Labiomental Angle: Lower Lip, Chin Fold, and Profile Shape

The labiomental angle is the bend between your lower lip and chin. One segment follows the lower lip into the deepest point of the labiomental fold. The other follows that fold toward soft tissue pogonion. A smaller angle creates a deeper, sharper fold. A larger angle creates a flatter transition. The measurement reflects chin projection, lower lip position, lower incisor support, vertical lower face pattern, and mentalis activity. Never read it as a chin variable alone.

Mark the lower lip point, the deepest point of the labiomental fold, and soft tissue pogonion. Draw one tangent down the lower lip into the fold and a second from the fold along the chin contour. The internal angle at the fold is the labiomental angle.

Some methods use tangents rather than direct landmark lines. This matters when the lower lip or chin is strongly curved. State the construction and keep it consistent across comparisons.

The lips must be relaxed. Active mentalis contraction can deepen the fold, raise the lower lip, and sharply change the angle without structural change.

A projected chin and forward lower lip can create a deep fold between two prominent structures. A retrusive chin can also create a sharp bend when the lip remains forward. A flatter chin and lip relation opens the angle.

Vertical lower face pattern matters. A short lower face with strong chin projection often has a more compact fold, while a long lower face can stretch the transition. These are tendencies, not rules.

A study in young Pakistani adults compared photographic and cephalometric evaluation of the nasolabial and labiomental angles, demonstrating both aesthetic relevance and method dependence (PMID 35124924).

A separate study introduced the lower lip to chin prominence angle to analyse chin prominence in direct relation to the lower lip (PMID 31331858). Use that construction when the labiomental angle alone cannot separate lip and chin contributions.

Orthodontic tooth movement can alter lower lip support and the lower face profile (PMID 35461792). Chin filler, genioplasty, or jaw movement changes the other arm of the angle. Mentalis contraction can change both the fold and chin surface temporarily.

A before and after angle needs matched lip rest and an explanation of which anatomical component changed.

Ask for relaxed lips and no chin strain. If the lips cannot close without effort, document that state rather than forcing closure. Use a true side profile with the entire lower lip and chin visible.

Soft shadow can define the fold, but hard side light can make it look deeper than it is. Use even lighting for measurement.

Solar estimates the lower lip to chin fold angle and reads it beside chin projection, lower lip position, chin height, and lower face balance. It does not reward the deepest possible fold.

A tense mentalis or parted lips can reduce profile confidence. Repeat the scan with a genuinely neutral expression rather than trying to correct the number through expression.

The labiomental angle describes how the lower lip and chin meet. The relationship is the point. One universal target is not.

Measure it with relaxed lips. Record the method. Read it beside direct chin and lip variables.

Read it against the rest of the measurements series. Trait context: what facial dimorphism is.

Want this measurement read across your own facial structure? Run the Solar facial analysis.