Both non-REM and REM sleep occur while having a temporal relationship under the influence of the circadian system. However, the mechanism of its occurrence greatly differs in terms of responsible parts and neural circuits. Even in terms of autonomic nervous activity, these two sleeps present quite different aspects. Roughly, non-REM sleep is in its “stability” and REM sleep is in “instability (unpredictability)”. Regarding the phenomenon of autonomic nervous activity during REM sleep, it has been classified into a tonic and a phasic phenomenon from long ago. The phasic phenomenon is a sudden and unpredictable phenomenon also called “a storm of the autonomic nervous system”. In blood pressure, surge or spike-like big ascent is seen. Observation at a decerebrating cat at Claude Bernard University was the first experiment to ask about where the phasic phenomenon of blood pressure originates from the central nervous system. I would like to have an opportunity to recognize again about the wonders of the phasic phenomenon in REM sleep.
Jaw activity directly relates to occlusion and is strongly associated with jaw movement. Movement is also an important part of occlusion examination and diagnosis. An instrument to measure jaw movement in six degrees of freedom is available, and several papers have already reported results using this device. However, the results are difficult to analyze due to the lack of clarity concerning instrument use and measurement values. It is necessary to fully understand the basic measuring theory, the technology, and the analysis method when using the device. This paper introduces a theory of measurement that calculates the spatial position of the analysis point based on the relationship of a two-dimensional orthogonal coordinate, assuming that the upper and lower jaw are a rigid-body. The paper also illustrates the differences between the basic activities used for the evaluation of jaw movement and the physiological activities related to jaw function from the aspect of measurement technology. The paper also explains the differences and uncertainties of typical movements of the mandible and complementary maxillary movements. Our future work will continue to study the development of instruments to measure jaw movement due to their application in high-precision 3DCG articulator and CAD/CAM dentures.
Purpose: In our previous study, we observed variations of occlusal plane inclination in adult patients, and investigated the factors affecting changes in occlusal plane inclination with aging. From our results, it was suggested that the mandibular morphology change and loss of teeth with aging, influence occlusal plane inclination. However, the investigations of the parameters regarding dentition characteristics were insufficient. In this current study, we add the dentition parameters and create a linear regression model to estimate the alteration of the occlusal plane in adults. Subjects and Methods: Subjects were 143 patients consecutively recruited, and were divided into 2 groups without/with missing teeth (no-MT group / MT group). Cephalometric images were taken. Our inquiry points included 13 variables regarding to cranio-mandibular morphology and dentition. We investigated the differences in age and the anatomical variables between no-MT group and MT group, the linear relationships between variables, and linear regression. Results: In the 8 variables, there were statistically significant differences between both groups. Camper-occlusal plane angle (COA) was correlated with all variables. The variables Number of missing molar teeth (MolarMT), Mandibular plane angle (MPA), and the inclination of upper and lower incisal axis to Camper plane (CamU1, CamL1), explained 69.8% of the variance in COA (p < .001). Conclusion: From our results, it was suggested that evaluation of occlusal plane inclination is important in adult patients with loss of occlusal posterior support. For these types of patients, we recommend evaluating the occlusal plane using Camper's plane in the clinic.