Gender is an important factor for deciding that. As a rule, women prefer a slightly less projecting, rounder chin while men tolerate a slightly more projecting, angular chin. Remember that the height of the chin pad as well as the location and depth of the labiomental fold will affect the appearance of the chin.

1. Lower Face Evaluations:

A) Lip Evaluation

Proportion of lips

The lower lip is normally fuller than the upper lip. The fullness of the lower lip determines the inclination of the lower lip, which affects the appearance of the chin.

B) Labiomental Fold

The position of the labiomental fold contributes to the appearance of the vertical height of the chin. A high labiomental fold will make the chin appear larger, and a low labiomental fold will make the chin appear smaller and more defined. A shallow labiomental fold makes the chin appear larger because the demarcation between the lower lip and the chin pad is less well defined.

C) Inclination of the Lower Lip

In conjunction with the labiomental fold, the inclination of the lower lip also affects one’s perception of chin size. The lower lip inclination helps to create a demarcation between the lip and the chin pad. Therefore, the more vertical the lower lip, the larger the chin appears.

D) Occlusion

Dental occlusion also affects the appearance of the lower third of the face. For example, a deep bite may contribute to lower lip eversion. It is important to assess dental occlusion and inquire about prior orthodontic or orthognathic treatment. Often orthognathic treatment and genioplasty are clubbed together.

2. Chin Evaluation

Chin pad thickness

The chin pad is assessed by palpation. Static chin pad position is noted.

Bony component

It is important to assess the size of the bony chin, especially in the case of the large chin. This is accomplished through palpation and dynamic evaluation: when smiling, a large chin due to a large bony component becomes even more pronounced, whereas a large chin due to excess soft tissue will appear better as the soft-tissue becomes effaced. Cephalograms (head x-rays) are especially useful in determining the size and shape of the bony component.

Orientation of deficiency or excess

In some patients, there is a prominent symphyseal ridge or bulky mentalis muscle which causes increased chin projection just below the labiomental fold. In some cases, bony reduction is indicated.

Chin point projection should coincide with the facial midline. Transverse chin point asymmetry should be noted.

Shape

The shape of the chin is important in preoperative planning. Women usually prefer a smaller, rounder chin while men tolerate a larger, more angular chin.

Dynamic assessment

During a normal smile, the lip muscles elevate the corners of the mouth moving the chin pad superiorly. Some patients have a horizontal, non-lifting smile. Patients with a horizontal smile have unbalanced lower lip activity which causes dynamic chin pad ptosis with smiling. Dynamic mentalis muscle activity should also be assessed. Activation of the mentalis produces upward movement of the lower lip enabling us to pout. Patients with congenital or iatrogenic low mentalis origin may have excessive tooth show in repose and a limited ability to elevate the lower lip to pout.