Occlusal forces cause stress which morphologically affects the supporting tissues of implants. The aim of this study was to examine the effects of occlusal forces on the distribution of neurofilament protein (NFP)-positive nerve fibers in the tissue of peri-implant bone. The bilateral 2nd, 3rd and 4th mandibular premolars and the 1st molars were extracted from three mongrel dogs. After 4 months of healing, 4 screw-type implants were inserted in the oral cavity. Three months after insertion, the implants on the molar site were loaded by occlusal forces, while those on the premolar site were unloaded. After a further 3 months, the dogs were sacrificed, and specimens were prepared for immunohistochemical NFP-positive staining by the labeled-streptavidin-biotin method. Many NFP-positive nerve fibers were found in the tissues of the loaded site when compared with the unloaded site. These fibers were localized in both the bone marrow space and in the peri-implant fibrous tissue. They had two types of nerve endings: simple free nerve endings, and nerve endings with tree-like ramifications. The present results suggest that loading by occlusal force causes an increase in the number of NFP-positive nerve fibers, many of which have free nerve endings in the peri-implant tissue. The possible role of these NFP-positive nerve fibers is discussed.

The tongue of Enhydra lutris (sea otter), died from brain contusion at the first day of its age, was investigated by light and scanning electron microscopy in this study. Three types of papillae (filiform, fungiform and circumvallate papillae) were present on this tongue. In our evaluation, the filiform papillae were divided into four shapes which were conical, club-shaped, large horny and triangular papillae. The different types of filiform papillae were located in different area of this tongue. The fungiform papillae were divided into two shapes, which were hemispherical or club-shaped, and were distributed among the filiform papillae on the dorsal and the margin of the tongue. These papillae had many taste buds in the epithelium of the dorsal aspect of them. The circumvallate papillae were present in a V-shaped row at the posterior part of the lingual body, and many taste buds lay in the epithelium of both the lateral walls facing the trench and dorsal aspect of the papillary body, and then the ducts of the serous glands opened into the floor of the trenches. The lingual mucosa of the interpapillae area at the pharyngeal part of the tongue contained taste buds and the ducts of the mixed glands opened there. Based on our examination, the lingual papillae of this newborn sea otter had many features which were described to be peculiar to young stage of mammals.

No abstract

This longitudinal study aimed to clarify the relationship of oral health in infancy with that in adulthood among participants who were the subjects of the oral health promotion project (OHPP) conducted in Miyako Island, Okinawa Prefecture, Japan, since 1984. Twenty-seven subjects, around 35 years of age, were examined for dental caries, periodontal diseases (community periodontal index), dental plaque, occlusion, and bite-force and compared with those at 4 and 13–15 years of age. The dental caries status and maximum bite force in adulthood was significantly reflected for those at 4 and 13–15 years of age (p < 0.05). CPI in adulthood was related to the dental caries status at 4 and 13–15 years of age but not to the gingival score at 4 years of age, and it was weakly related to the gingival score at 13–15 years (r = 0.264, p > 0.05). Most of the normal occlusion at 4 years of age became normal permanent occlusion in adulthood (88.9%). Most of the cases involving the discrepancy factor retained the same condition in both the deciduous and permanent dentitions (83.3%) (p < 0.001). Those who participated in the OHPP soon after birth showed significantly fewer DMFT (p < 0.05) compared with those who did not. This study revealed that oral health at 4 years of age was related to that in adulthood, suggesting that fostering good oral health soon after birth is of great importance.

The objective of this study was to clarify gaze information patterns of nurses gathering patient information using electronic health records. We recorded the electronic health record screen on which nurses’ gazes were presented using an eye tracker and analyzed the recorded images. The analysis revealed two types of gaze information patterns of nurses engaged in patient information gathering. However, no regularity was observed in the gaze information patterns of the nurses viewing the electronic health record sections after selecting a patient.