The use of injectable botulinum toxin on the inferior facial third is widespread. Nonetheless, clinicians need to act cautiously when injecting toxin around the mouth so as to prevent laxity of the cheek, the inability to close the mouth tightly or development of a lopsided smile. Furthermore, injecting botulinum toxin in this area may cause problems for people whose occupation involves singing or blowing wind instruments and who therefore make extensive use of the muscles of the lower face. A frequent patient complaint is the appearance of vertically oriented wrinkles periorally. They may arise from the hyperactivity of the orbicularis oris muscle or may be due to loss of facial volume, sunlight exposure or other causes. Frequently these rhytides are treated with injectable fillers or by resurfacing the skin with a laser, but these procedures have the disadvantage that the benefit is soon lost. It is probable that the intense muscular activity in this region of the face is what causes rhytides to reappear so quickly. Low-dose injected botulinum toxin may be indicated for treatment where muscles are the reason for wrinkles to appear. The site of injection is alongside the vermillion border and lateral to the philtral columns.