Riekie M. Smit explains why a systematic evaluation will help improve lip enhancement procedures with fillers, stressing the importance of artistic perspective and a classification system that divides the lips into subunits

Riekie M. Smit, MD
Aesthetic Medicine & Sports Medicine Private Practice, Pretoria, South Africa

Beautiful lips have long been admired, desired and applauded. Works of art from centuries ago reflect this fascination with the lips. Beautiful lips are often associated with fame, fortune, status, sexual desire and health1. This and various other theories can explain the high demand for lip enhancement procedures that does not seem to fade despite changes in fashion, economy and other social changes.

A very important aspect that is most often misunderstood is that beautiful lips do not necessarily equal full lips. Though full lips are often perceived as being more attractive than thin lips2, it is not that simple. There is more to attractive lips than just fullness or the lack of perioral wrinkles and a well-defined Cupid’s bow. 

Over the past decade, there has been a lot of focus on educating doctors on methods to enhance lips with neurotoxins, fillers, and combining this with perioral resurfacing treatments for skin wrinkling.

Most patients seeking lip improvement will end up with enhanced fullness.

While in most indications for perioral rejuvenation, enhanced fullness may undoubtedly improve the specific perioral concern, it may not be a complete or an appropriate treatment plan for the particular indication or concern of the patient. 

The drawback that regrettably often arises is not limited to excess fullness, but more often, the incorrect positioning of the fullness within the respective lips of the patients.

A deformed or overfilled lip is not difficult to notice. Furthermore, it certainly does not complement or enhance the beauty of the person either. In order to better understand the issue, strengthen education, and then prevent such unsatisfactory or unnatural looking lips following lip enhancement, one has to evaluate the factors leading to these consequences.

Excess lip fullness that is inappropriate for the patient’s proportions, ethnicity, age and social position may have resulted from multiple procedures where the patient just wanted more and more every time and not just from one session.

Possible factors leading to unsatisfactory results from lip fillers

An attempt to categorise the reasons for unaesthetic lip filler results may assist in reaching an educated explanation:

Lack of anatomical knowledge

For all aesthetic procedures, physicians need to have an in-depth knowledge of the anatomy of the region and how it relates to the surrounding regions. Although, the lack of in-depth knowledge of anatomical structures in this region is more hazardous due to the risk of intravascular placement or hematomas; the precise anatomical placement also contributes to unsatisfactory results. The placement of lip filler varies according to the region being injected. A subdermal injection should be used when filling the vermillion border. However, when filling the dry red lip region, the technique recommended is the submucosal or some authors recommend the intramuscular plane3.

Unattractiveness or visible lumps of fillers may occur due to injection too deep and visible filler in the wet mucosa region of the lip.

Incorrect choice of product

Although most new filler material is considered safe and inert, any material can cause an inflammatory reaction causing acute or chronic problems4. Permanent or longer-term fillers are generally not recommended for lip filling due to the higher risk of granuloma formation and the lack of reversibility. The most common late complications are nodules or foreign-body granulomas5. Hyaluronic acid fillers (HA) are known to be the ‘gold standard for lip filling, although a viscous or highly cross-linked HA is usually not recommended for the lips as it is not ideal for the finer definition of the lips and perioral area structures, and also comes with a higher risk of complications. It may be problematic when a practitioner ignores the manufacturer’s guidelines and recommendations of the specific product with regards to final results and patient satisfaction.

Excess product

Most probably the major contributor to unnatural looking lips. The problem that the practitioner faces is the patient may likely demand excessive volume, and some can be quite particular in such regards. Though full lips are usually more attractive in women than thin lips, there remains a fine line between what is attractive and what is too much. 

What often contributes to this problem is that the patient adores the result after the first procedure, and then comes back for more and often again for even more. This is where the risk proportionally increases for losing sight of reality and what is normal and appropriate. 

There are a number of guidelines and aspects that can be used by practitioners to maintain normal proportions when performing lip enhancement procedures, the most frequently used is the simple Rickett’s e-line drawn on a lateral aspect from the nose to the chin. According to this line in an average Caucasian profile, the upper and lower lips lie behind this line by a mean distance of 3–4 mm and 2 mm, respectively6. Disproportionate lips can easily be identified using this line, and it has also been adapted for various ethnicities to maintain proportion according to culture also.

Incorrect treatment plan

When treating any medical condition, a well thought out treatment plan is what ensures predictability, safety and efficacy for the treatment.

The importance of individualising a treatment plan for each patient is critically underestimated. 

A precise treatment plan for lip enhancement with fillers will ensure that results are appropriate for the individual facial shape, proportions, ethnicity and the patient’s respective social and occupational positioning.

A practitioner cannot just enhance the lip with soft tissue fillers as they’ve seen in typical textbook cases. The lip and perioral region necessitate a very precise evaluation, and this should be combined with an evaluation of the patient, their expectations and their insight in the procedure.

This aspect seems to be the most complex and variable for this specific procedure. 

Lack of artistic insight with evaluation

Aesthetic medical procedures require artistic insight; after all, the term aesthetic refers to being concerned with beauty or the appreciation of beauty as described in the Oxford Dictionary. The evaluation aims to help integrate artistic aspects of lip aesthetics into the aesthetic medical procedure of lip augmentation with fillers.

Evaluation of the perioral and lip region 

A comprehensive evaluation will ensure a more precise treatment plan for lip filler positioning.

Perioral evaluation

It is vital the adjacent perioral region is evaluated during the same lip enhancement session.

Perioral folds or wrinkles may reduce the attractiveness of the lips. This may include perioral or smoker’s lines (A), nasolabial folds (B) or marionette folds (C) as shown in Figure 1

Perioral proportions

At the same time, it is also important to evaluate the proportion of the lips to the nose and chin using the Rickett’s e-line6 during this stage of the evaluation. The moment we place fillers in either the lips, the nose or the chin, we alter the proportions, and this could give a positive or negative effect on the balance related to the Rickett’s e-line.

Artistic lip evaluation

The lips should be evaluated in much the same way as an artist draws the subunits of the lips. This way we can establish which part of the individual patient needs or does not need augmentation.

The way an artist draws the lips is by dividing the lips into subunits. The upper lip is divided into two lateral subunits (superolateral subunits 1a and 1 b) and a medial region (superomedial subunit 2). The lower lip is divided into two tubercles (inferolateral subunits 3a and 3b) as shown in Table 1.

This evaluation system can be applied when deciding how the filler is distributed into the lips, making the treatment more individualised for each patient. These subunits relate to the filling of the red lip (dry part).

Vermillion border and philtral columns

The last part to evaluate remains the philtral columns and the vermillion border. The philtral columns should only be augmented when there is volume loss (flattening) in the columns. The vermillion border is important to augment in patients with border loss and especially when ‘smoker’s lines’ or ‘code bar lines’ exist on the upper lip. This region is often referred to as the white roll of the lip and most commonly augmented with a small gauge needle8,9. The Cupid’s bow is the central region of the upper lip’s vermillion border that traverses the philtral columns. Practitioners should Keep in mind that the superior labial artery runs more superficial in this delicate region where the Cupid’s bow and philtral columns exist10.


The recommended evaluation system for lip augmentation treatment planning is designed to individualise lip filler procedures. Most fillers that we use for lip filling contains 0.8–1.2ml of product, and this cannot be equally distributed over the lips in all patients. A systematic evaluation of all the parts of the lips and which specific portion needs augmentation, and those that don’t, should be incorporated in the treatment plan for each patient. 

When performing lip filler treatments, anatomical knowledge as well as knowledge of the labial arteries which are at risk from intravascular injections remains essential to avoid complications, and secondly, but equally important, is the artistic insight to ensure acceptable aesthetic results.

  Declaration of interest None

  Figures 1–2 © Dr Smit redrawn by Prime Journal

 Table 1 
© Dr Smit redrawn by Prime Journal


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