sym*me*try (noun), plural -tries
[Latin symmetria, from Greek, from symmetros symmetrical, from syn- + metron measure -- more at MEASURE] First appeared 1541

1 : balanced proportions; also : beauty of form arising from balanced proportions

2 : the property of being symmetrical; especially : correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis

Frontal View Evaluation

Step 1. Vertical height - It has been well described that vertical height can be evaluated by dividing the face into equal thirds.

The boundaries of the upper third are the trichion and the glabella, with the mid third extending from the glabella to the subnasale and the lower third from the subnasale to the menton. The lower third can be further subdivided into thirds with the stomion marking the inferior boundary of the upper third, and the lower lip and chin forming the lower two-thirds. While some have advocated evaluating only the mid and lower face in men with receding hairlines, others have stated that the appropriate superior border for the upper third can be determined in these cases by locating the most superior movement of the frontalis muscle.

Step 2. Width - The easiest way to evaluate the relative width of facial structures is to divide the face into vertical fifths with each fifth being equal to one eye width. This technique is also helpful at determining the appropriate width of several individual subunits and will be discussed more later. Also transverse distances at bitemporal and bigonial lines should be equal and approximately ten percent shorter than the bizygomatic line drawn through the malar eminences.

Step 3. Symmetry - A midsagittal line is drawn and the symmetry of the various subunits (ears, eyes, eyebrows, nose, and mouth) is compared. This is also a good time to assess the overall facial shape which should be roughly oval.1

Lateral View Evaluation

Prior to evaluating the patient's profile, it is important to assure appropriate head position. This has traditionally been accomplished by placing the Frankfort horizontal line parallel to the floor. The Frankfort horizontal line is drawn between the superior aspect of the external auditory canal (or through the tragion) and the infraorbital rim. A second technique to obtain the patient's natural horizontal head position is to have them fix their eyes on a point at eye level.

Step 4. Vertical height - Again, facial height is divided into thirds as in step 1, and the equality of the thirds reassessed. The vertical placement of landmarks is also determined in this step. As stated above, the lower third can be further divided into thirds with the stomion separating the upper and mid thirds and the pogonion lying in the center of the lower subdivision.

Step 5. Midface projection - To assess the midface position relative to the upper face, a second line is drawn from the nasion to the subnasale. This line should form an angle of 85 to 92 degrees when compared to the Frankfort horizontal line and is termed the zero meridian.2,3 If this line is excessively anterior, the midface is described as anteface, and if posteriorly, a retroface profile is present.

Step 6. Lower face position - The position of the lower third of the face compared to the upper third is then established, again with the zero meridian providing the reference. A line is drawn from the subnasale to the pogonion. This line should lie at a ten degree posterior angle from the zero meridian. If the pogonion is placed significantly anteriorly, it is said to be protruding and if posteriorly, retruding.

Step 7. Nose-Lips-Chin Position - At this point the relationship of the nose, lips and chin to each other is evaluated using Rickett's E (esthetic) line.4 This line is drawn from the nasal tip to the pogonion. The lips should lie just posterior to this line with the upper lip approximately twice as far from the line as the lower lip. If this is the case, no further evaluation of these structures is indicated at this time. If not, one of the three structures is malpositioned. Since the pogonion was evaluated in step 4 and 6, only the lips and nasal projection are further evaluated at this time. A quick assessment of nasal projection is provided using Goode's ratio which compares a line form the alar groove to the tip to a second line from the nasion to the tip. The ratio of the former to the later should be approximately 0.55 to 0.6.2 The anterior-posterior position of the lips is quickly evaluated by the Holdaway H (harmony) line. This line starts at the ideal pogonion and is drawn ten degrees anterior to a line from the pogonion to the glabella. The lips are appropriately positioned if they approximate this line.2,5

Step 8. Evaluation Of Individual Subunits

The exam now focuses on a more detailed evaluation of the specific facial subunits including the forehead, eyes and eye brows, nose, mouth, chin, neck and ears.

Forehead - Although the forehead is rarely altered surgically, it is important to evaluate because of its relationship to other parts of the face. Additionally, certain aspects of the forehead may dictate the surgical approach as in the case of a receding hair line or the presence or absence of deep forehead creases. In regards to the normal contour of the forehead, men tend to have more prominent glabellar and supraorbital rim regions with women having a smoother transition into the midface.

Eyes and eyebrows - Again the eyebrows differ between sexes with the ideal male brow placed at the supraorbital rim and fairly flat. The female brow rest slightly superior to the rim and has a more prominent arch located at the level of the lateral limbus. The brow should start medially at a vertical line that passes through the alar groove and medial canthus, and continue laterally to end along an oblique line from the nasal ala through the lateral canthus at roughly the same height as the medial brow.6,7 Careful exam to rule out brow ptosis is extremely important if blepharoplasty is being considered. The intercanthal distance is usually 30 to 35 mm and can readily be evaluated when the frontal view is divided into vertical fifths with this distance equal to one eye width.1 Both upper and lower lids should be carefully examined both visually and manually to determine their shape and elasticity. The upper lid margin should have its highest point at the junction of its middle and medial thirds and the lower lids lowest point should be between the middle and lateral thirds. The upper lid should cover 2 to 3 millimeters of superior iris and the lower lid margin usually approximates the inferior iris.1

Lagophthalmos may be identified by having the patient look down while tilting the head backward.8 The superior palpebral lid crease identifies the attachment of the levator aponeurosis into the orbicularis muscle and should be located approximately 8 mm from the eyelash line.9 The presence and location of fat pseudoherniation should be determined and an inferiorly displaced lacrimal gland noted if present. Horizontal laxity of the lower lid can be tested by pulling the lid away from the globe and then releasing it. In the normal lid, it should snap back. If it returns slowly or not at all, significant laxity exist and may alter the surgical plan. Also the strength of the orbicularis muscle should be checked by having the patient close their eyes tightly while the examiner attempts to open them manually.

Nose - In addition to the initial evaluation presented above, the nose should be evaluated for dorsal deformities and appropriate width on frontal view. Again, dividing the face into vertical fifths helps quickly determine whether an acceptable lower nasal width is present. The alar- alar distance should be equal to one eye width (one fifth) in Caucasians with wider noses acceptable in Asian and African-Americans. This distance may also be evaluated by determining the length of the nose from nasion to tip, with the width being approximately 70% of the length. On profile view nasal projection, rotation and length as well as the nasofrontal, nasofacial and nasolabial angles are more closely evaluated. The nasofrontal angle is formed at the nasion by lines that extend from this point to the glabella and to the nasal tip. This angle should ideally be 120 to 135 degrees. The position of the vertex of this angle (nasion) is also important because moving it up or down will lengthen or shorten the nose, respectively. Its usual position is at the level of the superior limbus of the eye. Nasal tip projection is often difficult to determine and many techniques have been advanced. Goode's ratio of 0.55-0.6:1comparing projection to nasal length has been presented above. Another method involves the nasofacial angle which is formed by a line along the nasal dorsum intersecting a line from the glabella to the pogonion. The ideal nasofacial angle is 36 degrees. Nasal length, height and projection may also be examined simultaneously by creating a right triangle between the alar groove, the tip defining point and the nasion. The projection, height and length should create sides with a ratio of 3:4:5 respectively.

Finally, an easy but often inaccurate method of determining projection compares it to the length of the upper lip from subnasale to vermilion border with the two being roughly equal. The fault with this technique lies in the variability of the upper lip length. Tip rotation is assessed by evaluation of the nasolabial angle which is formed by lines along the columella and upper lip that intersect at the subnasale. The ideal nasolabial angle for women is 100 to 120 degrees and men between 90 and 105 degrees. Also on lateral view, the alar and lobular lengths should be equal and there should be between 2 and 4 mm of columellar show. On basal view, the nose should have the shape of an equilateral triangle and the columella should be approximately twice as long as the lobule. The lobule should be 75% as wide as the alar base and the nostrils should be roughly pear shaped.

Lips - The relative position of the lips as compared to the nose and chin have been discussed. It must be remembered that these structures as well as the patient's dentition will affect the appearance of the lips. Other considerations include the width of the lips, the interlabial gap and the degree of incisor show with smiling. The oral commissures should be located along vertical lines drawn from the medial limbus of the iris. Also, the lower lip should be slightly fuller than the upper lip. When relaxed and with teeth in occlusion, the lips should approximate one another with an interlabial gap of 3 mm being the upper limit of acceptable. When smiling, there should be no gingival show and no more than two thirds of the maxillary incisors exposed.

Chin and neck - The relative position of the chin has been determined in the initial evaluation and further evaluation is aimed mainly at the shape of the chin and its relation to the neck. The mentolabial sulcus depth is assessed by creating a line from the lower vermilion border to the pogonion. The sulcus should lie approximately 4 mm behind this line. In regards to the neck, Dedo developed a classification system based on the depth of the abnormality proceeding from superficial, skin and fat, to deep, muscle (platysma) and bone (chin or hyoid). Class I is the youthful, normal neck. Class II and III represent early abnormalities of skin and fat accumulation respectively. When platysmal abnormalities such as banding are identified, Class IV is defined, and the loss of an appropriate mentocervical angle because of a posteriorly positioned chin is labeled Class V. Finally Class VI results from an inferiorly placed hyoid bone. This final class is particularly important to identify because very little can be done surgically to correct this abnormality.10 Lastly, the appropriateness of the neck length can be determined by comparing the distance from menton to suprasternal notch, to the head height measured from menton to vertex, with the head being approximately twice as tall as the neck.

Ear - The auricular length should be slightly less than twice its width and the long axis should be inclined approximately 20 degrees posteriorly. The external auditory canal should be located at a level roughly halfway between the lateral canthus and the nasal base. The superior aspect of the ear should be at the level of the lateral brow and the inferior aspect at the level of the nasal base. The auriculocephalic angle should measure approximately 20 to 30 degrees.11 Specific landmarks of the ear including the helix, antihelix, scaphoid fossa, tragus, and lobule should be evaluated for obvious deformity. The thickness and flexibility of the cartilage should also be estimated.

Dental occlusion - As mentioned above, the patient's dentition may play a significant role in overall cosmesis. Although an in depth discussion is beyond the scope of this presentation, the dentition should be evaluated and correction considered if abnormalities are present that could cause aesthetic problems. Briefly, normal occlusion is present when the mesiobuccal cusp of the maxillary first molar occludes the buccal groove of the mandibular first molar. This is termed Type I occlusion. Type II occlusion occurs when the mandibular teeth occlude in a more posterior position and Type III occlusion is when they are more anteriorly located.

credit: FACIAL ANALYSIS; Dept of Otolaryngology, UTMB, Galveston, TX - October 1, 1997.

Horizontal Facial Thirds - Front

Horizontal Facial Thirds - Lateral

The face can be divided into fifths using the width of the eye from corner to corner as a point of measurement.  Starting from the very outside edge of one ear to the other -- the face ideally would be 5 eye widths apart.  Of course, since we are human and not designed by computers, it is perfectly fine if you are not exactly 5 eye widths a part.  The width of the base of the nose, at the nostrils (or ala), should be 1/5 of the face, or one eye width.

Frankfort Horizontal Line (or Frankfort Plane) 

To determine the Frankfort Horizontal Line (red horizontal line), a lateral photograph is taken and a vertical line is drawn from just in front of your glabella to your chin.  This line would ideally be perfectly vertical.  The next line is drawn horizontally from right at the supratip to above the auricular canal, right above the tragus.