Abstract
It seems that a person recognizes the face of another person by subconsciously determining a subjective facial midline unconsciously. We have defined such a subjectively defermined facial midline as an imaginary facial midline. It appears to be important to understand the ability of human visuognosis of space in order to elucidate the setting mechanism of an imaginary facial midline. In this study, we tried to clarify the ability of visuognosis that is thought to be the setting of an imaginary facial midline, by investigating 34 orthodontists with 3 years or more experience. The results were as follows. 1. The abillities of visuognosis of the orthodontists with the experience over 3 years were eguivalent. 2. Only in the case of ΔX, both the displacement and the variance changed in proportion to the distance between 2 points. 3. The recognition of middle points was significantly accurate if the distance between the 2 points was less than 60 mm. The results of this study are thought to be applicable to human faces.
