ACGs are intimately related to the aesthetics of the alar rim. The ideal alar rim is defined on lateral view by a smooth contour with a slight arch, peaking vertically between the level of the tip defining points and the columellar-lobular angle. Further, the height of the alae should be no higher than 2 mm above or 2 mm below the long axis of the nostril.

The alar rim is largely composed of thick, lower nasal skin superficially and mucosa internally.

The lateral crus of the LLC normally runs parallel to the alar rim. The LLC may be cephalically oriented, which predisposes to alar deformity. The orientation of the LLC helps determine the shape of the ala anteriorly in the area of the soft triangle.

The posterior half of the alar rim encompasses the alar lobule and is composed entirely of fibrofatty tissue and thick skin.^1,2

Visual inspection and manual palpation of the nose will indicate if any alar rim deformities are present in the preoperative state. Standard rhinoplasty imaging should be undertaken with AP, lateral, basal, and ¾ views of the nose. Visualization of the lateral crura of the LLC through the skin envelope can help diagnose a more vertical orientation, which may portend a higher risk of future alar deformities.

Forced inspiration through the nares will uncover any dynamic external nasal valve collapse or evidence of alar collapse.

No imaging is necessary or indicated to prepare for alar rim deformity correction with ACG.

Three-dimensional imaging may be useful as a preoperative planning and patient communication tool. Caution is advised not to “lower” the alar position with a computer program if one does not feel that this is a consistently reproducible surgical outcome in his or her hands. However, this imaging may help educate patients how reinforcement of alar retraction or collapse with ACG may be very useful, as well as indicating changes in alar-columellar relationships.

It is crucial that the correct diagnosis is made to ensure the most accurate surgical treatment. Most crucially, if the patient has had severe mucosal loss and shortening due to previous surgery, this must be disseminated to the patient. This is a much more difficult problem to correct and may require mucosal grafts or other interventions beyond placing ACGs.

In a virgin nose, alar retraction, notching, and collapse, both static and dynamic, can be treated with operative placement of ACGs. It is important to note the position of the LLCs as well. If they are cephalically oriented, some inferior repositioning may be indicated as well using lateral crural strut grafts or other techniques.