Facial thirds

Upper third: trichion to glabella

Horizontal fifths

Five equally divided vertical segments of the face

Frankfort plane

Plane defined by a line from the most superior point of auditory canal to most inferior point of infraorbital rim.

Nasofrontal angle

Angle defined by glabella-to-nasion line intersecting with nasion-to-tip line. Normal 115-130° (within this range, larger angle more favorable in females, smaller angle more favorable in males).

Nasofacial angle

Angle defined by glabella-to-pogonion line intersecting with nasion-to-tip line. Normal 30-40°. PEARL: "normal" projection with a 3-4-5 triangle described by Crumley (see below; nasofacial angle of 36°).

Nasomental angle

Angle defined by nasion-to-tip line intersecting with tip-to-pogonion line. Normal 120-132°.

Relationship of lips:

To nasomental line

Upper lip 4 mm behind, lower lip 2 mm behind line from nasal tip-to-menton

To subnasale-to-pogonion line

Upper lip 3.5 mm anterior, lower lip 2.2 mm anterior

Mentocervical angle

Angle defined by glabella-to-pogonion line intersecting with menton-to-cervical point line.

Nasolabial angle

Angle defined by columellar point-to-subnasale line intercepting with subnasale-to-labrale superius line; normal 90-120° (within this range, larger angle more favorable in females, smaller angle more favorable in males).

Columellar show

Alar-columellar relationship as noted on profile view, 2-4 mm of columellar show is "normal."

Nasal projection

Forward protrusion of nasal tip from face. One way to measure this is Goode's method: a line drawn through the alar crease, perpendicular to the Frankfurt plane; the length of a horizontal line drawn from the nasal tip to the alar line (alar point-to-nasal tip line) divided by the length of the nasion-to-nasal tip line. Normal is 0.55-0.60.

Powell & Humphries "Aesthetic Triangle"

Nasofrontal, 115-130°; nasofacial, 30-40°; nasomental, 120-132°; mentocervical, 80-95°