Appendix D - Surface Angles, Planes, and Measurements: Definitions

Facial thirds

Upper third: Trichion to glabella

Middle third: Glabella to subnasale

Lower third: Subnasale to menton

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 to 130 degrees (within this range, more-obtuse angle more favorable in female, and more acute angle in male patients)

Nasofacial angle: Angle defined by glabella-to-pogonion line intersecting with nasion-to-tip line. Normal, 30 to 40 degrees

Nasomental angle: Angle defined by nasion-to-tip line intersecting with tip-to-pogonion line. Normal, 120 to 132 degrees

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

Legan facial-convexity angle: Angle defined by glabella-to-subnasale line intersecting with subnasale-to-pogonion line; normal, 8 to 16 degrees

PEARL
Useful in assessing chin deficiency, candidacy for chin implant, chin advancement, or other chin alteration

Nasolabial angle: Angle defined by columellar point-to-subnasale line intersecting with subnasale-to-labrale superius line; normal, 90 to 120 degrees (within this range, more obtuse angle more favorable in female, and more acute in male patients)

Columellar show: Alar-columellar relationship as noted on profile view; 2 to 4 mm of col ­umellar show is normal

Nasal projection: Anterior protrusion of nasal tip from face

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 divided by the length of the nasion-to—nasal tip line. Normal, 0.55 to 0.60 (2,3)

Crumley's method: The nose with normal projection forms a 3-4-5 triangle (i.e., alar point-to-nasal tip line (3), alar point-to-nasion line (4), nasion-to-nasal tip line (5) (4). Byrd's method: Tip projection is two-thirds (0.67) the planned postoperative (or the ideal) nasal length. Ideal nasal length in this approach is two-thirds (0.67) the midfacial height (5)

Powell and Humphries "Aesthetic Triangle":

Nasofrontal: 115 to 130 degrees

Nasofacial: 30 to 40 degrees

Nasomental: 120 to 132 degrees Mentocervical: 80 to 95 degrees

REFERENCES

1. Tardy ME, Walter MA, Patt BS. The overprojecting nose: anatomic component analysis and repair. Facial Plast Surg 1993;9:306-316.
2. Ridley MB . Aesthetic facial proportions. In: Papel ID, Nachlas NE , eds. Facial plastic and reconst r uctive surgery. St. Louis : Mosby Year Book, 1992:99-109.
3. Crumley RL, Lamer M. Quantitative analysis of nasal tip projection. Laryngoscope 1998;98:202-208.
4. Byrd HS, Hobar PC. Rhinoplasty: a practical guide for surgical planning. Plast Recon.str Surg 1993;91: 642-654.

NOTE: CLICK HERE for information regarding privacy of your medical information. Additionally, all website users must agree to the terms and conditions of this site. Please CLICK HERE to review terms of use.