In orthodontic treatment planning, lip projection is a complex issue in comprehensive facial analysis. Using Ricketts Esthetic line (E-line) and Holdaway’s line measurements, the lower lip should be coincident with a line from the nasal tip to the chin, and the upper lip should be about 1mm behind it. From such measurements, the orthodontist is able to determine if the patient is suffering from excessive or inadequate lip projection.
Patients with excessive lip projection should seek an opinion from the orthodontist. Most orthodontists identify this to be dentally protrusive and would recommend premolar extractions to create space for retraction of the front teeth, hence reducing dental protrusion.
Inadequate lip projection is due to the backward displacement of teeth or severe crowding of teeth that causes a lack of dental and skeletal support. Extraction of the premolar teeth in braces treatment will solve the crowding problem and orthognathic surgery helps in the patient’s facial enhancement.
It is important to undergo such treatment to correct any lip projection. This is to avoid a labiomental sulcus which is defined as the fold of soft tissue between the lower lip and the chin. Form and depth of labiomental sulcus may vary depending on the facial height, overjet and chin projection.
