Assessing and Augmenting Lips

By Dr Yalda Jamali and Mr Ayad Harb / 12 Aug 2021

Dr Ayad Harb and Dr Yalda Jamali present five principles to lip assessment and treatment for successful results

The lips are a universal symbol of beauty and youth and throughout history have evolved as one of the key sensual landmarks in the face. Lip adornments, colours and cosmetics that draw attention to the lips, date back to fourth century BC, when lipstick was first used by Sumerians.1 Furthermore, lips are the focus for facial symmetry and the triangle of beauty.2 Added to this, lips play an important role in phonation, communication, feeding and intimacy.

With the rise in demand for lip treatments, lips have become one of the most popular areas that aesthetic providers learn to treat. Enhancement of the lips usually involves enlarging, defining, and reshaping. Undoubtedly, there are significant individual differences in lip appearances, however, through an in-depth knowledge of anatomy, comprehensive structural assessment and using an appropriate technique, a practitioner can achieve natural, safe, and repeatable results. Within Dr Ayad’s clinic, we have devised a methodical technique for lip assessment and treatment, based on five key principles, which helps us restore and maintain a natural appearance.

Lip development and ageing

The development of the lips in the foetus is an intricate process that occurs between four to six weeks’ gestation.3 The upper lip and palate are formed by the fusion of the maxillary processes bilaterally with the medial and lateral nasal prominences. These fusion lines remain visible as anatomical and aesthetic landmarks in the fully developed upper lip. The lower lip and mandible are formed by the meeting of two mandibular processes which fuse in the midline.4

The anatomical layers of the lips are composed of skin, muscle, and oral mucosa. The distribution of the superior and inferior labial arteries can vary, but they are predominantly submucosal (78.1%). Some variations exist whereby the vasculature is intramuscular (17.5%) or subcutaneous (2.1%).5

The lips follow a familiar pattern of decline and ageing, similar to the rest of the face, with the formation of wrinkles, loss of definition and decline in volume within the lip, as well as structural changes related to the underlying bone and muscle. The oral commissures drop, giving a downward turning of the lips and the intercommissural width reduces. Maxillary retrusion results in a reduction in maxillary angle and height, which leads to a more posterior position of the lip. Tooth loss and tooth wear can lead to a decreased projection of the lips. Lips can appear inverted and thinner.6

The skin in and around the lip shows typical signs of ageing, resulting from the decline in collagen and elastin within the dermis. The results are visible static and dynamic rhytids, which typically appear as vertical barcode lines. Loss of vermillion border definition, as well as flattening of the cupid’s bow are particular to the lips. Furthermore, as the epidermis thins and the dermal-epidermal junction flattens, this creates a suboptimal skin barrier that leads to water loss and dry lips.6

A decline in the orbicularis oris muscle tone leads to a widening of the lip, as well as a reduction in lip height. A combination of muscle and skin laxity results in elongation of the cutaneous lip. An increased tone of the lip depressors, particularly the depressor anguli oris, contributes to the down-slanting appearance of the oral commissures, so is a characteristic of the ageing lips.6

Five principles of lip assessment

For our lip assessment approach, it is considered in five components: lip volume, lip height, vermillion border and landmarks, oral commissures, and perioral skin condition. Each component is assessed separately, and a decision is made regarding the most appropriate treatment, if any.

Maxillary retrusion results in a reduction in maxillary angle and height, which leads to a more posterior position of the lip

1. Volume, symmetry, and proportion

The assessment begins with the patient at rest, examining the top to bottom lip ratio from a frontal view. It is thought that the top to bottom ratio of 1:1.6, is ‘the golden’ and most ideal proportion in patients. However, ethnic differences need to be considered, for example black lips are found to have a 1:1 ratio.2

Anterior projection of the lips is assessed from the profile view. The projection of the lips in relation to other anatomical features, including the nose tip and chin, need to be examined. Analytic reference lines such as Ricketts, Steiner and Burstone may be used for assistance.7

It is common to assess the lips in a static position only; however, accounting for dynamic movement can help achieve more natural results as it will aid in lateral and medial volume assessment.8 Therefore, dynamic examination should include the patient fully smiling with a clear tooth show and the patient pursing the lips.

It is generally accepted that lip volume is a personal and subjective decision that a patient can decide for themselves, based on personal preference and lifestyle. However, duty of care dictates that a medical professional must help the patient understand the natural limits of any desired volumetric enhancement. Furthermore, signs of unnaturally or disproportionally volumised lips should be pointed out to the patient and further volumisation should be avoided.

2. Vermillion border and landmarks

The natural aesthetic landmarks of the lip border are assessed, paying special attention to the vermillion border, cupid’s bow, philtral columns and philtral dimple. The vermillion border should ideally be a sharp demarcation between the lips and the surrounding skin, giving definition to the lips. Initial consideration is given to the integrity of the vermillion border. Ageing and lifestyle choices, such as smoking, can weaken and thin the appearance of the vermillion border.9

3. Vermillion height

The vermillion height is the distance between the superior and inferior vermillion border. Lip volume directly impacts this. Achieving an increased vermillion height is commonly sought after, but ethnic variations need to be considered. Vermillion height in Caucasian patients is lower when compared to lips of black or Asian patients. For example, Korean patients have a more diamond lip shape, and Chinese and black patients have an increased upper lip volume and increased vermillion height.10 There are also variations between male and female patients. It is important to note that narrower and wide lips are generally more favourable in men.11

4. Cutaneous upper lip

The upper cutaneous lip has skin superior to the vermillion border. This area can be divided into philtral and lateral subunits. This region is assessed for the presence of dynamic and static rhytids, pigmentation, scars, and the overall condition of the skin. Perioral vertical lines become visible as we age due to continuous activity of the orbicularis oris muscle, as well as collagen and elastin degradation within the dermis. Assessing the patient as they purse their lips, accentuates these lines. The philtrum and philtrum height should also be assessed, as with age they flatten and lengthen. It is essential to visualise the upper red lip and the white lip proportions when treatment planning. The ideal height for the philtrum column is around 11-13mm in females and 13-15mm in men.2,12

5. Commissure

The commissures are the corners of the mouth, where the top and bottom lip vermillion borders connect. The downward turning of the corners of the lips is a common aesthetic concern and worsens with age due to reduced structural support. Depressor anguli oris overactivity can also impact this drastically. This area should be assessed at rest and during dynamic movement.

Five principles of treatment

After systematic assessment of the five components of the lip is complete, a suitable treatment plan can be formulated and followed in the same logical and methodical way. It is important to note that patients may require treatments to none, some, or all components. For example, young patients may well benefit from added volume and vermillion height, however, they will almost certainly not require commissural or perioral treatment.

1. Volume

Volume should be injected within the tubercles (three in the upper and two in the lower lip) which are the natural volume centres of the lips. The filler is placed superficial, supramuscular and within the anterior dry mucosa. Broken linear threads or micro-blouses are preferred over large single bolus injections.

2. Vermillion border

This should only be treated if indicated following assessment. It is an area that is commonly overtreated, especially in young patients with no vermillion border requirement. Injections should be extremely superficial, slightly inferior to the border and remaining within the pink lip. From our experience, this helps to reduce the risk of migration and expansion of filler into the cutaneous lip.

3. Vermillion height

The most common approach to lengthen the vermillion height is ‘tenting’. This is where injections involve vertical retrograde linear threads, commonly starting at the vermillion border and aiming towards the wet-dry junction. However, our preference is to direct the vertical tenting injections from the wet-dry border towards the vermillion border. The aim is to reduce the risk of arterial injury or vascular occlusion, as well as reducing the risk of filler migration into or above the vermillion border.

4. Cutaneous lip

This area can be treated by using a combination of neurotoxin, dermal filler with or without subcision and resurfacing with medical skincare, chemical peels, and lasers. A small dose of neurotoxin can be placed in the orbicularis oris muscle to reduce the strength of dynamic vertical perioral lines. These lines can be further reduced by intradermally blanching a low G’ filler. For deeper ‘barcode’ lines, subcision and superficial fat volumisation may be necessary. The philtrum columns can be redefined by injecting intradermally from the white vermillion at the Glogau-Klein points towards the columella.

5. Commissure

Oral commissures can also be treated with neurotoxin and dermal fillers. Neurotoxin can be used to target the depressor anguli oris, whilst the oral commissures can be supported using dermal filler. Dermal filler is injected directly inferior to the fold and 5mm lateral to the mandibular ligament using a fanning/transverse threads technique.


Methodical, anatomical assessment and appropriate, systematic correction should remain central in our practice. The external appearances that we recognise as signs of abnormality or ageing are dictated by the underlying anatomy and the predictable changes within the constant layers of the lip. Assessment of the lips should be anatomical and follow a systematic process. Aesthetic enhancements should stick within the natural boundaries and landmarks to restore and maintain a natural appearance. By following this five-step assessment and treatment system we can provide patients with accurate assessments and reliable, appropriate, and safe treatments. Additionally, we find that it eliminates unnecessary treatment and reduces risk of overtreatment, migration, or unnatural results.

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