Dr Fiona Durban presents a case of a female patient who was injected with Botulinum Toxin Type A (Botox) to the mentalis and depressor angular oris (DAO) and later presented with a lower lip ptosis on the right side.

The Botox Treatment

I reviewed a 56 year old female patient who was treated with Botox by another practitioner 3 weeks prior. The patient had previously been injected with 5 units of Botox to the mentalis and 2.5 units had been injected in each depressor angular oris muscle.

The mentalis is a common area of the lower face to inject with Botox. The treatment helps with puckering or dimpling of the skin overlying the chin and can soften a deepening mental crease as well as prevent downturned mouth corners.

At review she presented with a drop of the right side of her lower lip only on active movement such as smiling with her mouth open or talking (see photos below). Her smile at the mouth corners remained symmetrical. She also reported some improvement had been noted in the few days prior to her review appointment.

Cause and Solution

The cause of her lower lip droop was likely to be diffusion of the product from the mentalis muscle into the adjacent depressor labii inferiori muscle. No other treatment could be given at this point. I recommended a ‘wait’ approach for resolution of this unwanted effect.

Key Points to Consider

The mentalis is an easily identified muscle and therefore is wrongly assumed in many cases to be a ‘safe’ area to inject with little chance of adverse outcome. It is important to only inject within your competencies, when you have sufficient training to inject with the correct dosage and placement.

It is also crucial that you make your patient aware of any potential adverse outcomes of treatment, however rare and support the patient during this time as it can be quite distressing.

Injections to the lower face with Botox can have positive results for your patients but only once you have sufficient training to perform these techniques correctly. The treatment of lower face Botox is covered within our advanced Botox and dermal filler training course. This is a full day course which can either be completed as a small group session or on a one-to-one basis.

Find out more

The Aesthetics Knowledge Hub is a great place for you to find answers to frequently asked questions. We recommend having a look at the Botox Training area.