[Location] Localized in the supine position, or in the erect sitting position and with the head holding up, on the region of the face, in the depression in the center of the mentolabial groove. ( Fig.78 )
[Regional Anatomy] Skin→subcutaneous tissue→orbicular muscle of mouth→depressor muscle of lower lip→mental muscle, there are mental nerve of the inferior alveolar nerve and the mental artery and vein in this area.