Ricketts E Line: Lip Position Between Nose and Chin

The Ricketts aesthetic line, usually called the E line, runs from the nasal tip to soft tissue pogonion on the chin. You measure upper and lower lip positions as perpendicular distances from that line. Lips behind the line get negative values. Lips ahead get positive values. The construction is simple. It is not a direct lip measurement. Nasal projection and chin projection move the reference line even when the lips stay still.

Mark pronasale and soft tissue pogonion, then draw a straight line between them. Measure the shortest perpendicular distance from upper and lower lip points to the line. Record whether each lip is in front of or behind it.

A classical Caucasian reference often places the upper lip about 4 millimetres behind the line and the lower lip about 2 millimetres behind it. Those values describe one framework. Do not treat them as universal targets.

Record nasal and chin projection too. If the nose projects farther forward, the line can move away from the lips. If the chin is retrusive, the line rotates and the same lips can appear more protrusive.

A longitudinal study of young adults with normal occlusion documented profile changes over time, showing that lip relationships are not fixed at one adult snapshot (PMID 18575305). Age related nose and chin changes can move the reference line even when dental position is stable.

A study comparing photographs and silhouettes across white and Black evaluators found that presentation and evaluator background affect profile judgments (PMID 23957665). Do not treat one historical aesthetic plane as a global hierarchy.

Laypeople and orthodontists can prefer different lip positions, and visual context such as lip colour can affect ratings (PMID 27051277). Preference evidence establishes relevance, not one biological optimum.

Use the E line to describe a profile and track change. Do not let it decide treatment by itself, especially when nose or chin position is the main driver.

Lip support can change with tooth position, prosthetic support, and aging. Work in complete denture wearers demonstrates that changing support alters the soft tissue profile measured against aesthetic references (PMID 16457669).

A change in E line distance does not automatically mean the lip tissue itself grew or shrank. The teeth, maxilla, nose, or chin can move the geometry.

Use an exact side profile with relaxed lips and teeth gently together. Include the entire nasal tip and chin. A pursed lip, smile, or open mouth invalidates comparison.

Stand far enough back that the nose does not enlarge. Keep head posture level. Repeat the same focal length and crop.

Solar estimates upper and lower lip distance from the nose to chin line. It also reads nasal projection, chin projection, facial convexity, and lower face balance, so an unusual E line value can be traced to its components.

The output is a geometric analysis, not a treatment prescription. Dental and skeletal diagnosis require clinical examination.

The E line is fast to trace and easy to track. Its weakness is built into its design: the nose and chin define the reference for the lips.

Use it with direct nose, chin, and lip measures. Treat historical reference values as population specific descriptions, not universal ideals.

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.