Extraoral anatomical landmarks

The following extra-oral anatomical features should be noted:
1- Philtrum: is a midline shallow depression of the upper lip, which starts at the labial tubercle and ends at the nose.
2- Labial tubercle: is a little swelling in the midportion of the vermillion border of the upper lip.
3- Vermillion borders: the lip is covered by the skin at its facial surface and the mucous membrane at its inner surface. The transitional area between the skin and the mucous membrane of the upper and lower lips is a pink or red zone of thinner epithelium, which is called the vermillion border.
4- Nasolabial groove: is a furrow of variable depth that extends from the wing (ala) of nose to end at some distance from the corner of the mouth.
5- Labiomental groove: is a sharp or deep groove that lies between the lower lip and the chin.
6- Nasolabial Angle: is an angle between columella of nose and philtrum of lip, normally, approximately 90° as viewed in profile.
7- Angle of the mouth and Labial commissure:
Angle of the mouth is the lateral limit of the oral fissure. Labial commissure is a junction of upper and lower lips lateral to the angle of the mouth.
8- Modiolus:
This muscular knot is at the angles of the mouth. Modiolus may lie laterally to the lower premolars so it will displace a lower denture if those teeth are set too far buccally.