Horizontal facial thirds

The lip dimensions include the relative vertical length of the upper “red” lip to the length of the philtrum, or upper “white” lip. Upper lip height must be less than that of the lower red lip, with anterior projection of upper lip approximately 2 mm over the lower lip.

The smile is a defining element of a face, expressing a multitude of emotion, of which the lips play an integral part. The lips should be in balance with the remaining face, and what constitutes the perfect lip can be influenced by age, ethnicity, culture, fashion, and current trends. It is accepted shape, size, fullness, colour and symmetry are essential aspects of lip attractiveness.

In this regard there is no fixed approach to lip augmentation as many factors interplay to formulate the perfect treatment. The ageing lip inverts when smiling and has a flattened cupid’s bow. There is lengthening of the upper lip with the vermillion border thinning. Continued use of the orbicularis oris muscle creates perioral rhytids secondary to breaking down soft tissue.

All aspects of ageing must be considered when assessing lips, including skin quality and overall facial ageing to ensure any enhancement is confluent with surrounding facial structures. The ideal lip ratio from a frontal view is suggested to be 1:1.6. Further to this, the horizontal width of the mouth should be one and a half times the width of the nose. This can be taken only as a guide, given the variations mentioned.

Lip positioning has also been evaluated in terms of how it affects the patient’s profile and is often assessed using the Ricketts line. This draws an imaginary line from the tip of the nose to chin prominence and examines lip projection past the line. Dr Ricketts considered for an attractive profile the lower lip would sit 2mm and the upper lip would sit 4mm behind the line.

Natural three-dimensional lip enhancement can be achieved by firstly assessing, and treating where appropriate, the whole perioral complex, rather than the lips in isolation. This is particularly important for older patients where a more extensive ageing curved may present.

There are numerous industry-developed scales to assess lips, one is the validated Allergan Lip Fullness Scale, which was developed to evaluate the effectiveness of lip augmentation in clinical trials. Initially a four-point scale, this was revised to include five scales, offering a broader range of lip presentations. It was concluded to be a reliable instrument for assessing clinically meaningful differences in lip volume. When discussing lip volume with patients, to determine where they fit within a scale upon initial presentation. Lip fullness grading scale is beneficial. Again, a five-point scale, the morphed images enable a comparison of the patient’s photographs, whereby their lips can be assessed as very thin, thin, moderately thick, thick, and full. Most patients looking for attractive augmentation would be seeking achievement of level 4, a thick lip.

The use of an assessment tool to discuss presenting lip anatomy, alongside a photograph of the patients own lips from various projections, can help in detecting and discussing body dysmorphia and in planning treatment goals and managing patient expectation regarding what is possible, but also what is sensible. It is often my experience, particularly with social media encouraging overly filled lips, that patients do not appreciate how full their lips already are. Comparing their photograph to a scale can emphasise this point objectively and facilitate a clinical discussion regarding any treatment options.