Little did popular 1950’s American chanteuse Connie Francis fully appreciate the strength of forensic evidence signifying her boyfriend’s alleged infidelity, when she happened to observe the colour of another woman’s lipstick on his collar!

There is now a scientific appreciation that the unique “lip print” left by the “lip stick”can be almost as secure as a finger print.

While a suspected transgression of fidelity raised by the presence of another’s lipstick adherent to the boyfriend’s collar may raise a personal issue, such an identification in a criminal matter is of public interest.

During forensic inspections, lip prints may be observed on objects such as drinking glasses, cigarette butts and duct tape. Assiduous lip print investigation can identify suspects and confirm their presence at a crime scene. (2) (3)

While lip dimensions are malleable, the lip print pattern itself remains fundamentally unalterable and unique. This remains so despite either age-related contraction or injectable filler induced expansion.

In the context of facial aesthetics, lip print patterns underling warmly contoured lips form a focal point of beauty in the lower face. It is germane to the uniqueness of lip prints and natural lip endowment that discerning practitioners can adopt a bespoke approach to lip aesthetics rather than acceding to patient demands for rather unattainable outcomes.

Marketing forces generate trends that have included fashionable ideals such as the “Paris Lip” and more recently the “Russian Lip”.

However, it is prudent to recognise that just as a Michelangelo could not have sculptured his magnificent David from the fundament of a pebble, principles of aesthetic lip enhancement must factor limitations determined by the inherent distensible capacity of the underlying lip anatomy.

During pre-treatment assessments, regional aesthetic incongruities should also be factored so that lips blend with other facial features. For example, an overly projected chin or nose can be compensated by the lip projection during lip filler enhancement resulting in a generally more harmonious facial aesthetic.

Concurrently, practitioners are always mindful of inducing vascular occlusion with injectable fillers and must navigate filler placement around hazardous vascular obstacles.

While ethnic ideals do vary, enhancement techniques should take into account the aesthetics of upper to lower lip height ratios. The “Phi “or “Golden” ratio of many facial features, including the lips, arguably form the basis of ideal aesthetic proportions. Several publications have addressed this proportional aesthetic philosophy. (4) (5)

Popular trends in lip enhancement treatment demand a focus on lip volumisation but sometimes neglect correcting insufficiencies in lip width which is quite consistently and measurably “phi” of 1.618 to the inter-canthal distance of 1.0.

However, while the inter-canthal distance remains stable with aging, the oral commissures invert and sag, imparting an impression of lip width contraction (i.e., a small mouth). Oral commissure inversion is also associated with formation of labio-mandibular folds, (also known as marionette lines). (6)

Corrective eversion of the oral commissures by lip filler injection can restore this aesthetic “phi” proportional harmony and re-establish the impression of a naturally wide “smiling” mouth.

Returning to a forensic perspective, commissure eversion may also provide a broader canvass to the underlying lip print, facilitating robust evidence in matters of crime (or perhaps embarrassingly, a more secure accusation of infidelity).

References
1. Lipstick On Your Collar by Connie Francis (Recorded: April 15 1959 at Metropolitan Studio, NYC)
2. S.A.Ahmed Hanan E.Salem Marwa M.Fawzy; Forensic dissection of lip print as an investigative tool in a mixed Egyptian population; Alexandria Journal of Medicine Volume 54, Issue 3, September 2018, Pages 235-239;
3. Venkatesh R, David MP. Cheiloscopy: An aid for personal identification.J Forensic Dent Sci. 2011;3(2):67-70. doi:10.4103/0975-1475.92147
4. Keramidas E, Rodopoulou S, Gavala MI. A Safe and Effective Lip Augmentation Method: The Step-by-Step (Phi) Technique. Plast Reconstr Surg Glob Open. 2021;9(2):e3332. Published 2021 Feb 2. doi:10.1097/GOX.0000000000003332
5. Kar M, Muluk NB, Bafaqeeh SA, Cingi C. Is it possible to define the ideal lips?. Acta Otorhinolaryngol Ital. 2018;38(1):67-72. doi:10.14639/0392-100X-1511
6. Arthur Swift, MD, Steven Liew, MD, Susan Weinkle, MD, Julie K Garcia, PhD, Michael B Silberberg, MD, MBA, , The Facial Aging Process From the “Inside Out”, Aesthetic Surgery Journal, Volume 41, Issue 10, October 2021, Pages 1107–1119,