The face in human beings is the entire region in front of the pinnae, stretching from the hairline above to the chin below. The upper face consists of the frontal region, which extends from the hairline to the supercilium. The shape of the forehead is created by the frontal bone, which is overlying, with adipose tissue pads between the skin and muscle layers and underneath the muscle. The glabella consists of a slight inter-superciliary prominence. When the procerus or corrugator muscles contract here, hyperdynamic wrinkles may appear. In men, the eyebrows are horizontal and over the supraorbital ridges. Several soft tissue landmarks are on the midline, used as reference points in cephalometry, extending from the glabella above to the neck below. The reference points are employed when analysing the proportions of facial features and when calculating angles. The external nose has the form of a pyramid, the base of which covers the pyriform aperture within the skull. The nasal radix is below the glabellar prominence in the midsagittal plane, overlying the frontonasal suture. The nation is the posteriormost point on the external nose. The rest of the nose then projects in an anteroinferior direction towards the nasal apex (i.e. nasal tip). The nasal dorsum is the region that lies between the nasion and tip. It has an osseous skeleton in the superior portion, which resists movement, and a more flexible cartilaginous skeleton in the inferior portion. The nose is widest at the nostrils (alae), which form the entrance to the vestibular portion of the interior nose. Between the nostrils lies the columella, which extends from the nasal tip to the philtrum. The philtrum is within the cutaneous portion of the superior lip. The vermillion border is where the red-coloured portion of the lips abuts the normal skin, and running right next to this border, in parallel with the lip, lies the tubular white roll. There is an anterior projection of the superior lip in the midline, referred to as the tuberculum labii superioris.