars crowns existed between Tanegashima inhabitants and the common Japanese, occurrence of Dryopithecus pattern in both first and second molars was slightly more frequent in the former than in the latter, and in first molar the frequency of Dryopithecus pattern nearly equaled that in Yayoi inhabitants. 7) To sum up the whole data of present study, the physical traits of teeth in Tanegashima islanders were generally similar to those found in the Japanese of Kyushu region and its neighboring districts. Some regional deviation, however, existed with regard to several traits of tooth crown studied. Comparison between Tanegashima inhabitants and Yayoi era inhabitants further revealed certain chronological difference present with regard to some parts of these physical traits.

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In order to study the fine surface structure of endocardial and endoarterial endothelium in mature rabbit, dog and rat and neonatal rabbit and dog, a new perfusion and fixation methods were devised, and the heart, aorta and some other arteries were observed with scanning and transmission electron microscopes. The main findings are summarized as follows : 1. As the surface of the endocardial and endoarterial endothelium in each animal were essentially similar in fine structure, the observation of each animal will be described together. Microvillous projections presented various distributions frequently occurred on the surface of endothelial cells, in all animals irrespectively mature or neonatal. Especially, in the sinus aortae and sinus trunci pulmonalis, the endothelial surface tended to show numerous and long projections. Endothelial cells with only a few or no projections were also mingled. In the interior of the microvillus, thin straight filaments (50∿70 Å in diameter) run parallel to the long axis were distinguished. These filaments were closely resembled to myofilaments in smooth muscle cells. The possibility that the microvillous projections are contractile is discussed. 2. Craters are found on the endothelial cell surface in the aorta ascendens, arcus aortae and aa. intercostales branching point. They may possibly reflect physiological damages to endothelial cells in respons to the rheological peculiarities that occur at the site of branching or bending of vessels. 3. In both endocardium and endoarteries, there are endothelial cells with a process probably corresponding to single cilium. In the rabbit and dog a single cilium was identified on each cell, though in the rat its occurrence wes equivocal. A single cilium with its typical microtubular structure was demonstrated in ultrathin sections. In the neonatal rabbits, cilium was sometimes extended downward from the base of endothelial cells. Frequently, most of distal part of the cilium showed edematous swelling, indistinctly microtubular structure and/or dropping. These findings suggest a cause for which the cilia is only rarely observed on the endothelial surface. 4. In the neonatal animals, the endothelial cells of immature type are characterized by the presence of numerous microvillous projections which interlace with similar structures from adjacent cells to form intercellular gaps which overlie a subendothelial tissue. The endothelial cells of sinus aortae, sinus trunci pulmonalis, aa. intercostales branching point and right and left auricle, tended to show relatively immature type.

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In our clinical practice, we occasionally severed nerve fibers in treating the lingual diseases or traumatic injury of the tongue. In such cases, it seems to be very interesting how the functional disturbance was recovered physiologically or pathohistologically. The rat's lingual nerve, which was cut off at the peripheral portion in the root of the tongue, was used for the experiment. The results obtained are summarized as follows. A. Physiological findings : 1. By the 18th day after the unilateral cutting of the lingual nerve, the afferent impulses were not elicited from cutting side by tactile and chemical stimulus of the tongue surface. 2. In one of two cases on 21th day after the operation, the afferent impulses in cutting side were elicited by tactile stimuli. 3. In two cases on 31th day after the operation, the afferent impulses in cutting side were elicited by tactile and chemical stimulus. 4. Among 11 cases which lapsed from 30th to the 35th day after the operation, 3 cases showed responses to both tactile and chemical stimulus, 3 cases only to tactile stimuli. 5. Both frequency and amplitude of the afferent impulses were slowly increased as time elapsed. B. Patho-histological findings : 1. The nerve fibers in the fungiform papillae showed a slight degeneration by 24 hours after the operation. 2. The degenerative process of the taste buds in the fungiform papillae continued to be seen until about the 7th day, while the nerve fibers in connective tissue and muscular layer showed a picture of degeneration, which was swelling, laceration, granular decomposition and rosary-degeneration. 3. Taste buds had completely disappeared by the 10th day and were replaced by normal cells by 14th day. 4. Regenerated nerve fibers along Schwann's cell were observed in connective tissue and muscular layer on 17th day after the operation. 5. Regeneration of taste buds was observed in one case on 23th day after the operation. 6. The number of regenerated nerve fibers and taste buds increased as time elapsed. C. Relation between physilogical and patho-histological findings : 1. Patho-histologically, regenerated nerve fibers in connective tissue and muscular layer were observed on 17th day after the operation, while the afferent impulses were elicited on 21th day by tactile stimuli. 2. Regenerated taste buds in the fungiform papillae were observed on 23th day after the operation, while the afferent impulses were elicited on 31th day by tactile and chemical stimulus. 3. In unilateral cutting of the lingual nerve, functional recovery was obtained after morphological one, which was indicative for this experiment that the taste regained a partial recovery functionally and morphologically.

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Examinations of the effect of Methohexital-Na were made in rabbits and its anesthetic action was observed by Girndt-Magnus's method. The action on the respiration and blood pressure were recorded by a tambour and a mercury manometer. The results were as follows. 1. Methohexital-Na did not cause narcosis in the dose of 1 mg/kg, but in the dose of 5 mg/kg deep anesthesia was obtained. The duration of anesthesia lasted only 2 to 3 minutes. After 6 to 8 minutes, the animal recovered consciousness. 2. In the dose of 5 mg/kg, the respiration and blood pressure were arrested sufficiently. But these depressions soon passed away. After 4 to 5 minutes, the animal recovered consciousness. 3. Narcotic effect of Methohexital-Na was influenced to some extent by its injection speed. When injection was given speedily, narcosis became deeper and depressions increased. But there was no distinct difference whether the injection speed was in 10 or in 60 seconds. Even injection in 10 seconds brought about above mentioned symptoms but it lasted only 10 to 20 seconds. In view of the foregoings, it is considered that Methohexital-Na is an adequate anesthetic without any apparent side-effect in narcotic dose (5 mg/kg) injected in the speed of about 30 seconds.

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This investigation was undertaken to study the nerve distribution in the pulp of rhesus monkeys and its variation following cavity preparations and fillings. For each tooth a Class V cavity was prepared. Specimens were taken immediately after cavity preparations and intermittently for 9 weeks after the zinc phosphate cement pulp caps and amalgam cavity fillings were completed. The microscopic findings were as follows : 1. Both immediately and 2 hours after cavity preparations there were cases which showed no distinct changes. Most cases, however, showed vascular degeneration, atrophy and disappearance of odontoblasts directly underneath the cavity floor as well as congestion of blood vessels and hemorrhage in some areas. In the region showing a notable change, many nerve fibers disappeared. Others were observed to have alternate areas of constriction and swelling as well as a decrease in staining. Moreover, a few intact nerve fibers were left. It was felt that the intact nerve fibers caused pain after cavity preparation. 2. The greatest changes were seen in the pulp 24 hours and 3 days after the cavity fillings were placed. They were seen in the region directly underneath the cavity floors, just as in the cases observed immediately after cavity preparations. A congestion of blood vessels, edema and hemorrhage were seen in some cases. Some slightly degenerated nerve fibers and a few intact nerve fibers were observed in the region which showed the greatest change directly underneath the cavity floor. On the other hand, nerve fibers were recognized to have migrated to the surrounding intact tissues in order to escape from the degenerated region. 3. Seven days after cavity fillings the pulp showed repair in the areas of notable change. The changes in the pulp were localized directly underneath the cavity floor. The congestion of blood vessels was decreased throughout the pulp. In the region directly underneath the cavity floor, there was a tendency for reparative dentin to form. No degenerated nerve fibers were present in this region, but a few thin regenerated nerve fibers were present. 4. In the process of forming reparative dentin, tissues such as predentin, which were evident by their slight staining with eosin, were at first seen on the dentin wall directly underneath the cavity floor. The round or polygonal cells, which had larger nuclei and were larger than other cells, were recognized in the stratified arrangement on the inside of the tissues such as predentin. These were the undifferentiated odontoblasts. More than 3 weeks after cavity fillings, the reparative dentin showed an increase in thickness as the cells differentiated into odontoblasts, increasing both in height and in the amount of cytoplasm. In this case, the nerve distribution in the region with the undifferentiated odontoblasts was extremely sparse. Consequently, the regenerated nerve fibers were not considered to actively affect the differentiation of the odontoblasts. 5. Five weeks and nine weeks after cavity fillings the formation of a thick layer of reparative dentin was observed. Also observed was an arrangement of normal shaped odontoblasts on the inside of the reparative dentin. In the nerve fibers directly underneath the odontoblastic layer, a tendency to form Raschkow's nerve networks was seen. Moreover, the nerve terminals of the nerve networks which terminated in the odontoblastic cell layer showed a decrease in number compared to the normal case. In addition, nerve fibers penetrating the predentin were infrequently observed.

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In order to clarify so called central cancer of the maxillar whigh has the highest rate of incidence clinically, importance of basic researches of the maxillary carcinoma is intensified. As a basic research, Nagai of our department surgically placed by his own method 9, 10-Dimethyl-1, 2-Benzanthracene (DMBA) into the maxillary sinus of domestic rabbits and made observations for about 14 months. He reported a success in inducing tumors similar to squamous cell carcinoma found most frequent histopathologically in human. The report on the experimental carcinogenesis contains various findings as guide to be applied to clinical work for human maxillary carcinoma. The report however does not contain any description in detail of the process of carcinogenesis from normal mucous memebrane of the maxillary sinus composed of multi-serial ciliated cylindrical epithelium to sqamous cell carcinoma. The author of this report undertook and experiment to induce tumors in the maxillary sinus of domestic rabbits by a similar method and made a histopathological investigation of the changes in the process of formation. The results obtained were as follows : 1. Bees wax pellets containing 10 mg of DMBA (concentration 25%) were prepared and placed surgically into the maxillary sinus of the rabbits. 2. The experiment animals were killed in 3rd, 6th, 9th, and 12th month and were examined for the extent of formation. Confirmation of squamous cell carcinoma was made in the 12th month in 2 of the 7 cases which were under the longest observation. 3. The maxillary mucous membrane of the rabbit consists of multiserial ciliated cylindrical epithelium. The process of carcinogenesis leading to squamous cell carcinoma, after placing of the pellet, was found to consist, in order, of appearance of non-heteromorphous epithelial cell in the epithelium of the base of maxillary sinus, proliferation of non-heteromorphous squamous epithelium, intensification of atypism and polymorphism, atypical proliferation of squamous epithelium, and formation of squamous cell carcinoma.

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Carcinoma of the tongue was produced by implantation of Vx2 carcinoma in the tongue of domestic rabbits. The mode of proliferation of Vx2 carcinoma, the changes with the proliferation in the tongue, and vascular invasion by the cancer cells were investigated on the seventh, tenth, fourteenth, and twenty-first day after implantation. The results were as follows : 1. The cancer in the tongue enlarged with an increase in the elapsed time after implantation and proliferated infiltratively in the tongue. The vertical muscle bundles in the midline, however, showed some resistance to infiltration by the cancer cells into the non-implanted side. 2. An edema was observed in the tongue anterior to the carcinoma with the enlargement. 3. The edema was caused by hydrops and the vascular invasion by the cancer cells were deemed to be related to the occurrence of hydrops. 4. The vascular invasion by the cancer cells was observed in all the subjects between the seventh and fourteenth day. 5. The sites of the vascular invasion were almost entirely limited to the venous system. Cancer cells were observed to proliferate along the long axis in the lumens of the veins. 6. Capillary invasion was also observed, although to a lesser degree compared with the venous system. 7. The majority of vascular invasions were observed with formation of an intravascular thrombus.

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The author performed osteoectomy of the mandible on 23 adult mongrels (about a year old) and grafted fresh autogenous rib-bone. Observations by tetracycline labelling and microradio-graphy were made of the changes in the grafted bones and the original bones. Pathohistological investigations were also made of the non-decalcified and decalcified stained specimens. The results were as follows : 1. In fluorohistological findings, tetracycline labelling of new bone was observed in the original bones, in the mandibular canal in particular, on the 5th day after grafting and in the grafted bones on the 15th day. On the 30th day, tetracycline labelling of new bone forming from the original bone and connected with the grafted bone was observed. Tetracycline of new bone forming from the upper parts of the resected ends of some of the grafted bones to the original bones was also observed. From the 45th to 60th days, tetracycline labelling of the whole of new bone trabecula between the resected ends of the original and grafted bones was observed. On the 90th day, however, tetracycline labelling of only a single layer around the marrow spacies was observed. 2. In microradiographyic findings, calcification of the reticulum, of low radiolucency, was observed in the original bone on the 5th day after grafting and in the grafted bone on the 15th day. On the 30th day, radiolucency of trabecula-like body, connected with the grafted bone, of new bone extending from the original bone was observed in the upper parts of the resected ends of the grafted bones. As for the new bone from the resected ends of the grafted bones to the original bones, calcification of low radiolucency was observed. From the 45th to 60th days, calcification of the new bone between the original and the grafted bones was low. Marked difference in radiolucency was observed when compared with that of the original bone, but on the 90th day, radiolucency was about the same. 3. In non-decalcified and decalcified stained specimens, marked fibrous plasia in the mandibular canal of the mesial and distal resected ends of the original bone was observed and bone generation was also active compared with other parts. In the marrow gradual transformation to granulation tissues from the resected ends to the center was observed and replacement by granulation tissues was nearly complete on the 30th day after grafting. On the 10th day, granulation tissues were observed in the marrow of the resected ends of the grafted bones and calcification was observed on the 15th day. On the 20th day, new formation of bone trabecula of the grafted bones was observed and the formation progressed gradually to the center. On the 30th day, union with the original bone was seen and formation of new bone was seen nearly to the center, although some original bone trabecula still remained. On the 60th day, repairing processes of new bone was active. Transformation to fatty marrow and the regular arrangement of the osteocytes were seen on the 90th day. However, the original bone trabecula was observed remaining although to a limited extent. 4. In the present experiment, osteocytes of the grafted bones did not die out completely. Rather, they seem to have some part in osteogenesis and bone union with the original bone.

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There are many patients complaining of disturbances in the region of the temporomandibular joint. To establish the etiology of temporomandibular joint dysfunction many fundamental and clinical studies have been made. In clinical examinations, the radiographic examination is valuable for evaluating morphology and pathology of the bony components of the temporomandibular joint. In this paper, to clarify the radiographic findings of temporomandibular joint dysfunction, a radiographic analysis was done on radiographs obtained from patients having complaints of the temporomandibular joint. Transcranial lateral oblique projections of the temporomandibular joint were performed on 266 patients with temporomandibular joint dysfunction at Kyushu Dental College Hospital from 1967 to 1976. The radiographs obtained were analyzed, and the results obtained are as follows : 1. Position of the condyle in the fossa with the patient's mouth closed : In both sexes, many condyles were located in the middle of the fossa. When the condyles were not located in the middle, they were located in the posterior region rather than in the anterior region of the fossa. 2. Position of the condyle in the fossa with the patient's mouth open : Female patients' condyles were more remained in the fossa more than male's. 3. Cortical bone of the condyle : In both sexes, many condyles showed a continuity of the cortical bone. Abnormalities of the cortical bone appeared as a break or disappearance of all of the cortical bone. 4. Cortical bone of the fossa : Female's fossae showed more continuity of the cortical bone than male's. Abnormalities showed as breaks or disappearance of the posterior region of the fossa, especially in male. Breaks or disappearance of all of the cortical bone was seen more in the left fossa than in the right one, especially in female. 5. Osteosclerosis or osteoporosis of the condyle : Osteosclerosis was seen equally in the both sexes but was more frequent in the left condyle than in the right one, especially in female. Osteoporosis was not seen often in the condyle. 6. Osteosclerosis or osteoporosis of the fossa : Osteosclerosis was more frequent in female and was more frequently seen in the left fossa than in the right one. Osteoporosis was not seen in the fossa. 7. Relation of condyle position and pathosis of it's cortical bone with the patient's mouth closed : There was no relation of condyle position and pathosis of it's cortical bone. 8. Relation of condyle position and pathosis of cortical bone of the fossa with the patient's mouth closed : There was no relation between the condyle position and pathosis of the cortical bone of the fossa. However, it seemed that if the condyle was located in the posterior region of the fossa, the cortical bone of the fossa sometimes showed abnormality. 9. Of the 266 cases, 15 cases (6%) were diagnosed as osseous ankylosis radiologically.

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The author undertook a pathohistological investigation of the daily changes in the female submandibular glands of rats of Wistar strain during sexual dimorphism, pregnancy, lactation and cessation of lactation periods (from the 7th day to 8 weeks of pregnancy). The results obtained were as follows : 1. Male-female difference was observed morphologically in the granular tubules and striated ducts. Compared with the female, the male showed a better extension of the granular tubules, the diameters of granular tubules were larger and hypertrophy of granular tubule cells was observed. Compression and disapperance of the nuclei were frequent and secretory granules were more abundant, the diameters of the striated ducts were larger and epithelial cells were higher in height. Incidence of eccentric location of the nuclei to the basal side was high. Appearance of vacuoles and disappearance of the basal striations were relatively high. 2. Male-female difference was not observed in the terminal portions, intercalated ducts, or interlobular ducts. 3. Measurements of the average diameters of the submandibular granular tubules in the male and in the female revealed a significant difference : female (39.3±5.7μ) : male (46.7±6.6μ). 4. Findings of spontaneous masculinization were seen in the granular tubules and striated ducts of the submandibular glands during pregnancy and lactation periods. 5. Findings of spontaneous masculinization during pregnancy and lactation became significant on the 14th day, reached a peak on the 7th after delivery and declined gradually thereafter. On the 14th day after cessation of lactation (first 8 weeks of pregnancy), the findings were about the same as those of the non-pregnant female submandibular glands. 6. No findings of spontaneous masculinization were seen in the terminal portions, intercalated ducts and interlocular ducts. 7. Measurements of the average diameters of the submandibular granular tubules revealed on the 14th day after pregnancy a significant difference compared with those of the non-pregnant female, as was the case in morphological changes. Thereafter, the diameters gradually increased and reached a maximum on the 7th day after delivery. The diameters then gradually decreased and were about the same as those of the non-pregnant on the 14th day after cessation of lactation (first 8 weeks of pregnancy). No significant difference then was observed.

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The authors have had problems at field in using conventoinal multi-channel universal telemeters hitherto used. Therefore, with a view to achieve portability of the apparatus and simplification of handling and data treatment concerning heart-beat of biological information, the authors made improvements which made possible the recording of heart-beat number on paper in numerals. The results are shown as follows : 1. As to the portability of the appratus, the total weight has been reduced to 14kg compared with 36kg before. 2. The measurements taken are highly reliable and decipherment of even minute and precise changes have been made possible, as the measurements are indicated in numerals. 3. As to data treatment, a various approaches in statistical treatment have been made possible, as the measurements are indicated in numerals. 4. The noise produced by the apparatus while measuring heart beat number is large either at recorder or printer, but as the apparatus is a wireless telemeter, and because the printer is small size, only this could be isolated at another place, so that the problem of the noise was solved. As above-mentioned, as the initial idea could be completed to some extent, the authors wish to continue to apply this apparatus from now on to various objects such as patients and operators during dental therapy, mental and somatic change while making exercise and so on.

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Branchial fistulas are commonly believed to be congenital abnormality arising from the remnants of branchial clefts in the embryonic life. A various cases of cervical fistulas have been reported by many in the fields of surgery and otorhinolaryngology. Few reports however have been made in the field of oral surgery. Furthermore, reports on cases of bilateral cervical fistulas are very rare in the literature of this country. We have recently experienced a case of congenital fistula occurring symmetrically in the bilateral neck of a girl aged 9. In this case, the fistulas of the bilateral neck were evident at birth. The complaints were swelling of the neck and intermittent drainage from a small orifice in the neck. The cutaneus orifice is located in the inferior carotid triangle and on a line along the anterior border of the sternomastoid muscle. The tracts are imcomplete (with an end each closed) and run from the external opening through the subcutaneus tissue, the platysma muscle, and to the superficial layer of the deep fascia. They then take a course upward along the internal jugular vein until they reach the deep structures around each hyoid bone. Pathohistological examinations revealed that columnar and stratified squamous epithelium lined the tract wall and that tract was composed of lymphoid tissue, salivary gland and muscle. Judging from the foregoings, the fistulas are considered to have originated from the second inner branchial groove in the embryonic life.

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