[A study on the meanings of various "angles" in the head]

The clarification of the terms related to the human body shape not only concerns the study of terminology but also the clinical practice of acupuncture. This paper analyzes the terms of "frontal angle" "head angle" "left angle", and "ear angle" in ancient acupuncture literature. The research suggests that "frontal angle" has 4 meanings: in LingShu-Meridians, it refers to the "head angle"; when used as a landmark for locating acupoints, it refers to the intersection of the frontal hairline and the anterior hairline; when used as a bony landmark of the forehead, it often refers to the bony prominences on the midline and both sides of the frontal bone, namely "FuXi Bone (Lingyun Bone)" and the frontal eminence. "Head angle" is often confused with "frontal angle". As the "master of intelligence and perception", the "head angle" refers to the "frontal angle" at the frontal eminence; in the context of the Meridian of the Foot-Shaoyang, the "head angle" refers to the frontal angle of the hairline; as a bony landmark in bone measurement, the "head angle" refers to the current "parietal eminence", also known as the "posterior forehead angle" "brain angle" or "mountain angle bone". The "left angle" has different meanings in different contexts: in the sinew of the Foot-Shaoyang Meridian, the "left angle" refers to the left parietal eminence; in the sinew of the Hand-Yangming Meridian, the "left angle" refers to the left frontal angle of the hairline; in SuWen - The Theory of Miu Ci, the "left angle" refers to the place where men and women keep their hair before reaching adulthood. Among the various "angles" of the ear, the "upper angle of the ear" is suspected to be a punctuation issue and should be read as "up to the ear/upper angle". This angle and the "upper angle behind the ear" both refer to the parietal eminence of the head angle; the "sharp angle behind the ear" refers to the mastoid process of the temporal bone; the "angle in front of the ear", also known as the "curved angle", refers to the temporal angle of the hairline.